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Sample records for polymethyl methacrylate-grafted polyethylene

  1. Physical properties of agave cellulose graft polymethyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan [Polymer Research Centre (PORCE), School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi Selangor (Malaysia)

    2013-11-27

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  2. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Adam, Nurul Ilham [Faculty of Applied Sciences, Universiti Teknologi MARA, KampusTapah, 35400 Tapah Road, Tapah, Perak (Malaysia); Yahya, Muhd Zu Azhan [Faculty of Defence Sciences and Technology, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia); Ali, Ab Malik Marwan [Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2015-08-28

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ({sup 1}HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in {sup 1}HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF{sub 3}SO{sub 3} show the highest conductivity. The complexation between EMG30 and LiCF{sub 3}SO{sub 3} were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  3. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    International Nuclear Information System (INIS)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-01-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ( 1 HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1 HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF 3 SO 3 show the highest conductivity. The complexation between EMG30 and LiCF 3 SO 3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  4. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Science.gov (United States)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance (1HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF3SO3 show the highest conductivity. The complexation between EMG30 and LiCF3SO3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR).

  5. Graft copolymerization of a series of alkyl acrylates and alkyl methacrylates onto polyethylene

    International Nuclear Information System (INIS)

    Zurakowska-Orszagh, J.; Soerjosoeharto, K.; Busz, W.; Oldziejewski, J.

    1977-01-01

    Graft copolymerization of a series of alkyl acrylates and alkyl methacrylates into polyethylene of Polish production was investigated, using benzoyl peroxide as the initiator as well as preirradiation technique, namely ionizing radiation from a 60 Co γ-source. The effect of α-carbon methyl substituent of methacrylates as well as the influence of the length of alkyl chains in the ester groups of both series of monomers into the grafting process was observed. The ungrafted and some of the grafted polyethylene film obtained was studied by infrared spectrophotometry. (author)

  6. Controlled Grafting of Poly(methyl methacrylate) Brushes on Poly(vinylidene fluoride) Powders by Surface-initiated Atom Transfer Radical Polymerization

    Institute of Scientific and Technical Information of China (English)

    TANG Zhaoqi; LI Wei; LIU Lanqin; HUANG Lei; ZHOU Jin; YU Haiyin

    2009-01-01

    Controlled grafting of well-defined polymer brushes of methyl methacrylate (MMA) on the poly(vinylidene fluoride) (PVDF) powders was carded out by the surface-initiated atom transfer radical polymerization (ATRP). The ATRP initiator was anchored on the PVDF surface by alkaline treatment, followed by UV-induced bromination; then methyl methacrylate (MMA) was grafted onto the brominated PVDF by the ATRP technique. The chemical composition changes of PVDF were characterized by Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). FT-IR and XPS results clearly indicated the successful graft of poly(methyl methacrylate) onto the PVDF surface.

  7. Radiation grafting of methyl methacrylate onto polyethylene separators for lithium secondary batteries

    Science.gov (United States)

    Gwon, Sung-Jin; Choi, Jae-Hak; Sohn, Joon-Yong; An, Sung-Jun; Ihm, Young-Eon; Nho, Young-Chang

    2008-08-01

    Micro-porous polyethylene separator was modified by radiation grafting of methyl methacrylate in order to improve its affinity with a liquid electrolyte. The degree of grafting (DOG) increased with the monomer concentration and grafting time. The morphological change of the modified separator was investigated by scanning electron microscopy. The degree of crystallinity upon grafting was reduced due to the formation of an amorphous PMMA layer. The electrolyte uptake and the ionic conductivity of the separator increased with an increase in the DOG. The ionic conductivity reached 2.0 mS/cm for the grafted polyethylene separator with 127 wt% DOG.

  8. Radiation grafting of methyl methacrylate onto polyethylene separators for lithium secondary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Gwon, Sung-Jin [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Department of Materials Engineering, Chnugnam National University, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Choi, Jae-Hak; Sohn, Joon-Yong; An, Sung-Jun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Ihm, Young-Eon [Department of Materials Engineering, Chnugnam National University, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Nho, Young-Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)], E-mail: ycnho@kaeri.re.kr

    2008-08-15

    Micro-porous polyethylene separator was modified by radiation grafting of methyl methacrylate in order to improve its affinity with a liquid electrolyte. The degree of grafting (DOG) increased with the monomer concentration and grafting time. The morphological change of the modified separator was investigated by scanning electron microscopy. The degree of crystallinity upon grafting was reduced due to the formation of an amorphous PMMA layer. The electrolyte uptake and the ionic conductivity of the separator increased with an increase in the DOG. The ionic conductivity reached 2.0 mS/cm for the grafted polyethylene separator with 127 wt% DOG.

  9. Enhancement of mechanical properties of poly(vinyl chloride with polymethyl methacrylate-grafted halloysite nanotube

    Directory of Open Access Journals (Sweden)

    2011-07-01

    Full Text Available Halloysite nanotubes(HNTs grafted with Polymethyl methacrylate(PMMA were synthesized via radical polymerization. The properties of PMMA-grafted HNTs were characterized by transmission electron microscopy (TEM, fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA and X-ray photoelectron spectroscopy (XPS. The results showed that PMMA grafted to the surfaces of HNTs successfully. Then, PVC/PMMA-grafted HNTs nanocomposites were prepared by melt compounding. The morphology, mechanical properties and thermal properties of the nanocomposites were investigated. PMMA-grafted HNTs can effectively improve the toughness, strength and modulus of PVC. The glass transition and thermal decomposition temperatures of PVC phase in PVC/PMMA-grafted HNTs nanocomposites are shifted toward slightly higher temperatures. The grafted HNTs were uniformly dispersed in PVC matrix as revealed by TEM photos. The fracture surfaces of the nanocomposites exhibited plastic deformation feature indicating ductile fracture behaviors. The improvement of toughness of PVC by PMMA-grafted HNTs was attributed to the improved interfacial bonding by grafting and the toughening mechanism was explained according to the cavitation mechanism.

  10. Modification of polyethylene films by radiation grafting of glycidyl methacrylate and immobilization of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Nava-Ortiz, C.A.B. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: burillo@nucleares.unam.mx; Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, C. [Departamento de Farmacia y Tecnologia Farmaceutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2009-01-15

    Glycidyl methacrylate was grafted onto polyethylene films using a preirradiation method with {gamma} rays. The effect of absorbed dose, monomer concentration, and reaction time on the degree of grafting was determined. The grafted samples were verified by FTIR-ATR spectroscopy. {beta}-Cyclodextrin was immobilized onto polypropylene modified with glycidyl methacrylate, and the ability of the cavities of {beta}-cyclodextrin to form inclusion complexes was demonstrated using the typically organic compound approach with m-toluic acid (3-MBA) as a probe.

  11. Radioisotope investigations on the stratigraphic distribution of poly/methyl methacrylate/grafted onto leather

    International Nuclear Information System (INIS)

    Pietrucha, K.; Kroh, J.

    1984-01-01

    Investigations on the stratigraphic distribution of poly/methyl methacrylate/ in leather follow our earlier experiments on radiation grafting of vinyl monomers in situ. Polymer distribution was determined for pigskins and cattlehides tanned with basic sulphates of chromium/III/. 14 C-labelled methyl methacrylate was used in present experiments. Precision slicing technique was employed to cut consecutive slices parallel to the grain surface of the radiation modified leather. Quantative analysis of polymer distribution in leather was based on radioactivity measurements. Each layer was burned in Oxymat apparatus and resulting 14 CO 2 was analysed by liquid scintillation method. On the basis of radioactivity measurements and visual observations with light microscope conclusion on desirable distribution of polymer was reached. In the midcorium part of leather polymer is evenly distributed and its content is much higher than for outer layers next to surface and flesh. Mechanism of relevant processes as well as formation and role played by peroxide compounds is discussed

  12. Radioisotope investigations on the stratigraphic distribution of poly(methyl methacrylate) grafted onto leather

    International Nuclear Information System (INIS)

    Pietrucha, K.; Kroh, J.

    1985-01-01

    Investigations on the stratigraphic distribution of poly(methyl methacrylate) in leather follow our earlier experiments on radiation grafting of vinyl monomers in situ. Polymer distribution was determined for pigskins and cattlehides tanned with basic sulphates of chromium (III). 14 C-labelled methyl methacrylate was used in present experiments. Precision slicing technique was employed to cut consecutive slices parallel to the grain surface of the radiation modified leather. Quantitative analysis of polymer distribution in leather was based on radioactivity measurements. Each layer was burned in Oxymat apparatus and resulting 14 CO 2 was analysed by liquid scintillation method. On the basis of radioactivity measurements and visual observations with light microscope conclusion on desirable distribution of polymer was reached. In the midcorium part of leather polymer is evenly distributed and its content is much higher than for outer layers next to surface and flesh. Mechanism of relevant processes as well as formation and role played by peroxide compounds are discussed. (author)

  13. Graft Copolymerization of Methyl Methacrylate Monomer onto Starch and Natural Rubber Latex Initiated by Gamma Irradiation

    Directory of Open Access Journals (Sweden)

    S. Iskandar

    2011-04-01

    Full Text Available To obtain the degradable plastic, the graft copolymerization of methyl methacrylate onto starch and natural rubber latex was conducted by a simultaneous irradiation technique. Gamma-ray from cobalt-60 source was used as the initiator. The grafted copolymer of starch-polymethyl methacrylate and the grafted copolymer of natural rubber-polymethyl methacrylate were mixed in the blender, and dried it in the oven. The dried grafted copolymer mixture was then molded using hydraulic press machine. The effect of irradiation dose, composition of the grafted copolymer mixture, film forming condition and recycle effect was evaluated. The parameters observed were tensile strength, gel fraction and soil burial degradability of grafted copolymer mixture. It was found that the tensile strength of grafted copolymer mixture increased by -ray irradiation. Increasing of the grafted copolymer of natural rubber-polymethyl methacrylate content, the gel fraction and tensile strength of the grafted copolymer mixture increased. The tensile strength of the grafted copolymer mixture was increased from 18 MPa to 23 MPa after recycled (film forming reprocessed 3 times. The grafted copolymer mixture was degraded completely after soil buried for 6 months

  14. Surface modification of hydroxyapatite with poly(methyl methacrylate) via surface-initiated ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yan; Zhang Xi; Yan Jinliang; Xiao Yan [Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Lang Meidong, E-mail: mdlang@ecust.edu.cn [Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

    2011-05-01

    This article describes the fabrication of hydroxyapatite (HAP) nanocomposites grafted with poly(methyl methacrylate) (PMMA). Surface-initiated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was carried out from hydroxyapatite particles derivatized with ATRP initiators. The structure and properties of the nanocomposites were investigated by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), differential scanning calorimeter (DSC) measurements, and contact angle analyses. TGA was used to estimate the grafting density of ATRP initiators (0.49 initiator/nm{sup 2}) and the amount of grafted PMMA on the HAP surface. The contact angle analyses indicated that grafting PMMA onto the HAP surface dramatically increased the hydrophobicity of the surface. Moreover, the HAP nanocomposites showed excellent dispersibility in both aqueous solution and organic solvent.

  15. Surface modification of hydroxyapatite with poly(methyl methacrylate) via surface-initiated ATRP

    International Nuclear Information System (INIS)

    Wang Yan; Zhang Xi; Yan Jinliang; Xiao Yan; Lang Meidong

    2011-01-01

    This article describes the fabrication of hydroxyapatite (HAP) nanocomposites grafted with poly(methyl methacrylate) (PMMA). Surface-initiated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was carried out from hydroxyapatite particles derivatized with ATRP initiators. The structure and properties of the nanocomposites were investigated by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), differential scanning calorimeter (DSC) measurements, and contact angle analyses. TGA was used to estimate the grafting density of ATRP initiators (0.49 initiator/nm 2 ) and the amount of grafted PMMA on the HAP surface. The contact angle analyses indicated that grafting PMMA onto the HAP surface dramatically increased the hydrophobicity of the surface. Moreover, the HAP nanocomposites showed excellent dispersibility in both aqueous solution and organic solvent.

  16. In Situ Synthesis of Poly(methyl methacrylate/SiO2 Hybrid Nanocomposites via “Grafting Onto” Strategy Based on UV Irradiation in the Presence of Iron Aqueous Solution

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    Hong Zhang

    2012-01-01

    Full Text Available Poly(methyl methacrylate/SiO2 (PMMA/SiO2 hybrid composites were prepared via “grafting onto” strategy based on UV irradiation in the presence of iron aqueous solution. Two steps were used to graft polymethyl methacrylate (PMMA onto the surface of nanosilica, anchoring 3-(methacryloxy propyl trimethoxysilane (MPTS onto the surface of nanosilica to modify it with double bonds, and then grafting PMMA onto the surface of nanosilica with FeCl3 as photoinitiator. The products were characterized by FT-IR, TGA, TEM, DLS, and XPS. The results showed that it is easy to graft PMMA onto the surface of nanosilica under UV irradiation, and the hybrid particles are monodisperse and have core-shell structure with nanosilica as the core and PMMA layers as the shell. Furthermore, the products initiated by FeCl3 have higher monomer conversion, percent grafting, and better monodispersion compared with the products initiated by traditional photoinitiator such as 2-hydroxy-4-(2-hydroxyethoxy-2-methyl-propiophenone (Irgacure 2959.

  17. Electron beam induced graft-polymerization of methyl methacrylate onto polyethylene films at high dose rates

    International Nuclear Information System (INIS)

    Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

    1991-01-01

    Electron beam induced graft-polymerization by the mutual irradiation technique of methyl methacrylate on the surface of low density polyethylene films (LD) and high density polyethylene films (HD) was investigated at high dose rates over 10 Mrad per second. Graft-polymerization mechanisms were discussed on the basis of O 2 permeability, tensile strength, elongation at break, and surface tension of the grafted films. As the degree of grafting increased, the O 2 permeability of LD decreased, while that of HD little changed at the grafting up to 4 ∼ 5 %. This indicates that the grafting occurred in the amorphous regions for LD and occurred in the amorphous regions in the neighborhood of crystalline regions for HD. For HD, when the degree of the grafting surpassed 4 ∼ 5 %, the O 2 permeability, tensile strength, elongation at break, and surface tension decreased with an increase in the degree of grafting. It was assumed that rapid grafting in the amorphous regions in the neighborhood of crystalline regions caused the increase in local temperature by the heat of polymerization, and the viscosity of polyethylene in the amorphous regions decreased with an increase in temperature. As a result, the graft chains, which formed micro domain structure, condensed in the amorphous regions and the domain increased in size. (author)

  18. Retention of krypton on polymethyl methacrylate

    International Nuclear Information System (INIS)

    Ciric, M.M.; Cvjeticanin, N.M.; Radak, B.B.

    1975-01-01

    Retention of krypton on polymethyl methacrylate was studied as a function of kryptonation pressure (P), temperature (T) and time (t). It was found that the dependence of the retained quantity on P, T, and t is in accordance with the diffusion theory. The optimum results (i.e., the maximum retained quantity and the best stability of the kryptonate) were obtained at elevated kryptonation temperatures (200 0 C). The diffusion coefficients of krypton in polymethyl methacrylate, determined from the dekryptonation process, vary from 1 x 10 -10 cm 2 /s to 0.2 x 10 -10 cm 2 /s for samples kryptonated at 20 0 C and 200 0 C respectively. The results have been discussed from the viewpoint of radiation and thermal stability of kryptonated polymethyl methacrylate. Inadequate radiation stability could be the main obstacle for practical purposes. (U.S.)

  19. Methyl methacrylate oligomerically-modified clay and its poly(methyl methacrylate) nanocomposites

    International Nuclear Information System (INIS)

    Zheng Xiaoxia; Jiang, David D.; Wilkie, Charles A.

    2005-01-01

    A methyl methacrylate oligomerically-modified clay was used to prepare poly(methyl methacrylate) clay nanocomposites by melt blending and the effect of the clay loading level on the modified clay and corresponding nanocomposite was studied. These nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis and cone calorimetry. The results show a mixed intercalated/delaminated morphology with good nanodispersion. The compatibility between the methylacrylate-subsituted clay and poly(methyl methacrylate) (PMMA) are greatly improved compared to other oligomerically-modified clays

  20. Graft Copolymerization Of Methyl Methacrylate Onto Agave Cellulose

    International Nuclear Information System (INIS)

    Noor Afizah Rosli; Ishak Ahmad; Ibrahim Abdullah; Farah Hannan Anuar

    2014-01-01

    The grafting polymerization of methyl methacrylate (MMA) and Agave cellulose was prepared and the grafting reaction conditions were optimized by varying the reaction time and temperature, and ratio of monomer to cellulose. The resulting graft copolymers were characterized by Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy (SEM). The experimental results showed that the optimal conditions were at a temperature of 45 degree Celsius for 90 min with ratio monomer to cellulose at 1:1 (g/ g). An additional peak at 1738 cm -1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted cellulose, respectively. Grafting of MMA onto cellulose enhanced its thermal stability and SEM observation further furnished evidence of grafting MMA onto Agave cellulose with increasing cellulose diameter and surface roughness. (author)

  1. Potassium diperiodatocuprate-mediated preparation of poly(methyl methacrylate/organo-montmorillonite composites via in situ grafting copolymerization

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available In this study, potassium diperiodatocuprate (Cu3+ was selected as an initiator to prepare poly(methyl methacrylate/organo-montmorillonite composites (OMMT-g-PMMA by in situ graft copolymerization. Three synthetic parameters were systematically evaluated as a function of the temperature, the concentration of initiator, pH and the ratio of MMA to OMMT. It was found that Cu3+ was a highly efficient initiator for the preparation of OMMT-g-PMMA i.e., monomer conversion and grafting efficiency were as higher as 95%. The X-ray diffraction measurement showed the intercalation of PMMA chains into OMMT layers on base of an increasing basal spacing after polymerization. FTIR analysis also suggested that the PMMA chains were effectively grafted onto OMMT substrate. The enhanced thermal stabilities of OMMT-g-PMMA composites were confirmed by the thermal gravimetric analysis (TGA. Finally, a single-electron-transfer mechanism was proposed to illustrate the formation of radicals and the preparation process of OMMT-g-PMMA composites. Cu3+ can be used as an effective and practical initiator in preparing the organic/inorganic composite due to its high grafting efficiency and the milder reaction condition.

  2. Effect of lithium salt concentrations on blended 49% poly(methyl methacrylate) grafted natural rubber and poly(methyl methacrylate) based solid polymer electrolyte

    International Nuclear Information System (INIS)

    Su’ait, M.S.; Ahmad, A.; Hamzah, H.; Rahman, M.Y.A.

    2011-01-01

    The effect of lithium salts (lithium tetrafluoroborate, LiBF 4 and lithium perchlorate, LiClO 4 ) as doping salts in rubber-polymer blends, 49% poly(methyl methacrylate) grafted natural rubber (MG49) and poly(methyl methacrylate) (PMMA) in solid polymer electrolyte (SPE) film for electrochemical devices application was investigated. The electrolyte films were prepared via the solution casting technique using 0–25 wt.% lithium salt. The effect of the lithium salts on chemical interaction, ionic conductivity and structural and morphological studies of (70:30) MG49-PMMA films was analyzed using Fourier Transform Infrared (FT-IR) Spectroscopy, Electrochemical Impedance Spectroscopy (EIS), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Infrared analysis showed that the interactions between lithium ions and oxygen atoms occur at the ether group (C–O–C) (1500–1100 cm −1 ) on the MMA structure in both MG49 and PMMA. The oxygen atoms in the structure of the polymer host act as electron donor atoms and form a coordinate bond with the lithium ions from the doping salt to form polymer–salt complexes. The ionic conductivity was investigated at room temperature as well as at a temperature range from 303 K to 373 K. The ionic conductivity without the addition of salt was 1.1 × 10 −12 S cm −1 . The highest conductivity at room temperature for (70:30) MG49-PMMA–LiBF 4 was 8.6 × 10 −6 S cm −1 at 25 wt.% of LiBF 4 . The ionic conductivity of (70:30) MG49-PMMA–LiClO 4 was 1.5 × 10 −8 S cm −1 at 25 wt.% of LiClO 4 . However, both electrolyte systems do not exhibit Arrhenius-like behavior. Systems with LiBF 4 salt have higher ionic conductivity than those with LiClO 4 salt because of the differences in anionic size and lattice energy of the appropriate salt. The observations from structural and morphology studies showed that complexation and re-crystallization occur in the system. The XRD studies showed a reduction of the MMA peak

  3. An effective approach to synthesis of poly(methyl methacrylate)/silica nanocomposites

    International Nuclear Information System (INIS)

    Ding Xuefeng; Wang Zichen; Han Dongxue; Zhang Yuanjian; Shen Yanfei; Wang Zhijuan; Niu Li

    2006-01-01

    A novel synthetic route for nearly monodispersed poly(methyl methacrylate)/SiO 2 composite particles (PMSCP) is reported. Silica nanoparticles modified with oleic acid were used as 'seeds'. Methyl methacrylate (MMA) monomer was copolymerized with oleic acid via in situ emulsion polymerization, in the presence of an initiator; it resulted finally in the formation of composites with core-shell morphology. The composite particles were examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The number of silica particles inside the composite particles increases with an increase in the silica concentration. The effect of grafted silica concentration on the morphology of PMSCP is also reported in detail. It was found by thermogravimetric analysis that PMSCP show a potential application for fire retardance

  4. Chemical structure of chromium(III) crosslinked collagen-poly(methyl methacrylate) copolymers in radiation grafting

    International Nuclear Information System (INIS)

    Pietrucha, K.

    1991-01-01

    Upon γ-irradiation of aqueous emulsions of methyl methacrylate embedded into chrome tanned skin, the formation of graft copolymers is observed. The number-average molecular weight of the grafted poly(methyl methacrylate) side chains was in the range of 430000 (for a dose of 10 kGy) and practically independent of grafting degree. However, the number of branches per graft copolymer molecule increases from 0.3 to 0.8 when the degree of grafting increases from 32% to 88%. Similarly, the radiation yield, i.e. the number of branches formed per 100 eV of energy absorbed in the substrate polymer increases from 0.75 to 1.94. The value and meaning of molecular weight of graft copolymer is discussed along with the mechanism of polymer chain termination. (author) 14 refs.; 3 figs.; 4 tabs

  5. Pre-irradiation grafting of hydrophilic monomers onto polyethylene: Pt. 1

    International Nuclear Information System (INIS)

    Gargan, K.; Kronfli, E.; Lovell, K.V.

    1990-01-01

    An investigation was carried out to identify compounds which are suitable for use as homopolymerisation inhibitors when grafting acrylic acid or methacrylic acid onto pre-irradiated low-density polyethylene. It was found that certain transition metal compounds were able to suppress the formation of homopolymer whilst still allowing significant levels of grafting to take place. For acrylic acid the most suitable inhibitor found was ferrous sulphate, whilst cupric sulphate or potassium ferrocyanide were favoured for use with methacrylic acid. The influence of the inhibitor concentration on the degree of grafting was also investigated. (author)

  6. Thin-film type Li-ion battery, using a polyethylene separator grafted with glycidyl methacrylate

    International Nuclear Information System (INIS)

    Ko, J.M.; Min, B.G.; Kim, D.-W.; Ryu, K.S.; Kim, K.M.; Lee, Y.G.; Chang, S.H.

    2004-01-01

    For the improvement of organic electrolyte holding ability, the hydrophobic surface of a porous polyethylene (PE)-membrane separator was modified by grafting a hydrophilic monomer, glycidyl methacrylate (GMA), PE-g-GMA, by using electron beam technology, and applied to a thin film type Li-ion battery to elucidate the effect of a surface modification of a PE membrane separator on the cyclic life of Li-ion batteries. The Li-ion battery using the PE-g-GMA membrane separator showed a better cycle life than that of the unmodified PE membrane separator, indicating that the surface hydrophilicity of the PE membrane separator improved the electrolyte holding capability between the electrodes in the Li-ion cell and prevented the electrolyte leakage

  7. Radiation induced graft copolymerization of methyl methacrylate onto chrome-tanned pig skins

    International Nuclear Information System (INIS)

    Pietrucha, K.; Pekala, W.; Kroh, J.

    1981-01-01

    Graft copolymerization of methyl methacrylate (MMA) onto chrome-tanned pig skins was carried out by irradiation with 60 Co γ-rays. The grafted polymethyl methacrylate (PMMA) chains were isolated by acid hydrolysis of the collagen backbone in order to characterize the graft copolymers. Proof of grafting was obtained through the detection of amino acid endgroups in the isolated grafts by reaction with ninhydrin. The grafting yield of MMA in aqueous emulsion was found to be higher than that for pure MMA and MMA in acetone. The degree of grafting increases with increasing monomer concentration in emulsion and reaches maximum at radiation dose ca 15 kGy. The yield of grafting is very high. The present paper reports the physical properties of chrome-tanned pig skins after graft polymerization with MMA in emulsion. Modified leathers are more resistant against water absorption and abrasion in comparison with unmodified ones. They have more uniform structure over the whole surface, greater thickness and stiffness. The mechanism of some of the processes occurring during radiation grafting of MMA in water emulsion on tanned leathers has been also suggested and discussed. (author)

  8. Radiation induced graft copolymerization of methyl methacrylate onto chrome-tanned pig skins

    Energy Technology Data Exchange (ETDEWEB)

    Pietrucha, K.; Pekala, W.; Kroh, J. (Lodz Univ. (Poland))

    1981-01-01

    Graft copolymerization of methyl methacrylate (MMA) onto chrome-tanned pig skins was carried out by irradiation with /sup 60/Co ..gamma..-rays. The grafted polymethyl methacrylate (PMMA) chains were isolated by acid hydrolysis of the collagen backbone in order to characterize the graft copolymers. Proof of grafting was obtained through the detection of amino acid endgroups in the isolated grafts by reaction with ninhydrin. The grafting yield of MMA in aqueous emulsion was found to be higher than that for pure MMA and MMA in acetone. The degree of grafting increases with increasing monomer concentration in emulsion and reaches maximum at radiation dose ca 15 kGy. The yield of grafting is very high. The present paper reports the physical properties of chrome-tanned pig skins after graft polymerization with MMA in emulsion. Modified leathers are more resistant against water absorption and abrasion in comparison with unmodified ones. They have more uniform structure over the whole surface, greater thickness and stiffness. The mechanism of some of the processes occurring during radiation grafting of MMA in water emulsion on tanned leathers has been also suggested and discussed.

  9. Observations of crystallization and melting in poly(ethylene oxide)/poly(methyl methacrylate) blends by hot-stage atomic-force microscopy

    NARCIS (Netherlands)

    Pearce, R.; Vancso, Gyula J.

    1998-01-01

    The binary blend of poly(ethylene oxide)/atactic poly(methyl methacrylate) is examined using hot-stage atomic-force microscopy (AFM) in conjunction with differential scanning calorimetry and optical microscopy. It was found possible to follow in real time the melting process, which reveals itself to

  10. Study by the positron annihilation technique of Graft copolimerization of methyl methacrylate in polyethylene induced by gamma radiation

    International Nuclear Information System (INIS)

    Zaldivar Gonzalez, M.E.

    1992-01-01

    Radiation initiated grafting is a very broad field which has attracted considerable interest over the last two decades. Graft copolymers may combine suitable properties of two polymeric components. Radiation methods are particulary appropiate for the production of a large variety of graft copolymers having interesting properties. Ionizing radiation has provided a convenient and clean method to activate a sustrate polymer and undoubtedly, it has added impetus to this field of research. In the present work, graft polymerization of methyl methacrylate (MMA) onto low density polyethylene (LDPE) was carried out. The effect of gamma ray irradiation dose on the grafting degree was investigated for two different methods: direct and preirradiation. The best method to prepare the copolymer for the LDPE film thickness studied: 0.05 and 0.2 mm., was direct method. In both polyethylene thickness, the grafting degree increased as a function of the reaction time. However, grafting for LDPE 0.2 mm. it is better, because the copolymer with that thickness conserve the main physical-chemistry properties of the LDPE along the different grafting degrees obtained, which it is important for practical purposes. Infrared spectroscopy was used to probe the changes ocurred in the LDPE structure with the graft of MMA, first spectrum showed typical bands for LDPE structure, while in the second spectrum new bands appeared which corresponded to PMMA structure grafted onto LDPE. Positron annihilation lifetime technique was applied to study the copolymer microstructure according to increase of grafting degree. O-PS lifetime and intensity tend to decrease. This behavior could be due to the diminution of free volume in the original LDPE matrix as grafting proceeds. Copolymer morphology was observed using optical microscopy (Author)

  11. Radiation Graft Copolymerization of Butyl methacrylate and Acrylamide onto Low density polyethylene and polypropylene films and its application in wastewater treatment

    International Nuclear Information System (INIS)

    Abdel Ghaffar, A.M.; El-Arnaouty, M.B.; Aboulfotouh, M.E.; Taher, N.H.

    2012-01-01

    Butyl methacrylate and Acrylamide (BMA/AAm) comonomer were grafted onto Low density polyethylene and polypropylene films using direct gamma radiation by grafting technique. The influences of grafting conditions such as solvent, monomer concentration, monomer composition, and irradiation dose on the grafting yield were determined. It was found that, using DMF as a solvent enhanced the copolymerization process. The grafting yield increases with comonomer concentration up to 60 %. . Also it was found that, the degree of grafting of (BMA/AAm) onto LDPE and PP films increases as the AAm content increases till optimum value at (50:50) %. The grafting yield of the comonomer found to be increased with increasing radiation dose. It was observed that the degree of grafting of polyethylene films is higher than that for polypropylene films. Some selected properties of the graft copolymers, such as water uptake and thermal properties determined by using thermogravimetric analysis (TGA) has been carried out. The morphology and structure of grafted films was investigated by using SEM, IR and X-ray diffraction. The improvement in such properties of the prepared copolymers was observed which makes possible uses in some practical applications such as in the removal of some heavy metals from wastewater. It was found that the maximum metal uptake by the copolymer is ordered in the sequence of Cu 2+ > CO 2+ > Ni 2+ ions.

  12. Preparation of poly(methyl methacrylate) grafted titanate nanotubes by in situ atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Gao Yuan; Zhou Yongfeng; Yan Deyue; Gao Xueping

    2008-01-01

    This paper reports the successful preparation of core-shell hybrid nanocomposites by a 'grafting from' approach based on in situ atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) from titanate nanotubes (TNTs). Transmission electron microscope (TEM) images of the products provide direct evidence for the formation of a core-shell structure, possessing a hard core of TNTs and a soft shell of poly-MMA (PMMA). Fourier-transform infrared spectroscopy (FT-IR), hydrogen nuclear magnetic resonance ( 1 H NMR), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA) were used to determine the chemical structure, morphology, and the grafted PMMA quantities of the resulting products. The grafted PMMA content was well controlled and increased with increasing monomer/initiator ratio. Further copolymerization of hydroxyethyl methacrylate (HEMA) with PMMA-coated TNTs as initiators was realized, illustrating the 'living' characteristics of the ATRP method used in this paper.

  13. The role of hydroperoxides as a precursor in the radiation-induced graft polymerization of methyl methacrylate to ultra-high molecular weight polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, Ichiro, E-mail: enomoto.ichiro@iri-tokyo.j [Tokyo Metropolitan Industrial Technology Research Institute, KFC bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan); School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Katsumura, Yosuke [School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai-mura, Ibaraki 319-1195 (Japan); Kudo, Hisaaki [School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Sekiguchi, Masayuki [Tokyo Metropolitan Industrial Technology Research Institute, KFC bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan)

    2010-06-15

    A graft polymerization of methyl methacrylate (MMA) to ultra-high molecular weight polyethylene (UHMWPE) with Co-60 gamma-ray irradiation in air at room temperature has been carried out. The grafting yields were measured as a function of the storage time (elapsed time from the end of irradiation to the start of grafting), and it was found that the yields reach at the maximum values at around several days since the end of irradiation. In order to clarify the precursor of the graft polymerization, changes of the radical yields and the carbonyl groups were measured as a function of storage time with ESR and microscopic FT-IR, respectively. From the similarities between the depth profiles of the hydroperoxide formation and the grafting products, it was concluded that the hydroperoxides can be main precursors of the grafting of the radiation-induced polymerization of MMA to UHMWPE under the given conditions.

  14. The role of hydroperoxides as a precursor in the radiation-induced graft polymerization of methyl methacrylate to ultra-high molecular weight polyethylene

    International Nuclear Information System (INIS)

    Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Sekiguchi, Masayuki

    2010-01-01

    A graft polymerization of methyl methacrylate (MMA) to ultra-high molecular weight polyethylene (UHMWPE) with Co-60 γ-ray irradiation in air at room temperature has been carried out. The grafting yields were measured as a function of the storage time (elapsed time from the end of irradiation to the start of grafting), and it was found that the yields reach at the maximum values at around several days since the end of irradiation. In order to clarify the precursor of the graft polymerization, changes of the radical yields and the carbonyl groups were measured as a function of storage time with ESR and microscopic FT-IR, respectively. From the similarities between the depth profiles of the hydroperoxide formation and the grafting products, it was concluded that the hydroperoxides can be main precursors of the grafting of the radiation-induced polymerization of MMA to UHMWPE under the given conditions.

  15. Surface modification of magnesium aluminum hydroxide nanoparticles with poly(methyl methacrylate) via one-pot in situ polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Guo Xiaojun, E-mail: guoxj6906@163.com [College of Chemistry and Chemical Engineering, Northwest Normal University, 967 Anning East Road, Lanzhou 730070 (China); Zhao Leihua; Zhang Li; Li Jing [College of Chemistry and Chemical Engineering, Northwest Normal University, 967 Anning East Road, Lanzhou 730070 (China)

    2012-01-15

    Hydrophobic magnesium aluminum hydroxide composite particles (PMMA-MAH) were obtained by means of grafting poly(methyl methacrylate) (PMMA) onto the surface of magnesium aluminum hydroxide(MAH) nanoparticles after a novel type of phosphate coupling agent (DN-27) modification. The introduction of functional double bonds was firstly conducted on the surface of nanoparticles by DN-27 modification, followed by one-pot in situ polymerization on the particles surface using methyl methacrylate (MMA) as monomer, azoisobutyronitrile (AIBN) as initiator and sodium dodecyl sulfate (SDS) as stabilizer to graft PMMA on the surface of DN-27-modified MAH particles. The obtained composite particles were characterized by field-emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD). The results show that the organic macromolecule PMMA could be successfully grafted on the surface of DN-27-modified MAH nanoparticles and the thermal stability of the PMMA-MAH composite particles had been improved. Compared with unmodified blank MAH sample, the product obtained with this method possesses better hydrophobic properties such as a higher water contact angle of 108 Degree-Sign and a well dispersion.

  16. Tensile properties of polymethyl methacrylate coated natural fabric Sterculia urens

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2009-04-01

    Full Text Available stress, Young's modulus and % elongation at break were determined using a Universal Testing Machine. The effect of alkali treatment and the polymethyl methacrylate coating on tensile properties of the fabric was studied. The morphology of the fabric...

  17. Phase holograms in polymethyl methacrylate

    Science.gov (United States)

    Maker, P. D.; Muller, R. E.

    1992-01-01

    A procedure is described for the fabrication of complex computer-generated phase holograms in polymethyl methacrylate (PMMA) by means of partial-exposure e-beam lithography and subsequent carefully controlled partial development. Following the development, the pattern appears (rendered in relief) in the PMMA, which then acts as the phase-delay medium. The devices fabricated were designed with 16 equal phase steps per retardation cycle, were up to 3 mm square, and consisted of up to 10 millions of 0.3-2.0-micron square pixels. Data files were up to 60 Mb-long, and the exposure times ranged to several hours. A Fresnel phase lens was fabricated with a diffraction-limited optical performance of 83-percent efficiency.

  18. Superparamagnetic poly(methyl methacrylate) beads for nattokinase purification from fermentation broth.

    Science.gov (United States)

    Yang, Chengli; Xing, Jianmin; Guan, Yueping; Liu, Huizhou

    2006-09-01

    An effective method for purification of nattokinase from fermentation broth using magnetic poly(methyl methacrylate) (PMMA) beads immobilized with p-aminobenzamidine was proposed in this study. Firstly, magnetic PMMA beads with a narrow size distribution were prepared by spraying suspension polymerization. Then, they were highly functionalized via transesterification reaction with polyethylene glycol. The surface hydroxyl-modified magnetic beads obtained were further modified with chloroethylamine to transfer the surface amino-modified magnetic functional beads. The morphology and surface functionality of the magnetic beads were examined by scanning electron microscopy and Fourier transform infrared. An affinity ligand, p-aminobenzamidine was covalently immobilized to the amino-modified magnetic beads by the glutaraldehyde method for nattokinase purification directly from the fermentation broth. The purification factor and the recovery of the enzyme activity were found to be 8.7 and 85%, respectively. The purification of nattokinase from fermentation broth by magnetic beads only took 40 min, which shows a very fast purification of nattokinase compared to traditional purification methods.

  19. Mössbauer studies of iron doped poly(methyl methacrylate) before ...

    Indian Academy of Sciences (India)

    Unknown

    Mössbauer studies of iron doped poly(methyl methacrylate) before and after ion beam modification. D R S SOMAYAJULU, C N MURTHY†, D K AWASTHI‡, N V PATEL and M SARKAR. Physics Department, Faculty of Science, MS University of Baroda, Vadodara 390 002, India. †Applied Chemistry Department, Faculty ...

  20. A highly selective sorbent for removal of Cr(VI) from aqueous solutions based on Fe3O4/poly(methyl methacrylate) grafted Tragacanth gum nanocomposite: Optimization by experimental design

    International Nuclear Information System (INIS)

    Sadeghi, Susan; Rad, Fatemeh Alavi; Moghaddam, Ali Zeraatkar

    2014-01-01

    In this work, poly(methyl methacrylate) grafted Tragacanth gum modified Fe 3 O 4 magnetic nanoparticles (P(MMA)-g-TG-MNs) were developed for the selective removal of Cr(VI) species from aqueous solutions in the presence of Cr(III). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), a vibrating sample magnetometer (VSM), and thermo-gravimetric analysis (TGA). A screening study on operational variables was performed using a two-level full factorial design. Based on the analysis of variance (ANOVA) with 95% confidence limit, the significant variables were found. The central composite design (CCD) has also been employed for statistical modeling and analysis of the effects and interactions of significant variables dealing with the Cr(VI) uptake process by the developed sorbent. The predicted optimal conditions were situated at a pH of 5.5, contact time of 3.4 h, and 3.0 g L −1 dose. The Langmuir, Freundlich, and Temkin isotherm models were used to describe the equilibrium sorption of Cr(VI) by the absorbent, and the Langmuir isotherm showed the best concordance as an equilibrium model. The adsorption process was followed by a pseudo-second-order kinetic model. Thermodynamic investigations showed that the biosorption process was spontaneous and exothermic. - Highlights: • Fe3O4 nanoparticles were modified with Poly(methyl methacrylate) grafted Tragacanth gum • P(MMA)-g-TG -MNPs can preferentially adsorb Cr(VI) in the presence of Cr(III) • The effects of operational parameters on Cr(VI) removal were evaluated by RSM • Adsorption mechanism, kinetics, and isotherm have been explored • The sorbent was successfully used to remove Cr(VI) from different water samples

  1. Rheo-optical near-infrared (NIR) spectroscopy study of partially miscible polymer blend of polymethyl methacrylate (PMMA) and polyethylene glycol (PEG)

    Science.gov (United States)

    Shinzawa, Hideyuki; Mizukado, Junji

    2018-03-01

    Tensile deformations of a partially miscible blend of polymethyl methacrylate (PMMA) and polyethylene glycol (PEG) is studied by a rheo-optical characterization near-infrared (NIR) technique to probe deformation behavior during tensile deformation. Sets of NIR spectra of the polymer samples were collected by using an acousto-optic tunable filter (AOTF) NIR spectrometer coupled with a tensile testing machine as an excitation device. While deformations of the samples were readily captured as strain-dependent NIR spectra, the entire feature of the spectra was overwhelmed with the baseline fluctuation induced by the decrease in the sample thickness and subsequent change in the light scattering. Several pretreatment techniques, including multiplicative scatter collection (MSC) and null-space projection, are subjected to the NIR spectra prior to the determination of the sequential order of the spectral intensity changes by two-dimensional (2D) correlation analysis. The comparison of the MSC and null-space projection provided an interesting insight into the system, especially deformation-induced variation of light scattering observed during the tensile testing of the polymer sample. In addition, the sequential order determined with the 2D correlation spectra revealed that orientation of a specific part of PMMA chain occurs before that of the others because of the interaction between Cdbnd O group of PMMA and terminal sbnd OH group of PEG.

  2. Syntheses of amine-type adsorbents with emulsion graft polymerization of glycidyl methacrylate

    International Nuclear Information System (INIS)

    Seko, N.; Bang, L.T.; Tamada, M.

    2007-01-01

    Glycidyl methacrylate (GMA) which was precursor monomer for the synthesis of metal ion adsorbent was emulsified by surfactant of Tween 20 (Tw-20). The emulsion of 5% GMA in the water was stable for 48 h at Tw-20 concentration of 0.5%. Graft polymerization of GMA on polyethylene fiber was carried out in the emulsion state at various pre-irradiation doses. Degree of grafting (Dg) reached 103%, 301% and 348% for 1 h grafting at 40 deg. C with pre-irradiation of 10, 30 and 40 kGy, respectively. But the Dg was depressed when the pre-irradiation dose was over 50 kGy since cross-linking occurred simultaneously in the trunk polymer. Dg decreased with increment of Tw-20 concentration in emulsion of 5% GMA at pre-irradiation of 40 kGy. The three kinds of amine-type adsorbents were synthesized by reacting diethylenetriamine (DETA), triethylenetetramine (TETA) and ethylenediamine (EDA) with GMA-grafted polyethylene fiber. The synthesized EDA-type adsorbent had the highest selectivity against U ion and the distribution coefficient was 2.0 x 10 6

  3. Tuning Surface Properties of Poly(methyl methacrylate) Film Using Poly(perfluoromethyl methacrylate)s with Short Perfluorinated Side Chains.

    Science.gov (United States)

    Sohn, Eun-Ho; Ha, Jong-Wook; Lee, Soo-Bok; Park, In Jun

    2016-09-27

    To control the surface properties of a commonly used polymer, poly(methyl methacrylate) (PMMA), poly(perfluoromethyl methacrylate)s (PFMMAs) with short perfluorinated side groups (i.e., -CF3, -CF2CF3, -(CF3)2, -CF2CF2CF3) were used as blend components because of their good solubility in organic solvents, low surface energies, and high optical transmittance. The surface energies of the blend films of PFMMA with the -CF3 group and PMMA increased continuously with increasing PMMA contents from 17.6 to 26.0 mN/m, whereas those of the other polymer blend films remained at very low levels (10.2-12.6 mN/m), similar to those of pure PFMMAs, even when the blends contained 90 wt %PMMA. Surface morphology and composition measurements revealed that this result originated from the different blend structures, such as lateral and vertical phase separations. We expect that these PFMMAs will be useful in widening the applicable window of PMMA.

  4. A highly selective sorbent for removal of Cr(VI) from aqueous solutions based on Fe{sub 3}O{sub 4}/poly(methyl methacrylate) grafted Tragacanth gum nanocomposite: Optimization by experimental design

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Susan, E-mail: ssadeghi@birjand.ac.ir; Rad, Fatemeh Alavi; Moghaddam, Ali Zeraatkar

    2014-12-01

    In this work, poly(methyl methacrylate) grafted Tragacanth gum modified Fe{sub 3}O{sub 4} magnetic nanoparticles (P(MMA)-g-TG-MNs) were developed for the selective removal of Cr(VI) species from aqueous solutions in the presence of Cr(III). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), a vibrating sample magnetometer (VSM), and thermo-gravimetric analysis (TGA). A screening study on operational variables was performed using a two-level full factorial design. Based on the analysis of variance (ANOVA) with 95% confidence limit, the significant variables were found. The central composite design (CCD) has also been employed for statistical modeling and analysis of the effects and interactions of significant variables dealing with the Cr(VI) uptake process by the developed sorbent. The predicted optimal conditions were situated at a pH of 5.5, contact time of 3.4 h, and 3.0 g L{sup −1} dose. The Langmuir, Freundlich, and Temkin isotherm models were used to describe the equilibrium sorption of Cr(VI) by the absorbent, and the Langmuir isotherm showed the best concordance as an equilibrium model. The adsorption process was followed by a pseudo-second-order kinetic model. Thermodynamic investigations showed that the biosorption process was spontaneous and exothermic. - Highlights: • Fe3O4 nanoparticles were modified with Poly(methyl methacrylate) grafted Tragacanth gum • P(MMA)-g-TG -MNPs can preferentially adsorb Cr(VI) in the presence of Cr(III) • The effects of operational parameters on Cr(VI) removal were evaluated by RSM • Adsorption mechanism, kinetics, and isotherm have been explored • The sorbent was successfully used to remove Cr(VI) from different water samples.

  5. Fabrication of poly(methyl methacrylate)-block-poly(methacrylic acid) diblock copolymer as a self-embrittling strippable coating for radioactive decontamination

    International Nuclear Information System (INIS)

    Liu Renlong; Zhang Huiyan; Li Yintao; Zhou Yuanlin; Zhang Quanping; Zheng Jian; Wang Shanqiang

    2016-01-01

    The poly(methyl methacrylate)-block-poly(methacrylic acid) diblock copolymer with different monomer compositions was synthesized via reversible addition-fragmentation chain transfer polymerization. Meanwhile, a novel self-embrittling strippable coating was prepared using the diblock copolymers, which is proposed to be used as radioactive decontamination agents without manual operation. Furthermore, the decontamination efficiencies of self-embrittling strippable coatings for radioactive contamination on glass, marble, and stainless steel surfaces were studied. (author)

  6. Microindentation of Polymethyl Methacrylate (PMMA Based Bone Cement

    Directory of Open Access Journals (Sweden)

    F. Zivic

    2011-12-01

    Full Text Available Characterization of polymethyl methacrylate (PMMA based bone cement subjected to cyclical loading using microindentation technique is presented in this paper. Indentation technique represents flexible mechanical testing due to its simplicity, minimal specimen preparation and short time needed for tests. The mechanical response of bone cement samples was studied. Realised microindentation enabled determination of the indentation testing hardness HIT and indentation modulus EIT of the observed bone cement. Analysis of optical photographs of the imprints showed that this technique can be effectively used for characterization of bone cements.

  7. All solid-state polymer electrolytes prepared from a hyper-branched graft polymer using atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Higa, Mitsuru; Fujino, Yukiko; Koumoto, Taihei; Kitani, Ryousuke; Egashira, Satsuki

    2005-01-01

    We propose an all solid-state (liquid free) polymer electrolyte (SPE) prepared from a hyper-branched graft copolymer. The graft copolymer consisting of a poly(methyl methacrylate) main chain and poly(ethylene glycol) methyl ether methacrylate side chains was synthesized by atom transfer radical polymerization changing the average chain distance between side chains, side chain length and branched chain length of the proposed structure of the graft copolymer. The ionic conductivity of the SPEs increases with increasing the side chain length, branched chain length and/or average distance between the side chains. The ionic conductivity of the SPE prepared from POEM 9 whose POEM content = 51 wt% shows 2 x 10 -5 S/cm at 30 deg. C. The tensile strength of the SPEs decreases with increases the side chain length, branched chain length and/or average distance between the side chains. These results indicate that a SPE prepared from the hyper-branched graft copolymer has potential to be applied to an all-solid polymer electrolyte

  8. Graft copolymerization of water soluble mixed monomers onto polyethylene by the pre-irradiation method

    International Nuclear Information System (INIS)

    Long Fu; Tang Liming; Zhao Jin; Gao Zhenyong

    1993-01-01

    Grafting of water soluble mixed monomers of acrylic acid (AA)/acrylamide (Am) and acrylic acid/methacrylic acid (MA) onto polyethylene film by the pre-irradiation grafting method was investigated. The results showed that the grafting proceeded successfully with the adding of ferric salt in the solution. In the case of AA/Am system, a synergistic effect was noticed. In the case of AA/MA system, the graft percent increased with the increase in the concentration of MA in the feed ratio. Furthermore, the effects of monomer concentration, radiation dose and temperature on the grafting were also studied

  9. Well-defined 4-arm stars with hydroxy-terminated polyethylene, polyethylene-b-polycaprolactone and polyethylene-b-(polymethyl methacrylate) 2 arms

    KAUST Repository

    Zhang, Zhen

    2016-07-20

    Bis-boron-thexyl-silaboracycle was prepared by hydroboration of 1,4-bis(methyldivinylsilyl)butane with thexylborane and used to initiate the polyhomologation of dimethylsulfoxonium methylide to afford well-defined hydroxy-terminated 4-arm polyethylene (PE) stars. The synthesized PE stars were transformed to (PE-b-PCL)4 starblock copolymers via the ring-opening polymerization of ϵ-caprolactone (CL) initiated by the hydroxyl end groups of (PE-OH)4 in the presence of P2-tBu phosphazene base. Esterification of the hydroxyl groups of the OH-terminated PE star with 2,2-dichloroacetyl chloride led to (PE-Cl2)4 which was used as initiator (eight initiating atom transfer radical polymerization, ATRP, sites) for the synthesis of (PE-b-PMMA2)4 dendrimer-like stars by the ATRP of methyl methacrylate (MMA). All intermediates and final products were characterized by high temperature gel permeation chromatography and proton nuclear magnetic resonance spectroscopy. © 2016 The Royal Society of Chemistry.

  10. Mechanical Properties of Surface-Charged Poly(Methyl Methacrylate as Denture Resins

    Directory of Open Access Journals (Sweden)

    Sang E. Park

    2009-01-01

    Full Text Available The aim of this study was to examine the mechanical properties of a new surface-modified denture resin for its suitability as denture base material. This experimental resin is made by copolymerization of methacrylic acid (MA to poly(methyl methacrylate (PMMA to produce a negative charge. Four experimental groups consisted of Orthodontic Dental Resin (DENTSPLY Caulk as a control and three groups of modified PMMA (mPMMA produced at differing ratios of methacrylic acid (5 : 95, 10 : 90, and 20 : 80 MA : MMA. A 3-point flexural test using the Instron Universal Testing Machine (Instron Corp. measured force-deflection curves and a complete stress versus strain history to calculate the transverse strength, transverse deflection, flexural strength, and modulus of elasticity. Analysis of Variance and Scheffe Post-test were performed on the data. Resins with increased methacrylic acid content exhibited lower strength values for the measured physical properties. The most significant decrease occurred as the methacrylic acid content was increased to 20% mPMMA. No significant differences at P<.05 were found in all parameters tested between the Control and 5% mPMMA.

  11. Effect of solubility parameter of solvents on electron beam induced graft-polymerization onto polyethylene films

    International Nuclear Information System (INIS)

    Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

    1992-01-01

    Electron beam induced graft-polymerization by the mutual irradiation technique of methyl methacrylate (MMA) and methacrylic acid (MAAc) blended with solvents, which have different solubility parameters δ, onto high density polyethylene films (PE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic rations on the surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of solvents, and grafting rates for MMA were larger than those for MAAc. Graft chain contents on the surface, which were evaluated in terms of surface tensions and atomic ratios on the surface, increased with increasing δ of solvents, and graft chain contents on the surface of MAAc grafted PE were higher than those of MMA grafted PE. It is assumed that mutual solubility of PE and solvents (monomer solutions), i.e., infiltration of monomer solutions into PE during graft-polymerization, influenced grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

  12. Composite poly(methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate) latex for immunoassay. The case of plasminogen.

    Science.gov (United States)

    Miksa, B; Wilczynska, M; Cierniewski, C; Basinska, T; Slomkowski, S

    1995-01-01

    Poly(methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate) latex (ACRYLAT) was synthesized by radical precipitation polymerization. The mass median diameter (MMD) and the geometrical standard deviation (GSD) of the ACRYLAT particles were 138 nm and 1.2, respectively. The concentration of the titrable carboxylic groups in the surface layer of latex particles was equal to 8.41 x 10(-6) mol m-2. Latex was able to bind up to 2.82 x 10(-7) mol of 1-aminopyrene per 1 m2 of the surface of the latex particles due to the ionic interactions between carboxylate anions and ammonium cations of protonated 1-aminopyrene. ACRYLAT was able to immobilize covalently human serum albumin in amounts up to 0.23 mg m-2. Aggregation of ACRYLAT with immobilized HSA, induced with specific antibodies (anti-HSA), was investigated turbidimetrically. The results indicated that in the model turbidimetric immunoassay, ACRYLAT coated with HSA can be used for the detection of anti-HSA in the goat anti-HSA serum diluted from 50 to 7000-fold. Immobilization of rabbit antibodies to plasminogen (anti-Plg) to ACRYLAT via the epsilon-aminocaproic acid linkers provided particles which were used for the development of the turbidimetric immunoassay for plasminogen. In this assay plasminogen could be detected in concentration ranging from 0.75 to 75 micrograms ml-1 in the blood plasma.

  13. MALDI-TOF MS coupled with collision-induced dissociation (CID) measurements of poly(methyl methacrylate)

    NARCIS (Netherlands)

    Baumgaertel, A.; Becer, C.R.; Gottschaldt, M.; Schubert, U.S.

    2008-01-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was chosen for an in-detail analysis of poly(methyl methacrylate) (PMMA) in order to determine the possible fragmentation mechanism with the help of collision-induced dissociation (CID). All experiments were

  14. Third-order nonlinear optical properties of the poly(methyl methacrylate)-phenothiazinium dye hybrid thin films

    International Nuclear Information System (INIS)

    Sun, Ru; Lu, Yue-Ting; Yan, Bao-Long; Lu, Jian-Mei; Wu, Xing-Zhi; Song, Ying-Lin; Ge, Jian-Feng

    2014-01-01

    The third-order nonlinear optical properties of poly(methyl methacrylate) films doped with charge flowable 3,7-di(piperidinyl)phenothiazin-5-ium chloride, which tested by Z-scan method with nanosecond laser beam at 532 nm, are reported. Large third-order nonlinear optical susceptibilities (up to 10 −7 esu) and high second hyperpolarizabilities (up to 10 −27 esu) are found. The third-order nonlinear absorptions change from reverse saturated absorptions to saturated absorptions with different percentage of the phenothiazinium dye in the poly(methyl methacrylate) films, which can be explained by the accumulation phenomenon of the phenothiazinium. The results suggest that the phenothiazinium salt is a promising material for third order non-linear applications. - Highlights: • Phenothiazinium containing optical films • Strong third-order nonlinear optical (NLO) absorption • Large third-order NLO susceptibilities

  15. New CO2 adsorbent containing aminated poly(glycidyl methacrylate) grafted onto irradiated PE-PP nonwoven sheet

    Science.gov (United States)

    Mahmoud Nasef, Mohamed; Abbasi, Ali; Ting, T. M.

    2014-10-01

    A new CO2 adsorbent containing triethylamine (TEA) was prepared by radiation induced grafting of glycidyl methacrylate (GMA) onto polyethylene coated polypropylene (PE-PP) non-woven sheet followed by amination reaction. The degree of grafting (DOG%) was controlled by variation of monomer concentration and absorbed dose. The incorporation of aminated poly(GMA) was investigated by Fourier transform infrared (FTIR) and scanning electron microscope (SEM). The adsorbent with DOG of 350% and amination yield of 60% exhibited CO2 adsorption capacity of 4.52 mol/kg at ambient temperature and pressure.

  16. Surface characterization of poly(vinyl chloride) urinary catheters functionalized with acrylic acid and poly(ethylene glycol) methacrylate using gamma-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Islas, Luisa [Departamento de Química de Radiaciones y Radioquímica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico D.F. 04510 (Mexico); Ruiz, Juan-Carlos [División de Ciencias Básicas e Ingeniería, Depto. de Ingeniería de Procesos e Hidráulica, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 México D.F. (Mexico); Muñoz-Muñoz, Franklin [Facultad de Ingeniería, Arquitectura y Diseño, Universidad Autónoma de Baja California, Carretera Transpeninsular Ensenada-Tijuana 3917, Ensenada, B.C. C.P 22860 (Mexico); Isoshima, Takashi [Nano Medical Engineering Laboratory, RIKEN, 2-1Hirosawa, Wako, Saitama 351-0198 (Japan); Burillo, Guillermina, E-mail: burillo@nucleares.unam.mx [Departamento de Química de Radiaciones y Radioquímica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico D.F. 04510 (Mexico)

    2016-10-30

    Highlights: • Polymer grafting using gamma-radiation allowed for acrylic acid and poly(ethylene glycol) methacrylate to graft on the inner and outer surface of poly(vinyl chloride) urinary catheters. • HR-XPS revealed the different compositional percentages of the compounds present on the surface of the catheter. • Catheters that were grafted with PEGMA had the roughest surface as observed using scanning electron microscopy (SEM) and confocal laser microscopy (CLM). - Abstract: Poly(vinyl chloride) (PVC) urinary catheters were modified with either a single or binary graft of acrylic acid (AAc) and/or poly(ethylene glycol) methacrylate (PEGMA) using gamma-radiation from {sup 60}Co to obtain PVC-g-AAc, PVC-g-PEGMA, [PVC-g-AAc]-g-PEGMA, and [PVC-g-PEGMA]-g-AAc copolymers. The outer and inner surfaces of the modified catheters were characterized using scanning electron microscopy (SEM), confocal laser microscopy (CLM) and X-ray photoelectron spectroscopy (XPS). The XPS analyses, by examining the correlation between the variation of the C{sub 1s} and O{sub 1s} content at the catheter’s surface, revealed that the catheter’s surfaces were successfully grafted with the chosen compounds, with those that were binary grafted showing a slightly more covered surface as was evidenced by the disappearance of PVC’s Cl peak. The SEM and CLM analyses revealed that catheters that had been grafted with PEGMA had a rougher outer surface as compared to those that had only been grafted with AAc. In addition, these imaging techniques showed that the inner surface of the singly grafted catheters, whether they had been grafted with AAc or PEGMA, retained some smoothness at the analyzed grafting percentages, while the binary grafted catheters showed many protuberances and greater roughness on both outer and inner surfaces.

  17. Synthesis of hydrophilic carbon nanotubes by grafting poly(methyl methacrylate) via click reaction and its effect on poly(vinylidene fluoride)-carbon nanotube composite membrane properties1

    Science.gov (United States)

    Ma, Wenzhong; Zhao, Yuchen; Li, Yuxue; Zhang, Peng; Cao, Zheng; Yang, Haicun; Liu, Chunlin; Tao, Guoliang; Gong, Fanghong; Matsuyama, Hideto

    2018-03-01

    Surface modification of azide-decorated multiwalled carbon nanotubes (MWCNTs) with well-defined alkyne-terminated poly(methyl methacrylate) (PMMA) chains was accomplished via the combination of reversible addition fragmentation chain transfer (RAFT) and "click" chemistry. Successful attachment of PMMA onto MWCNT was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), gel permeation chromatography, Raman spectroscopy, and transmission electron microscopy. The highest grafting percentage (GP) of the PMMA chains (GP = 23.3%) was calculated using TGA. The effect of the PMMA-grafted-MWCNTs (MWCNTs-g-PMMA) content on the performance of the poly(vinylidene fluoride) (PVDF)-MWCNTs-g-PMMA composite membrane was studied. The MWCNTs-g-PMMA was found to be well dispersed in the PVDF composite membrane matrix because of the excellent compatibility between the PMMA and PVDF chains. The composite membranes showed improved porosity, hydrophilicity, water flux, β-PVDF content, and mechanical properties at an optimal amount of 2 wt% MWCNTs-g-PMMA incorporated in the PVDF membrane matrix. In contrast, the hydroxyl functionalized MWCNTs (MWCNTs-OH) showed limited enhancement in the water flux and mechanical strength, which is mainly due to the poor dispersion of MWCNT because of the weak interaction between the MWCNT and PVDF chains. This study reveals the excellent prospect of the MWCNT-based ultrafiltration membrane with enhanced properties in water treatment applications.

  18. Thermal and electrical conductivity enhancement of graphite nanoplatelets on form-stable polyethylene glycol/polymethyl methacrylate composite phase change materials

    International Nuclear Information System (INIS)

    Zhang, Lei; Zhu, Jiaoqun; Zhou, Weibing; Wang, Jun; Wang, Yan

    2012-01-01

    Graphite nanoplatelets (GnPs), obtained by sonicating the expanded graphite, were employed to simultaneously enhance the thermal (k) and electrical (σ) conductivity of organic form-stable phase change materials (FSPCMs). Using the method of in situ polymerization upon ultrasonic irradiation, GnPs serving as the conductive fillers and polyethylene glycol (PEG) acting as the phase change material (PCM) were uniformly dispersed and embedded inside the network structure of polymethyl methacrylate (PMMA), which contributed to the well package and self-supporting properties of composite FSPCMs. X-ray diffraction and Fourier transform infrared spectroscopy results indicated that the GnPs were physically combined with PEG/PMMA matrix and did not participate in the polymerization. The GnPs additives were able to effectively enhance the k and σ of organic FSPCM. When the mass ratio of GnP was 8%, the k and σ of FSPCM changed up to 9 times and 8 orders of magnitude over that of PEG/PMMA matrix, respectively. The improvements in both k and σ were mainly attributed to the well dispersion and large aspect ratio of GnPs, which were endowed with benefit of forming conducting network in polymer matrix. It was also confirmed that all the prepared specimens possessed available thermal storage density and thermal stability. -- Highlights: ► GnPs were employed to simultaneously enhance the k and σ of organic FSPCMs. ► PEG/PMMA/GnPs composite FSPCMs were prepared by in situ polymerization method. ► The composite FSPCMs exhibited well package and self-supporting properties. ► GnPs additives effectively enhanced the k and σ of composite FSPCMs. ► All the composites possessed available thermal storage density and thermal stability.

  19. Graphene and poly(methyl methacrylate) composite laminates on flexible substrates for volatile organic compound detection

    Science.gov (United States)

    Rattanabut, Chanoknan; Wongwiriyapan, Winadda; Muangrat, Worawut; Bunjongpru, Win; Phonyiem, Mayuree; Song, Young Jae

    2018-04-01

    In this paper, we present a gas sensor for volatile organic compound (VOC) detection based on graphene and poly(methyl methacrylate) (GR/PMMA) composite laminates fabricated using CVD-grown graphene. Graphene was transferred to a poly(ethylene terephthalate) (PET) substrate by PMMA-supported wet transfer process without PMMA removal in order to achieve the deposition of GR/PMMA composite laminates on PET. The GR/PMMA and graphene sensors show completely different sensitivities to VOC vapors. The GR/PMMA and graphene sensors showed the highest sensitivities to dichloromethane (DCM). The response of the GR/PMMA sensor to DCM was 3 times higher than that of the graphene sensor but the GR/PMMA sensor hardly responded to acetone, chloroform, or benzene. The sensing mechanism of the graphene sensor can be based on the dielectric constant of VOCs, the size of VOC molecule, and electron hopping effects on defect graphene, while that of the GR/PMMA sensor can be explained in terms of the polymer swelling owing to the Hansen solubility parameter.

  20. Dynamics of poly(ethylene oxide) in a blend with poly(methyl methacrylate): A quasielastic neutron scattering and molecular dynamics simulations study

    International Nuclear Information System (INIS)

    Genix, A.-C.; Arbe, A.; Alvarez, F.; Colmenero, J.; Willner, L.; Richter, D.

    2005-01-01

    In this paper, we have addressed the question of the dynamic miscibility in a blend characterized by very different glass-transition temperatures, T g , for the components: poly(ethylene oxide) and poly(methyl methacrylate) (PEO/PMMA). The combination of quasielastic neutron scattering with isotopic labeling and fully atomistic molecular dynamics simulations has allowed us to selectively investigate the dynamics of the two components in the picosecond--10 nanoseconds scale at temperatures close and above the T g of the blend. The main focus was on the PEO component, i.e., that of the lowest T g , but first we have characterized the dynamics of the other component in the blend and of the pure PEO homopolymer as reference. In the region investigated, the dynamics of PMMA in the blend is strongly affected by the α-methyl rotation; an additional process detected in the experimental window 65 K above the blend-T g can be identified as the merged αβ process of this component that shows strong deviations from Gaussian behavior. On the other hand, pure PEO displays entropy driven dynamics up to very large momentum transfers. Such kind of motion seems to freeze when the PEO chains are in the blend. There, we have directly observed a very heterogeneous and moreover confined dynamics for the PEO component. The presence of the hardly moving PMMA matrix leads to the creation of little pockets of mobility where PEO can move. The characteristic size of such confined islands of mobility might be estimated to be of ≅1 nm. These findings are corroborated by the simulation study, which has been an essential support and guide in our data analysis procedure

  1. Polydimethylsiloxane microspheres with poly(methyl methacrylate) coating: Modelling, preparation, and characterization

    DEFF Research Database (Denmark)

    Ma, Baoguang; Hansen, Jens Henrik; Hvilsted, Søren

    2015-01-01

    functional PDMS microspheres were coated with poly(methyl methacrylate) (PMMA) by spin coating with different concentrations of PMMA solutions. The quality of the resulting PMMA shell is investigated using rheological measurements at 50 8C with a timesweep procedure. The results strongly suggest that PMMA-coated...... PDMS microspheres react around 20 times slower than the uncoated ones, and that the PMMA shell significantly hinders the reaction between the PDMS microsphere and cross-linker. Thus the thin PMMA shells are very efficient in protecting the reactive PDMS microspheres, since the PMMA shell forms...

  2. Influence of Glycidyl Methacrylate Grafting on the Mechanical, Water Absorption, and Thermal Properties of Recycled High-Density Polyethylene/Rubber Seed Shell Particle Composites

    Directory of Open Access Journals (Sweden)

    Kaimeng Xu

    2016-01-01

    Full Text Available Rubber seed shell (RSS was modified by grafting treatment using glycidyl methacrylate (GMA at various concentrations. The RSS was then used to reinforce high-density polyethylene (HDPE. The effects of modification on the mechanical, water absorption, and thermal properties of the RSS/HDPE composites were studied using a mechanical testing instrument, weighing method, Vicat softening temperature (VST testing, thermogravimetry, and dynamic mechanical analysis. The results showed that the GMA grafting produced an improvement in the flexural and tensile properties of the composites. The water absorption rate of the composites also had an obvious decrease. While a slight increase in VST was found, the various concentrations of GMA showed no improvement in VST. GMA modification also could elevate the thermal stability of the composites at the initial decomposition stage. The optimum grafting concentration of GMA (2.5% led to the lowest thermal weight loss (37.07% and 26.56% during the first and second decomposition stages. The E’ values of the composites had a significant increase with the addition of GMA. There were two peaks of tan δ for the untreated samples, but the modified samples exhibited a shift in the transition peak at higher temperatures; moreover, the second peak disappeared.

  3. Carrier transport in flexible organic bistable devices of ZnO nanoparticles embedded in an insulating poly(methyl methacrylate) polymer layer

    International Nuclear Information System (INIS)

    Son, Dong-Ick; Park, Dong-Hee; Choi, Won Kook; Cho, Sung-Hwan; Kim, Won-Tae; Kim, Tae Whan

    2009-01-01

    The bistable effects of ZnO nanoparticles embedded in an insulating poly(methyl methacrylate) (PMMA) polymer single layer by using flexible polyethylene terephthalate (PET) substrates were investigated. Transmission electron microscopy (TEM) images revealed that ZnO nanoparticles were formed inside the PMMA polymer layer. Current-voltage (I-V) measurement on the Al/ZnO nanoparticles embedded in an insulating PMMA polymer layer/ITO/PET structures at 300 K showed a nonvolatile electrical bistability behavior with a flat-band voltage shift due to the existence of the ZnO nanoparticles, indicative of trapping, storing, and emission of charges in the electronic states of the ZnO nanoparticles. The carrier transport mechanism of the bistable behavior for the fabricated organic bistable device (OBD) structures is described on the basis of the I-V results by analyzing the effect of space charge.

  4. Determination of trace elements in poly(methyl methacrylate) by neutron activation analysis

    International Nuclear Information System (INIS)

    Kobayashi, M.

    1979-01-01

    The results are reported of the neutron activation analysis of poly(methyl methacrylate) polymerized with a redox system of chromium (II) acetate and p-chlorobenzyl peroxide in dimethylformamide at 30 0 C. Since the polymer was originally synthesized in experiments for kinetic studies, the results indicate an arbitrary background of purity of polymers obtained in a laboratory. Samples were irradiated for 28m and gamma spectra detected trace amounts of chlorine, aluminum, vanadium, magnesium, manganese, potassium, copper, zinc, sodium, bromine, lanthanum, gold, and chromium. 2 figures, 1 table

  5. Fracture resistance of Kevlar-reinforced poly(methyl methacrylate) resin: a preliminary study.

    Science.gov (United States)

    Berrong, J M; Weed, R M; Young, J M

    1990-01-01

    The reinforcing effect of Kevlar fibers incorporated in processed poly(methyl methacrylate) resin samples was studied using 0% (controls), 0.5%, 1%, and 2% by weight of the added fibers. The samples were subjected to impact testing to determine fracture resistance, and sample groups were statistically compared using an ANOVA. Each reinforced sample had significantly greater fracture resistance (P less than 0.05) than the control, and no difference was found either within or between control groups. The use of reinforcing Kevlar fibers appears to enhance the fracture resistance of acrylic resin denture base materials.

  6. Preparation and its drug release property of radiation-polymerized poly(methyl methacrylate) capsule including potassium chloride

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Kumakura, Minoru; Kaetsu, Isao

    1979-01-01

    Porous flat circular capsules including KCl as a drug were prepared by radiation-induced polymerization of methyl methacrylate at room temperature in the presence of polyethylene glycol No. 600. The porous structure can be controlled by the methyl methacrylate-polyethylene glycol No. 600 composition. The amount of drug released was linearly related to the square root of time. The magnitude of drug release increased roughly in proportional to the water content of capsule, which can be related to porosity in the capsule. (author)

  7. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan Shifang, E-mail: sfluan@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yang Huawei; Shi Hengchong; Zhao Jie; Jin Jing [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy)

    2012-01-15

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  8. Cellulose nanocrystals as a reinforcing material for electrospun poly(methyl methacrylate) fibers: formation, properties and nanomechanical characterization

    Science.gov (United States)

    Hong Dong; Kenneth E. Strawhecker; James A. Snyder; Joshua A. Orlicki; Richard S. Reiner; Alan W. Rudie

    2012-01-01

    Uniform fibers composed of poly(methyl methacrylate) (PMMA) reinforced with progressively increasing contents of cellulose nanocrystals (CNCs), up to 41 wt% CNCs, have been successfully produced by electrospinning. The morphological, thermal and nanomechanical properties of the composite sub-micron fibers were investigated. The CNCs derived from wood pulp by sulfuric...

  9. Poly(methyl methacrylate) films for organic vapour sensing

    CERN Document Server

    Capan, R; Hassan, A K; Tanrisever, T

    2003-01-01

    Optical constants and fabrication parameters are investigated using surface plasmon resonance (SPR) studies on spun films of poly(methyl methacrylate) (PMMA) derivatives in contact with two different dielectric media. A value of 1.503 for the refractive index of PMMA films produced from a solution having concentration of 1 mg ml sup - sup 1 at the speed of 3000 rpm is in close agreement with the data obtained from ellipsometric measurements. The film thickness shows a power-law dependence on the spin speed but the thickness increases almost linearly with the concentration of the spreading solution. These results are in good agreement with the hydrodynamic theory for a low-viscosity and highly volatile liquid. On the basis of SPR measurements under dynamic conditions, room temperature response of PMMA films to benzene vapours is found to be fast, highly sensitive and reversible. The sensitivity of detection of toluene, ethyl benzene and m-xylene is much smaller than that of benzene.

  10. Rehabilitation of orbital cavity after orbital exenteration using polymethyl methacrylate orbital prosthesis

    Directory of Open Access Journals (Sweden)

    Sumeet Jain

    2016-01-01

    Full Text Available Squamous cell carcinoma of the eyelid is the second most common malignant neoplasm of the eye with the incidence of 0.09 and 2.42 cases/100 000 people. Orbital invasion is a rare complication but, if recognized early, can be treated effectively with exenteration. Although with advancements in technology such as computer-aided design and computer-aided manufacturing, material science, and retentive methods like implants, orbital prosthesis with stock ocular prosthesis made of methyl methacrylate retained by anatomic undercuts is quiet effective and should not be overlooked and forgotten. This clinical report describes prosthetic rehabilitation of two male patients with polymethyl methacrylate resin orbital prosthesis after orbital exenteration, for squamous cell carcinoma of the upper eyelid. The orbital prosthesis was sufficiently retained by hard and soft tissue undercuts without any complications. The patients using the prosthesis are quite satisfied with the cosmetic results and felt comfortable attending the social events.

  11. Grafting of poly[(methyl methacrylate)-block-styrene] onto cellulose via nitroxide-mediated polymerization, and its polymer/clay nanocomposite.

    Science.gov (United States)

    Karaj-Abad, Saber Ghasemi; Abbasian, Mojtaba; Jaymand, Mehdi

    2016-11-05

    For the first time, nitroxide-mediated polymerization (NMP) was used for synthesis of graft and block copolymers using cellulose (Cell) as a backbone, and polystyrene (PSt) and poly(methyl metacrylate) (PMMA) as the branches. For this purpose, Cell was acetylated by 2-bromoisobutyryl bromide (BrBiB), and then the bromine group was converted to 4-oxy-2,2,6,6-tetramethylpiperidin-1-oxyl group by a substitution nucleophilic reaction to afford a macroinitiator (Cell-TEMPOL). The macroinitiator obtained was subsequently used in controlled graft and block copolymerizations of St and MMA monomers to yield Cell-g-PSt and Cell-g-(PMMA-b-PSt). The chemical structures of all samples as representatives were characterized by FTIR and (1)H NMR spectroscopies. In addition, Cell-g-(PMMA-b-PSt)/organophilic montmorillonite nanocomposite was prepared through a solution intercalation method. TEM was used to evaluate the morphological behavior of the polymer-clay system. It was demonstrated that the addition of small percent of organophilic montmorillonite (O-MMT; 3wt.%) was enough to improve the thermal stability of the nanocomposite. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Radiation induced graft copolymerization of vinyl monomers onto synthetic polymeric films

    International Nuclear Information System (INIS)

    Chauhan, G.S.; Kaur, Inderjeet; Misra, B.N.

    1997-01-01

    Polyethylene (PE) and polyamide (PA) films have been modified by radiochemical grafting of methylacrylate (MA), ethylacrylate (EA), methyl methacrylate (MMA) and ethyl methacrylate (EMA) in aqueous medium in air. Grafted films show increased area and lower thermal stability. The swelling behaviour of these films vary as a function of percent grafting (P g ). (author). 8 refs., 1 tab

  13. Luminescent polymethyl methacrylate modified by gamma radiation

    International Nuclear Information System (INIS)

    Morais, Guilherme F.; Forster, Pedro L.; Marchini, Leonardo G.; Lugao, Ademar B.; Parra, Duclerc F.

    2011-01-01

    Thin films of PMMA (polymethyl methacrylate) doped with luminescent complexes have been studied and developed for applications in advanced technologies. The problem of stability of these films is focused in this study. Films stabilization by reaction with fluorinated monomers is a recent study that aims to increase its luminescence properties for long time. The films were prepared by dilution of PMMA in chloroform with addition of europium complex, at proportion of 5% by weight of polymer. The luminescent polymer films were obtained by casting. Thin layer slides of the film were separated in three parts. One was reacted with fluorinated monomers (C 2 F 4 ) in closed reactor for 48 hours. A second part was reacted with C 2 F 4 after irradiation in gamma source at 5 kGy in simultaneous process. The last part was used as obtained. The luminescent polymer matrices were characterized using the techniques of infrared (FTIR) and thermogravimetry (TGA/DTG). Samples of the films were, in presence of fluorine monomers, exposed to ionizing radiation in dose of 5 kGy, for react with monomers in the doped polymer surface. In this case the effects of radiation were evaluated on the luminescent films. (author)

  14. Surface modification of silica nanoparticles by UV-induced graft polymerization of methyl methacrylate.

    Science.gov (United States)

    Kim, Sooyeon; Kim, Eunhye; Kim, Sungsoo; Kim, Woosik

    2005-12-01

    In this study we modified the surface of silica nanoparticles with methyl methacrylate by UV-induced graft polymerization. It is a surface-initiated polymerization reaction induced by ultraviolet irradiation. The resulting organic-inorganic nanocomposites were near-monodisperse and fabricated without homopolymerization of the monomer. Substantial increase in mean particle size was observed by SEM image analysis after UV-induced grafting of methyl methacrylate onto pure silica particles. FT-Raman spectroscopy and X-ray photoelectron spectroscopy studies of these materials revealed the successful grafting of methyl methacrylate onto the silica surface. The formation of a covalent bond between the grafted PMMA chains and silica surface was indicated by FT-Raman spectra. Thermogravimetric analysis of the PMMA-grafted silica particles indicated the polymer contents in good agreement with SEM photographs.

  15. Mechanism of radiation-induced degradation of poly(methyl methacrylate)

    International Nuclear Information System (INIS)

    Ichikawa, Tsuneki; Oyama, Ken-ichi; Yoshida, Hiroshi

    1995-01-01

    ESR and gel permeation chromatographic measurements of poly(methyl methacrylate) γ-irradiated between 77 K and 300 K have been carried out to elucidate the mechanism of radiation-induced degradation of the polymer. It is revealed that the scission of the main chain is not taken place immediately after the absorption of radiation energy but is induced by the intramolecular radical conversion of the side-chain -COOCH 2 radical to the tertiary -CH 2 -C(CH 3 )- radical followed by the main-chain β-scission of the latter radical. The degradation is not taken place below 190 K, because the side-chain radical starts to convert only above 190 K. The residual monomer in the polymer reacts with the side-chain radical below 190 K to generate the stable propagating-type radical, so that the degradation is suppressed even after warming the polymer to the ambient temperature. (author)

  16. Thermogravimetric studies on alkyl methacrylate polymers and poly(alkyl methacrylate)-grafted polypropylene fibers

    International Nuclear Information System (INIS)

    Hayakawa, Kiyoshi; Taoda, Hiroshi; Kawase, Kaoru; Tazawa, Masato; Yamakita, Hiromi

    1986-01-01

    Thermal behavior of several kinds of poly (alkyl methacrylate) and polypropylene-g-poly (alkyl methacrylate) fibers prepared by γ-irradiation was investigated by thermogravimetric measurements with the intermittent analysis of the gaseous products. The degradation of poly (methyl methacrylate) proceeded according to the deploymerization mechanism reproducing the pristine monomer exclusively. The thermogram in inert atmosphere showed the features of a two-step depolymerization, while in air it showed no such a stepwise decrease with the elevating temperature. The dissolution-precipitation treatment of polymer seemed to affect the decomposition behavior. On other alkyl methacrylate polymers, the thermal decomposition generally proceeded also according to the depolymerization mechanism. But, for instance, at least two kinds of products besides its own monomer were formed from poly (isobutyl methacrylate), and their relative fractions differed with the temperature. Polypropylene-g-poly (alkyl methacrylate) fibers showed lowering of initiation temperature of decomposition with the increase in extent of the grafting, and their initiation temperatures of decomposition in air were lower than those in inert atmosphere. (author)

  17. Reduction of space charge breakdown in e-beam irradiated nano/polymethyl methacrylate composites

    International Nuclear Information System (INIS)

    Zheng Feihu; Zhang Yewen; An Zhenlian; Dong Jianxing; Lei Qingquan

    2013-01-01

    Fast discharge of numerous space charges in dielectric materials can cause space charge breakdown. This letter reports the role of nanoparticles in affecting space charge breakdown of nano/polymethyl methacrylate composites. Space charge distributions in the composites, implanted by electron beam irradiation, were measured by pressure wave propagation method. The results show that the nanoparticles have significant effects on the isothermal charge decay and space charge breakdown in the nanocomposites. The resistance to space charge breakdown in the nanocomposites is attributed to the combined action of the introduction of deep trapping states and the scattering effect by the added nanoparticles.

  18. Thermal Properties of Polymethyl Methacrylate Composite Containing Copper Nanoparticles.

    Science.gov (United States)

    Yu, Wei; Xie, Huaqing; Xin, Sha; Yin, Junshan; Jiang, Yitong; Wang, Mingzhu

    2015-04-01

    Thermal functional Materials have wide applications in thermal management fields, and inserting highly thermal conductive materials is effective in enhancing thermal conductivity of matrix. In this paper, copper nanoparticles were selected as the additive to prepare polymethyl methacrylate (PMMA) based nanocomposite with enhanced thermal properties. Uniform copper nanoparticles with pure face-centered lattice were prepared by liquid phase reduction method. Then, they were added into PMMA/N, N-Dimethylmethanamide (DMF) solution according to the different mass fraction for uniform dispersion. After DMF was evaporated, Cu-PMMA nanocomposites were gained. The thermal analysis measurement results showed that the decomposition temperature of nanocomposites decreased gradually with the increasing particle loadings. The thermal conductivity of the Cu-PMMA nanocomposites rose with the increasing contents of copper nanoparticles. With a 20 vol.% addition, the thermal conductivity was up to 1.2 W/m · K, a 380.5% increase compared to the pure PMMA. The results demonstrate that copper nanoparticles have great potential in enhancing thermal transport properties of polymer.

  19. Synthesis and characterization of poly(methyl methacrylate)/OMMT nanocomposites by γ-ray irradiation polymerization

    International Nuclear Information System (INIS)

    Zhang Weian; Shen Xiaofeng; Li Yu; Fang Yuee

    2003-01-01

    Organophilic montmorillonite (OMMT) was synthesized by cationic exchange between Na-MMT and cetyltrimethylammonium bromide in an aqueous solution. Poly(methyl methacrylate)(PMMA)/(OMMT) nanocomposites was prepared by γ-ray irradiation polymerization. The dispersion degree and the intercalation spacing of these nanocomposites were investigated with the X-ray diffraction and high-resolution transmission electron microscopy, respectively. The thermal stabilities of the samples were studied by the thermal gravimetric analysis. The nanocomposites had higher storage modulus and higher glass transition temperature (T g ) than the pure PMMA, which were measured by dynamic mechanical analysis

  20. Luminescent polymethyl methacrylate modified by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Guilherme F. [Faculdade de Tecnologia de Sao Paulo (FATEC-ZL), Sao Paulo, SP (Brazil); Forster, Pedro L.; Marchini, Leonardo G.; Lugao, Ademar B.; Parra, Duclerc F., E-mail: dfparra@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Thin films of PMMA (polymethyl methacrylate) doped with luminescent complexes have been studied and developed for applications in advanced technologies. The problem of stability of these films is focused in this study. Films stabilization by reaction with fluorinated monomers is a recent study that aims to increase its luminescence properties for long time. The films were prepared by dilution of PMMA in chloroform with addition of europium complex, at proportion of 5% by weight of polymer. The luminescent polymer films were obtained by casting. Thin layer slides of the film were separated in three parts. One was reacted with fluorinated monomers (C{sub 2}F{sub 4}) in closed reactor for 48 hours. A second part was reacted with C{sub 2}F{sub 4} after irradiation in gamma source at 5 kGy in simultaneous process. The last part was used as obtained. The luminescent polymer matrices were characterized using the techniques of infrared (FTIR) and thermogravimetry (TGA/DTG). Samples of the films were, in presence of fluorine monomers, exposed to ionizing radiation in dose of 5 kGy, for react with monomers in the doped polymer surface. In this case the effects of radiation were evaluated on the luminescent films. (author)

  1. Novel transparent ternary nanocomposite films of trialkoxysilane-capped poly(methyl methacrylate)/zirconia/titania with incorporating networks

    International Nuclear Information System (INIS)

    Wang Yuan; Zhang Dengsong; Shi Liyi; Li Li; Zhang Jianping

    2008-01-01

    Novel ternary nanocomposite trialkoxysilane-capped poly(methyl methacrylate)/zirconia/titania optical films were successfully prepared through a nonaqueous in situ sol-gel method. The acrylic monomers used were methyl methacrylate (MMA) and 3-(trimethoxysilyl)propyl methacrylate (MSMA). PMMA/ZrO 2 -TiO 2 incorporating networks formed from alcoholysis of poly(MMA-co-MSMA), zirconium n-butoxide and titanium isoproproxide. The structure, morphology and property of the obtained nanocomposite films were investigated by X-ray photoelectron spectra, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, scanning probe microscopy, thermogravimetric analyses, UV-vis spectrum and spectro-ellipsometer. The nanoparticle size, roughness, thermal stability, UV-shielding property, and refractive index of nanocomposite films increase with the increasing of inorganic contents. The formation mechanism and reason of such improvements were examined and interpreted in a theoretical model. The nanocomposite films possess interesting properties in thermal stability and optical response due to the uniform incorporating networks between organic polymer chains and inorganic clusters

  2. Novel transparent ternary nanocomposite films of trialkoxysilane-capped poly(methyl methacrylate)/zirconia/titania with incorporating networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuan [Research Center of Nano Science and Technology, Department of Chemistry, Shanghai University, Shanghai 200444 (China); Zhang Dengsong [Research Center of Nano Science and Technology, Department of Chemistry, Shanghai University, Shanghai 200444 (China)], E-mail: dszhang@shu.edu.cn; Shi Liyi [Research Center of Nano Science and Technology, Department of Chemistry, Shanghai University, Shanghai 200444 (China)], E-mail: sly0726@163.com; Li Li; Zhang Jianping [Research Center of Nano Science and Technology, Department of Chemistry, Shanghai University, Shanghai 200444 (China)

    2008-08-15

    Novel ternary nanocomposite trialkoxysilane-capped poly(methyl methacrylate)/zirconia/titania optical films were successfully prepared through a nonaqueous in situ sol-gel method. The acrylic monomers used were methyl methacrylate (MMA) and 3-(trimethoxysilyl)propyl methacrylate (MSMA). PMMA/ZrO{sub 2}-TiO{sub 2} incorporating networks formed from alcoholysis of poly(MMA-co-MSMA), zirconium n-butoxide and titanium isoproproxide. The structure, morphology and property of the obtained nanocomposite films were investigated by X-ray photoelectron spectra, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, scanning probe microscopy, thermogravimetric analyses, UV-vis spectrum and spectro-ellipsometer. The nanoparticle size, roughness, thermal stability, UV-shielding property, and refractive index of nanocomposite films increase with the increasing of inorganic contents. The formation mechanism and reason of such improvements were examined and interpreted in a theoretical model. The nanocomposite films possess interesting properties in thermal stability and optical response due to the uniform incorporating networks between organic polymer chains and inorganic clusters.

  3. Raman spectra of bilayer graphene covered with Poly(methyl methacrylate) thin film

    Energy Technology Data Exchange (ETDEWEB)

    Xia Minggang [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi' an Jiaotong University, 710049 (China); Center on Experimental Physics, School of Science, Xi' an Jiaotong University, 710049 (China); Su Zhidan; Zhang Shengli [MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi' an Jiaotong University, 710049 (China); Department of Applied Physics, School of Science, Xi' an Jiaotong University, 710049 (China)

    2012-09-15

    The Raman spectra of bilayer graphene covered with poly(methyl methacrylate) (PMMA) were investigated. Both the G and 2D peaks of PMMA-coated graphene were stiff and broad compared with those of uncovered graphene. This could be attributed to the residual strain induced by high-temperature baking during fabrication of the nanodevice. Furthermore, the two 2D peaks stiffened and broadened with increasing laser power, which is just the reverse to uncovered graphene. The stiffness is likely caused by graphene compression induced by the circular bubble of the thin PMMA film generated by laser irradiation. Our findings may contribute to the application of PMMA in the strain engineering of graphene nanodevices.

  4. Raman spectra of bilayer graphene covered with Poly(methyl methacrylate thin film

    Directory of Open Access Journals (Sweden)

    Minggang Xia

    2012-09-01

    Full Text Available The Raman spectra of bilayer graphene covered with poly(methyl methacrylate (PMMA were investigated. Both the G and 2D peaks of PMMA-coated graphene were stiff and broad compared with those of uncovered graphene. This could be attributed to the residual strain induced by high-temperature baking during fabrication of the nanodevice. Furthermore, the two 2D peaks stiffened and broadened with increasing laser power, which is just the reverse to uncovered graphene. The stiffness is likely caused by graphene compression induced by the circular bubble of the thin PMMA film generated by laser irradiation. Our findings may contribute to the application of PMMA in the strain engineering of graphene nanodevices.

  5. Colored polyethylene soil covers and grafting effects on cucumber flowering and yield

    Directory of Open Access Journals (Sweden)

    Fonseca Inês Cristina de Batista

    2003-01-01

    Full Text Available Cucumber (Cucumis sativus L. is one of the most cultivated vegetable crops in plastic greenhouses in Brazil because of the short cycle and its high economic value in off-season harvests. To better understand this management technique the effect of different colored polyethylene soil covers was evaluated in relation to flowering and yield of the hybrid cucumber 'Yoshinari' grafted or not on the hybrid squash 'Ikky'. The polyethylene cover colors were black, white on black and green plus a control without cover. Covered but not grafted crops had a more uniform flowering distribution. The number of flowers was greater for the white/black grafted treatment. All the polyethylene covers favored flowering for the non grafted plants. Grafting reduced flowering for the black or green polyethylene covers treatments. The fruit set increased with the use of polyethylene cover but was not influenced by grafting. The uniform distribution of flowering remained during fruiting only for grafted plants and soil covered with black or green polyethylene. Both polyethylene cover and grafting favored early harvesting. The 'Yoshinari'/'Ikky' graft caused taller plants but fruit were thicker and smaller and did not meet the commercial standard. The best quality fruit and highest yields were obtained in the black and white/black treatments, without grafting.

  6. Bonding at Compatible and Incompatible Amorphous Interfaces of Polystyrene and Poly(Methyl Methacrylate) Below the Glass Transition Temperature

    DEFF Research Database (Denmark)

    Boiko, Yuri M.; Lyngaae-Jørgensen, Jørgen

    2004-01-01

    Films of high-molecular-weight amorphous polystyrene (PS, M-w = 225 kg/mol, M-w/M-n = 3, T-g-bulk = 97degreesC, where T-g-bulk is the glass transition temperature of the bulk sample) and poly(methyl methacrylate) (PMMA, M-w = 87 kg/mol, M-w/M-n = 2, Tg-bulk = 109degreesC) were brought into contact...

  7. Blood compatibility of AAc, HEMA, and PEGMA-grafted cellulose film

    International Nuclear Information System (INIS)

    Nho, Young Chang.; Kwon, Oh Hyun

    2003-01-01

    To improve surface blood compatibility on cellulose film for hemodialysis, acrylic acid, 2-hydroxyethyl methacrylate and three kinds of polyethylene glycol methacrylates were grafted onto the cellulose film surface by radiation grafting technique. Heparin was introduced onto the grafted cellulose film surfaces. The grafting and heparinization were confirmed by Fourier transform infrared spectroscopy in the attenuated total reflectance mode and electron spectroscopy for chemical analysis. The blood compatibility of the modified cellulose film was examined by the determination of platelet adhesion and thrombus formation

  8. Flexible poly(methyl methacrylate)-based neural probe: An affordable implementation

    Science.gov (United States)

    Gasemi, Pejman; Veladi, Hadi; Shahabi, Parviz; Khalilzadeh, Emad

    2018-03-01

    This research presents a novel technique used to fabricate a deep brain stimulation probe based on a commercial poly(methyl methacrylate) (PMMA) polymer. This technique is developed to overcome the high cost of available probes crucial for chronic stimulation and recording in neural disorders such as Parkinson’s disease and epilepsy. The probe is made of PMMA and its mechanical properties have been customized by controlling the reaction conditions. The polymer is adjusted to be stiff enough to be easily inserted and, on the other hand, soft enough to perform required movements. As cost is one of the issues in the use of neural probes, a simple process is proposed for the production of PMMA neural probes without using expensive equipment and operations, and without compromising performance and quality. An in vivo animal test was conducted to observe the recording capability of a PMMA probe.

  9. PREPARATION OF POLY(METHYL METHACRYLATE)/LAYERED DOUBLE HYDROXIDES NANOCOMPOSITES via in situ SOLUTION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An exfoliated layered double hydroxides/poly(methyl methacrylate) (LDHs/PMMA) nanocomposite was prepared by in situ solution polymerization of methyl methacrylate (MMA) in the presence of 4-vinylbenzenesulfonate intercalated LDHs(MgAl-VBS LDHs). MgAl-VBS LDHs was prepared by the ion exchange method, and the structure and composition of the MgAl-VBS LDHs were determined by X-ray diffraction (XRD), infrared spectroscopy and elemental analysis. XRD and transmission electron microscopy (TEM) were employed to examine the structure of LDHs/PMMA nanocomposite. It was indicated that the LDHs layers were well exfoliated and dispersed in the PMMA matrix. The grafting of PMMA onto LDHs was confirmed by the extraction result and the weight fraction of grafted PMMA increased as the weight fraction of LDHs in the nanocomposites increased.

  10. Thrombin immobilization to methacrylic acid grafted poly(3-hydroxybutyrate) and its in vitro application.

    Science.gov (United States)

    Akkaya, Alper; Pazarlioglu, Nurdan

    2013-01-01

    Poly(3-hydroxybutyrate) is nontoxic and biodegradable, with good biocompatibility and potential support for long-term implants. For this reason, it is a good support for enzyme immobilization. Enzyme immobilization could not be done directly because poly(3-hydroxybutyrate) has no functional groups. Therefore, modification should be done for enzyme immobilization. In this study, methacrylic acid was graft polymerized to poly(3-hydroxybutyrate) and thrombin was immobilized to polymethacrylic acid grafted poly(3-hydroxybutyrate). In fact, graft polymerization of methacrylic acid to poly(3-hydroxybutyrate) and thrombin immobilization was a model study. Biomolecule immobilized poly(3-hydroxybutyrate) could be used as an implant. Thrombin was selected as a biomolecule for this model study and it was immobilized to methacrylic acid grafted poly(3-hydroxybutyrate). Then the developed product was used to stop bleeding.

  11. Biomimetic porous high-density polyethylene/polyethylene- grafted-maleic anhydride scaffold with improved in vitro cytocompatibility.

    Science.gov (United States)

    Sharma, Swati; Bhaskar, Nitu; Bose, Surjasarathi; Basu, Bikaramjit

    2018-05-01

    A major challenge for tissue engineering is to design and to develop a porous biocompatible scaffold, which can mimic the properties of natural tissue. As a first step towards this endeavour, we here demonstrate a distinct methodology in biomimetically synthesized porous high-density polyethylene scaffolds. Co-extrusion approach was adopted, whereby high-density polyethylene was melt mixed with polyethylene oxide to form an immiscible binary blend. Selective dissolution of polyethylene oxide from the biphasic system revealed droplet-matrix-type morphology. An attempt to stabilize such morphology against thermal and shear effects was made by the addition of polyethylene- grafted-maleic anhydride as a compatibilizer. A maximum ultimate tensile strength of 7 MPa and elastic modulus of 370 MPa were displayed by the high-density polyethylene/polyethylene oxide binary blend with 5% maleated polyethylene during uniaxial tensile loading. The cell culture experiments with murine myoblast C2C12 cell line indicated that compared to neat high-density polyethylene and high-density polyethylene/polyethylene oxide, the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride scaffold significantly increased muscle cell attachment and proliferation with distinct elongated threadlike appearance and highly stained nuclei, in vitro. This has been partly attributed to the change in surface wettability property with a reduced contact angle (∼72°) for 5% PE- g-MA blends. These findings suggest that the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride can be treated as a cell growth substrate in bioengineering applications.

  12. Radiolytic stabilization of industrial poly(methyl methacrylate)

    International Nuclear Information System (INIS)

    Aquino, Katia Aparecida da Silva

    2005-03-01

    Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterilisable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its physical properties. Therefore, radiolytic stabilization of PMMA is important for to become it commercially radio sterilisable. In this work we investigated the radiolytic stabilization of PMMA by using HALS (Hindered Amine Light Stabilizer) additive, commercially used for photo and thermo oxidative stabilization of polymers. The investigation of the radiation-induced main chain scissions was carried out by viscometric method. The additive added to the polymer system at 0.3 % w/w promotes a molecular radioprotection of 61%. That means a reduction of G value (scissions/100 eV) from 2.6 to 1.0. In addition, the glassy transition temperature (Tg) of PMMA (no additive), significantly changed by radiation, does not change when PMMA (with additive) is irradiated. TGA analysis showed that the additive promotes thermal stability to the system, increasing decomposition temperature of PMMA. Spectroscopy analysis, FT-IR and RMN ( 1 H), showed that the radioprotector additive added to the system does not change the PMMA structure. Analysis on mechanical (tensile strength and elongation at break) and optical (yellowness index and refractive index) properties showed a good influence of the additive on polymer system. (author)

  13. Study on grafting glycidyl methacrylate onto HDPE membranes by pre-irradiation graft copolymerization

    International Nuclear Information System (INIS)

    Tong Long; Zu Jianhua; Liu Xinwen; Sun Guisheng; Yu Chunhui

    2006-01-01

    Glycidyl methacrylate (GMA) was grafted onto HDPE membranes by pre-irradiation method with 1.8 MeV E-beam and a kind of membranes having reactive epoxy groups was successfully synthesized. Effects of monomer concentration, reaction temperature and time and irradiation dose on the grafting yield were studied. Composition, thermo-property and surface morphology of the grafted membranes were studied by FTIR, DSC and Tapping-mode AFM, respectively. The FTIR measurements proved the synthesized copolymer is HDPE-g-GMA. The DSC results indicated the grafted HDPE's melting temperature (T m ) and heat of fusion (ΔH f ( HDPE) ) which was reduced with increasing grafting yield. The AFM images indicated that surface of the HDPE-g-GMA membranes was rougher than the virgin HDPE. (authors)

  14. Grafting functional antioxidants on highly crosslinked polyethylene

    Science.gov (United States)

    Al-Malaika, S.; Riasat, S.; Lewucha, C.

    2016-05-01

    The problem of interference of antioxidants, such as hindered phenols, with peroxide-initiated crosslinking of polyethylene was addressed through the use of functional (reactive) graftable antioxidants (g-AO). Reactive derivatives of hindered phenol and hindered amine antioxidants were synthesised, characterised and used to investigate their grafting reactions in high density polyethylene; both non-crosslinked (PE) and highly peroxide-crosslinked (PEXa). Assessment of the extent of in-situ grafting of the antioxidants, their retention after exhaustive solvent extraction in PE and PEXa, and the stabilising performance of the grafted antioxidants (g-AO) in the polymer were examined and benchmarked against conventionally stabilised crosslinked & non-crosslinked polyethylene. It was shown that the functional antioxidants graft to a high extent in PEXa, and that the level of interference of the g-AOs with the polymer crosslinking process was minimal compared to that of conventional antioxidants which bear the same antioxidant function. The much higher level of retention of the g-AOs in PEXa after exhaustive solvent extraction, compared to that of the corresponding conventional antioxidants, accounts for their superior long-term thermal stabilising performance under severe extractive conditions.

  15. Increased cellular uptake of lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles due to surface modification with folic acid.

    Science.gov (United States)

    Feuser, Paulo Emilio; Arévalo, Juan Marcelo Carpio; Junior, Enio Lima; Rossi, Gustavo Rodrigues; da Silva Trindade, Edvaldo; Rocha, Maria Eliane Merlin; Jacques, Amanda Virtuoso; Ricci-Júnior, Eduardo; Santos-Silva, Maria Claudia; Sayer, Claudia; de Araújo, Pedro H Hermes

    2016-12-01

    Lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles surface modified with folic acid were synthesized by miniemulsion polymerization in just one step. In vitro biocompatibility and cytotoxicity assays on L929 (murine fibroblast), human red blood, and HeLa (uterine colon cancer) cells were performed. The effect of folic acid at the nanoparticles surface was evaluated through cellular uptake assays in HeLa cells. Results showed that the presence of folic acid did not affect substantially the polymer particle size (~120 nm), the superparamagnetic behavior, the encapsulation efficiency of lauryl gallate (~87 %), the Zeta potential (~38 mV) of the polymeric nanoparticles or the release profile of lauryl gallate. The release profile of lauryl gallate from superparamagnetic poly(methyl methacrylate) nanoparticles presented an initial burst effect (0-1 h) followed by a slow and sustained release, indicating a biphasic release system. Lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles with folic acid did not present cytotoxicity effects on L929 and human red blood cells. However, free lauryl gallate presented significant cytotoxic effects on L929 and human red blood cells at all tested concentrations. The presence of folic acid increased the cytotoxicity of lauryl gallate loaded in nanoparticles on HeLa cells due to a higher cellular uptake when HeLa cells were incubated at 37 °C. On the other hand, when the nanoparticles were incubated at low temperature (4 °C) cellular uptake was not observed, suggesting that the uptake occurred by folate receptor mediated energy-dependent endocytosis. Based on presented results our work suggests that this carrier system can be an excellent alternative in targeted drug delivery by folate receptor.

  16. Preparation of superhydrophobic poly(methyl methacrylate)-silicon dioxide nanocomposite films

    International Nuclear Information System (INIS)

    Wang Jinyan; Chen Xinhua; Kang Yingke; Yang Guangbin; Yu Laigui; Zhang Pingyu

    2010-01-01

    Superhydrophobic poly(methyl methacrylate)-SiO 2 (coded as PMMA-SiO 2 ) nanocomposite films with micro-nanohierarchical structure were prepared via a simple approach in the absence of low surface-energy compounds. By spin-coating the suspension of hydrophobic silica (SiO 2 ) nanoparticles dispersed in PMMA solution, target nanocomposite films were obtained on glass slides. The wetting behavior of PMMA-SiO 2 nanocomposite films was investigated in relation to the dosage of SiO 2 nanoparticles dispersed in PMMA solution. It was found that hydrophilic PMMA film was transferred to superhydrophobic PMMA-SiO 2 nanocomposite films when hydrophobic SiO 2 nanoparticles were introduced into the PMMA solution at a high enough dosage (0.2 g and above). Resultant PMMA-SiO 2 nanocomposite films had a static water contact angle of above 162 o , showing promising applications in selfcleaning and waterproof for outer wall of building, outer covering for automobile, sanitary wares, and so forth.

  17. Electrical and mechanical behavior of polymethyl methacrylate/cadmium sulphide composites

    Science.gov (United States)

    Kaur, Rajdeep; Samra, Kawaljeet Singh

    2018-06-01

    In the present investigation, electrical and mechanical behavior of cadmium sulphide (CdS) doped polymethyl methacrylate (PMMA) have been studied using different techniques. Dip casting technique was used for preparing free standing films of pristine and CdS doped PMMA at different compositions (i.e. 1 and 5 wt%). Optical absorbance as a function of wavelength was studied, by UV-visible spectroscopy, to find the impact of CdS doping on the optical band gap of synthesized PMMA/CdS composite. DC and AC conductivities were measured as a function of dopant concentration and temperature. Considerable increase in electrical conductivity was observed with the increase of CdS contents in polymer matrix. Overall electrical conduction mechanism in PMMA/CdS composites was attributed to movement of electrons through the uniformly distributed CdS aggregates within the matrix of PMMA. Mechanical properties, such as Young's modulus, tensile strength, elongation and ductility, of PMMA/CdS composites were determined and relevant responsible phenomena were discussed.

  18. Surface modification of silk fibroin fibers with poly(methyl methacrylate) and poly(tributylsilyl methacrylate) via RAFT polymerization for marine antifouling applications

    Energy Technology Data Exchange (ETDEWEB)

    Buga, Mihaela-Ramona [National Research and Development Institute for Cryogenics and Isotopic Technologies, ICIT Rm. Valcea, 240050 Rm. Valcea, Uzinei 4, CP7, Raureni, Valcea (Romania); Zaharia, Cătălin, E-mail: zaharia.catalin@gmail.com [Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7, Gh. Polizu Street, Sector 1, 011061 Bucharest (Romania); Bălan, Mihai [National Research and Development Institute for Cryogenics and Isotopic Technologies, ICIT Rm. Valcea, 240050 Rm. Valcea, Uzinei 4, CP7, Raureni, Valcea (Romania); Bressy, Christine [Université de Toulon, MAPIEM, EA 4323, 83957 La Garde (France); Ziarelli, Fabio [Fédération des Sciences Chimiques de Marseille, CNRS-FR1739, Spectropole, 13397 Marseille (France); Margaillan, André [Université de Toulon, MAPIEM, EA 4323, 83957 La Garde (France)

    2015-06-01

    In this study, silk fibroin surface containing hydroxyl and aminogroups was firstly modified using a polymerizable coupling agent 3-(trimethoxysilyl) propyl methacrylate (MPS), in order to induce vinyl groups onto the fiber surface. The reversible addition–fragmentation chain transfer (RAFT)-mediated polymerization of methyl methacrylate (MMA) and tributylsilyl methacrylate (TBSiMA) through the immobilized vinyl bond on the silk fibroin surface in the presence of 2-cyanoprop-2-yl dithiobenzoate (CPDB) as chain-transfer agent and 2,2′-azobis(isobutyronitrile) (AIBN) as initiator was conducted in toluene solution at 70 °C for 24 h. The structure and properties of the modified fiber were characterized by Fourier Transform Infrared Spectroscopy, {sup 13}C, {sup 29}Si Nuclear Magnetic Resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), confirming the presence of the coupling molecule and the methacrylate groups onto the silk fibroin fiber surface. Molecular weight distributions were assessed by triple detection size exclusion chromatography (TD-SEC) in order to verify the livingness of the polymerization. - Highlights: • SF surface containing hydroxyl and amino groups was firstly modified with MPS. • RAFT polymerizations of MMA and TBSiMA were studied. • TD-SEC was used to verify the livingness of the RAFT polymerization. • The grafted polymer chains enhance the thermal stability of the SF fibers. • The grafted fibers could be potentially promising candidates as antifouling agents.

  19. Surface modification of silk fibroin fibers with poly(methyl methacrylate) and poly(tributylsilyl methacrylate) via RAFT polymerization for marine antifouling applications

    International Nuclear Information System (INIS)

    Buga, Mihaela-Ramona; Zaharia, Cătălin; Bălan, Mihai; Bressy, Christine; Ziarelli, Fabio; Margaillan, André

    2015-01-01

    In this study, silk fibroin surface containing hydroxyl and aminogroups was firstly modified using a polymerizable coupling agent 3-(trimethoxysilyl) propyl methacrylate (MPS), in order to induce vinyl groups onto the fiber surface. The reversible addition–fragmentation chain transfer (RAFT)-mediated polymerization of methyl methacrylate (MMA) and tributylsilyl methacrylate (TBSiMA) through the immobilized vinyl bond on the silk fibroin surface in the presence of 2-cyanoprop-2-yl dithiobenzoate (CPDB) as chain-transfer agent and 2,2′-azobis(isobutyronitrile) (AIBN) as initiator was conducted in toluene solution at 70 °C for 24 h. The structure and properties of the modified fiber were characterized by Fourier Transform Infrared Spectroscopy, 13 C, 29 Si Nuclear Magnetic Resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), confirming the presence of the coupling molecule and the methacrylate groups onto the silk fibroin fiber surface. Molecular weight distributions were assessed by triple detection size exclusion chromatography (TD-SEC) in order to verify the livingness of the polymerization. - Highlights: • SF surface containing hydroxyl and amino groups was firstly modified with MPS. • RAFT polymerizations of MMA and TBSiMA were studied. • TD-SEC was used to verify the livingness of the RAFT polymerization. • The grafted polymer chains enhance the thermal stability of the SF fibers. • The grafted fibers could be potentially promising candidates as antifouling agents

  20. Luminescent Properties of Surface Functionalized BaTiO₃ Embedded in Poly(methyl methacrylate).

    Science.gov (United States)

    Requena, Sebastian; Lacoul, Srijan; Strzhemechny, Yuri M

    2014-01-16

    As-received BaTiO₃ nanopowders of average grain sizes 50 nm and 100 nm were functionalized by (3-aminopropyl)triethoxysilane (APTES) and mixed with poly(methyl methacrylate)/toluene solution. The nanocomposite solution was spin coated on Si substrates to form thin films. The photoluminescence spectrum of the pure powder was composed of a bandgap emission at 3.0 eV and multiple bands centered about 2.5 eV. Surface functionalization of the BaTiO₃ powder via APTES increases overall luminescence at room temperature while only enhancing bandgap emission at low-temperature. Polymer coating of the functionalized nanoparticles significantly enhances bandgap emissions while decreasing emissions associated with near-surface lattice distortions at 2.5 eV.

  1. The Synthesis of Cellulose Graft Copolymers Using Cu(0)-Mediated Polymerization

    Science.gov (United States)

    Donaldson, Jason L.

    Cellulose is the most abundant renewable polymer on the planet and there is great interest in expanding its use beyond its traditional applications. However, its hydrophilicity and insolubility in most common solvent systems are obstacles to its widespread use in advanced materials. One way to counteract this is to attach hydrophobic polymer chains to cellulose: this allows the properties of the copolymer to be tailored by the molecular weight, density, and physical properties of the grafts. Two methods were used here to synthesize the graft copolymers: a 'grafting-from' approach, where synthetic chains were grown outward from bromoester moieties on cellulose (Cell-BiB) via Cu(0)-mediated polymerization; and a 'grafting-to' approach, where fully formed synthetic chains with terminal sulfide functionality were added to cellulose acetate with methacrylate functionality (CA-MAA) via thiol-ene Michael addition. The Cell-BiB was synthesized in the ionic liquid 1-butyl-3-methylimidazolium chloride and had a degree of substitution of 1.13. Polymerization from Cell-BiB proceeded at similar but slightly slower rate than an analogous non-polymeric initiator (EBiB). The average graft density of poly(methyl acrylate) chains was 0.71 chains/ring, with a maximum of 1.0 obtained. The graft density when grafting poly(methyl methacrylate) was only 0.15, and this appeared to be due to the slow initiation of BiB groups. Using EBiB to model the reaction and improve the design should allow this to be overcome. Chain extension experiments demonstrated the living behaviour of the polymer. The CA-MAA was synthesized by esterification with methacrylic acid. Reactions of CA-MAA with thiophenol and dodecanethiol resulted in quantitative addition of the thiol to the alkene. The grafts were synthesized by Cu(0)-mediated polymerization from a bifunctional initiator containing a disulfide bond, followed by reduction to sulfides. The synthetic polymers were successfully grafted to CA-MAA but the

  2. Preparation of poly(methyl methacrylate) microcapsules by in situ polymerization on the surface of calcium carbonate particles.

    Science.gov (United States)

    Sato, Katsuhiko; Nakajima, Tatsuya; Anzai, Jun-ichi

    2012-12-01

    Poly(methyl methacrylate) (PMMA) microcapsules were prepared by the in situ polymerization of methyl methacrylate (MMA) and N,N'-methylenebisacrylamide on the surface of calcium carbonate (CaCO(3)) particles, followed by the dissolution of the CaCO(3) core in ethylenediaminetetraacetic acid solution. The microcapsules were characterized using fluorescence microscopy, atomic force microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. The average sizes of the CaCO(3) particles and PMMA capsules were 3.8±0.6 and 4.0±0.6 μm, respectively. A copolymer consisting of MMA and rhodamine B-bearing MMA was also used to prepare microcapsules for fluorescent microscopy observations. Fluorescein isothiocyanate-labeled bovine serum albumin was enclosed in the PMMA microcapsules and its release properties were studied. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Water-enhanced adhesion at interface in immiscible bilayer film of polystyrene and poly(methyl methacrylate)

    International Nuclear Information System (INIS)

    Harada, M; Koga, T; Fukumori, K; Sugiyama, J; Geue, T

    2014-01-01

    From nano-scratch tests, strong interfacial adhesion has been found for polystyrene (PS) and poly(methyl methacrylate) (PMMA) bilayer films prepared by a water floating (WF) method, while a PS layer on a PMMA film produced by a spin coating (SC) method peels off easily at the interface. Neutron reflectivity measurements demonstrated a clear difference in the interfacial width (σ) between the two bilayers; σ = 9 nm for the film obtained by the WF method, whereas σ = 5 nm for that by the SC method. Plasticization of the films by water would be responsible for broadening of the interface to enhance adhesion strength.

  4. Quaternized poly(methyl methacrylate-co-butyl acrylate-co-vinylbenzyl chloride) membrane for alkaline fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yanting; Guo, Juchen; Wang, Chunsheng [Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742 (United States); Chu, Deryn [Sensors and Electron Device Directorate, U.S. Army Research Laboratory, Adelphi, MD 20783 (United States)

    2010-06-15

    Instead of modification of pre-existing polymers, a new route of preparation of polyelectrolyte OH{sup -} conductive membranes via copolymerization of selected functional monomers was reported in this study. A random copolymer of poly(methyl methacrylate-co-butyl acrylate-co-vinylbenzyl chloride) was synthesized via copolymerization, which was followed by quaternization and membrane casting. The intrinsic OH{sup -} conductivity of the free-standing polyelectrolyte membranes can reach 8.2 x 10{sup -3} S cm{sup -1} at 80 C. The alkaline fuel cells using copolymer polyelectrolytes demonstrated the feasibility of the preparation concept of these membranes. (author)

  5. Radiolytic stabilization of poly(methyl methacrylate) using commercial additives

    International Nuclear Information System (INIS)

    Aquino, Katia Aparecida da Silva

    2000-04-01

    Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterelizable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its mechanical properties. Therefore, radiolytic of PMMA is important for it to become commercially radiosterizable. In this work some commercial additives, originally used in photo-and thermo-oxidate stabilization of polymers, were tested. Only two additives, type HALS (Hindered Amine Light Stabilizer), denoted Scavenger, showed a good protective quality. The investigation of radiation-induced main scissions was carried out by viscosimetric method. The most effective additive, added to the polymer system at 0.3 w/w%, promotes a great molecular radioprotection of 93%. That means a reduction of G-value (scissions/100 eV) from 0.611 to 0.053. In addition, the glassy transition temperature (T g ) of PMMA (no additive) significantly changed by radiation does not change when PMMA (with additive) is irradiated. The spectroscopy analysis, FT-IR and NMR ( 1 H), showed that the radioprotector added to the system does not change the PMMA structure. (author)

  6. Preparation of superhydrophobic poly(methyl methacrylate)-silicon dioxide nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jinyan [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Jinming Road, Kaifeng, Henan Province 475004 (China); Chen Xinhua [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Jinming Road, Kaifeng, Henan Province 475004 (China); College of Chemistry and Chemical Engineering, Xuchang University, Xuchang 461000 (China); Kang Yingke; Yang Guangbin; Yu Laigui [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Jinming Road, Kaifeng, Henan Province 475004 (China); Zhang Pingyu, E-mail: pingyu@henu.edu.cn [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Jinming Road, Kaifeng, Henan Province 475004 (China)

    2010-12-15

    Superhydrophobic poly(methyl methacrylate)-SiO{sub 2} (coded as PMMA-SiO{sub 2}) nanocomposite films with micro-nanohierarchical structure were prepared via a simple approach in the absence of low surface-energy compounds. By spin-coating the suspension of hydrophobic silica (SiO{sub 2}) nanoparticles dispersed in PMMA solution, target nanocomposite films were obtained on glass slides. The wetting behavior of PMMA-SiO{sub 2} nanocomposite films was investigated in relation to the dosage of SiO{sub 2} nanoparticles dispersed in PMMA solution. It was found that hydrophilic PMMA film was transferred to superhydrophobic PMMA-SiO{sub 2} nanocomposite films when hydrophobic SiO{sub 2} nanoparticles were introduced into the PMMA solution at a high enough dosage (0.2 g and above). Resultant PMMA-SiO{sub 2} nanocomposite films had a static water contact angle of above 162{sup o}, showing promising applications in selfcleaning and waterproof for outer wall of building, outer covering for automobile, sanitary wares, and so forth.

  7. Effect of barium-coated halloysite nanotube addition on the cytocompatibility, mechanical and contrast properties of poly(methyl methacrylate) cement

    OpenAIRE

    Jammalamadaka U; Tappa K; Weisman JA; Nicholson JC; Mills DK

    2017-01-01

    Uday Jammalamadaka,1 Karthik Tappa,1 Jeffery A Weisman,1 James Connor Nicholson,2 David K Mills1,3 1Center for Biomedical Engineering and Rehabilitation Science, 2Nanosystems Engineering, 3The School of Biological Sciences, Louisiana Tech University, Ruston, LA, USA Abstract: Halloysite nanotubes (HNTs) were investigated as a platform for tunable nanoparticle composition and enhanced opacity in poly(methyl methacrylate) (PMMA) bone cement. Halloysite has been widely used to increase ...

  8. Polyol mediated nano size zinc oxide and nanocomposites with poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    2011-07-01

    Full Text Available Organophilic nano ZnO particles have been synthesized in various diols (ethylene glycol – EG, 1,2 propane diol – PD, 1,4 butane diol – BD and tetra(ethylene glycol – TEG in the presence of p-toluenesulfonic acid, p-TsOH, as an end capping agent. The addition of p-TsOH reduces the ZnO particle size and increases its crystallite size. With increasing diol main chain length the ZnO particle size increases (EG (32 nm < PD (33 nm < BD (72 nm < TEG (86 nm. Using the assynthesized and unmodified ZnO nanocomposites with poly(methyl methacrylate, PMMA, matrix have been prepared by the in-situ bulk polymerization of methyl methacrylate, MMA. The addition of surface modifiers is avoided which is an advantage for the application since they can influence other properties of the material. ZnO particles, especially those with smaller particle sizes (EG – 32 nm, PD – 33 nm showed enhanced effect on the thermal stability of PMMA, ultraviolet, UV, absorption and transparency for visible light. Transparent materials with high UV absorption and with enhanced resistance to sunlight were obtained by optimizing the nanocomposite preparation procedure using ZnO particles of about 30 nm size in concentrations between 0.05 and 0.1 wt%. The reported nanocomposite preparation procedure is compatible with the industrial process of PMMA sheet production.

  9. Photosensitivity mechanism of undoped poly(methyl methacrylate) under UV radiation at 325 nm and its spatial resolution limit

    DEFF Research Database (Denmark)

    Sáez-Rodríguez, D.; Nielsen, Kristian; Bang, Ole

    2014-01-01

    that increasing strain during photo-inscription leads to an increased photosensitivity, which is evidence of photodegradation. Likewise, refractive index change in the fiber was measured to be positive, which provides evidence for further polymerization of the material. Finally, we relate the data obtained......In this Letter, we provide evidence suggesting that the main photosensitive mechanism of an undoped poly(methyl methacrylate)-based microstructured optical fiber under UV radiation at 325 nm is a competitive process of both photodegradation and polymerization. We found experimentally...

  10. One-pot synthesis of biocompatible boronic acid-functionalized poly(methyl methacrylate) nanoparticles at sub-100 nm scale for glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sakalak, Huseyin [Selcuk University, Metallurgy and Materials Engineering (Turkey); Ulasan, Mehmet; Yavuz, Emine [Selcuk University, Advanced Technology Research and Application Center (Turkey); Camli, Sevket Tolga, E-mail: tolgacamli@gmail.com [Biyotez Machinery Chemistry R& D Co. Ltd. (Turkey); Yavuz, Mustafa Selman, E-mail: selmanyavuz@selcuk.edu.tr [Selcuk University, Metallurgy and Materials Engineering (Turkey)

    2014-12-15

    Poly(methyl methacrylate) nanoparticles containing 4-vinylphenyl boronic acid were synthesized in one pot by surfactant-free emulsion polymerization. The nanoparticles were characterized by scanning electron microscopy and dynamic light scattering. Boron content in the nanoparticles was confirmed by electron-dispersive X-ray spectroscopy. In polymerization process, several co-monomer ratios were studied in order to obtain optimum nanoparticle size. Average hydrodynamic diameter and polydispersity index of nanoparticles versus variation of acetone percentage in the solvent mixture and total monomer concentration were investigated. The effect of boronic acid concentration in the monomer mixture on nanoparticle size and size distribution was also reported. Without further functionalization to the nanoparticles, the catechol dye, alizarin red S, was bound to boronic acid-containing nanoparticles. These nanoparticles behave as a nanosensor by which glucose or fructose can be easily detected. Dye-containing nanoparticles were undertaken displacement reaction by glucose or fructose. The glucose or fructose content was also monitored by UV–Visible spectrophotometer. Furthermore, cytotoxicity studies of boronic acid-carrying poly(methyl methacrylate) nanoparticles were carried out in 3T3 cells, which showed no toxicity effect on the cells.

  11. One-pot synthesis of biocompatible boronic acid-functionalized poly(methyl methacrylate) nanoparticles at sub-100 nm scale for glucose sensing

    International Nuclear Information System (INIS)

    Sakalak, Huseyin; Ulasan, Mehmet; Yavuz, Emine; Camli, Sevket Tolga; Yavuz, Mustafa Selman

    2014-01-01

    Poly(methyl methacrylate) nanoparticles containing 4-vinylphenyl boronic acid were synthesized in one pot by surfactant-free emulsion polymerization. The nanoparticles were characterized by scanning electron microscopy and dynamic light scattering. Boron content in the nanoparticles was confirmed by electron-dispersive X-ray spectroscopy. In polymerization process, several co-monomer ratios were studied in order to obtain optimum nanoparticle size. Average hydrodynamic diameter and polydispersity index of nanoparticles versus variation of acetone percentage in the solvent mixture and total monomer concentration were investigated. The effect of boronic acid concentration in the monomer mixture on nanoparticle size and size distribution was also reported. Without further functionalization to the nanoparticles, the catechol dye, alizarin red S, was bound to boronic acid-containing nanoparticles. These nanoparticles behave as a nanosensor by which glucose or fructose can be easily detected. Dye-containing nanoparticles were undertaken displacement reaction by glucose or fructose. The glucose or fructose content was also monitored by UV–Visible spectrophotometer. Furthermore, cytotoxicity studies of boronic acid-carrying poly(methyl methacrylate) nanoparticles were carried out in 3T3 cells, which showed no toxicity effect on the cells

  12. PMMA-g-OEtOx Graft Copolymers: Influence of Grafting Degree and Side Chain Length on the Conformation in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Irina Muljajew

    2018-03-01

    Full Text Available Depending on the degree of grafting (DG and the side chain degree of polymerization (DP, graft copolymers may feature properties similar to statistical copolymers or to block copolymers. This issue is approached by studying aqueous solutions of PMMA-g-OEtOx graft copolymers comprising a hydrophobic poly(methyl methacrylate (PMMA backbone and hydrophilic oligo(2-ethyl-2-oxazoline (OEtOx side chains. The graft copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT copolymerization of methyl methacrylate (MMA and OEtOx-methacrylate macromonomers of varying DP. All aqueous solutions of PMMA-g-OEtOx (9% ≤ DG ≤ 34%; 5 ≤ side chain DP ≤ 24 revealed lower critical solution temperature behavior. The graft copolymer architecture significantly influenced the aggregation behavior, the conformation in aqueous solution and the coil to globule transition, as verified by means of turbidimetry, dynamic light scattering, nuclear magnetic resonance spectroscopy, and analytical ultracentrifugation. The aggregation behavior of graft copolymers with a side chain DP of 5 was significantly affected by small variations of the DG, occasionally forming mesoglobules above the cloud point temperature (Tcp, which was around human body temperature. On the other hand, PMMA-g-OEtOx with elongated side chains assembled into well-defined structures below the Tcp (apparent aggregation number (Nagg = 10 that were able to solubilize Disperse Orange 3. The thermoresponsive behavior of aqueous solutions thus resembled that of micelles comprising a poly(2-ethyl-2-oxazoline (PEtOx shell (Tcp > 60 °C.

  13. Si+ and N+ ion implantation for improving blood compatibility of medical poly(methyl methacrylate)

    International Nuclear Information System (INIS)

    Li, D.J.; Cui, F.Z; Cui, F.Z.

    1998-01-01

    Si + and N + ion implantation into medical poly(methyl methacrylate) (PMMA) were performed at an energy of 80 keV with fluences ranging from 5x10 12 to 5x10 15 ions/cm 2 at room temperature to improve blood compatibility. The results of the blood contacting measurements in vitro showed that the anticoagulability and anticalcific behaviour on the surface morphology were enhanced after ion implantation. No appreciable change in the surface morphology was detected by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) analysis indicated that ion implantation broke some original chemical bonds on the surface to form some new Si- and N-containing groups. These results were considered responsible for the enhancement in the blood compatibility of PMMA. (author)

  14. Luminescent Properties of Surface Functionalized BaTiO3 Embedded in Poly(methyl methacrylate)

    Science.gov (United States)

    Requena, Sebastian; Lacoul, Srijan; Strzhemechny, Yuri M.

    2014-01-01

    As-received BaTiO3 nanopowders of average grain sizes 50 nm and 100 nm were functionalized by (3-aminopropyl)triethoxysilane (APTES) and mixed with poly(methyl methacrylate)/toluene solution. The nanocomposite solution was spin coated on Si substrates to form thin films. The photoluminescence spectrum of the pure powder was composed of a bandgap emission at 3.0 eV and multiple bands centered about 2.5 eV. Surface functionalization of the BaTiO3 powder via APTES increases overall luminescence at room temperature while only enhancing bandgap emission at low-temperature. Polymer coating of the functionalized nanoparticles significantly enhances bandgap emissions while decreasing emissions associated with near-surface lattice distortions at 2.5 eV. PMID:28788468

  15. Luminescent Properties of Surface Functionalized BaTiO3 Embedded in Poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Sebastian Requena

    2014-01-01

    Full Text Available As-received BaTiO3 nanopowders of average grain sizes 50 nm and 100 nm were functionalized by (3-aminopropyltriethoxysilane (APTES and mixed with poly(methyl methacrylate/toluene solution. The nanocomposite solution was spin coated on Si substrates to form thin films. The photoluminescence spectrum of the pure powder was composed of a bandgap emission at 3.0 eV and multiple bands centered about 2.5 eV. Surface functionalization of the BaTiO3 powder via APTES increases overall luminescence at room temperature while only enhancing bandgap emission at low-temperature. Polymer coating of the functionalized nanoparticles significantly enhances bandgap emissions while decreasing emissions associated with near-surface lattice distortions at 2.5 eV.

  16. Radiation grafting of dimethylaminopropylacrylamide and dimethylaminopropylmethacrylamide onto polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Burillo, Guillermina; Oseguera, M.A. [UNAM, Inst. de Ciencias Nucleares, Mexico City (Mexico); Vazquez, Carmen; Castillo, L.P. del [UNAM, Inst. de Investigaciones en Materiales, Mexico City (Mexico)

    1997-11-01

    Radiation-induced grafting of dimethylaminopropylacrylamide and dimethylamino-propylmethacrylamide onto polyethylene films, by direct grafting of the vinyl monomers to a polymer by mutual irradiation, has been investigated. The kinetics of the reaction were studied at different irradiation temperatures, monomer concentration and dose rates of gamma rays, and the appropriate reaction conditions for graft polymerization were determined. The thermal and mechanical behavior of the grafted films by means of DMA, TMA, DSC and TGA were also investigated. (author).

  17. Surface modification of polymethyl methacrylate intraocular lenses by plasma for improvement of antithrombogenicity and transmittance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lihua; Wu Di; Chen Yashao; Wang Xiaoli; Zhao Guowei; Wan Haiyan [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, School of Chemistry and Materials Science, Chang' an South Road 199, Xi' an 710062 (China); Huang Changzheng [Able Eye Device Co. Ltd, Zhengzhou 450008 (China)

    2009-05-15

    To improve antithrombogenicity and reduce ultraviolet transmittance, polymethyl methacrylate intraocular lenses (PMMA IOLs) were pretreated with Ar plasma and combined with heparin (Hp), with polyglycol (PEG) and with both Hp and PEG in a plasma atmosphere. The resulting modified PMMA IOLs denoted as PEG-PMMA, Hp-PMMA and Hp-PEG-PMMA were characterized by attenuated total reflectance Fourier transfer infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis), contact angle (CA) and platelet adhesion experiments. The results indicated that Hp and PEG had been successfully immobilized onto the surfaces of PMMA IOLs. Antithrombogenicity was improved remarkably and ultraviolet transmittance was reduced as well.

  18. Process Development for Reactive-Ion Etching of Molybdenum Disulfide (MoS2) Utilizing a Poly(methyl methacrylate) (PMMA) Etch Mask

    Science.gov (United States)

    2017-10-01

    Nichols, Matthew L Chin, Sina Najmaei, Eugene Zakar, and Madan Dubey Sensors and Electron Devices Directorate, ARL Approved for public...EBL; Vistec EBPG5000+) with an exposure dose of 850 μC/cm2 and development in 25 mL of isopropyl alcohol (IPA): 10 mL methyl isobutyl ketone for...deposition EBL electron beam lithography IPA isopropyl alcohol MoS2 molybdenum disulfide O2 oxygen PMMA poly(methyl methacrylate) RIE reactive

  19. Electrospinning of functional poly(methyl methacrylate) nanofibers containing cyclodextrin-menthol inclusion complexes

    International Nuclear Information System (INIS)

    Uyar, Tamer; Besenbacher, Flemming; Nur, Yusuf; Hacaloglu, Jale

    2009-01-01

    Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: α-CD, β-CD, and γ-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 deg. C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order α-CD β-CD>α-CD.

  20. Fluorinated polyimides grafted with poly(ethylene glycol) side chains by the RAFT-mediated process and their membranes

    International Nuclear Information System (INIS)

    Chen Yiwang; Chen Lie; Nie Huarong; Kang, E.T.; Vora, R.H.

    2005-01-01

    Graft polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) from fluorinated polyimide (FPI) was carried out by the reversible addition-fragmentation chain transfer (RAFT)-mediated process. The peroxides generated by the ozone treatment on FPI facilitated the thermally-initiated graft copolymerization from FPI backbone. The 'living' character of the graft chain growing was ascertained in the subsequent chain extension of PEGMA. Nuclear magnetic resonance (NMR) and molecular weight measurements were used to characterize the chemical composition and structure of the copolymers. Microfiltration (MF) membranes were fabricated from the FPI-g-PEGMA comb copolymers by phase inversion in aqueous media. Surface composition analysis of the membranes scanned by X-ray photoelectron spectroscopy (XPS) revealed a substantial surface enrichment of the hydrophilic components. The pore size distribution of the resulting membranes was found to be much more uniform than that of the corresponding membranes cast from FPI-g-PEGMA prepared by the conventional radical polymerization process in the absence of the chain transfer agent. The morphology of the membranes was characterized by scanning electron microscopy (SEM)

  1. Investigation on polyethylene-supported and nano-SiO2 doped poly(methyl methacrylate-co-butyl acrylate) based gel polymer electrolyte for high voltage lithium ion battery

    International Nuclear Information System (INIS)

    Xie, Huili; Liao, Youhao; Sun, Ping; Chen, Tingting; Rao, Mumin; Li, Weishan

    2014-01-01

    Highlights: • P(MMA-co-BA)/nano-SiO 2 /PE based GPE was developed for high voltage lithium ion battery. • P(MMA-co-BA)/nano-SiO 2 /PE has uniform and interconnected pore structure. • The GPE exhibits improved ionic conductivity and compatibility with electrodes. • 5 V battery using the GPE presents excellent cyclic stability. - Abstract: Nano-SiO 2 as dopant was used for preparing polyethylene-supported poly(methyl methacrylate-co-butyl acrylate) (P(MMA-co-BA)/PE) based membrane and corresponding gel polymer electrolyte (GPE), which is applied to improve the cyclic stability of high voltage lithium ion battery. P(MMA-co-BA)/nano-SiO 2 /PE based membranes and corresponding GPEs were characterized with scanning electron spectroscopy, X-ray diffraction, electrochemical impedance spectroscopy, mechanical test, thermogravimetric analysis, linear sweep voltammetry, and charge/discharge test. It is found that the GPE with 5 wt.% nano-SiO 2 shows the best performance. Compared to the undoped membrane, the 5 wt.% nano-SiO 2 doped membrane has a better pore structure and higher electrolyte uptake, leading to the enhancement in ionic conductivity of the resulting GPE from 1.23 × 10 −3 to 2.26 × 10 −3 S.cm −1 at room temperature. Furthermore, the thermal stability of the doped membrane is increased from 300 to 320 °C while its decomposition potential of GPE is from 5.0 to 5.6 V (vs. Li/Li + ). The cyclic stability of Li/GPE/Li(Li 0.13 Ni 0.30 Mn 0.57 )O 2 cell at the high voltage range of 3.5 V ∼ 5.0 V is consequently improved, the capacity retention of the cell using the doped membrane is 92.8% after 50 cycles while only 88.9% for the cell using undoped membrane and 66.9% for the cell using liquid electrolyte

  2. The thermal degradation of poly(iso-butyl methacrylate and poly(sec-butyl methacrylate

    Directory of Open Access Journals (Sweden)

    IVANKA G. POPOVIC

    2000-12-01

    Full Text Available The non-oxidative thermal degradation of poly(iso-butyl methacrylate and poly(sec-butyl methacrylate was investigated by studying changes in the polymer residue. Due to the different number of b-hydrogens in their ester substituents, these two polymeric isomers behave differently when subjected to elevated temperatures. Poly(iso-butyl methacrylate degrades quantitatively by depolymerisation with zip lengths of the same order of magnitude as those of poly(methyl methacrylate. Poly(sec-butyl methacrylate degrades by a combined degradation mechanism of depolymerisation and de-esterification. De-esterification becomes a significant thermolysis route at temperatures higher than 240°C.

  3. Surface treatment of poly(ethylene terephthalate) by gamma-ray induced graft copolymerization of methyl acrylate and its toughening effect on poly(ethylene terephthalate)/elastomer blend

    International Nuclear Information System (INIS)

    Ma, Liang; Wang, Mozhen; Ge, Xuewu

    2013-01-01

    To improve the compatibility between ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (E-MA-GMA) elastomer and poly(ethylene terephthalate) (PET), thereby enhance the toughening effect of E-MA-GMA on PET, γ-radiation-induced graft copolymerization technique was used to graft methyl acrylate (MA) monomer onto PET. The produced PET-g-PMA copolymer can be used as a self-compatibilizer in PET/E-MA-GMA blend since the copolymer contains the same segments, respectively, with PET and E-MA-GMA. The impact strength of PET/E-MA-GMA blend increased nearly by 30% in the presence of less than 0.1 wt% PET-g-PMA compared with that of the neat PET/elastomer blend, without loss of the tensile strength of the blends. This work proposed a potential application of radiation-induced grafting copolymerization technique on the in-situ compatibilization of PET/elastomer blends so as to improve the integral mechanical properties of PET based engineering plastic. - Highlights: • PMA was grafted onto PET resins by γ-ray radiation-induced copolymerization. • The obtained PET-g-PMA can improve the compatibility between PET and E-MA-GMA. • A small amount of PET-g-PMA can enhance the impact strength of PET/E-MA-GMA blend

  4. Effect of nanosized silica in poly(methyl methacrylate)-lithium bis(trifluoromethanesulfonyl)imide based polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, S.; Lu, Soon-Chien [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Setapak, 53300 Kuala Lumpur (Malaysia)

    2008-12-01

    The effect of nanosized silica when incorporated in polymer electrolytes is analyzed by means of Fourier transform infrared (FTIR) spectroscopy, conductivity and thermal properties. Nanocomposite polymer electrolytes are synthesized by the dispersion of nanosized silica (SiO{sub 2}), up to 10 wt.% maximum, into a matrix formed by poly(methyl methacrylate) (PMMA) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The highest conductivity is 2.44 x 10{sup -6} S cm{sup -1} at room temperature, with 4 wt.% of silica added. The FTIR spectra show evidence of complexation between PMMA, LiTFSI and SiO{sub 2}. The addition of silica to the polymer electrolytes also improves the thermal stability and the ability to retain conductivity over time. (author)

  5. The formation of hollow poly(methyl methacrylate)/multiwalled carbon nanotube nanocomposite cylinders by microwave irradiation

    International Nuclear Information System (INIS)

    Wang Huan; Hu Xijun; Ka Ming Ng; Feng Jiyun

    2009-01-01

    Poly(methyl methacrylate) (PMMA)/multiwalled carbon nanotube (MWCNT) nanocomposite particles with 1, 2 and 4 wt% of MWCNTs were prepared by mechanical grinding of PMMA and MWCNT powders in a mortar at room temperature. Both scanning electron microscopy and Raman scattering characterizations revealed that these nanocomposite particles consist of a PMMA core and a MWCNT shell. The PMMA/MWCNT nanocomposite particles were used to fabricate the corresponding nanocomposites in the form of a hollow cylinder with various diameters and heights under 700 W microwave irradiation within 1 min. A mechanism for the fast microwave assisted forming process is proposed. These experimental results may lead to a new technology for forming hollow polymeric articles that is different from the conventional injection and blowing process.

  6. Graft polymerization of vinyl acetate onto starch. Saponification to starch-g-poly(vinyl alcohol)

    International Nuclear Information System (INIS)

    Fanta, G.F.; Burr, R.C.; Doane, W.M.; Russell, C.R.

    1979-01-01

    Graft polymerizations of vinyl acetate onto granular cornstarch were initiated by cobalt-60 irradiation of starch-monomer-water mixtures, and ungrafted poly(vinyl acetate) was separated from the graft copolymer by benzene extraction. Conversions of monomer to polymer were quantitative at a radiation dose of 1.0 Mrad. Over half of the polymer was present as ungrafted poly(vinyl acetate) (grafting efficiency less than 50%), and the graft copolymer contained only 34% grafted synthetic polymer (34% add-on). Lower irradiation doses produced lower conversions of monomer to polymer and gave graft copolymers with lower % add-on. Addition of minor amounts of acrylamide, methyl acrylate, and methacrylic acid as comonomers produced only small increases in % add-on and grafting efficency. Grafting efficiency was increased to 70% when a monomer mixture containing about 10% methyl methacrylate was used. Grafting efficiency could be increased to over 90% if the graft polymerization of vinyl acetate--methyl methacrylate was carried out near 0 0 C; although conversion of monomers to polymer was low and grafted polymer contained 40 to 50% poly(methyl methacrylate). Selected graft copolymers were treated with methanolic sodium hydroxide to convert starch-g-poly(vinyl acetate) to starch-g-poly(vinyl alcohol). The molecular weight of the poly(vinyl alcohol) moiety was about 30,000. The solubility of starch-g-poly(vinyl alcohol) in hot water was less than 50; however, solubility could be increased by substituting either acid-modified or hypochlorite-oxidized for unmodified starch in the graft polymerization reaction. Vinyl acetate was also graft polymerized onto acid-modified starch which had been dispersed and partially solubilized by heating in water. A total irradiation dose of either 1.0 or 0.5 Mrad gave starch-g-poly

  7. Grafting of Maleic Anhydride onto Polyethylene by Blend Process forEnvironmentally Friendly Plastics

    International Nuclear Information System (INIS)

    Hendrana, Sunit; Retno-Yusiasih; Sudirman; Ipit-Karyaningsih; Djimat-Lisnawati

    2000-01-01

    Grafting maleic anhydride (MAH) onto polyethylene is one of the route tomake plastics which can be consumed by microbe in the soil. High temperaturesolution process is one of the method to perform grafting. This method is notreally handy since it involves many steps. Therefore, in this work a simplemethod is performed to graft MAH onto polyethylene, i.e., blending process.As the process occurs in melt, the reaction is more likely to be diffusioncontrol rather than chemical control. Therefore, there are many parameterscan affect the grafting such as temperature of the blending, speed of therotation, concentration of MAH and concentration of dicumyl peroxide (DCP).Preliminary work in our laboratorium found an optimum condition for the firsttwo parameters. Thus, in this work the effect of concentration of MAH and DCPis studied into the effectiveness of grafting process. One of the indicationof unexpected reaction is formation of gel, or in other words the formationof X-link among polyethylene molecules. The grafted polyethylene ischaracterized by calculation of gel content, thermal properties by TG/DTA andFourier Transform Infrared (FTIR). The results show the concentration of MAHand DCP play roles. However, initiator DCP has more significance effect thanthe MAH. (author)

  8. Dehydrogenation mechanism of LiBH{sub 4} by Poly(methyl methacrylate)

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jianmei [School of Materials Science and Engineering, and Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, South China University of Technology, Guangzhou 510641 (China); China-Australia Joint Laboratory for Energy & Environmental Materials, South China University of Technology, Guangzhou 510641 (China); Yan, Yurong [School of Materials Science and Engineering, and Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, South China University of Technology, Guangzhou 510641 (China); Ouyang, Liuzhang, E-mail: meouyang@scut.edu.cn [School of Materials Science and Engineering, and Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, South China University of Technology, Guangzhou 510641 (China); China-Australia Joint Laboratory for Energy & Environmental Materials, South China University of Technology, Guangzhou 510641 (China); Key Laboratory for Fuel Cell Technology in Guangdong Province, South China University of Technology, Guangzhou 510641 (China); Wang, Hui [School of Materials Science and Engineering, and Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, South China University of Technology, Guangzhou 510641 (China); China-Australia Joint Laboratory for Energy & Environmental Materials, South China University of Technology, Guangzhou 510641 (China); Zhu, Min, E-mail: memzhu@scut.edu.cn [School of Materials Science and Engineering, and Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, South China University of Technology, Guangzhou 510641 (China); China-Australia Joint Laboratory for Energy & Environmental Materials, South China University of Technology, Guangzhou 510641 (China)

    2015-10-05

    Highlights: • LiBH{sub 4} is amorphous after modified with PMMA. • Dehydrogenation temperature of LiBH{sub 4} decreases by 120 °C after modifying with PMMA. • The LiBH{sub 4}@PMMA composite releases 10 wt.% hydrogen at 360 °C within 1 h. • C=O group of PMMA weakens the B−H bonds to lower dehydrogenation temperature. - Abstract: We investigated the dehydrogenation properties and mechanism of Poly(methyl methacrylate) (PMMA) confined LiBH{sub 4}. Thermal stability of LiBH{sub 4} was reduced by PMMA, with a decrease in dehydrogenation temperature by 120 °C. At 360 °C, the composite showed fast dehydrogenation kinetics with 10 wt.% of hydrogen released within 1 h. The improved dehydrogenation performance was mainly attributed to the reaction between LiBH{sub 4} and PMMA forming Li{sub 3}BO{sub 3} as a final product. Furthermore, the presence of electrostatic interaction between B atom of LiBH{sub 4} and O atom in the carbonyl group of PMMA may weaken the B−H bonding of [BH{sub 4}]{sup −} and lower the hydrogen desorption temperature.

  9. Carboxymethyl Cellulose From Kenaf Reinforced Composite Polymer Electrolytes Based 49 % Poly (Methyl Methacrylate)-Grafted Natural Rubber

    International Nuclear Information System (INIS)

    Serawati Jafirin; Ishak Ahmad; Azizan Ahmad; Ishak Ahmad; Azizan Ahmad

    2014-01-01

    Composite polymer electrolytes based 49 % poly(methyl methacrylate)-grafted natural rubber (MG49) incorporating lithium triflate (LiCF 3 SO 3 ) were prepared. The study mainly focuses on the ionic conductivity performances and mechanical properties. Prior to that, carboxymethyl cellulose was synthesized from kenaf fiber. The films were characterized by electrochemical impedance (EIS) spectroscopy, linear sweep voltammetry (LSV), universal testing machine and scanning electron microscopy (SEM). The conductivity was found to increase with carboxymethyl cellulose loading. The highest conductivity value achieved was 6.5 x 10 -6 Scm -1 upon addition of 6 wt % carboxymethyl cellulose. LSV graph shows the stability of this film was extended to 2.7 V at room temperature. The composition with 6 wt % carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of Young's modulus. The morphology of the electrolytes showed a smooth surface of films after addition of salt and filler indicating amorphous phase in electrolytes system. Excellent mechanical properties and good ionic conductivity are obtained, enlightening that the film is suitable for future applications as thin solid polymer electrolytes in lithium batteries. (author)

  10. Durability of Poly(Methyl Methacrylate) Lenses Used in Concentrating Photovoltaic Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Gedvilas, L. M.; To, B.; Kennedy, C. E.; Kurtz, S. R.

    2010-08-01

    Concentrating photovoltaic (CPV) technology has recently gained interest based on their expected low levelized cost of electricity, high efficiency, and scalability. Many CPV systems use Fresnel lenses made of poly(methyl methacrylate)(PMMA) to obtain a high optical flux density. The optical and mechanical durability of such components, however, are not well established relative to the desired service life of 30 years. Specific reliability issues may include: reduced optical transmittance, discoloration, hazing, surface erosion, embrittlement, crack growth, physical aging, shape setting (warpage), and soiling. The initial results for contemporary lens- and material-specimens aged cumulatively to 6 months are presented. The study here uses an environmental chamber equipped with a xenon-arc lamp to age specimens at least 8x the nominal field rate. A broad range in the affected characteristics (including optical transmittance, yellowness index, mass loss, and contact angle) has been observed to date, depending on the formulation of PMMA used. The most affected specimens are further examined in terms of their visual appearance, surface roughness (examined via atomic force microscopy), and molecular structure (via Fourier transform infrared spectroscopy).

  11. Modification of macroporous membranes by graft co-polymerization induced by pre-irradiation with an electron accelerator

    International Nuclear Information System (INIS)

    Grasselli, M.; Yoshii, Fumio

    1999-01-01

    Glycidyl methacrylate (GMA) and N,N-dimethylacrylamide (DMAA) have been co-grafted on hollow fiber membranes of macroporous polyethylene. Grafted copolymers have been obtained with different ratios of the monomers (molar ratio between 0 and 2 DMAA/GMA). The properties of the modified membranes are studied

  12. Synthesis of polymer gel electrolyte with high molecular weight poly(methyl methacrylate)-clay nanocomposite

    International Nuclear Information System (INIS)

    Meneghetti, Paulo; Qutubuddin, Syed; Webber, Andrew

    2004-01-01

    Polymer nanocomposite gel electrolytes consisting of high molecular weight poly(methyl methacrylate) PMMA-clay nanocomposite, ethylene carbonate (EC)/propylene carbonate (PC) as plasticizer, and LiClO 4 electrolyte are reported. Montmorillonite clay was ion exchanged with a zwitterionic surfactant (octadecyl dimethyl betaine) and dispersed in methyl methacrylate, which was then polymerized to synthesize PMMA-clay nanocomposites. The nanocomposite was dissolved in a mixture of EC/PC with LiClO 4 , heated and pressed to obtain polymer gel electrolyte. X-ray diffraction (XRD) of the gels indicated intercalated clay structure with d-spacings of 2.85 and 1.40 nm. In the gel containing plasticizer, the clay galleries shrink suggesting intercalation rather than partial exfoliation observed in the PMMA-clay nanocomposite. Ionic conductivity varied slightly and exhibited a maximum value of 8 x 10 -4 S/cm at clay content of 1.5 wt.%. The activation energy was determined by modeling the conductivity with a Vogel-Tamman-Fulcher expression. The clay layers are primarily trapped inside the polymer matrix. Consequently, the polymer does not interact significantly with LiClO 4 electrolyte as shown by FTIR. The presence of the clay increased the glass transition temperature (Tg) of the gel as determined by differential scanning calorimetry. The PMMA nanocomposite gel electrolyte shows a stable lithium interfacial resistance over time, which is a key factor for use in electrochemical applications

  13. Preparation and characterization of poly(methyl methacrylate)-clay nanocomposites via melt intercalation: Effect of organoclay on thermal, mechanical and flammability properties

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, Lakshmi; Mohanty, Smita [Laboratory for Advanced Research in Polymeric Materials (LARPM), Central Institute of Plastics Engineering and Technology, Bhubaneswar 751024 (India); Nayak, Sanjay K., E-mail: drsknayak@gmail.com [Laboratory for Advanced Research in Polymeric Materials (LARPM), Central Institute of Plastics Engineering and Technology, Bhubaneswar 751024 (India); Ali, Anwar [Laboratory for Advanced Research in Polymeric Materials (LARPM), Central Institute of Plastics Engineering and Technology, Bhubaneswar 751024 (India)

    2011-05-15

    Research highlights: {yields} The present work deals with preparation and characterization of poly(methyl methacrylate) nanocomposites via melt intercalation technique. {yields} The effect of various modified nanoclays on the properties of base matrix has been investigated. {yields} It was observed that compatibilization using maleic anhydride improved the performance characteristics of PMMA/layered silicate nanocomposites. - Abstract: The PMMA nanocomposites were prepared by melt processing method. The influence of organoclay loading on extent of intercalation, thermal, mechanical and flammability properties of poly(methyl methacrylate) (PMMA)-clay nanocomposites were studied. Three different organoclay modifiers with varying hydrophobicity (single tallow vs. ditallow) were investigated. The nanocomposites were characterized by using wide angle X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry (DSC), and tensile tests. The intercalation of polymer chain within the silicate galleries was confirmed by WAXD and TEM. Mechanical properties such as tensile modulus (E), tensile strength, percentage elongation at break and impact strength were determined for nanocomposites at various clay loadings. Overall thermal stability of nanocomposites increased by 16-17 deg. C. The enhancement in T{sub g} of nanocomposite is merely by 2-4 deg. C. The incorporation of maleic anhydride as compatibilizer further enhanced all the properties indicating improved interface between PMMA and clay. The flammability characteristics were studied by determining the rate of burning and LOI.

  14. Preparation and characterization of poly(methyl methacrylate)-clay nanocomposites via melt intercalation: Effect of organoclay on thermal, mechanical and flammability properties

    International Nuclear Information System (INIS)

    Unnikrishnan, Lakshmi; Mohanty, Smita; Nayak, Sanjay K.; Ali, Anwar

    2011-01-01

    Research highlights: → The present work deals with preparation and characterization of poly(methyl methacrylate) nanocomposites via melt intercalation technique. → The effect of various modified nanoclays on the properties of base matrix has been investigated. → It was observed that compatibilization using maleic anhydride improved the performance characteristics of PMMA/layered silicate nanocomposites. - Abstract: The PMMA nanocomposites were prepared by melt processing method. The influence of organoclay loading on extent of intercalation, thermal, mechanical and flammability properties of poly(methyl methacrylate) (PMMA)-clay nanocomposites were studied. Three different organoclay modifiers with varying hydrophobicity (single tallow vs. ditallow) were investigated. The nanocomposites were characterized by using wide angle X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry (DSC), and tensile tests. The intercalation of polymer chain within the silicate galleries was confirmed by WAXD and TEM. Mechanical properties such as tensile modulus (E), tensile strength, percentage elongation at break and impact strength were determined for nanocomposites at various clay loadings. Overall thermal stability of nanocomposites increased by 16-17 deg. C. The enhancement in T g of nanocomposite is merely by 2-4 deg. C. The incorporation of maleic anhydride as compatibilizer further enhanced all the properties indicating improved interface between PMMA and clay. The flammability characteristics were studied by determining the rate of burning and LOI.

  15. Structural and magnetic characterization of copper sulfonated phthalocyanine grafted onto treated polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Reznickova, A., E-mail: alena.reznickova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Kolska, Z. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Faculty of Science, J.E. Purkyne University, 400 96 Usti nad Labem (Czech Republic); Orendac, M.; Cizmar, E. [Faculty of Science, P.J. Safarik University, Park Angelinum 9, 04013 Kosice (Slovakia); Sajdl, P. [Department of Power Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic); Svorcik, V. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28, Prague 6 (Czech Republic)

    2016-08-30

    Highlights: • Polyethylene (PE) surface was activated by argon plasma discharge. • Monolayer of copper phthalocyanine was achieved. • ESR proved that CuPc coated PE surface exhibits magnetic properties. • The studied structures may have potential application in spintronics and data storage. - Abstract: This study focuses on high density polyethylene (HDPE) activated by Ar plasma treatment, subsequently grafted with copper sulfonated phthalocyanine (CuPc) especially pointing out to the surface and magnetic properties of those composites. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, zeta potential and by electron spin resonance (ESR). XPS analysis confirmed the successful grafting of phthalocyanine. The highest absorption was found for the sample grafted with {sup b}CuPc for 1 h. Electrokinetic analysis also confirmed the plasma treatment and also subsequent CuPc grafting influence significantly the surface chemistry and charge. These results correspond well with XPS determination. ESR studies confirmed the presence of CuPc grafted on HDPE. It was found, that grafting is mediated by magnetically inactive functional groups, rather than radicals. Magnetic properties of CuPc do not seem to change significantly after grafting CuPc on polyethylene surface.

  16. Fluorescence enhancement of samarium complex co-doped with terbium complex in a poly(methyl methacrylate) matrix

    International Nuclear Information System (INIS)

    Jiu Hongfang; Zhang Lixin; Liu Guode; Fan Tao

    2009-01-01

    The fluorescence property of Sm(DBM) 3 phen- (DBM-dibenzoylmethide, phen-1,10-phenanthroline) and Tb(DBM) 3 phen-co-doped poly(methyl methacrylate) (PMMA) was investigated. The excitation, emission spectra and fluorescence lifetime of the co-doped samples were examined. In the co-doped samples, the luminescence intensities of Sm 3+ enhance with an increase of the Tb(DBM) 3 phen content and with a decrease of the Sm(DBM) 3 phen content. The reason for the fluorescence enhancement effect in the co-doped polymer is the intermolecular energy transfer. To give a vivid picture for this co-doped system, a model for the fluorescence enhancement of Sm(DBM) 3 phen- and Tb(DBM) 3 phen-co-doped PMMA is presented

  17. AFM study of the morphologic change of HDPE surface photografted with glycidyl methacrylate.

    Science.gov (United States)

    Wang, Huiliang; Han, Jianmei

    2009-05-01

    The UV-induced grafting of glycidyl methacrylate (GMA) onto high-density polyethylene (HDPE) and the atomic force microscopy (AFM) study of the morphologic change of the grafted surface are reported. The grafting was carried out in GMA acetone solutions with different monomer concentrations. Grafting was much faster in a solution with a higher monomer concentration. FTIR analyses proved that GMA had been successfully grafted onto HDPE. The morphologies of grafted HDPE surfaces changed with UV irradiation time. The monomer concentration had a significant effect on the morphologies of the grafted HDPE surfaces. The HDPE surface grafted in a solution with a higher monomer concentration was much rougher than that grafted in a solution with a lower monomer concentration. The growth models of the grafted granules or clusters are also proposed.

  18. Fabrication and characterization of perovskite solar cells added with MnCl2, YCl3 or poly(methyl methacrylate)

    Science.gov (United States)

    Taguchi, Masaya; Suzuki, Atsushi; Tanaka, Hiroki; Oku, Takeo

    2018-01-01

    Perovskite-type CH3NH3PbI3-based photovoltaic devices were fabricated and characterized. Effects of manganese (Mn), yttrium (Y) compounds addition into the perovskite crystal on the photovoltaic properties were investigated. Also, the effects of poly(methyl methacrylate) (PMMA) addition on perovskite layer on the photovoltaic properties were investigated. When 3 % MnCl2 was added, the short circuit current density and conversion efficiency were improved by promoting the crystal growth of perovskite phase. The photoelectric conversion efficiency for 0.9 mg mL-1 PMMA added was 7.36 %. Open circuit voltage and fill factor were improved by 5 % YCl3 addition.

  19. Preparation of High Density Polyethylene/Waste Polyurethane Blends Compatibilized with Polyethylene-Graft-Maleic Anhydride by Radiation

    Directory of Open Access Journals (Sweden)

    Jong-Seok Park

    2015-04-01

    Full Text Available Polyurethane (PU is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, PU recycling has received significant attention due to environmental issues. In this study, we developed a recycling method for waste PU that utilizes the radiation grafting technique. Grafting of waste PU was carried out using a radiation technique with polyethylene-graft-maleic anhydride (PE-g-MA. The PE-g-MA-grafted PU/high density polyethylene (HDPE composite was prepared by melt-blending at various concentrations (0–10 phr of PE-g-MA-grafted PU. The composites were characterized using fourier transform infrared spectroscopy (FT-IR, and their surface morphology and thermal/mechanical properties are reported. For 1 phr PU, the PU could be easily introduced to the HDPE during the melt processing in the blender after the radiation-induced grafting of PU with PE-g-MA. PE-g-MA was easily reacted with PU according to the increasing radiation dose and was located at the interface between the PU and the HDPE during the melt processing in the blender, which improved the interfacial interactions and the mechanical properties of the resultant composites. However, the elongation at break for a PU content >2 phr was drastically decreased.

  20. Air plasma processing of poly(methyl methacrylate) micro-beads: Surface characterisations

    International Nuclear Information System (INIS)

    Liu Chaozong; Cui Naiyi; Osbeck, Susan; Liang He

    2012-01-01

    Highlights: ► PMMA micro-beads were processed using a rotary air plasma reactor. ► Surface chemistry and surface texture of PMMA micro-beads were characterised. ► Surface wettability was evaluated using “floating” water contact angle method. ► Surface oxidation and texture changes induced by air plasma attributed to the improvement of surface wettability. - Abstract: This paper reports the surface processing of poly(methyl methacrylate) (PMMA) micro-beads by using a rotary air plasma reactor, and its effects on surface properties. The surface properties, including surface wettability, surface chemistry and textures of the PMMA beads, were characterised. It was observed that the air plasma processing can improve the surface wettability of the PMMA microbeads significantly. A 15 min plasma processing can reduce the surface water contact angle of PMMA beads to about 50° from its original value of 80.3°. This was accompanied by about 8% increase in surface oxygen concentration as confirmed by XPS analysis. The optical profilometry examination revealed the air plasma processing resulted in a rougher surface that has a “delicate” surface texture. It is concluded that the surface chemistry and texture, induced by air plasma processing, co-contributed to the surface wettability improvement of PMMA micro-beads.

  1. Customized Polymethyl Methacrylate Implants for the Reconstruction of Craniofacial Osseous Defects

    Directory of Open Access Journals (Sweden)

    André Luis Fernandes da Silva

    2014-01-01

    Full Text Available Craniofacial defects represent alterations in the anatomy and morphology of the cranial vault and the facial bones that potentially affect an individual’s psychological and social well-being. Although a variety of techniques and restorative procedures have been described for the reconstruction of the affected area, polymethyl methacrylate (PMMA, a biocompatible and nondegradable acrylic resin-based implant, is the most widely used alloplastic material for such craniomaxillofacial reconstruction. The aim of this study was to describe a technique for aesthetic and functional preoperative customized reconstruction of craniofacial bone defects from a small series of patients offered by the Brazilian public health system. Three adult male patients attended consultation with chief complaints directly related to their individual craniofacial bone defects. With the aid of multislice computed tomography scans and subsequent fabrication of the three-dimensional craniofacial prototype, custom-made PMMA implants were fabricated preoperatively. Under general anesthesia, with access to the craniofacial defects with a coronal approach, the PMMA implants were adapted and fixated to the facial skeleton with titanium plates and screws. Postoperative evaluation demonstrated uneventful recovery and an excellent aesthetic result. Customized prefabricated PMMA implants manufactured over the rapid prototyping models proved to be effective and feasible.

  2. Utilization of poly(methyl methacrylate) – carbon nanotube and polystyrene – carbon nanotube in situ polymerized composites as masterbatches for melt mixing

    OpenAIRE

    M. Lahelin; M. Annala; J. Seppala

    2012-01-01

    Carbon nanotubes (CNTs) were melt mixed directly or by using an in situ polymerized masterbatch into a matrix polymer, polystyrene (PS) or poly(methyl methacrylate) (PMMA). The mechanical properties of the composites were mostly determined by the amount of CNTs, and not by the use of directly melt mixed CNTs or the use of the masterbatch. In contrast, the electrical resistivity of the composites was dependent on the manner in which the CNTs were added to the matrix polymer. When there was inc...

  3. Poly(methyl methacrylate) as a self-assembled gate dielectric for graphene field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Sanne, A.; Movva, H. C. P.; Kang, S.; McClellan, C.; Corbet, C. M.; Banerjee, S. K. [Microelectronics Research Center, University of Texas, Austin, Texas 78758 (United States)

    2014-02-24

    We investigate poly(methyl methacrylate) (PMMA) as a low thermal budget organic gate dielectric for graphene field effect-transistors (GFETs) based on a simple process flow. We show that high temperature baking steps above the glass transition temperature (∼130 °C) can leave a self-assembled, thin PMMA film on graphene, where we get a gate dielectric almost for “free” without additional atomic layer deposition type steps. Electrical characterization of GFETs with PMMA as a gate dielectric yields a dielectric constant of k = 3.0. GFETs with thinner PMMA dielectrics have a lower dielectric constant due to decreased polarization arising from neutralization of dipoles and charged carriers as baking temperatures increase. The leakage through PMMA gate dielectric increases with decreasing dielectric thickness and increasing electric field. Unlike conventional high-k gate dielectrics, such low-k organic gate dielectrics are potentially attractive for devices such as the proposed Bilayer pseudoSpin Field-Effect Transistor or flexible high speed graphene electronics.

  4. Lithography exposure characteristics of poly(methyl methacrylate) (PMMA) for carbon, helium and hydrogen ions

    Science.gov (United States)

    Puttaraksa, Nitipon; Norarat, Rattanaporn; Laitinen, Mikko; Sajavaara, Timo; Singkarat, Somsorn; Whitlow, Harry J.

    2012-02-01

    Poly(methyl methacrylate) is a common polymer used as a lithographic resist for all forms of particle (photon, ion and electron) beam writing. Faithful lithographic reproduction requires that the exposure dose, Θ, lies in the window Θ0⩽ΘChiang Mai and Jyväskylä to determine the exposure characteristics in terms of fluence for 2 MeV protons, 3 MeV 4He and 6 MeV 12C ions, respectively. After exposure the samples were developed in 7:3 by volume propan-2-ol:de-ionised water mixture. At low fluences, where the fluence is below the clearing fluence, the exposed regions were characterised by rough regions, particularly for He with holes around the ion tracks. As the fluence (dose) increases so that the dose exceeds the clearing dose, the PMMA is uniformly removed with sharp vertical walls. When Θ exceeds the cross-linking onset fluence, the bottom of the exposed regions show undissolved PMMA.

  5. Surface grafting of cellulose nanocrystals with poly(ethylene oxide) in aqueous media.

    Science.gov (United States)

    Kloser, Elisabeth; Gray, Derek G

    2010-08-17

    Aqueous suspensions of poly(ethylene oxide)-grafted nanocrystalline cellulose (PEO-grafted NCC) were prepared in order to achieve steric instead of electrostatic stabilization. A two-step process was employed: in the first step NCC suspensions prepared by sulfuric acid hydrolysis were desulfated with sodium hydroxide, and in the second step the surfaces of the crystals were functionalized with epoxy-terminated poly(ethylene oxide) (PEO epoxide) under alkaline conditions. The PEO-grafted samples were analyzed by conductometric titration, ATR-IR, solid-state NMR, MALDI-TOF MS, SEC MALLS, and AFM. The covalent nature of the linkage was confirmed by weight increase and MALDI-TOF analysis. The PEO-grafted cellulose nanocrystals (CNCs) formed a stable colloidal suspension that remained well dispersed, while the desulfated nanoparticles aggregated and precipitated. Upon concentration of the PEO-grafted aqueous NCC suspension, a chiral nematic phase was observed.

  6. Electrospinning of functional poly(methyl methacrylate) nanofibers containing cyclodextrin-menthol inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Uyar, Tamer; Besenbacher, Flemming [Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000, Aarhus C (Denmark); Nur, Yusuf; Hacaloglu, Jale [Department of Chemistry, Middle East Technical University, Ankara, 06530 (Turkey)], E-mail: tamer@inano.dk, E-mail: tamer@unam.bilkent.edu.tr

    2009-03-25

    Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: {alpha}-CD, {beta}-CD, and {gamma}-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 deg. C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order {alpha}-CD<{beta}-CD<{gamma}-CD, the thermal evolution of menthol shifted to higher temperatures, suggesting that the strength of interaction between menthol and the CD cavity is in the order {gamma}-CD>{beta}-CD>{alpha}-CD.

  7. Fundamental study on dissolution behavior of poly(methyl methacrylate) by quartz crystal microbalance

    Science.gov (United States)

    Konda, Akihiro; Yamamoto, Hiroki; Yoshitake, Shusuke; Kozawa, Takahiro

    2016-03-01

    Ionizing radiations such as extreme ultraviolet (EUV) and electron beam (EB) are the most promising exposure source for next-generation lithographic technology. In the realization of high resolution lithography, it is necessary for resist materials to improve the trade-off relationship among sensitivity, resolution, and line width roughness (LWR). In order to overcome them, it is essential to understand basic chemistry of resist matrices in resist processes. In particular, the dissolution process of resist materials is a key process. Therefore, it is essential for next-generation resist design for ionizing radiation to clarify the dissolution behavior of the resist film into developer. However, the details in dissolution process of EUV and EB resist films have not been investigated thus far. In this study, main chain scission and dissolution behavior of poly(methyl methacrylate) (PMMA) as main chain scission type resist was investigated using quartz crystal microbalance (QCM) method and gel permeation chromatography (GPC) in order to understand the relationship between the degree of PMMA degradation and dissolution behavior. The relationship between the molecular weight after irradiation and the swelling behavior was clarified.

  8. Chemical grafting of the superhydrophobic surface on copper with hierarchical microstructure and its formation mechanism

    Science.gov (United States)

    Cai, Junyan; Wang, Shuhui; Zhang, Junhong; Liu, Yang; Hang, Tao; Ling, Huiqin; Li, Ming

    2018-04-01

    In this paper, a superhydrophobic surface with hierarchical structure was fabricated by chemical deposition of Cu micro-cones array, followed by chemical grafting of poly(methyl methacrylate) (PMMA). Water contact measurements give contact angle of 131.0° on these surfaces after PMMA grafting of 2 min and 165.2° after 6 min. The superhydrophobicity results from two factors: (1) the hierarchical structure due to Cu micro-cones array and the second level structure caused by intergranular corrosion during grafting of PMMA (confirmed by the scanning electron microscopy) and (2) the chemical modification of a low surface energy PMMA layer (confirmed by Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy). In the chemical grafting process, the spontaneous reduction of nitrobenzene diazonium (NBD) tetrafluoroborate not only causes the corrosion of the Cu surface that leads to a hierarchical structure, but also initiates the polymerization of methyl methacrylate (MMA) monomers and thus the low free energy surface. Such a robust approach to fabricate the hierarchical structured surface with superhydrophobicity is expected to have practical application in anti-corrosion industry.

  9. High optical and switching performance electrochromic devices based on a zinc oxide nanowire with poly(methyl methacrylate) gel electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Young Tea; Chu, Daping, E-mail: dpc31@cam.ac.uk [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Neeves, Matthew; Placido, Frank [Thin Film Centre, University of the West of Scotland, Paisley PA1 2BE (United Kingdom); Smithwick, Quinn [Disney Research, 521 Circle Seven Drive, Glendale, Los Angeles, California 91201 (United States)

    2014-11-10

    High performance electrochromic devices have been fabricated and demonstrated utilizing a solid polymer electrolyte and zinc oxide (ZnO) nanowire (NW) array counter electrode. The poly(methyl methacrylate) based polymer electrolyte was spin coated upon hydrothermally grown ZnO NW array counter electrodes, while electron beam evaporated NiO{sub x} thin films formed the working electrodes. Excellent optical contrast and switching speeds were observed in the fabricated devices with active areas of 2 cm{sup 2}, exhibiting an optical contrast of 73.11% at the wavelength of 470 nm, combined with a fast switching time of 0.2 s and 0.4 s for bleaching and coloration, respectively.

  10. Performance comparison of four kinds of flat nonimaging Fresnel lenses made of polycarbonates and polymethyl methacrylate for concentrated photovoltaics.

    Science.gov (United States)

    Languy, Fabian; Habraken, Serge

    2011-07-15

    Solar concentrators made of a single refractive primary optics are limited to a concentration ratio of about 1000× [Opt. Express 19, A280 (2011)], due only to longitudinal chromatic aberration, while mirrors are limited to ∼46,000× by the angular size of the Sun. To reduce the chromatic aberration while keeping cost-effective systems for concentrated photovoltaics, a study of four different kinds of flat Fresnel doublets made of polycarbonates and polymethyl methacrylate is presented. It reveals that Fresnel doublets may have fewer optical losses than non-Fresnel doublets, with a lower lateral chromatic split allowing for even higher concentration ratio. © 2011 Optical Society of America

  11. High optical and switching performance electrochromic devices based on a zinc oxide nanowire with poly(methyl methacrylate) gel electrolytes

    International Nuclear Information System (INIS)

    Chun, Young Tea; Chu, Daping; Neeves, Matthew; Placido, Frank; Smithwick, Quinn

    2014-01-01

    High performance electrochromic devices have been fabricated and demonstrated utilizing a solid polymer electrolyte and zinc oxide (ZnO) nanowire (NW) array counter electrode. The poly(methyl methacrylate) based polymer electrolyte was spin coated upon hydrothermally grown ZnO NW array counter electrodes, while electron beam evaporated NiO x thin films formed the working electrodes. Excellent optical contrast and switching speeds were observed in the fabricated devices with active areas of 2 cm 2 , exhibiting an optical contrast of 73.11% at the wavelength of 470 nm, combined with a fast switching time of 0.2 s and 0.4 s for bleaching and coloration, respectively

  12. Immobilization of enzymes and antibodies to radiation grafted polymers for therapeutic and diagnostic applications

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, A.S.; Gombotz, W.R.; Uenoyama, S.; Dong, L.C.; Schmer, G.

    1986-01-01

    Pre-irradiation and mutual radiation grafting were employed to produce poly(methacrylic acid) (MAAc) hydrogels on polypropylene/polyethylene (PP/PE) copolymer films, and porous PP fibers of a plasma filter. A diphenyl picryl hydrazyl (DPPH) assay was developed to measure the surface peroxide concentration of the pre-irradiated PP/PE films prior to grafting. Mutually grafted porous PP fibers were used for subsequent immobilization of L-asparaginase while the mutually grafted PP/PE films were used to immobilize a schistosoma monoclonal antibody.

  13. Radiation-grafted membranes based on polyethylene for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sherazi, Tauqir A. [Department of Chemistry, Government College University, Lahore 54000 (Pakistan); Institute for Chemical Process and Environmental Technology, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Guiver, Michael D.; Kingston, David; Xue, Xinzhong [Institute for Chemical Process and Environmental Technology, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Ahmad, Shujaat [PIEAS/PINSTECH, P O Nilore, Islamabad 45650 (Pakistan); Kashmiri, M. Akram [Department of Chemistry, Government College University, Lahore 54000 (Pakistan); Board of Intermediate and Secondary Education, Lahore 54000 (Pakistan)

    2010-01-01

    Styrene was grafted onto ultrahigh molecular weight polyethylene powder (UHMWPE) by gamma irradiation using a {sup 60}Co source. Compression moulded films of selected pre-irradiated styrene-grafted ultrahigh molecular weight polyethylene (UHMWPE-g-PS) were post-sulfonated to the sulfonic acid derivative (UHMWPE-g-PSSA) for use as proton exchange membranes (PEMs). The sulfonation was confirmed by X-ray photoelectron spectroscopy (XPS). The melting and flow properties of UHMWPE and UHMWPE-g-PS are conducive to forming homogeneous pore-free membranes. Both the ion conductivity and methanol permeability coefficient increased with degree of grafting, but the grafted membranes showed comparable or higher ion conductivity and lower methanol permeability than Nafion {sup registered} 117 membrane. One UHMWPE-g-PS membrane was fabricated into a membrane-electrode assembly (MEA) and tested as a single cell direct methanol fuel cell (DMFC). Low membrane cost and acceptable fuel cell performance indicate that UHMWPE-g-PSSA membranes could offer an alternative approach to perfluorosulfonic acid-type membranes for DMFC. (author)

  14. Study of energy transfer to solvent in radiation graft polymerization of styrene onto polyethylene

    International Nuclear Information System (INIS)

    Rabie, A.; Odian, G.

    1977-01-01

    The radiation-initiated graft polymerization of styrene onto polyethylene was studied to determine whether energy transfer to diluent was responsible for the previously observed high orders of dependence of the grafting rate on monomer concentration. n-Octane was used as the diluent instead of benzene. If energy transfer from excited polyethylene to benzene were present, it should not be with n-octane. The percent swelling of polyethylene by various n-octane--styrene mixtures was determined. The compositions of various n-octane--styrene mixtures absorbed inside polyethylene were determined by ultraviolet and refractive index measurements and found to be richer in styrene than the corresponding mixtures in which the polyethylene had been placed. The graft polymerization rates were determined at 0.000761, 0.0371, and 0.213 Mrad/hr and plotted against the inside styrene concentrations on a log-log scale to yield the kinetic orders of dependence of rate on monomer as 2, 3, and 3, respectively. It was concluded that energy transfer to diluent was not responsible for the high-order dependence observed

  15. Optimization of process parameter for graft copolymerization of glycidyl methacrylate onto delignified banana fibers

    International Nuclear Information System (INIS)

    Selambakkannu, S.; Nor Azillah Fatimah Othman; Siti Fatahiyah Mohamad

    2016-01-01

    This paper focused on pre-treated banana fibers as a trunk polymer for optimization of radiation-induced graft copolymerization process parameters. Pre-treated banana fiber was grafted with glycidyl methacrylate (GMA) via electron beam irradiation. Optimization of grafting parameters in term of grafting yield was analyzed at numerous radiation dose, monomer concentration and reaction time. Grafting yield had been calculated gravimetrically against all the process parameters. The grafting yield at 40 kGy had increases from 14 % to 22.5 % at 1 h and 24 h of reaction time respectively. Grafting yield at 1 % of GMA was about 58 % and it increases to 187 % at 3 % GMA. The grafting of GMA onto pre-treated banana fibers confirmed with the characterization using FTIR, SEM and TGA. Grafting of GMA onto pre-treated fibers was successfully carried out and it was confirmed by the results obtained via the characterization. (author)

  16. Polymethyl methacrylate and polystyrene with layered double hydroxide nano composites: In situ synthesis, morphology and thermal properties

    International Nuclear Information System (INIS)

    Botan, Rodrigo; Nogueira, Telma R.; Lona, Liliane M.F.; Wypych, Fernando

    2011-01-01

    Over the past decade, polymer nanocomposites have attracted interest, both in industry and in academia, because they often exhibit remarkable improvement in their properties when compared with pure polymer or conventional micro and macro-composites using low levels of reinforcements. In this work polymethyl methacrylate and polystyrene reinforced with layered double hydroxide, which was intercalated with sodium dodecyl sulfate were synthesized by in situ bulk polymerization. The nanocomposites were characterized and compared by X-ray diffraction, thermogravimetric analysis and flammability test. The X-ray diffraction demonstrated that synthesized nanocomposites showed a high global dispersion of layered double hydroxide, suggesting exfoliated morphology. The result of thermogravimetric analysis and flammability test for synthesized polystyrene/ layered double hydroxide nanocomposite presented a significant improvement in thermal stability and flammability property when compared with pure polymer. (author)

  17. Biconvex intraocular lenses and Nd:YAG capsulotomy: Experimental comparison of surface damage with different poly(methyl methacrylate) formulations

    Energy Technology Data Exchange (ETDEWEB)

    Downing, J.E.; Alberhasky, M.T. (Greenview Hospital, Bowling Green, KY (USA))

    1990-11-01

    Biconvex posterior chamber lenses have optical advantages and decrease the risk of capsular opacification, but they are more likely to be pitted during ND:YAG capsulotomy because of apposition of the lens to the capsule. This study reports the likelihood of surface damage to different formulations of poly(methyl methacrylate) at the energy levels required to open posterior capsules. Molded lenses are more easily damaged than higher molecular weight lathe-cut materials (P less than .01), as expected. However, by keeping energy output low, even injection-molded lenses showed minimal damage, with mean pit size 39 +/- 39 microns at 1 mJ. By using a converging contact lens, low power, and keeping the focus behind the capsule, damage to all materials tested should be clinically insignificant.

  18. Surface grafted polymer brushes: potential applications in dengue biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco, E-mail: ozahiga@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de, E-mail: alencar@unifei.edu.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Instituto de Fisica e Quimica

    2013-07-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar{sup +} ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  19. Surface grafted polymer brushes: potential applications in dengue biosensors

    International Nuclear Information System (INIS)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco; Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de

    2013-01-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar + ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  20. Electrical bistabilities and memory stabilities of nonvolatile bistable devices fabricated utilizing C60 molecules embedded in a polymethyl methacrylate layer

    International Nuclear Information System (INIS)

    Cho, Sung Hwan; Lee, Dong Ik; Jung, Jae Hun; Kim, Tae Whan

    2009-01-01

    Current-voltage (I-V) measurements on Al/fullerene (C 60 ) molecules embedded in polymethyl methacrylate/Al devices at 300 K showed a current bistability due to the existence of the C 60 molecules. The on/off ratio of the current bistability for the memory devices was as large as 10 3 . The retention time of the devices was above 2.5 x 10 4 s at room temperature, and cycling endurance tests on these devices indicated that the ON and OFF currents showed no degradation until 50 000 cycles. Carrier transport mechanisms for the nonvolatile bistable devices are described on the basis of the I-V experimental and fitting results.

  1. Dynamic mechanical analysis of single walled carbon nanotubes/polymethyl methacrylate nanocomposite films

    International Nuclear Information System (INIS)

    Badawi, Ali; Al Hosiny, N.

    2015-01-01

    Dynamic mechanical properties of nanocomposite films with different ratios of single walled carbon nanotubes/polymethyl methacrylate (SWCNTs/PMMA) are studied. Nanocomposite films of different ratios (0, 0.5, 1.0, and 2.0 weight percent (wt%)) of SWCNTs/PMMA are fabricated by using a casting technique. The morphological and structural properties of both SWCNT powder and SWCNTs/PMMA nanocomposite films are investigated by using a high resolution transmission electron microscope and x-ray diffractometer respectively. The mechanical properties including the storage modulus, loss modulus, loss factor (tan δ) and stiffness of the nanocomposite film as a function of temperature are recorded by using a dynamic mechanical analyzer at a frequency of 1 Hz. Compared with pure PMMA film, the nanocomposite films with different ratios of SWCNTs/PMMA are observed to have enhanced storage moduli, loss moduli and high stiffness, each of which is a function of temperature. The intensity of the tan δ peak for pure PMMA film is larger than those of the nanocomposite films. The glass transition temperature (T g ) of SWCNTs/PMMA nanocomposite film shifts towards the higher temperature side with respect to pure PMMA film from 91.2 °C to 99.5 °C as the ratio of SWCNTs/PMMA increases from 0 to 2.0 wt%. (paper)

  2. Molecular Dynamics Simulations of Silica Nanoparticles Grafted with Poly(ethylene oxide) Oligomer Chains

    KAUST Repository

    Hong, Bingbing; Panagiotopoulos, Athanassios Z.

    2012-01-01

    A molecular model of silica nanoparticles grafted with poly(ethylene oxide) oligomers has been developed for predicting the transport properties of nanoparticle organic-hybrid materials (NOHMs). Ungrafted silica nanoparticles in a medium of poly(ethylene

  3. An angled nano-tunnel fabricated on poly(methyl methacrylate) by a focused ion beam

    International Nuclear Information System (INIS)

    Her, Eun Kyu; Chung, Hee-Suk; Oh, Kyu Hwan; Moon, Myoung-Woon

    2009-01-01

    Angled nano-scale tunnels with high aspect ratio were fabricated on poly(methyl methacrylate) (PMMA) using a focused ion beam (FIB). The fabrication parameters such as ion fluence, incidence angle, and acceleration voltage of the Ga + ion beam were first studied on the PMMA surface to explore the formation of the nano-scale configurations such as nano-holes and cones with diameter in the range of 50-150 nm at an ion beam acceleration voltage of 5-20 kV. It was also found that the PMMA surface exposed to FIB was changed into an amorphous graphitic structure. Angled nano-scale tunnels were fabricated with high aspect ratio of 700-1500 nm in depth and 60 nm in mean diameter at an ion beam acceleration voltage of 5 kV and under a specific ion beam current. The angle of the nano-tunnels was found to follow the incident angle of the ion beam tilted from 0 0 to 85 0 , which has the potential for creating a mold for anisotropic adhesives by mimicking the hairs on a gecko's feet.

  4. Periodic nanostructures formed on a poly-methyl methacrylate surface with a femtosecond laser for biocompatibility improvement

    Science.gov (United States)

    Takenaka, Keisuke; Tsukamoto, Masahiro; Sato, Yuji; Ooga, Takahiro; Asai, Satoru; Murai, Kensuke

    2018-06-01

    Poly(methyl methacrylate) (PMMA) is widely used as a biomaterial. The formation of periodic nanostructures on the surface is necessary to improve the biocompatibility. A method was proposed and developed to form periodic nanostructures on a PMMA surface. A PMMA plate was placed on titanium (Ti) plate, and then the Ti plate was irradiated with a laser through the PMMA plate. We try to effectively produce periodic nanostructures on PMMA with a femtosecond laser at a fundamental wavelength by increasing the contact pressure and using titanium (Ti) plate. The contact pressure between PMMA and Ti required to form a periodic nanostructure is 300 kPa, and for a contact pressure of 2400 kPa, periodic nanostructures are formed in 62% of the laser-irradiated area on the PMMA surface. These results suggest that the formation efficiency of the periodic nanostructure depends on the laser conditions and the contact pressure.

  5. Graft copolymerization of vinyl monomers onto nylon 6 fibers by γ-ray pre-irradiation in air

    International Nuclear Information System (INIS)

    Iwasaki, Tatsuo; Ueda, Yoshitsugu

    1992-01-01

    Vinyl acetate, methyl methacrylate, alkyl acrylates, acrylonitrile, and acrylamide, were grafted onto nylon 6 fibers by the γ-ray pre-irradiation technique, and the effects of grafting on the microstructure and the mechanical properties of the graft copolymers were investigated. According to the analysis by wide-angle X-ray diffraction, the degree of crystallization decreased by increasing the percent graft of poly(vinyl acetate) in the grafted nylon 6 films. The mechanical parameters, such as the Young's modulus and the tensile strength at break, increased with increasing percent graft up to 50%. When percent grafting was smaller than 50%, rather homogeneous amorphous materials were obtained with vinyl acetate, while heterogeneous ones were obtained with other vinyl monomers. A poly(vinyl alcohol) grafted nylon 6 was obtained effectively by saponification of poly(vinyl acetate) grafted nylon 6, the former showing higher mechanical properties than the latter. Similar behavior was observed after saponification of the poly(methyl acrylate) grafted nylon 6. (author)

  6. The study on grafting comonomer of n-butyl acrylate and styrene onto poly(ethylene terephthalate) film by gamma-ray induced graft copolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Ping Xiang; Wang Mozhen [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ge Xuewu, E-mail: xwge@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2010-09-15

    Poly(ethylene terephthalate) (PET) film was successfully grafted with n-butyl acrylate and styrene comonomer through gamma-ray induced graft copolymerization. The degree of grafting (DG) and the composition of grafted side chain were characterized by {sup 1}H NMR. It was found that St can inhibit the homopolymerization of BA effectively and increase the DG when the concentration of comonomer mixture is kept constant. The proportion of St to BA in grafted side chain has a positive dependence on the feed ratio of St, which ultimately approaches the feed ratio. The thermal properties of poly(ethylene terephthalate)-graft-poly(n-butyl acrylate-co-styrene) (PET-g-P(BA-co-St)) films were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The T{sub g} of PET decreases with the DG, indicating that the grafted P(BA-co-St) copolymer has good compatibility with PET backbone.

  7. Capturing of staphylococcus aureus onto an interface containing graft chains

    International Nuclear Information System (INIS)

    Lee, W.; Furusaki, Shintaro; Saito, Kyoichi; Sugo, Takanobu; Makuuchi, Keizo.

    1995-01-01

    A microbial-cell-capturing material was prepared by radiation-induced grafting of glycidyl methacrylate onto a polyethylene-based fiber before the introduction of diethylamine. The prepared fiber was tested against a Staphylococcus aureus and Escherichia coli solution. The results showed that the grafted-type fiber had a capturing rate constant 1000-fold higher than the commercial crosslinked-type bead for S. aureus and that an activation energy of 39 kJ/mol was obtained for the microbial-cell-capturing action. (author)

  8. Evaluation of the quality of cyanoacrylate adhesive joints using the example of poly(methyl methacrylate and polycarbonate

    Directory of Open Access Journals (Sweden)

    Piotr Mazur

    2017-04-01

    Full Text Available Adhesive bonding is one of the simplest and most common methods used for joining materials. It is applied in both production and repair works. The most commonly used adhesives are cyanoacrylates, due to the possibility of combining various materials and short curing time. One of the ways to assess the quality of the adhesive used is testing the shear strength of bonded joints. Three adhesives commonly available on the Polish market, from various manufacturers and with different prices per gram of product were tested. The polymer materials bonded were poly(methyl methacrylate and polycabonate, since they are broadly used in the automotive industry and household equipment. The study revealed significant differences in bonding strength, reaching as much as 38% The adhesive’s price was not commensurate with the quality of the product tested in all cases.

  9. Flocculation and adsorption properties of biodegradable gum-ghatti-grafted poly(acrylamide-co-methacrylic acid) hydrogels

    CSIR Research Space (South Africa)

    Mittal, H

    2015-01-01

    Full Text Available This study reports the microwave-assisted synthesis of gum-ghatti (Gg)-grafted poly(acrylamide-co-methacrylic acid) (AAm-co-MAA) hydrogels for the development of biodegradable flocculants and adsorbents. The synthesized hydrogels were characterized...

  10. Metal Adsorbent Prepared from Poly(Methyl Acrylate)-Grafted Cassava Starch via Gamma Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Suwanmala, P; Hemvichian, K; Srinuttrakul, W [Nuclear Research and Development Group, Thailand Institute of Nuclear Technology, Bangkok (Thailand)

    2012-09-15

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, %Dg = 191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum conditions: in a mixture solution of 20% HA (w/v) and methanol solution (methanol:H{sub 2}O = 5:1) 300 mL, pH 13, reaction time 2 h, and 20 g of grafted copolymer. The adsorbent was characterized by FTIR, TGA, and DSC. The presence of electron donating groups in adsorbent containing hydroxamic acid groups gives the ability to form polycomplexes with metal ions. The ability of the adsorbent to adsorb various metals was investigated in order to evaluate the possibility of its use in metal adsorption. The adsorbent exhibited a remarkable % adsorption for Cd{sup 2+}, Al{sup 3+}, UO{sub 2} {sup 2+}, V{sup 5+} and Pb{sup 2+} at pH 3, 4, 5, 4, and 3, respectively. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15, and 1.6 mmol/g adsorbent for Cd{sup 2+}, Al{sup 3+}, UO{sub 2} {sup 2+}, V{sup 5+} and Pb{sup 2+}, respectively, in the batch mode adsorption. (author)

  11. Effect of solubility parameter of monomers on electron beam induced graft-polymerization onto polyethylene films

    International Nuclear Information System (INIS)

    Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

    1991-01-01

    Electron beam induced graft-polymerization by the mutual irradiation technique of monomers with different solubility parameters δ onto low density polyethylene films (LDPE) and high density polyethylene films (HDPE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic ratios of surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of monomers, and grafting rates onto LDPE were larger than those onto HDPE. Graft chain contents on surface, which were evaluated in terms of surface tensions and atomic ratios of the surface, increased with increasing δ of monomers, and graft chain contents on surface of HDPE were higher than those of LDPE. It is assumed that mutual solubility of PE and monomers, i.e., infiltration of monomers into PE during graft-polymerization influence grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

  12. Ionogels Based on Poly(methyl methacrylate) and Metal-Containing Ionic Liquids: Correlation between Structure and Mechanical and Electrical Properties.

    Science.gov (United States)

    Zehbe, Kerstin; Kollosche, Matthias; Lardong, Sebastian; Kelling, Alexandra; Schilde, Uwe; Taubert, Andreas

    2016-03-16

    Ionogels (IGs) based on poly(methyl methacrylate) (PMMA) and the metal-containing ionic liquids (ILs) bis-1-butyl-3-methlimidazolium tetrachloridocuprate(II), tetrachloride cobaltate(II), and tetrachlorido manganate(II) have been synthesized and their mechanical and electrical properties have been correlated with their microstructure. Unlike many previous examples, the current IGs show a decreasing stability in stress-strain experiments on increasing IL fractions. The conductivities of the current IGs are lower than those observed in similar examples in the literature. Both effects are caused by a two-phase structure with micrometer-sized IL-rich domains homogeneously dispersed an IL-deficient continuous PMMA phase. This study demonstrates that the IL-polymer miscibility and the morphology of the IGs are key parameters to control the (macroscopic) properties of IGs.

  13. The polymer gel electrolyte based on poly(methyl methacrylate) and its application in quasi-solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Yang Hongxun; Huang Miaoliang; Wu Jihuai; Lan Zhang; Hao Sancun; Lin Jianming

    2008-01-01

    Using poly(methyl methacrylate) as polymer host, ethylene carbonate, 1,2-propanediol carbonate and dimethyl carbonate as organic mixture solvents, sodium iodide and iodine as source of I - /I 3 - , a polymer gel electrolyte PMMA-EC/PC/DMC-NaI/I 2 with ionic conductivity of 6.89 mS cm -1 was prepared. Based on the polymer gel electrolyte, a quasi-solid-state dye-sensitized solar cell (DSSC) was fabricated. The quasi-solid-state DSSC possessed a good long-term stability and a light-to-electrical energy conversion efficiency of 4.78% under irradiation of 100 mW cm -2 simulated sunlight, which is almost equal to that of DSSC with a liquid electrolyte

  14. Radiation graft post-polymerization of sodium styrene sulfonate onto polyethylene

    International Nuclear Information System (INIS)

    Kitaeva, N.K.; Duflot, V.R.; Ilicheva, N.S.

    2013-01-01

    Post-irradiation grafting of sodium styrene sulfonate (SSS) in the presence of acrylic acid (AA) has been investigated on polyethylene (PE) pre-exposed to gamma radiation at room temperature in the air. Special attention was paid to the effect of low molecular weight salt additives on the kinetics of graft copolymerization of SSS and AA. The presence of SSS links in the grafted PE copolymers was detected by the methods of UV and FTIR spectroscopy. Based on the FTIR spectroscopy and element analysis data, a mechanism was proposed for graft copolymerization of SSS and AA onto PE. The mechanical properties of the graft copolymers were studied. It was established that PE copolymers grafted with sulfonic acid and carboxyl groups have higher strength characteristics (16.3 MPa) compared to the samples containing only carboxyl groups (11 MPa). (author)

  15. Surface functionalization of solid state ultra-high molecular weight polyethylene through chemical grafting

    Science.gov (United States)

    Sherazi, Tauqir A.; Rehman, Tayyiba; Naqvi, Syed Ali Raza; Shaikh, Ahson Jabbar; Shahzad, Sohail Anjum; Abbas, Ghazanfar; Raza, Rizwan; Waseem, Amir

    2015-12-01

    The surface of ultra-high molecular weight polyethylene (UHMWPE) powder was functionalized with styrene using chemical grafting technique. The grafting process was initiated through radical generation on base polymer matrix in the solid state by sodium thiosulfate, while peroxides formed at radical sites during this process were dissociated by ceric ammonium nitrate. Various factors were optimized and reasonably high level of monomer grafting was achieved, i.e., 15.6%. The effect of different acids as additive and divinyl benzene (DVB) as a cross-linking agent was also studied. Post-grafting sulfonation was conducted to introduce the ionic moieties to the grafted polymer. Ion-exchange capacity (IEC) was measured experimentally and is found to be 1.04 meq g-1, which is in close agreement with the theoretical IEC values. The chemical structure of grafted and functionalized polymer was characterized by attenuated total reflection infrared spectroscopy (ATR-FTIR) and thermal properties were investigated by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal analysis depicts that the presence of radicals on the polymer chain accelerates the thermal decomposition process. The results signify that the chemical grafting is an effective tool for substantial surface modification and subsequent functionalization of polyethylene.

  16. Reaction mechanism for radiation-induced degradation of poly(methyl methacrylate) as studied by ESR and ESE

    International Nuclear Information System (INIS)

    Yoshida, H.; Ichikawa, T.

    1991-01-01

    Reaction mechanism for the radiation-induced degradation of poly(methyl methacrylate) has been studied based on the ESR and electron spin echo observations of the free radicals in the polymer irradiated with γ-rays. It is indicated that the side-chain radical, -CH 2 -CCH 3 (COOC-radicalH 2 )-, is the precursor for the main-chain scission. This radical transforms into the propagating-type radical, a fingerprint of the main-chain scission, without loss of the total radical concentration. UV illumination converts the side-chain radical into the acyl-type radical, -CH 2 -CCH 3 (-C-radical=O)-, which thermally transforms into the propagating-type radical. The radical of the type, -CH 2 -C-radicalCH 3 -CH 2 -, is suggested as a common, immediate precursor for the main-chain scission with and without the UV illumination, though it has not been detected because of its short life-time. (author) 7 refs.; 2 figs

  17. Graft polymerization using radiation-induced peroxides and application to textile dyeing

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, Ichiro, E-mail: enomoto.ichiro@iri-tokyo.j [Tokyo Metropolitan Industrial Technology Research Institute, KFC Bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan); School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Katsumura, Yosuke [School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai-mura, Ibaraki 319-1195 (Japan); Kudo, Hisaaki [School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Soeda, Shin [Tokyo Metropolitan Industrial Technology Research Institute, KFC Bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan)

    2011-02-15

    To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

  18. Graft polymerization using radiation-induced peroxides and application to textile dyeing

    International Nuclear Information System (INIS)

    Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Soeda, Shin

    2011-01-01

    To improve the dyeing affinity of ultra high molecular weight polyethylene (UHMWPE) fiber, surface treatment by radiation-induced graft polymerization was performed. Methyl methacrylate (MMA), acrylic acid (AA) and styrene (St) were used as the monomers. The grafting yields as a function of storage time after irradiation were examined. Although the grafting yield of St after the sulfonation processing was quite low compared with those of MMA and AA, it was successfully dyed to a dark color with a cationic dye. Some acid dyes can dye the grafted fiber with AA. The acid dye is distributed to the amorphous domains of the AA grafted fiber. The dyeing concentration depended on the grafting yield, and the higher the grafting yield the darker the dye color.

  19. Marine bacterial prodigiosin as dye for rubber latex, polymethyl ...

    African Journals Online (AJOL)

    Prodigiosin is known for its immunomodulatory, antibacterial, antimycotic, antimalarial, algicidal and anticancer activities. Here, we reported the evaluation of prodigiosin pigment as a dyeing agent in rubber latex, paper and polymethyl methacrylate (PMMA) so that it can be considered as an alternative to synthetic pigments.

  20. Kinetic investigations of emulsion- and solvent-mediated radiation induced graft copolymerization of glycidyl methacrylate onto nylon-6 fibres

    International Nuclear Information System (INIS)

    Teo Ming Ting; Paveswari Sithambaranathan

    2017-01-01

    Kinetic behaviour of graft copolymerisation of glycidyl methacrylate onto nylon-6 fibres in solvent- and emulsion- media was investigated. The order for the dependence of the initial rate of grafting on the monomer concentration for solvent and emulsion grafting systems were found to be 1.65 and 1.57, respectively. The order of dependence of the initial rate of grafting on the absorbed dose was found to be 1.55 for solvent and 0.62 emulsion grafting systems. The results showed that grafting in both systems is controlled by diffusion mechanism and the degree of grafting can be effectively tuned by variation of the grafting parameters. (author)

  1. Grafting of polyethylene films with acrylic acid and acrylonitril using gamma radiation

    International Nuclear Information System (INIS)

    Ajji, Z.; Al-Nesr, E.

    2003-12-01

    Acrylic acid (AAc) and acrylonitrile (AN) and their binary mixtures were graft copolymerized onto low density polyethylene (LDPE) films using gamma irradiation. The effects of different parameters on the graft yield were studies such as monomer concentration, inhibitor concentration, and irradiation dose. The obtained grafted films were characterized using FTIR spectroscopy, thermal gravimetry, and differential scanning calorimetry. Water uptake and the ion uptake were also evaluated, and the ability of grafted films to uptake heavy ions such as Ni 2+ and Cu 2+ was discussed. (author)

  2. Poly(Poly(Ethylene Glycol Methyl Ether Methacrylate Grafted Chitosan for Dye Removal from Water

    Directory of Open Access Journals (Sweden)

    Bryan Tsai

    2017-03-01

    Full Text Available As the demand for textile products and synthetic dyes increases with the growing global population, textile dye wastewater is becoming one of the most significant water pollution contributors. Azo dyes represent 70% of dyes used worldwide, and are hence a significant contributor to textile waste. In this work, the removal of a reactive azo dye (Reactive Orange 16 from water by adsorption with chitosan grafted poly(poly(ethylene glycol methyl ether methacrylate (CTS-GMA-g-PPEGMA was investigated. The chitosan (CTS was first functionalized with glycidyl methacrylate and then grafted with poly(poly(ethylene glycol methyl ether methacrylate using a nitroxide-mediated polymerization grafting to approach. Equilibrium adsorption experiments were carried out at different initial dye concentrations and were successfully fitted to the Langmuir and Freundlich adsorption isotherm models. Adsorption isotherms showed maximum adsorption capacities of CTS-g-GMA-PPEGMA and chitosan of 200 mg/g and 150 mg/g, respectively, while the Langmuir equations estimated 232 mg/g and 194 mg/g, respectively. The fundamental assumptions underlying the Langmuir model may not be applicable for azo dye adsorption, which could explain the difference. The Freundlich isotherm parameters, n and K, were determined to be 2.18 and 17.7 for CTS-g-GMA-PPEGMA and 0.14 and 2.11 for chitosan, respectively. An “n” value between one and ten generally indicates favorable adsorption. The adsorption capacities of a chitosan-PPEGMA 50/50 physical mixture and pure PPEGMA were also investigated, and both exhibited significantly lower adsorption capacities than pure chitosan. In this work, CTS-g-GMA-PPEGMA proved to be more effective than its parent chitosan, with a 33% increase in adsorption capacity.

  3. Effects of sterilization on the mechanical properties of poly(methyl methacrylate) based personalized medical devices.

    Science.gov (United States)

    Münker, T J A G; van de Vijfeijken, S E C M; Mulder, C S; Vespasiano, V; Becking, A G; Kleverlaan, C J; Becking, A G; Dubois, L; Karssemakers, L H E; Milstein, D M J; van de Vijfeijken, S E C M; Depauw, P R A M; Hoefnagels, F W A; Vandertop, W P; Kleverlaan, C J; Münker, T J A G; Maal, T J J; Nout, E; Riool, M; Zaat, S A J

    2018-05-01

    Nowadays, personalized medical devices are frequently used for patients. Due to the manufacturing procedure sterilization is required. How different sterilization methods affect the mechanical behavior of these devices is largely unknown. Three poly(methyl methacrylate) (PMMA) based materials (Vertex Self-Curing, Palacos R+G, and NextDent C&B MFH) were sterilized with different sterilization methods: ethylene oxide, hydrogen peroxide gas plasma, autoclavation, and γ-irradiation. Mechanical properties were determined by testing the flexural strength, flexural modulus, fracture toughness, and impact strength. The flexural strength of all materials was significantly higher after γ-irradiation compared to the control and other sterilization methods, as tested in a wet environment. NextDent C&B MFH showed the highest flexural and impact strength, Palacos R+G showed the highest maximum stress intensity factor and total fracture work. Autoclave sterilization is not suitable for the sterilization of PMMA-based materials. Ethylene oxide, hydrogen peroxide gas plasma, and γ-irradiation appear to be suitable techniques to sterilize PMMA-based personalized medical devices. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Poly(methyl methacrylate) and thiophene-coated single-walled carbon nanotubes for volatile organic compound discrimination

    Science.gov (United States)

    Muangrat, Worawut; Chodjarusawad, Thanawee; Maolanon, Rungroj; Pratontep, Sirapat; Porntheeraphat, Supanit; Wongwiriyapan, Winadda

    2016-02-01

    Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were fabricated for use in volatile organic compound (VOC) detection. Pristine SWNTs were separately coated with PMMA (PMMA/SWNTs) and thiophene (thiophene/SWNTs) by spin-coating. Pristine SWNTs showed the highest response to methanol, while PMMA/SWNTs enabled 5.4-fold improved dichloromethane detection and thiophene/SWNTs enabled 1.4-fold improved acetone detection compared with pristine SWNTs. The sensor response of PMMA/SWNTs to dichloromethane and that of thiophene/SWNTs to acetone can be attributed to the Hildebrand solubility parameter (HSP). The more similar the HSP, the higher the sensor response. The sensor response of pristine SWNTs to methanol is related to the diffusion coefficient and molecular size. The relationships between the vapor concentration and sensor response of PMMA/SWNTs to dichloromethane and thiophene/SWNTs to acetone are based on Henry’s adsorption isotherm, while that of pristine SWNTs to methanol is based on the Henry-clustering model. Principal component analysis (PCA) results show that dichloromethane, acetone, and methanol were successfully discriminated.

  5. Self-supported poly(methyl methacrylate-acrylonitrile-vinyl acetate)-based gel electrolyte for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Y.H.; Zhou, D.Y.; Rao, M.M.; Cai, Z.P.; Liang, Y. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Li, W.S.; Tan, C.L. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Key Lab of Electrochemical Technology on Energy Storage and Power Generation in Guangdong Universities, Guangzhou 510006 (China)

    2009-04-01

    Self-supported gel polymer electrolyte (GPE) was prepared based on copolymer, poly(methyl methacrylate-acrylonitrile-vinyl acetate) (P(MMA-AN-VAc)). The copolymer P(MMA-AN-VAc) was synthesized by emulsion polymerization and the copolymer membrane was prepared through phase inversion. The structure and the performance of the copolymer, the membrane and the GPE were characterized by FTIR, NMR, SEM, XRD, DSC/TG, LSV, CA, and EIS. It is found that the copolymer was formed through the breaking of double bond C=C in each monomer. The membrane has low crystallinity and has low glass transition temperature, 39.1 C, its thermal stability is as high as 310 C, and its mechanical strength is improved compared with P(MMA-AN). The GPE is electrochemically stable up to 5.6 V (vs. Li/Li{sup +}) and its conductivity is 3.48 x 10{sup -3} S cm{sup -1} at ambient temperature. The lithium ion transference number in the GPE is 0.51 and the conductivity model of the GPE is found to obey the Vogel-Tamman-Fulcher (VTF) equation. (author)

  6. A novel bonding method for large scale poly(methyl methacrylate) micro- and nanofluidic chip fabrication

    Science.gov (United States)

    Qu, Xingtian; Li, Jinlai; Yin, Zhifu

    2018-04-01

    Micro- and nanofluidic chips are becoming increasing significance for biological and medical applications. Future advances in micro- and nanofluidics and its utilization in commercial applications depend on the development and fabrication of low cost and high fidelity large scale plastic micro- and nanofluidic chips. However, the majority of the present fabrication methods suffer from a low bonding rate of the chip during thermal bonding process due to air trapping between the substrate and the cover plate. In the present work, a novel bonding technique based on Ar plasma and water treatment was proposed to fully bond the large scale micro- and nanofluidic chips. The influence of Ar plasma parameters on the water contact angle and the effect of bonding conditions on the bonding rate and the bonding strength of the chip were studied. The fluorescence tests demonstrate that the 5 × 5 cm2 poly(methyl methacrylate) chip with 180 nm wide and 180 nm deep nanochannels can be fabricated without any block and leakage by our newly developed method.

  7. Modification of macroporous membranes by graft co-polymerization induced by pre-irradiation with an electron accelerator; Modificacion de membranas macroporosas para la recuperacion de protemas por intercambio ionico

    Energy Technology Data Exchange (ETDEWEB)

    Grasselli, M [Buenos Aires Univ. (Argentina). Facultad de Farmacia y Bioquimica; Yoshii, Fumio [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1999-07-01

    Glycidyl methacrylate (GMA) and N,N-dimethylacrylamide (DMAA) have been co-grafted on hollow fiber membranes of macroporous polyethylene. Grafted copolymers have been obtained with different ratios of the monomers (molar ratio between 0 and 2 DMAA/GMA). The properties of the modified membranes are studied.

  8. Photoluminescence and reflectivity studies of high energy light ions irradiated polymethyl methacrylate films

    Science.gov (United States)

    Bharti, Madhu Lata; Singh, Fouran; Ramola, R. C.; Joshi, Veena

    2017-11-01

    The self-standing films of non-conducting polymethyl methacrylate (PMMA) were irradiated in vacuum using high energy light ions (HELIs) of 50 MeV Lithium (Li+3) and 80 MeV Carbon (C+5) at various ion dose to induce the optical changes in the films. Upon HELI irradiation, films exhibit a significant enhancement in optical reflectivity at the highest dose. Interestingly, the photoluminescence (PL) emission band with green light at (514.5 nm) shows a noticeable increase in the intensity with increasing ion dose for both ions. However, the rate of increase in PL intensity is different for both HELI and can be correlated with the linear energy transfer by these ions in the films. Origin of PL is attributed to the formation of carbon cluster and hydrogenated amorphous carbon in the polymer films. HAC clusters act as PL active centres with optical reflectivity. Most of the harmful radiation like UV are absorbed by the material and is becoming opaque after irradiation and this PL active material are useful in fabrication of optoelectronic devices, UV-filter, back-lit components in liquid crystal display systems, micro-components for integrate optical circuits, diffractive elements, advanced materials and are also applicable to the post irradiation laser treatment by means of ion irradiation.

  9. A simplified technique for polymethyl methacrylate cranioplasty: combined cotton stacking and finger fracture method.

    Science.gov (United States)

    Kung, Woon-Man; Lin, Muh-Shi

    2012-01-01

    Polymethyl methacrylate (PMMA) is one of the most frequently used cranioplasty materials. However, limitations exist with PMMA cranioplasty including longer operative time, greater blood loss and a higher infection rate. To reduce these disadvantages, it is proposed to introduce a new surgical method for PMMA cranioplasty. Retrospective review of nine patients who received nine PMMA implants using combined cotton stacking and finger fracture method from January 2008 to July 2011. The definitive height of skull defect was quantified by computer-based image analysis of computed tomography (CT) scans. Aesthetic outcomes as measured by post-reduction radiographs and cranial index of symmetry (CIS), cranial nerve V and VII function and complications (wound infection, hardware extrusions, meningitis, osteomyelitis and brain abscess) were evaluated. The mean operation time for implant moulding was 24.56 ± 4.6 minutes and 178.0 ± 53 minutes for skin-to-skin. Average blood loss was 169 mL. All post-operative radiographs revealed excellent reduction. The mean CIS score was 95.86 ± 1.36%, indicating excellent symmetry. These results indicate the safety, practicability, excellent cosmesis, craniofacial symmetry and stability of this new surgical technique.

  10. Radiation-induced grafting of acrylic acid onto polyethylene filaments

    International Nuclear Information System (INIS)

    Kaji, K.; Sakurada, I.; Okada, T.

    1981-01-01

    Radiation-induced grafting of acrylic acid onto high density polyethylene (PE) filaments was carried out in order to raise softening temperature and impart flame retardance and hydrophilic properties. Mutual γ-irradiation method was employed for the grafting in a mixture of acrylic acid (AA), ethylene dichloride and water containing a small amount of ferrous ammonium sulfate. The rate of grafting was very low at room temperature. On the other hand, large percent grafts were obtained when the grafting was performed at an elevated temperature. Activation energy for the initial rate of grafting was found to be 17 kcal/mol between 20 and 60 0 C and 10 kcal/ mol between 60 and 80 0 C. Original PE filament begins to shrink at 70 0 C, shows maximum shrinkage of 50% at 130 0 C and then breaks off at 136 0 C. When a 34% AA graft is converted to metallic salt the graft filament retains its filament form even above 300 0 C and gives maximum shrinkage of 15%. Burning tests by a wire-netting basket method indicate that graft filaments and their metallic salts do not form melting drops upon burning and are self-extinguishing. Original PE filament shows no moisture absorption; however, that of AA-grafted PE increases with increasing graft percent. (author)

  11. Hydrophobic modification of cellulose isolated from Agave angustifolia fibre by graft copolymerisation using methyl methacrylate.

    Science.gov (United States)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan; Mohamed, Faizal

    2015-07-10

    Graft copolymerisation of methyl methacrylate (MMA) onto Agave angustifolia was conducted with ceric ammonium nitrate (CAN) as the redox initiator. The maximum grafting efficiency was observed at CAN and MMA concentrations of 0.91 × 10(-3) and 5.63 × 10(-2)M, respectively, at 45°C for 3h reaction time. Four characteristic peaks at 2995, 1738, 1440, and 845 cm(-1), attributed to PMMA, were found in the IR spectrum of grafted cellulose. The crystallinity index dropped from 0.74 to 0.46, while the thermal stability improved upon grafting. The water contact angle increased with grafting yield, indicating increased hydrophobicity of cellulose. SEM images showed the grafted cellulose to be enlarged and rougher. The changes in the physical nature of PMMA-grafted cellulose can be attributed to the PMMA grafting in the amorphous regions of cellulose, causing it to expand at the expense of the crystalline component. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Gamma irradiation effects on the grafting of low-density polyethylene with diethyl maleate

    International Nuclear Information System (INIS)

    Sanchez, Y.; Albano, C.; Karam, A.; Perera, R.; Silva, P.; Gonzalez, J.

    2005-01-01

    In this work, a low-density polyethylene (LDPE) was grafted with diethyl maleate (DEM) using gamma-rays from a Cobalt-60 source at different absorbed doses and monomer concentrations between 5 and 30 wt.%. This process was carried out in a decalin solution at 10 w/v% to obtain a homogeneous dispersion of the monomer into the polyethylene matrix. It was found that the grafting degree increases with the absorbed doses, as a consequence of the increased amount of energy given to the system, which made the grafting process more favorable. The grafting degree also increases with the concentration of DEM, because a higher concentration makes the insertion easier due to the increased availability of the free monomer. The highest grafting degree was obtained at 200 kGy of absorbed dose and with 30 wt.% of DEM. The melt flow index (MFI) values showed a decreasing trend as the absorbed dose was increased. This fact reveals that crosslinking and grafting are taking place simultaneously, this behavior being remarkable at higher irradiation doses. The results from thermogravimetric analysis (TGA) showed that the initial degradation temperatures remained almost unchanged with the absorbed dose

  13. Covalent bonding of PMMA, PBMA, and poly(HEMA) to hydroxyapatite particles

    NARCIS (Netherlands)

    Liu, Q.; de Wijn, J.R.; van Blitterswijk, Clemens

    1998-01-01

    In our earlier study, we showed that the surface hydroxyl groups of hydroxyapatite have the ability to react with organic isocyanate groups. In this study, the feasibility of grafting poly(methyl methacrylate) (PMMA), poly(n-butyl methacrylate) (PBMA), and Poly(hydroxyethyl methacrylate)

  14. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    Science.gov (United States)

    Docters, E. H.; Smolko, E. E.; Suarez, C. E.

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All this grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA).

  15. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    International Nuclear Information System (INIS)

    Docters, E.H.; Smolko, E.E.

    1990-01-01

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All these grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA). (author)

  16. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    Energy Technology Data Exchange (ETDEWEB)

    Docters, E H; Smolko, E E [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Direccion de Radioisotopos y Radiaciones; Suarez, C E [Instituto Nacional de Tecnologia Agropecuaria, Castelar (Argentina)

    1990-01-01

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All these grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA). (author).

  17. Synthesis of ion exchange membrane by radiation grafting of acrylic acid onto polyethylene

    International Nuclear Information System (INIS)

    Ishigaki, I.; Sugo, T.; Senoo, K.; Takayama, T.; Machi, S.; Okamoto, J.; Okada, T.

    1981-01-01

    Radiation grafting of vinyl monomers onto polymer films has been extensively studied by many workers. In the preirradiation method of grafting a polymer substrate is activated by irradiation (either in the presence or absence of oxygen) and subsequently allowed to react with a monomer. The preirradiation method was utilized in this study to synthesize an ion exchange membrane useful for a battery separator by grafting acrylic acid onto polyethylene film. The battery separator should be chemically and thermally stable, sufficiently durable in electrolyte as well as highly electrically conductive. Membranes made from regenerated cellulose, e.g., cellophane, have long been used as a separator in the batteries with alkaline electrolyte, such as silver oxide primary cell. However, it has poor durability, as short as one year, due to breakdown of the membrane during operation or storing. The acrylic acid-grafted polyethylene film was found to be quite useful for a separator in the alkaline batteries. This membrane has a high electric conductivity and an excellent durability. (author)

  18. Ionogels Based on Poly(methyl methacrylate and Metal-Containing Ionic Liquids: Correlation between Structure and Mechanical and Electrical Properties

    Directory of Open Access Journals (Sweden)

    Kerstin Zehbe

    2016-03-01

    Full Text Available Ionogels (IGs based on poly(methyl methacrylate (PMMA and the metal-containing ionic liquids (ILs bis-1-butyl-3-methlimidazolium tetrachloridocuprate(II, tetrachloride cobaltate(II, and tetrachlorido manganate(II have been synthesized and their mechanical and electrical properties have been correlated with their microstructure. Unlike many previous examples, the current IGs show a decreasing stability in stress-strain experiments on increasing IL fractions. The conductivities of the current IGs are lower than those observed in similar examples in the literature. Both effects are caused by a two-phase structure with micrometer-sized IL-rich domains homogeneously dispersed an IL-deficient continuous PMMA phase. This study demonstrates that the IL-polymer miscibility and the morphology of the IGs are key parameters to control the (macroscopic properties of IGs.

  19. Improvement of blood compatibility of polyurethane elastomer by radiation graft copolymerization of 2-hydroxyethyl methacrylate in polymer matrix

    International Nuclear Information System (INIS)

    Li Ximing; Chen Wenming; Yuan Zhijian; Li Song; Lu Mei

    1988-01-01

    The γ-radiation induced grafting of 2-hydroxyethyl methacrylate (HEMA) onto polyurethane-elastomers (PUE) tube by preswelling technique to prepare biomedical materials with blood compatibility is studied. The graft yield can be controlled by regulating the preswelling time and temperature, or by change the irradiation dose and dose rate. After antithrombogenic test in vitro it has been confirmed that the blood compatibility of original polyurethane tube has been considerably improved by grafting

  20. Organic inorganic hybrid coating (poly(methyl methacrylate)/monodisperse silica)

    Science.gov (United States)

    Rubio, E.; Almaral, J.; Ramírez-Bon, R.; Castaño, V.; Rodríguez, V.

    2005-04-01

    Polymethylmethacrylate-silica hybrid coatings were prepared from methyl methacrylate and monodisperse colloidal silica prepared by the Stöber method. The surfaces of the spheres were successfully modified by chemical reaction with 3-(trimethoxysilyl) propyl methacrylate (TMSPM) to compatibilise the organic and inorganic components of the precursor solution mixture. The coatings were deposited by dip-coating on glass substrates. They result with good properties of homogeneity, optical transparence, hardness and adhesion.

  1. Graft copolymerization of glycidyl methacrylate onto delignified kenaf fibers through pre-irradiation technique

    International Nuclear Information System (INIS)

    Sharif, Jamaliah; Mohamad, Siti Fatahiyah; Fatimah Othman, Nor Azilah; Bakaruddin, Nurul Azra; Osman, Hasnul Nizam; Güven, Olgun

    2013-01-01

    Glycidyl methacrylate grafted kenaf (GMA-g-Kenaf) was prepared by pre-irradiation grafting technique. Kenaf fibers were treated with different concentration of sodium chlorite solution before used as trunk polymer. Treated kenaf fibers were irradiated by electron beam followed by grafting reaction in GMA/water emulsion system. The degree of grafting was determined as a function of absorbed dose, reaction time, reaction temperature and concentration of monomer. The results showed that the lignin content was decreased from 14.3% to as low as 3.3% with the increased of sodium chlorite concentration. This was evidenced by SEM pictures which show the surface of treated kenaf fibers was cleaner and smoother compared to that of untreated one. The degree of grafting increased with the increase of absorbed dose, reaction temperature, reaction time and monomer concentration as well as with decreasing lignin content. Formation of graft copolymer was confirmed with SEM, FTIR analysis. The structural investigation by XRD showed that degree of crystallinity of graft copolymers decreased with the increase in degree of grafting. - Highlights: • We used kenaf fibers for radiation induce graft copolymerization with GMA. • Kenaf fibers was treated to remove lignin in order to increase grafting yield. • Treated kenaf fibers were graft copolymerize through preirradiation technique. • Optimum conditions for graft copolymerization of kenaf fibers were established. • Formation of graft copolymer is also confirmed with SEM, FTIR and XRD

  2. Ultraviolet-induced surface grafting of octafluoropentyl methacrylate on polyether ether ketone for inducing antibiofilm properties.

    Science.gov (United States)

    Amdjadi, Parisa; Nojehdehian, Hanieh; Najafi, Farhood; Ghasemi, Amir; Seifi, Massoud; Dashtimoghadam, Erfan; Fahimipour, Farahnaz; Tayebi, Lobat

    2017-07-01

    Since octafluoropentyl methacrylate is an antifouling polymer, surface modification of polyether ether ketone with octafluoropentyl methacrylate is a practical approach to obtaining anti-biofilm biocompatible devices. In the current study, the surface treatment of polyether ether ketone by the use of ultraviolet irradiation, so as to graft (octafluoropentyl methacrylate) polymer chains, was initially implemented and then investigated. The Fourier-transform infrared and nuclear magnetic resonance spectra corroborated the appearance of new signals associated with the fluoroacrylate group. Thermogravimetric curves indicated enhanced asymmetry in the polymer structure due to the introduction of the said new groups. Measuring the peak area in differential scanning calorimetry experiments also showed additional bond formation. Static water contact angle measurements indicated a change in wettability to the more hydrophobic surface. The polyether ether ketone-octafluoropentyl methacrylate surface greatly reduced the protein adsorption. This efficient method can modulate and tune the surface properties of polyether ether ketone according to specific applications.

  3. Influence of acrylonitrile butadiene rubber on recyclability of blends prepared from poly(vinyl chloride) and poly(methyl methacrylate).

    Science.gov (United States)

    Suresh, Sunil S; Mohanty, Smita; Nayak, Sanjay K

    2018-06-01

    The current investigation deals with the recycling possibilities of poly(vinyl chloride) and poly(methyl methacrylate) in the presence of acrylonitrile butadiene rubber. Recycled blends of poly(vinyl chloride)/poly(methyl methacrylate) are successfully formed from the plastic constituents, those are recovered from waste computer products. However, lower impact performance of the blend and lower stability of the poly(vinyl chloride) phase in the recycled blend restricts its further usage in industrial purposes. Therefore, effective utilisation acrylonitrile butadiene rubber in a recycled blend was considered for improving mechanical and thermal performance. Incorporation of acrylonitrile butadiene rubber resulted in the improvement in impact performance as well as elongation-at-break of the recycled blend. The optimum impact performance was found in the blend with 9 wt% acrylonitrile butadiene rubber, which shows 363% of enhancement as compared with its parent blend. Moreover, incorporated acrylonitrile butadiene rubber also stabilises the poly(vinyl chloride) phase present in the recycled blend, similarly Fourier transform infrared spectroscopy studies indicate the interactions of various functionalities present in the recycled blend and acrylonitrile butadiene rubber. In addition to this, thermogravimetric analysis indicates the improvement in the thermal stability of the recycled blend after the addition of acrylonitrile butadiene rubber into it. The existence of partial miscibility in the recycled blend was identified using differential scanning calorimetry and scanning electron microscopy.

  4. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    International Nuclear Information System (INIS)

    Liu Hanzhou; Yu Ming; Deng Bo; Li Linfan; Jiang Haiqing; Li Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA). - Highlights: → Acrylonitrile is grafted onto pre-irradiated polyethylene (PE) nonwoven fabrics. → Emulsion system is applied, for the graft polymerization avoids organic solvent. → Kinetic of the pre-irradiation induced graft polymerization is studied. → Optimal condition is determined at the temperature below the b.p. of acrylonitrile.

  5. Modification of flax fibres by radiation induced emulsion graft copolymerization of glycidyl methacrylate

    Science.gov (United States)

    Moawia, Rihab Musaad; Nasef, Mohamed Mahmoud; Mohamed, Nor Hasimah; Ripin, Adnan

    2016-05-01

    Flax fibres were modified by radiation induced graft copolymerization of glycidyl methacrylate (GMA) by pre-irradiation method in an emulsion medium. The effect of reaction parameters on the degree of grafting (DOG) such as concentration of bleaching agent, absorbed dose, monomer concentration, temperature and reaction time were investigated. The DOG was found to be dependent on the investigated parameters. The incorporation of poly(GMA) grafts in the bleached flax fibres was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The structural and mechanical changes were evaluated by X-ray diffraction (XRD) and mechanical tester, respectively. The results revealed that reacting bleached flax fibres irradiated with 20 kGy with 5% GMA emulsion containing 0.5% polyoxyethylene-sorbitan monolaurate (Tween 20) surfactant at 40 °C for 1 h led to a maximum DOG of 148%. The grafted fibres showed sufficient mechanical strength and hydrophobicity which make them promising precursors for development of adsorbents after appropriate chemical treatments.

  6. Radiolytic stabilization of poly(methyl methacrylate) in blends with polystyrene

    International Nuclear Information System (INIS)

    Lima, Ivania Soares de

    2002-04-01

    In this work the radiolytic stabilization of poly(methyl methacrylate) was analyzed by three radioprotective agents: polystyrene (PS) and hindered amine light stabilizers (HEALS), respectively, PMMA/PS systems, so a called polymeric blends were prepared with different compositions, where the miscibility of these blends were studied using viscometric, microscopy (SEM) and spectroscopy (FT-IR) techniques. The results show that PMMA/PS blends in the compositions below 10 wt% of PS are miscible, on films casting from solution of toluene and methyl-ethyl-ketone (1;1) mixture. On the other hand, in the composition above 10 wt% of PS, PMMA/PS blends show imminiscibility behavior. These polymer solutions were irradiated with gamma rays ( 60 Co) and viscometric, microscopic and spectroscopic experiments show gamma radiation-induced compatibilization on PMMA/PS blends on proportion 50/50 and 30/70 take place. Viscometric interaction parameters of miscible and compatibilized PMMA/PS bends were calculated in the range of - 50 kGy, with the goal to find out the polymeric interactions after irradiation of the films. G values of PMMA, PMMA/PS and PMMA+St systems were calculated in order to analyze the radioprotection of PS and St into PMMA matrix. The results show that (90/10) PMMA/PS and PMMA+1,5%St systems promote protection against the gamma the radiation-induced scissions, effect that leads to polymer degradation. Moreover, a small amount of crosslinking observed in irradiated blends has contributed to stabilize mechanical properties of PMMA films. PMMA+0,3% HALS system irradiated in doses above 60 kGy showed little stabilization of the mechanical properties of PMMA, since it was observed mechanical degradation this system. Based on these results, PS and St showed to be the best radioprotective agents to PMMA. (author)

  7. Studied by electron paramagnetic resonance (EPR) of polymethyl methacrylate (PMMA) irradiated with gamma photons from cobalt 60

    International Nuclear Information System (INIS)

    Jalali, Hajer

    2013-01-01

    Ionizing radiation is radiation able to deposit enough energy in the material through which they pass to create ionization. These ionizing radiations, when mastered, have many practical uses beneficial (areas of health, industry ...). Gamma rays are emitted by radioactive nuclei. The objective of our work is the study of polymethyl methacrylate (PMMA) irradiated by gamma photons from cobalt-60. To study the technique of radio spectroscopy (9 to 10Hz) electron paramagnetic resonance EPR is used. This technique is specific to characterize transient free radicals involved in chemical reactions such as oxidation, combustion, polymerization reactions ... We analyzed the EPR spectra three batch KS, EB, and JF our dosimeter according to the dose (high and low) and showed that the dosimetric response can be represented in exponential form (high dose) and linear form (low dose). We also studied the kinetics of decay of the EPR signal as a function of time (fading) and showed that the responses relating to stabilize after 20 min of irradiation.

  8. Supercritical CO2 drying of poly(methyl methacrylate) photoresist for deep x-ray lithography: a brief note

    Science.gov (United States)

    Shukla, Rahul; Abhinandan, Lala; Sharma, Shivdutt

    2017-07-01

    Poly(methyl methacrylate) (PMMA) is an extensively used positive photoresist for deep x-ray lithography. The post-development release of the microstructures of PMMA becomes very critical for high aspect ratio fragile and freestanding microstructures. Release of high aspect ratio comb-drive microstructure of PMMA made by one-step x-ray lithography (OXL) is studied. The effect of low-surface tension Isopropyl alcohol (IPA) over water is investigated for release of the high aspect ratio microstructures using conventional and supercritical (SC) CO2 drying. The results of conventional drying are also compared for the samples released or dried in both in-house developed and commercial SC CO2 dryer. It is found that in all cases the microstructures of PMMA are permanently deformed and damaged while using SC CO2 for drying. For free-standing high aspect ratio microstructures of PMMA made by OXL, it is advised to use low-surface tension IPA over DI water. However, this brings a limitation on the design of the microstructure.

  9. Preparation and characterization of poly(glycidyl methacrylate) grafted from magnesium hydroxide particles via SI-ATRP

    International Nuclear Information System (INIS)

    Liu Jianhui; Feng Na; Chang Suqin; Kang Hongliang

    2012-01-01

    In order to improve the compatibility of magnesium hydroxide particles [Mg(OH) 2 ] and polymer matrix, poly(glycidyl methacrylate) (PGMA) grafted from magnesium hydroxide particles were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP). In this work, two approaches for the immobilization of ATRP initiator on the magnesium hydroxide particles surface were compared and selected. The density of initiator was significantly increased by the method of introducing more hydroxyl groups via ATRP of 2-hydroxyethyl methacrylate (HEMA) on the surface. The percentage of bromine atom for the initiator-functionalized magnesium hydroxide particles [Mg(OH) 2 -g-PHEMA-Br] reached to 1.75%, compared to 0.48% for Mg(OH) 2 -Br determined by XPS analysis. The surface-initiated ATRP of glycidyl methacrylate (GMA) can be conducted in a controlled manner, as revealed by the linear kinetic plot, linear increase of number average molecular weight (M n ) with monomer conversions, and the relatively narrow molecular weight distributions (M w /M n ∼ 1.4) of PGMA chains. The percentage of grafting PG (%) and the thickness of the grafted polymer layer increased with the increasing of polymerization time and reached to 116.6% and 197.6 nm after 300 min respectively. As for the polymerization with different initial monomer concentration, the number average molecular weights (M n ) and weight average molecular weights (M w ) of PGMA increased with the increasing of initial monomer concentration. TGA indicated that the initial decomposition temperature of Mg(OH) 2 -g-PHEMA-PGMA composite particles (253 °C) was much lower than that of unmodified magnesium hydroxide particles (337 °C).

  10. Preparation and characterization of poly(glycidyl methacrylate) grafted from magnesium hydroxide particles via SI-ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jianhui [School of Textile and Materials Engineering, Dalian Polytechnic University, Dalian 116034 (China); Feng Na, E-mail: fengna12@163.com [School of Textile and Materials Engineering, Dalian Polytechnic University, Dalian 116034 (China); Chang Suqin [China Leather and Footwear Industry Research Institute, Beijing 100015 (China); Kang Hongliang [State Key Laboratory of Polymer Physics and Chemistry, Joint Laboratory of Polymer Science and Material, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2012-06-01

    In order to improve the compatibility of magnesium hydroxide particles [Mg(OH){sub 2}] and polymer matrix, poly(glycidyl methacrylate) (PGMA) grafted from magnesium hydroxide particles were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP). In this work, two approaches for the immobilization of ATRP initiator on the magnesium hydroxide particles surface were compared and selected. The density of initiator was significantly increased by the method of introducing more hydroxyl groups via ATRP of 2-hydroxyethyl methacrylate (HEMA) on the surface. The percentage of bromine atom for the initiator-functionalized magnesium hydroxide particles [Mg(OH){sub 2}-g-PHEMA-Br] reached to 1.75%, compared to 0.48% for Mg(OH){sub 2}-Br determined by XPS analysis. The surface-initiated ATRP of glycidyl methacrylate (GMA) can be conducted in a controlled manner, as revealed by the linear kinetic plot, linear increase of number average molecular weight (M{sub n}) with monomer conversions, and the relatively narrow molecular weight distributions (M{sub w}/M{sub n} {approx} 1.4) of PGMA chains. The percentage of grafting PG (%) and the thickness of the grafted polymer layer increased with the increasing of polymerization time and reached to 116.6% and 197.6 nm after 300 min respectively. As for the polymerization with different initial monomer concentration, the number average molecular weights (M{sub n}) and weight average molecular weights (M{sub w}) of PGMA increased with the increasing of initial monomer concentration. TGA indicated that the initial decomposition temperature of Mg(OH){sub 2}-g-PHEMA-PGMA composite particles (253 Degree-Sign C) was much lower than that of unmodified magnesium hydroxide particles (337 Degree-Sign C).

  11. Synthesis of block copolymers derived from N-trityl-(S)-serine and pyrene end-labeled poly(methyl methacrylate) or poly(N-isopropylacrylamide) via ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Buruiana, Emil C., E-mail: emilbur@icmpp.ro [Petru Poni Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley 700487, Iasi (Romania); Podasca, Viorica; Buruiana, Tinca [Petru Poni Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley 700487, Iasi (Romania)

    2012-10-15

    A new monomer bearing N-trityl-L-serine methyl ester in structure, methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine (MTS), was prepared to be further polymerized by atom transfer radical polymerization (ATRP) with pyrene-endcapped poly(methyl methacrylate) (Py-PMMA-Br) or poly(N-isopropylacrylamide) (Py-PNIPA-Br). The resulting block copolymers, poly(methyl methacrylate-block-methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine) (Py-PMMA-b-PMTS) and poly(N-isopropylacrylamide-block-methacryloyloxyethyl carbamoyloxy-N-trityl methyl serine (Py-PNIPA-b-PMTS) were characterized by {sup 1}H ({sup 13}C) NMR, ultraviolet, FTIR and fluorescence spectroscopy, thermal analysis, differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), and gel permeation chromatography (GPC) measurements. The chemical composition in Py-PMMA-b-PMTS was estimated from the {sup 1}H NMR analysis that indicated a ratio of the repeating units of 46:19 (MMA:MTS). For the Py-PNIPA-b-PMTS the composition rate in the copolymer was 61:25 (NIPA:MTS). Quenching of the pyrene species with N,N-diethylaniline, nitrobenzene, nitrophenol, potassium iodide, p-nitrotoluene and tetracyanoquinodimethane (TCNQ) in DMF solution excited at 348 nm was evidenced, more efficiently being nitrophenol and TCNQ. In this case, the monomer emission at 388-409 nm underwent a significant decrease caused of an electron transfer from the electron-reach photoexcited pyrene molecule to the electron-deficient quenchers. - Highlights: Black-Right-Pointing-Pointer Diblock copolymers combine the fluorescence of pyrene-PMMA (PNIPA) with the characteristics of PMTS. Black-Right-Pointing-Pointer Such copolymers could be used for nitroderivatives detecting. Black-Right-Pointing-Pointer UV/vis and fluorescence measurements give a good correlation for LCST of Py-PNIPA-Br.

  12. Radiation grafting of methacrylate onto carbon nanofiber surface

    International Nuclear Information System (INIS)

    Evora, M.C.; Klosterman, D.; Lafdi, K.; Li, L.

    2011-01-01

    Radiation can be used to modify and improve the properties of materials. Electron beam irradiation has potential application in modifying the structure of carbon fibers in order to produce useful defects in the graphite structure and create reactive sites. In this study, vapor grown carbon nano fibers (VGCF) were irradiated with a high energy (3 MeV) electron beam in air to dose of 1000 kGy to create active sites and added to methyl methacrylate (MMA) dissolved in water/methanol (50% V). The irradiated samples were analyzed by X-Ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy to assess the impact on surface and bulk properties. Oxygen was readily incorporated enhancing the dispersion of VGCF. Raman spectroscopy analyses indicated that the sample irradiated and preirradiated grafted sample with MMA had the intensity ratio increased. (author)

  13. Salt-Induced Control of the Grafting Density in Poly(ethylene glycol) Brush Layers by a Grafting-to Approach

    DEFF Research Database (Denmark)

    Ortiz, Roberto; Olsen, Stefan; Thormann, Esben

    2018-01-01

    In this work, a method to obtain control of the grafting density during the formation of polymer brush layers by the grafting-to method of thiolated poly(ethylene glycol) onto gold is presented. The grafting density of the polymer chains was adjusted by adding Na2SO4 in concentrations between 0.......2 and 0.9 M to the aqueous polymer solution during the grafting process. The obtained grafting densities ranged from 0.26 to 1.60 chains nm-2, as determined by surface plasmon resonance. The kinetics of the grafting process were studied in situ by a quartz crystal microbalance with dissipation......, and a mushroom to brush conformational transition was observed when the polymer was grafted in the presence of Na2SO4. The transition from mushroom to brush was only observed for long periods of grafting, highlighting the importance of time to obtain high grafting densities. Finally, the prepared brush layer...

  14. Poly(methyl methacrylate) nanocomposites based on TiO{sub 2} nanocrystals: Tailoring material properties towards sensing

    Energy Technology Data Exchange (ETDEWEB)

    Convertino, A., E-mail: annalisa.convertino@ismn.cnr.i [ISMN-CNR Istituto per lo Studio dei Materiali Nanostrutturati, Via Salaria km. 29.300, 00016 Roma (Italy); Tamborra, M., E-mail: m.tamborra@ba.ipcf.cnr.i [IPCF-CNR Istituto per i Processi Chimici e Fisici, Bari Division, Via Orabona 4, 70126 Bari (Italy); Striccoli, M., E-mail: m.striccoli@ba.ipcf.cnr.i [IPCF-CNR Istituto per i Processi Chimici e Fisici, Bari Division, Via Orabona 4, 70126 Bari (Italy); Leo, G., E-mail: gabriella.leo@ismn.cnr.i [ISMN-CNR Istituto per lo Studio dei Materiali Nanostrutturati, Via Salaria km. 29.300, 00016 Roma (Italy); Agostiano, A., E-mail: a.agostiano@ba.ipcf.cnr.i [IPCF-CNR Istituto per i Processi Chimici e Fisici, Bari Division, Via Orabona 4, 70126 Bari (Italy); Dipartimento di Chimica., Universita di Bari, Via Orabona 4, 70126 Bari (Italy); Curri, M.L., E-mail: lucia.curri@ba.ipcf.cnr.i [IPCF-CNR Istituto per i Processi Chimici e Fisici, Bari Division, Via Orabona 4, 70126 Bari (Italy)

    2011-03-31

    Nanocomposite materials have been obtained by dispersing organic capped TiO{sub 2} nanocrystals (NCs) with different shape and surface chemistry in poly(methyl methacrylate) (PMMA) as a host medium. Films of the prepared nanocomposites based on TiO{sub 2} NCs have been fabricated by spin coating and morphologically characterized as a function of the preparative conditions. The organic vapor absorption ability of the PMMA/TiO{sub 2} NC based nanocomposites has been then investigated both for spherical and rod-like NCs, and the chemical nature of the coordinating organic molecules has been also varied. The results of the investigation have demonstrated that NC geometry and surface chemistry can modulate the specific absorption characteristics of the modified PMMA in order to absorb different solvent molecules (i.e. acetone, ethanol, propan-2-ol and water). Such features, due to specific interactions between the potential analyte vapors and the functionalized surface of NCs, can effectively be addressed in a controlled and reproducible way, thus offering original opportunities for designing innovative chemical sensors.

  15. Segmental dynamics in poly(methyl acrylate)-poly(methyl methacrylate) sequential interpenetrating polymer networks: structural relaxation experiments

    International Nuclear Information System (INIS)

    Ribelles, J L Gomez; Duenas, J M Meseguer; Cabanilles, C Torregrosa; Pradas, M Monleon

    2003-01-01

    The miscibility of poly(methyl acrylate)-poly(methyl methacrylate) sequential interpenetrating polymer networks (IPNs) has been studied by probing the conformational mobility of the component polymer chains. These IPNs exhibit the phenomenon of forced compatibilization. In a conventional heating differential scanning calorimetry (DSC) thermogram, the highly cross-linked IPN shows a single glass transition which covers a temperature interval of around 100 d eg C; in contrast, loosely cross-linked IPNs show two glass transitions. The conformational mobility in these IPNs is studied by subjecting them to isothermal annealings at temperatures in the region of the glass transition and below it. The DSC scans measured after these treatments allow one to determine the temperature interval in which the sample is out of thermodynamic equilibrium but keeps enough conformational mobility to relax during the isothermal annealing in such a way that the enthalpy loss is measurable with the sensitivity of a conventional DSC. The results allow one to reach some conclusions about the compositional distribution of the IPN on the nanometre scale

  16. Grafting of molecularly imprinted polymer to porous polyethylene filtration membranes by plasma polymerization.

    Science.gov (United States)

    Cowieson, D; Piletska, E; Moczko, E; Piletsky, S

    2013-08-01

    An application of plasma-induced grafting of polyethylene membranes with a thin layer of molecularly imprinted polymer (MIP) was presented. High-density polyethylene (HDPE) membranes, "Vyon," were used as a substrate for plasma grafting modification. The herbicide atrazine, one of the most popular targets of the molecular imprinting, was chosen as a template. The parameters of the plasma treatment were optimized in order to achieve a good balance between polymerization and ablation processes. Modified HDPE membranes were characterized, and the presence of the grafted polymeric layer was confirmed based on the observed weight gain, pore size measurements, and infrared spectrometry. Since there was no significant change in the porosity of the modified membranes, it was assumed that only a thin layer of the polymer was introduced on the surface. The experiments on the re-binding of the template atrazine to the membranes modified with MIP and blank polymers were performed. HDPE membranes which were grafted with polymer using continuous plasma polymerization demonstrated the best result which was expressed in an imprinted factor equal to 3, suggesting that molecular imprinting was successfully achieved.

  17. Fabrication of poly(methyl methacrylate)-MoS{sub 2}/graphene heterostructure for memory device application

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, Sachin M.; Tanemura, Masaki [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Center for Fostering Young and Innovative Researchers, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)

    2014-12-07

    Combination of two dimensional graphene and semi-conducting molybdenum disulfide (MoS{sub 2}) is of great interest for various electronic device applications. Here, we demonstrate fabrication of a hybridized structure with the chemical vapor deposited graphene and MoS{sub 2} crystals to configure a memory device. Elongated hexagonal and rhombus shaped MoS{sub 2} crystals are synthesized by sulfurization of thermally evaporated molybdenum oxide (MoO{sub 3}) thin film. Scanning transmission electron microscope studies reveal atomic level structure of the synthesized high quality MoS{sub 2} crystals. In the prospect of a memory device fabrication, poly(methyl methacrylate) (PMMA) is used as an insulating dielectric material as well as a supporting layer to transfer the MoS{sub 2} crystals. In the fabricated device, PMMA-MoS{sub 2} and graphene layers act as the functional and electrode materials, respectively. Distinctive bistable electrical switching and nonvolatile rewritable memory effect is observed in the fabricated PMMA-MoS{sub 2}/graphene heterostructure. The developed material system and demonstrated memory device fabrication can be significant for next generation data storage applications.

  18. Effects of synchrotron radiation spectrum energy on polymethyl methacrylate photosensitivity to deep x-ray lithography

    International Nuclear Information System (INIS)

    Mekaru, Harutaka; Utsumi, Yuichi; Hattori, Tadashi

    2003-01-01

    Since X-ray lithography requires a high photon flux to achieve deep resist exposure, a synchrotron radiation beam, which is not monochromatized, is generally used as a light source. If the synchrotron radiation beam is monochromatized, photon flux will decrease rapidly. Because of this reason, the wavelength dependence of the resist sensitivity has not been investigated for deep X-ray lithography. Measuring the spectrum of a white beam with a Si solid-state detector (SSD) is difficult because a white beam has a high intensity and an SSD has a high sensitivity. We were able to measure the spectrum and the photocurrent of a white beam from a beam line used for deep X-ray lithography by keeping the ring current below 0.05 mA. We evaluated the characteristics of the output beam based on the measured spectrum and photocurrent, and used them to investigate the relationship between the total exposure energy and the dose-processing depth with polymethyl methacrylate (PMMA). We found that it is possible to guess the processing depth of PMMA from the total exposure energy in deep X-ray lithography. (author)

  19. Modification of flax fibres by radiation induced emulsion graft copolymerization of glycidyl methacrylate

    International Nuclear Information System (INIS)

    Moawia, Rihab Musaad; Nasef, Mohamed Mahmoud; Mohamed, Nor Hasimah; Ripin, Adnan

    2016-01-01

    Flax fibres were modified by radiation induced graft copolymerization of glycidyl methacrylate (GMA) by pre-irradiation method in an emulsion medium. The effect of reaction parameters on the degree of grafting (DOG) such as concentration of bleaching agent, absorbed dose, monomer concentration, temperature and reaction time were investigated. The DOG was found to be dependent on the investigated parameters. The incorporation of poly(GMA) grafts in the bleached flax fibres was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The structural and mechanical changes were evaluated by X-ray diffraction (XRD) and mechanical tester, respectively. The results revealed that reacting bleached flax fibres irradiated with 20 kGy with 5% GMA emulsion containing 0.5% polyoxyethylene-sorbitan monolaurate (Tween 20) surfactant at 40 °C for 1 h led to a maximum DOG of 148%. The grafted fibres showed sufficient mechanical strength and hydrophobicity which make them promising precursors for development of adsorbents after appropriate chemical treatments. - Highlights: • Flax fibers were modified by radiation induced emulsion grafting of GMA. • Bleaching with 0.7 wt% Na-chlorite was essential for achieving high DOGs. • Effect of reaction parameters on the degree of grafting were established. • The incorporation of poly-GMA grafts was proved by SEM, FTIR and XRD. • The obtained poly-GMA grafted flax fibers have potential for adsorbent making.

  20. Grafting of 2 (2-hydroxy-5-vinylphenyl) 2H-benzotriazole onto polymers with aliphatic groups. Synthesis and polymerization of 2 (2-hydroxy-5-isopropenylphenyl) 2H-benzotriazole and a new synthesis of 2 (2-hydroxy-5-vinylphenyl) 2H-benzotriazole

    Science.gov (United States)

    Pradellok, W.; Nir, Z.; Vogl, O.

    1981-01-01

    Successful grafting of 2(2-hydroxy-5-vinylphenyl)2H-benzotriazole onto saturated aliphatic C-H groups of polymers has been accomplished. When the grafting reaction was carried out in chlorobenzene at 150 C = 160 C with di-tertiarybutylperoxide as the grafting initiator, grafts as high as 20 percent - 30 percent at a grafting efficiency of 50 percent and 80 percent have readily been obtained. The grafting reaction was carried out in tubes sealed under high vacuum since trace amounts of oxygen cause complete inhibition of the grafting reaction by the phenolic monomer. On a variety of different polymers including atactic polypropylene, ethylene/vinyl acetate copolymer, poly(methyl methacrylate), poly(butyl acrylate), and polycarbonate were used.

  1. Poly(methyl methacrylate)/layered zinc sulfide nanocomposites: Preparation, characterization and the improvements in thermal stability, flame retardant and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Biao; Zhou, Keqing; Jiang, Saihua [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Shi, Yongqian [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road, Suzhou, Jiangsu 215123 (China); Wang, Bibo [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Gui, Zhou, E-mail: zgui@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road, Suzhou, Jiangsu 215123 (China)

    2014-08-15

    Highlights: • Layered zinc sulfide (LZnS) was synthesized successfully via hydrothermal method. • We prepare PMMA/LZnS nanocomposites by in situ bulk polymerization of MMA. • PMMA/LZnS nanocomposites were investigated by TGA, DSC, MCC, UV–vis and PL test. • The thermal stability, flame retardant and optical properties of PMMA are improved. - Abstract: Layered zinc sulfide (LZnS) was synthesized successfully via hydrothermal method and poly(methyl methacrylate) (PMMA)/layered zinc sulfide nanocomposites were obtained by in situ bulk polymerization of methyl methacrylate (MMA). X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the as-synthesized layered zinc sulfide and PMMA/layered zinc sulfide nanocomposites. Microscale combustion calorimeter (MCC), differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) were used to test the thermal properties of the composites. Ultraviolet visible (UV–vis) transmittance spectra and photoluminence (PL) spectra were obtained to investigate the optical properties of the composites. From the results, the thermal degradation temperature is increased by 20–50 °C, the peak of heat release rate (pHRR) and total heat release (THR) are both decreased by above 30%, and the photoluminence intensity is enhanced with the increasing loading of layered zinc sulfide.

  2. Poly(methyl methacrylate)/layered zinc sulfide nanocomposites: Preparation, characterization and the improvements in thermal stability, flame retardant and optical properties

    International Nuclear Information System (INIS)

    Wang, Biao; Zhou, Keqing; Jiang, Saihua; Shi, Yongqian; Wang, Bibo; Gui, Zhou; Hu, Yuan

    2014-01-01

    Highlights: • Layered zinc sulfide (LZnS) was synthesized successfully via hydrothermal method. • We prepare PMMA/LZnS nanocomposites by in situ bulk polymerization of MMA. • PMMA/LZnS nanocomposites were investigated by TGA, DSC, MCC, UV–vis and PL test. • The thermal stability, flame retardant and optical properties of PMMA are improved. - Abstract: Layered zinc sulfide (LZnS) was synthesized successfully via hydrothermal method and poly(methyl methacrylate) (PMMA)/layered zinc sulfide nanocomposites were obtained by in situ bulk polymerization of methyl methacrylate (MMA). X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the as-synthesized layered zinc sulfide and PMMA/layered zinc sulfide nanocomposites. Microscale combustion calorimeter (MCC), differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) were used to test the thermal properties of the composites. Ultraviolet visible (UV–vis) transmittance spectra and photoluminence (PL) spectra were obtained to investigate the optical properties of the composites. From the results, the thermal degradation temperature is increased by 20–50 °C, the peak of heat release rate (pHRR) and total heat release (THR) are both decreased by above 30%, and the photoluminence intensity is enhanced with the increasing loading of layered zinc sulfide

  3. 3D scaffolds from vertically aligned carbon nanotubes/poly(methyl methacrylate) composites via atom transfer radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Tebikachew, Behabtu; Magina, Sandra [CICECO, Department of Chemistry, University of Aveiro (Portugal); Mata, Diogo; Oliveira, Filipe J.; Silva, Rui F. [CICECO, Department of Materials and Ceramic Engineering, University of Aveiro (Portugal); Barros-Timmons, Ana, E-mail: anabarros@ua.pt [CICECO, Department of Chemistry, University of Aveiro (Portugal)

    2015-01-15

    Vertically aligned carbon nanotubes (VACNTs) synthesized by Thermal Chemical Vapour Deposition (TCVD) were modified using an Ar:O{sub 2} (97:3) plasma to generate oxygen-containing functional groups on the surface for subsequent modification. X-ray photo-emission spectroscopy (XPS) and micro-Raman analyses confirmed the grafting of those functional groups onto the surface of the nanotubes as well as the removal of amorphous carbon produced and deposited on the VACNT forests during the CVD process. The plasma treated VACNT forests were further modified with 2-bromo-2-methylpropionyl bromide, an atom transfer radical polymerization (ATRP) initiator, to grow poly(methyl methacrylate) (PMMA) chains from the forests via ATRP. Scanning transmission electron microscopy (STEM) of the ensuing VACNT/PMMA composites confirmed the coating of the nanotube forests with the PMMA polymer. 3D scaffolds of polymeric composites with honeycomb like structure were then obtained. Compressive tests have shown that the VACNT/PMMA composite has higher compressive strength than the pristine forest. - Highlights: • Vertically aligned carbon nanotubes (VACNTs) were synthesized and plasma modified. • X-ray photo-emission and Raman spectroscopies confirmed the VACNTs modification. • Poly(methyl methacrylate) chains were grown via ATRP from the VACNTs. • STEM of the VACNT/PMMA composites confirmed that PMMA surrounds the nanotubes. • VACNT/PMMA composite has higher compressive strength compared to the pristine forest.

  4. 3D scaffolds from vertically aligned carbon nanotubes/poly(methyl methacrylate) composites via atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Tebikachew, Behabtu; Magina, Sandra; Mata, Diogo; Oliveira, Filipe J.; Silva, Rui F.; Barros-Timmons, Ana

    2015-01-01

    Vertically aligned carbon nanotubes (VACNTs) synthesized by Thermal Chemical Vapour Deposition (TCVD) were modified using an Ar:O 2 (97:3) plasma to generate oxygen-containing functional groups on the surface for subsequent modification. X-ray photo-emission spectroscopy (XPS) and micro-Raman analyses confirmed the grafting of those functional groups onto the surface of the nanotubes as well as the removal of amorphous carbon produced and deposited on the VACNT forests during the CVD process. The plasma treated VACNT forests were further modified with 2-bromo-2-methylpropionyl bromide, an atom transfer radical polymerization (ATRP) initiator, to grow poly(methyl methacrylate) (PMMA) chains from the forests via ATRP. Scanning transmission electron microscopy (STEM) of the ensuing VACNT/PMMA composites confirmed the coating of the nanotube forests with the PMMA polymer. 3D scaffolds of polymeric composites with honeycomb like structure were then obtained. Compressive tests have shown that the VACNT/PMMA composite has higher compressive strength than the pristine forest. - Highlights: • Vertically aligned carbon nanotubes (VACNTs) were synthesized and plasma modified. • X-ray photo-emission and Raman spectroscopies confirmed the VACNTs modification. • Poly(methyl methacrylate) chains were grown via ATRP from the VACNTs. • STEM of the VACNT/PMMA composites confirmed that PMMA surrounds the nanotubes. • VACNT/PMMA composite has higher compressive strength compared to the pristine forest

  5. Bio-compatibility of ion beam-modified and RGD-grafted polyethylene

    Czech Academy of Sciences Publication Activity Database

    Ročková-Hlaváčková, K.; Švorčík, V.; Bačáková, L.; Dvořánková, B.; Heitz, J.; Hnatowicz, Vladimír

    2004-01-01

    Roč. 225, č. 3 (2004), s. 275-282 ISSN 0168-583X R&D Projects: GA AV ČR IAA5011301 Institutional research plan: CEZ:AV0Z1048901 Keywords : modified polyethylene * ion beam * RGD grafting Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.997, year: 2004

  6. Immobilization of α-amylase onto poly(glycidyl methacrylate) grafted electrospun fibers by ATRP

    International Nuclear Information System (INIS)

    Oktay, Burcu; Demir, Serap; Kayaman-Apohan, Nilhan

    2015-01-01

    In this study, novel α-amylase immobilized poly(vinyl alcohol) (PVA) nanofibers were prepared. The PVA nanofiber surfaces were functionalized with 2-bromoisobutyryl bromide (BiBBr) and followed by surface initiated atom transfer radical polymerization (SI-ATRP) of glycidyl methacrylate (GMA). The morphology of the poly(glycidyl methacrylate) (PGMA) grafted PVA nanofibers was characterized by scanning electron microscopy (SEM). Also PGMA brushes were confirmed by X-ray photo electron microscopy (XPS). α-Amylase was immobilized in a one step process onto the PGMA grafted PVA nanofiber. The characteristic properties of the immobilized and free enzymes were examined. The thermal stability of the enzyme was improved and showed maximum activity at 37 °C by immobilization. pH values of the maximum activity of the free and immobilized enzymes were also found at 6.0 and 6.5, respectively. Free enzyme lost its activity completely within 15 days. The immobilized enzyme lost only 23.8% of its activity within 30 days. - Highlights: • Electrospun photocrosslinkable PVA nanofiber was prepared. • PGMA brushes were conducted on PVA nanofiber via SI-ATRP. • The immobilized enzyme showed maximum activity at pH 6.0 and at 37 °C. • Functionalized nanofibers may be used as promising supports for enzyme immobilization

  7. Surface-Initiated Graft Atom Transfer Radical Polymerization of Methyl Methacrylate from Chitin Nanofiber Macroinitiator under Dispersion Conditions

    Directory of Open Access Journals (Sweden)

    Ryo Endo

    2015-08-01

    Full Text Available Surface-initiated graft atom transfer radical polymerization (ATRP of methyl methacrylate (MMA from self-assembled chitin nanofibers (CNFs was performed under dispersion conditions. Self-assembled CNFs were initially prepared by regeneration from a chitin ion gel with 1-allyl-3-methylimidazolium bromide using methanol; the product was then converted into the chitin nanofiber macroinitiator by reaction with α-bromoisobutyryl bromide in a dispersion containing N,N-dimethylformamide. Surface-initiated graft ATRP of MMA from the initiating sites on the CNFs was subsequently carried out under dispersion conditions, followed by filtration to obtain the CNF-graft-polyMMA film. Analysis of the product confirmed the occurrence of the graft ATRP on the surface of the CNFs.

  8. 2,2,2-Trifluoroethyl methacrylate-graft-natural rubber: Synthesis and application as compatibilizer in natural rubber/fluoroelastomer blends

    Energy Technology Data Exchange (ETDEWEB)

    Hinchiranan, N., E-mail: nhn78@hotmail.com [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Wannako, P. [Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Paosawatyanyong, B. [Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Prasassarakich, P. [Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2013-05-15

    The incompatibility and immiscibility of natural rubber (NR)/fluoroelastomers (FKM) blends were improved by incorporation of a graft copolymer synthesized from the free radical graft copolymerization of 2,2,2-trifluoroethyl methacrylate (TFEM) onto NR initiated by benzoyl peroxide via a melt-mixing process. The grafting properties were investigated as functions of the initiator and monomer concentrations, reaction temperature and time. At the optimal conditions, the obtained graft NR (GNR) purified by Soxhlet extraction contained a maximum grafting efficiency of 1.34% with 49.1% monomer conversion. The structure of the purified GNR was analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and nuclear magnetic resonance spectroscopy ({sup 1}H NMR and {sup 19}F NMR). The gross GNR was then applied as the compatibilizer for NR/FKM vulcanizates (20/80 (w/w)) cured by peroxide vulcanization. The addition of GNR at 15 parts per hundred of rubber (phr) gave a vulcanizate with the highest tensile strength (9.93 MPa), some 5.31-fold higher than that of the incompatibilized one (1.87 MPa). This is likely to be due to the higher degree of homogeneity of the constituent phases in the GNR-compatibilized blends, as observed by scanning electron microscopy (SEM). The GNR-compatibilized NR/FKM vulcanizates were also resistant to gasohol E85 (85% (w/w) of ethanol). Highlights: ► 2,2,2-Trifluoroethyl methacrylate could be grafted on NR via melt-mixing process. ► Effect of grafting parameters on grafting efficiency and gel content was observed. ► NR/FKM containing graft NR had higher tensile strength than uncompatibilized ones. ► The compatibilized NR/FKM vulcanizates had higher gasohol-swelling resistance.

  9. Some investigations on the post radiation grafting of acrylamide onto polyethylene films

    International Nuclear Information System (INIS)

    Hegazy, E-S.A.; El-Dessouky, M.M.; El-Sharabasy, S.A.

    1986-01-01

    A study has been made on the post radiation grafting of aqueous acrylamide onto low density polyethylene film. It was found that the addition of 0.05 wt % Mohr's salt reduced effectively the homopolymerization of acrylamide and the grafting process was successfully achieved. The dependence of the grafting rate on the preirradiation dose and monomer concentration was found to be of 1.43 and 1.4 order, respectively. The overall activation energy for the graft polymerization was found to be 13.5 and 1.95 Kcal/mol below and above 45 0 C, respectively. Some properties of the graft co-polymer such as swelling behaviour, electrical conductivity, and reverse osmosis desalination of saline water (water flux and salt rejection), were also investigated and the possibility of its uses in the practical applications was discussed. (author)

  10. Self-assembly and omniphobic property of fluorinated unit end-functionalized poly(methyl methacrylate)

    Science.gov (United States)

    Junyan, Liang; Pingdi, Xu; Jingxian, Bao; Ling, He; Nan, Zhu

    2018-03-01

    The self-assembly behavior of fluorinated unit end-functionalized poly(methyl methacrylate) (PDFHM-ef-PMMA) in solution and its influence on the surface microstructure, elemental composition and omniphobic property of cast film was investigated in this work. Specifically, three mixed solutions of tetrahydrofuran (THF)/methanol (MeOH), THF/H2O and THF/H2O/MeOH in various compositions were employed separately as the selective solvents. In THF/MeOH solution, the aggregate morphologies of PDFHM-ef-PMMA changed gradually from core-shell spheres to worm, and then to elliptical vesicles as MeOH content increased. In THF/H2O solution, spherical and bowl-shaped aggregates with significantly larger sizes than those in THF/MeOH solution were favored despite lower H2O content. The further addition of MeOH to THF/H2O mixture could reduce the size of aggregate but hardly change original aggregate morphology. During the film formation process, those self-assembled aggregates in THF/MeOH solution fused with one another to form a smooth surface. When such surface was fully covered by fluorinated segments, the outstanding hexadecane and water slide-off properties and ink-resistant property required for antifouling application were demonstrated. Instead, the aggregates formed in THF/H2O/MeOH mixture were subjected to secondary aggregation of PDFHM-ef-PMMA chains during solvent evaporation, leading to the formation of a particulate film with poor adhesion towards glass plate and hexadecane-repellent property.

  11. A sol-gel-modified poly(methyl methacrylate) electrophoresis microchip with a hydrophilic channel wall.

    Science.gov (United States)

    Chen, Gang; Xu, Xuejiao; Lin, Yuehe; Wang, Joseph

    2007-01-01

    A sol-gel method was employed to fabricate a poly(methyl methacrylate) (PMMA) electrophoresis microchip that contains a hydrophilic channel wall. To fabricate such a device, tetraethoxysilane (TEOS) was injected into the PMMA channel and was allowed to diffuse into the surface layer for 24 h. After removing the excess TEOS, the channel was filled with an acidic solution for 3 h. Subsequently, the channel was flushed with water and was pretreated in an oven to obtain a sol-gel-modified PMMA microchip. The water contact angle for the sol-gel-modified PMMA was approximately 27.4 degrees compared with approximately 66.3 degrees for the pure PMMA. In addition, the electro-osmotic flow increased from 2.13x10(-4) cm2 V(-1) s(-1) for the native-PMMA channel to 4.86x10(-4) cm2 V(-1) s(-1) for the modified one. The analytical performance of the sol-gel-modified PMMA microchip was demonstrated for the electrophoretic separation of several purines, coupled with amperometric detection. The separation efficiency of uric acid increased to 74,882.3 m(-1) compared with 14,730.5 m(-1) for native-PMMA microchips. The result of this simple modification is a significant improvement in the performance of PMMA for microchip electrophoresis and microfluidic applications.

  12. Polyethylene/hydrophilic polymer blends for biomedical applications.

    Science.gov (United States)

    Brynda, E; Houska, M; Novikova, S P; Dobrova, N B

    1987-01-01

    Polyethylene blends with poly(2-hydroxyethyl methacrylate) [poly(HEMA)] or poly(2,3-dihydroxypropyl methacrylate) [poly(DHPMA)] were prepared by swelling polyethylene with HEMA or 2,3-epoxypropyl methacrylate (EPMA) and by polymerization of the respective monomers. Poly(EPMA) in blends was hydrolysed to poly(DHPMA) with acetic acid. The blends had similar surface and bulk compositions. Swelling with water and surface wettability were proportional to the content of the hydrophilic component; at the same content the polyethylene/poly(DHPMA) blends appeared more hydrophilic than those of polyethylene/poly(HEMA). Thrombus formation in contact with blood examined ex vivo and in vivo was considerably slower on the blends than on unmodified polyethylene. The tests indicated optima in composition; the best biological response was achieved with the blends containing about 14% poly(HEMA) or 16% poly(DHPMA).

  13. Bio-compatibility of ion beam-modified and RGD-grafted polyethylene

    Czech Academy of Sciences Publication Activity Database

    Ročková-Hlaváčková, K.; Švorčík, V.; Bačáková, Lucie; Dvořánková, B.; Heitz, J.; Hnatowicz, Vladimír

    2004-01-01

    Roč. 225, č. 3 (2004), s. 275-282 ISSN 0168-583X R&D Projects: GA AV ČR IAA5011301; GA ČR GA106/03/0514 Grant - others:CZ-AT(CZ) Aktion 2002-7 Institutional research plan: CEZ:AV0Z5011922 Keywords : modified polyethylene * ion beam * RGD grafting Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.997, year: 2004

  14. Grafting of glycidyl methacrylate/styrene onto polyvinyldine fluoride membranes for proton exchange fuel cell

    International Nuclear Information System (INIS)

    Abdel-Hady, E.E.; El-Toony, M.M.; Abdel-Hamed, M.O.

    2013-01-01

    Simultaneous gamma irradiation was used effectively for grafting facilitation of glycidyl methacrylate (GMA) and styrene (Sty) onto polyvinylidine fluoride (PVDF). Grafting percent was 122 when monomers ratio are 30% Sty and 70% GMA at 20 KGy gamma irradiation dose. Characterization of the membrane was performed using FT-IR, ion exchange capacity (IEC), water uptake. Mechanical behavior such as tensile strength was studied while morphological structure of the membrane was carried out by scan electron microscope (SEM). The membrane with degree of grafting 122% showed higher IEC (1.2 m mol/cm) than those of Nafion membrane with corresponding proton conductivity of 5.7 × 10 −2 S/cm similar to it. Operating the fuel cell unit showed higher voltage of the prepared membranes than that of Nafion 211. The prepared membranes stability for 300 h work approved their applicability from the cost benefit point of view

  15. Introduction of various amine groups onto polyethylene bead prepared by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Kim, M.S.; Choi, S.H.; Lee, K.P.

    2002-01-01

    Complete text of publication follows. Radiation-induced graft polymerization is a good method for modification of chemical and physical properties of polymeric materials because it can endow properties such as membrane quality, ion exchange, blood compatibility, dyeability, protein adsorption, and immobilization of bioactive materials. Polyethylene microbead is very useful material due to the following advantages; low price, simple purchase, high sensitivity, and simple analysis. On the other hand, the epoxy group of the glycidyl methacrylate (GMA) can easily be converted to the various functional groups such as amines, alcohols, phosphoric acid, sulfonic acid, and amino acid, etc. Cyclodextrin have been applied universally in various industries such as foods, cosmetics, pharmaceutical industry, analytical chemistry, and chemical industry. In order to obtain cyclodextrins, polyethylene microbead with the epoxy group were prepared by radiation-induced graft polymerization of GMA onto polyethylene microbead. The physical and chemical properties of the GMA-induced polyethylene microbeads were investigated by IR, thermal analysis (TGA/DSC), and SEM, respectively. Subsequently, the various amine groups such as diethylamine. diethylenetriamine, triethylamine, triethylenetetramine, and 1,6-hexanediamine were induced onto the epoxy group in polyethylene microbead. Finally, cyclodextrin glucanotransferase were immobilized onto polyethylene microbead with various amines under the various experimental conditions, such as pH, amin content, immobilization time, and etc. The activity of CGTase-immobilized polyethylene microbead was determined by Phenolphthein method. The production of the cyclodextrins from starch is in progress

  16. Management of an irradiated anophthalmic socket following dermis-fat graft rejection: A case report

    Directory of Open Access Journals (Sweden)

    Raizada Kuldeep

    2008-01-01

    Full Text Available Dermis-fat graft (DFG is often the only promising option in cases of severely contracted sockets. However, there is an increased risk of graft failure in irradiated sockets with decreased vascularity. In such difficult cases, repeat DFG implantation also has higher risks of graft failure. We describe an ingenious method of successful management of an irradiated anophthalmic socket following DFG infection and necrosis, with acceptable cosmetic results. At surgery, an orbital impression was taken with ophthalmic grade alginate. Based on this measurement, a custom-made stem pressure socket-expander made up of high density polymethyl methacrylate (PMMA was fitted, a week post surgery and kept in situ for six weeks. On review, the fornices had considerably deepened. The expander device was removed and the patient was now fitted with a custom-made thicker prosthesis made up of high-density PMMA. The patient has followed up for a year subsequently and the prosthesis has remained stable.

  17. Molecular Dynamics Simulations of Silica Nanoparticles Grafted with Poly(ethylene oxide) Oligomer Chains

    KAUST Repository

    Hong, Bingbing

    2012-03-01

    A molecular model of silica nanoparticles grafted with poly(ethylene oxide) oligomers has been developed for predicting the transport properties of nanoparticle organic-hybrid materials (NOHMs). Ungrafted silica nanoparticles in a medium of poly(ethylene oxide) oligomers were also simulated to clarify the effect of grafting on the dynamics of nanoparticles and chains. The model approximates nanoparticles as solid spheres and uses a united-atom representation for chains, including torsional and bond-bending interactions. The calculated viscosities from Green-Kubo relationships and temperature extrapolation are of the same order of magnitude as experimental data but show a smaller activation energy relative to real NOHMs systems. Grafted systems have higher viscosities, smaller diffusion coefficients, and slower chain dynamics than the ungrafted ones at high temperatures. At lower temperatures, grafted systems exhibit faster dynamics for both nanoparticles and chains relative to ungrafted systems, because of lower aggregation of particles and enhanced correlations between nanoparticles and chains. This agrees with the experimental observation that NOHMs have liquidlike behavior in the absence of a solvent. For both grafted and ungrafted systems at low temperatures, increasing chain length reduces the volume fraction of nanoparticles and accelerates the dynamics. However, at high temperatures, longer chains slow down nanoparticle diffusion. From the Stokes-Einstein relationship, it was determined that the coarse-grained treatment of nanoparticles leads to slip on the nanoparticle surfaces. Grafted systems obey the Stokes-Einstein relationship over the temperature range simulated, but ungrafted systems display deviations from it. © 2012 American Chemical Society.

  18. Graft polymerization of acrylic acid and methacrylic acid onto poly(vinylidene fluoride) powder in presence of metallic salt and sulfuric acid

    Science.gov (United States)

    Deng, Bo; Yu, Yang; Zhang, Bowu; Yang, Xuanxuan; Li, Linfan; Yu, Ming; Li, Jingye

    2011-02-01

    Poly(vinylidene fluoride) (PVDF) powder was grafted with acrylic acid (AAc) or methacrylic acid (MAA) by the pre-irradiation induced graft polymerization technique. The presence of graft chains was proven by FT-IR spectroscopy. The degree of grafting (DG) was calculated by the acid-base back titration method. The synergistic effect of acid and Mohr's salt on the grafting kinetics was examined. The results indicated that adding sulfuric acid and Mohr's salt simultaneously in AAc or MAA solutions led to a strong enhancement in the degree of grafting. The grafted PVDF powder was cast into microfiltration (MF) membranes using the phase inversion method and some properties of the obtained MF membranes were characterized.

  19. Graft polymerization of acrylic acid and methacrylic acid onto poly(vinylidene fluoride) powder in presence of metallic salt and sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Deng Bo [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China); Yu Yang; Zhang Bowu; Yang Xuanxuan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China); Graduate University of Chinese Academy of Sciences, No. 19, Yuquan Road, Shijingshan Dist., 100049 Beijing (China); Li Linfan; Yu Ming [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China); Li Jingye, E-mail: jingyeli@sinap.ac.c [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China)

    2011-02-15

    Poly(vinylidene fluoride) (PVDF) powder was grafted with acrylic acid (AAc) or methacrylic acid (MAA) by the pre-irradiation induced graft polymerization technique. The presence of graft chains was proven by FT-IR spectroscopy. The degree of grafting (DG) was calculated by the acid-base back titration method. The synergistic effect of acid and Mohr's salt on the grafting kinetics was examined. The results indicated that adding sulfuric acid and Mohr's salt simultaneously in AAc or MAA solutions led to a strong enhancement in the degree of grafting. The grafted PVDF powder was cast into microfiltration (MF) membranes using the phase inversion method and some properties of the obtained MF membranes were characterized.

  20. Graft polymerization of acrylic acid and methacrylic acid onto poly(vinylidene fluoride) powder in presence of metallic salt and sulfuric acid

    International Nuclear Information System (INIS)

    Deng Bo; Yu Yang; Zhang Bowu; Yang Xuanxuan; Li Linfan; Yu Ming; Li Jingye

    2011-01-01

    Poly(vinylidene fluoride) (PVDF) powder was grafted with acrylic acid (AAc) or methacrylic acid (MAA) by the pre-irradiation induced graft polymerization technique. The presence of graft chains was proven by FT-IR spectroscopy. The degree of grafting (DG) was calculated by the acid-base back titration method. The synergistic effect of acid and Mohr's salt on the grafting kinetics was examined. The results indicated that adding sulfuric acid and Mohr's salt simultaneously in AAc or MAA solutions led to a strong enhancement in the degree of grafting. The grafted PVDF powder was cast into microfiltration (MF) membranes using the phase inversion method and some properties of the obtained MF membranes were characterized.

  1. Cytocompatibility of polyethylene grafted with triethylenetetramine functionalized carbon nanoparticles

    Science.gov (United States)

    Žáková, Pavlína; Slepičková Kasálková, Nikola; Slepička, Petr; Kolská, Zdeňka; Karpíšková, Jana; Stibor, Ivan; Švorčík, Václav

    2017-11-01

    Various carbon nanostructures are widely researched as scaffolds for tissue engineering. We evaluated the surface properties and cell-substrate interactions of carbon nanoparticles functionalized with triethylenetetramine (CNPs) grafted polymer film. Two forms of polyethylene (HDPE, LDPE) were treated in an inert argon plasma discharge and, subsequently, grafted with CNPs. The surface properties were studied using multiple methods, including Raman spectroscopy, goniometry, atomic force microscopy, X-ray photoelectron spectroscopy and electrokinetic analysis. Cell-substrate interactions were determined in vitro by studying adhesion, proliferation and viability of vascular smooth muscle cells (VSMCs) from the aorta of a rat. Cell-substrate interactions on pristine and modified substrates were compared to standard tissue culture polystyrene. Our results show that CNPs affect surface morphology and wettability and therefore adhesion, proliferation and viability of cultured muscle cells.

  2. Crosslinked superhydrophobic films fabricated by simply casting poly(methyl methacrylate-butyl acrylate-hydroxyethyl methacrylate)-b-poly(perfluorohexylethyl methacrylate) solution

    Science.gov (United States)

    Wen, Xiufang; Ye, Chao; Cai, Zhiqi; Xu, Shouping; Pi, Pihui; Cheng, Jiang; Zhang, Lijuan; Qian, Yu

    2015-06-01

    This study focuses on the preparation of superhydrophobic films by crosslinkable polymer material-Poly(methyl methacrylate-butyl acrylate-hydroxyethyl methacrylate)-b-Poly(perfluorohexylethyl methacrylate) (P (MMA-BA-HEMA)-b-PFMA) with a simple one-step casting process. Nanoscale micelle particles with core-shell structure was obtained by dissolving the polymer and curing agent in the mixture of acetone and 1H, 1H, 5H octafluoropentyl-1,1,2,2 tetrafluoroethyl ether (FHT). Superhydrophobic films were fabricated by casting the micelle solution on the glass slides. By controlling the polymer concentration and acetone/FHT volume ratio, superhydrophobic polymer film with water contact angle of 153.2 ± 2.1° and sliding angle of 4° was obtained. By introducing a curing agent into the micelle solution, mechanical properties of the films can be improved. The adhension grade and hardness of the crosslinked superhydrophobic films reached 2 grade and 3H, respectively. The hydrophobicity is attributed to the synergistic effect of micro-submicro-nano-meter scale roughness by nanoscale micelle particles and low surface energy of fluoropolymer. This procedure makes it possible for widespread applications of superhydrophobic film due to its simplicity and practicability.

  3. Thermal, Mechanical and UV-Shielding Properties of Poly(Methyl Methacrylate/Cerium Dioxide Hybrid Systems Obtained by Melt Compounding

    Directory of Open Access Journals (Sweden)

    María A. Reyes-Acosta

    2015-09-01

    Full Text Available Thick and homogeneous hybrid film systems based on poly(methyl methacrylate (PMMA and CeO2 nanoparticles were synthesized using the melt compounding method to improve thermal stability, mechanical and UV-shielding properties, as well as to propose them for use in the multifunctional materials industry. The effect of the inorganic phase on these properties was assessed by using two different weight percentages of synthesized CeO2 nanoparticles (0.5 and 1.0 wt % with the sol–gel method and thermal treatment at different temperatures (120, 235, 400, 600 and 800 °C. Thereafter, the nanoceria powders were added to the polymer matrix by single screw extrusion. The absorption in the UV region was increased with the crystallite size of the CeO2 nanoparticles and the PMMA/CeO2 weight ratio. Due to the crystallinity of CeO2 nanoparticles, the thermal, mechanical and UV-shielding properties of the PMMA matrix were improved. The presence of CeO2 nanostructures exerts an influence on the mobility of PMMA chain segments, leading to a different glass transition temperature.

  4. Oral delivery of insulin using pH-sensitive hydrogels based on polyvinyl alcohol grafted with acrylic acid/methacrylic acid by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young-Chang [Radiation Application Research Division, Korea Atomic Energy Research Institute, Daejeon 305-600 (Korea, Republic of)]. E-mail: ycnho@kaeri.re.kr; Park, Sung-Eun [Radiation Application Research Division, Korea Atomic Energy Research Institute, Daejeon 305-600 (Korea, Republic of); Kim, Hyung-Il [College of Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Hwang, Taek-Sung [College of Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2005-07-01

    The pH-responsive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing in the small intestine. Hydrogels based on poly(vinyl alcohol) networks grafted with acrylic acid or methacrylic acid were prepared via a two-step process. Poly(vinyl alcohol) hydrogels were prepared by gamma ray irradiation (50 kGy) and then followed by grafting either acrylic acid or methacrylic acid onto this poly(vinyl alcohol) hydrogels with subsequent irradiation (5-20 kGy). These graft hydrogels showed pH-sensitive swelling behavior. These hydrogels were used as carrier for the controlled release of insulin. The in vitro release of insulin was observed for the insulin-loaded hydrogels in a simulated intestinal fluid (pH 6.8) but not in a simulated gastric fluid (pH 1.2). The release behavior of insulin in vivo in a rat model confirmed the effectiveness of the oral delivery of insulin to control the level of glucose.

  5. Oral delivery of insulin using pH-sensitive hydrogels based on polyvinyl alcohol grafted with acrylic acid/methacrylic acid by radiation

    International Nuclear Information System (INIS)

    Nho, Young-Chang; Park, Sung-Eun; Kim, Hyung-Il; Hwang, Taek-Sung

    2005-01-01

    The pH-responsive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing in the small intestine. Hydrogels based on poly(vinyl alcohol) networks grafted with acrylic acid or methacrylic acid were prepared via a two-step process. Poly(vinyl alcohol) hydrogels were prepared by gamma ray irradiation (50 kGy) and then followed by grafting either acrylic acid or methacrylic acid onto this poly(vinyl alcohol) hydrogels with subsequent irradiation (5-20 kGy). These graft hydrogels showed pH-sensitive swelling behavior. These hydrogels were used as carrier for the controlled release of insulin. The in vitro release of insulin was observed for the insulin-loaded hydrogels in a simulated intestinal fluid (pH 6.8) but not in a simulated gastric fluid (pH 1.2). The release behavior of insulin in vivo in a rat model confirmed the effectiveness of the oral delivery of insulin to control the level of glucose

  6. Bacterial Adhesion and Surface Roughness for Different Clinical Techniques for Acrylic Polymethyl Methacrylate

    Directory of Open Access Journals (Sweden)

    Lucas Costa de Medeiros Dantas

    2016-01-01

    Full Text Available This study sought to assess the effect of different surface finishing and polishing protocols on the surface roughness and bacterial adhesion (S. sanguinis to polymethyl methacrylates (PMMA. Fifty specimens were divided into 5 groups (n=10 according to their fabrication method and surface finishing protocol: LP (3 : 1 ratio and laboratory polishing, NF (Nealon technique and finishing, NP (Nealon technique and manual polishing, MF (3 : 1 ratio and manual finishing, and MP (3 : 1 ratio and manual polishing. For each group, five specimens were submitted to bacterial adhesion tests and analyzed by scanning electron microscopy (SEM. Two additional specimens were subjected to surface topography analysis by SEM and the remaining three specimens were subjected to surface roughness measurements. Data were compared by one-way ANOVA. The mean bacterial counts were as follows: NF, 19.6±3.05; MP, 5.36±2.08; NP, 4.96±1.93; MF, 7.36±2.45; and LP, 1.56±0.62 (CFU. The mean surface roughness values were as follows: NF, 3.23±0.15; MP, 0.52±0.05; NP, 0.60±0.08; MF, 2.69±0.12; and LP, 0.07±0.02 (μm. A reduction in the surface roughness was observed to be directly related to a decrease in bacterial adhesion. It was verified that the laboratory processing of PMMA might decrease the surface roughness and consequently the adhesion of S. sanguinis to this material.

  7. THE GRAFTING OF MALEIC-ANHYDRIDE ON HIGH-DENSITY POLYETHYLENE IN AN EXTRUDER

    NARCIS (Netherlands)

    GANZEVELD, KJ; JANSSEN, LPBM

    The grafting of maleic anhydride (MAH) on high density polyethylene in a counter-rotating twin screw extruder has been studied. As the reaction kinetics appear to be affected by mass transfer, good micro mixing in the extruder is important. Due to the competing mechanisms of increasing mixing and

  8. Tribological and mechanical investigation of acrylic-based nanocomposite coatings reinforced with PMMA-grafted-MWCNT

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kawaz, A. [UPR22/CNRS, Institut Charles Sadron, Université de Strasbourg, 23 Rue du Loess, BP 84047, F-67034 Strasbourg Cedex 2 (France); Rubin, A., E-mail: anne.rubin@ics-cnrs.unistra.fr [UPR22/CNRS, Institut Charles Sadron, Université de Strasbourg, 23 Rue du Loess, BP 84047, F-67034 Strasbourg Cedex 2 (France); Badi, N.; Blanck, C.; Jacomine, L. [UPR22/CNRS, Institut Charles Sadron, Université de Strasbourg, 23 Rue du Loess, BP 84047, F-67034 Strasbourg Cedex 2 (France); Janowska, I.; Pham-Huu, C. [Institute of Chemistry and Processes for Energy, Environment and Health (UMR 7515) CNRS - University of Strasbourg, 25 Rue Becquerel Strasbourg, 67087 Cedex 08 (France); Gauthier, C. [UPR22/CNRS, Institut Charles Sadron, Université de Strasbourg, 23 Rue du Loess, BP 84047, F-67034 Strasbourg Cedex 2 (France)

    2016-06-01

    The chemical functionalization of carbon nanotubes (CNTs) could improve their chemical compatibility. Poly(methyl methacrylate) (PMMA)-functionalized multi-walled carbon nanotubes (MWCNTs) are prepared by in situ atom transfer radical polymerization (ATRP) using a “grafting from” approach. It allows the control of the thickness of the polymer layer grafted on MWCNTs from two parameters: the feed ratio of MMA to MWCNT, the volume fraction of solvent to MMA. This work compared the effect of several PMMA-grafted-MWNCT fillers embedded into a PMMA matrix, PMMA-grafted-MWCNT/PMMA, and obtained by solution mixing technique. We studied the tribological performances of 20 μm coatings of these nanocomposites deposited on neat PMMA. The percentage of embedded fillers is kept low to maintain the transparency of the PMMA. The coefficient of friction was found to relatively decrease with the increase of the weight fraction of polymer grafted to the surface of MWCNT. Moreover the elastic modulus also increased with increasing the weight fraction of PMMA coated MWCNT. - Highlights: • Synthesis of MWCNT-PMMA nanoparticles by ATRP “grafting from” approach. • PMMA-grafted-MWCNT/PMMA coatings with good mechanical properties. • High tribological performance of PMMA-grafted-MWCNT/PMMA coatings.

  9. The effect of gamma radiation on hardness evolution in high density polyethylene at elevated temperatures

    International Nuclear Information System (INIS)

    Chen, Pei-Yun; Chen, C.C.; Harmon, Julie P.; Lee, Sanboh

    2014-01-01

    This research focuses on characterizing hardness evolution in irradiated high density polyethylene (HDPE) at elevated temperatures. Hardness increases with increasing gamma ray dose, annealing temperature and annealing time. The hardness change is attributed to the variation of defects in microstructure and molecular structure. The kinetics of defects that control the hardness are assumed to follow the first order structure relaxation. The experimental data are in good agreement with the predicted model. The rate constant follows the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The defects that control hardness in post-annealed HDPE increase with increasing dose and annealing temperature. The structure relaxation of HDPE has a lower energy of mixing in crystalline regions than in amorphous regions. Further, the energy of mixing for defects that influence hardness in HDPE is lower than those observed in polycarbonate (PC), poly(methyl methacrylate) (PMMA) and poly (hydroxyethyl methacrylate) (HEMA). This is due to the fact that polyethylene is a semi-crystalline material, while PC, PMMA and PHEMA are amorphous. - Highlights: • Hardness of HDPE increases with increasing gamma ray dose, annealing time and temperature. • The hardness change arises from defects in microstructure and molecular structure. • Defects affecting hardness follow a kinetics of structure relaxation. • The structure relaxation has a low energy of mixing in crystalline regime

  10. The effect of gamma radiation on hardness evolution in high density polyethylene at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Pei-Yun [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China); Chen, C.C. [Institute of Nuclear Energy Research, Longtan, Taoyuan 325, Taiwan (China); Harmon, Julie P. [Department of Chemistry, University of South Florida, Tampa, FL 33620 (United States); Lee, Sanboh, E-mail: sblee@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan (China)

    2014-08-01

    This research focuses on characterizing hardness evolution in irradiated high density polyethylene (HDPE) at elevated temperatures. Hardness increases with increasing gamma ray dose, annealing temperature and annealing time. The hardness change is attributed to the variation of defects in microstructure and molecular structure. The kinetics of defects that control the hardness are assumed to follow the first order structure relaxation. The experimental data are in good agreement with the predicted model. The rate constant follows the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The defects that control hardness in post-annealed HDPE increase with increasing dose and annealing temperature. The structure relaxation of HDPE has a lower energy of mixing in crystalline regions than in amorphous regions. Further, the energy of mixing for defects that influence hardness in HDPE is lower than those observed in polycarbonate (PC), poly(methyl methacrylate) (PMMA) and poly (hydroxyethyl methacrylate) (HEMA). This is due to the fact that polyethylene is a semi-crystalline material, while PC, PMMA and PHEMA are amorphous. - Highlights: • Hardness of HDPE increases with increasing gamma ray dose, annealing time and temperature. • The hardness change arises from defects in microstructure and molecular structure. • Defects affecting hardness follow a kinetics of structure relaxation. • The structure relaxation has a low energy of mixing in crystalline regime.

  11. Enhanced electrical conductivity of poly(methyl methacrylate) filled with graphene and in situ synthesized gold nanoparticles

    Science.gov (United States)

    Feng, Jie; Athanassiou, Athanassia; Bonaccorso, Francesco; Fragouli, Despina

    2018-06-01

    The improvement of the electrical conductivity of polymers by incorporating graphene has been intensively studied in recent years. To further boost the electrical conductivity, blending third-party additives into the polymer/graphene systems has been demonstrated as a viable strategy. Herein, we propose a simple route to increase the electrical conductivity of poly(methyl methacrylate) (PMMA)/graphene nanoplatelet (GnP) composites, by the in situ synthesis of gold nanoparticles directly into the solid film. In particular, PMMA, GnPs and a gold precursor are solution blended to form the composite films. The subsequent heat-induced formation of gold nanoparticles directly in the solid state film, cause the significant decrease of the percolation threshold of GnPs loading, from 3% to 1% by weight in the composite. This is attributed to the preferential formation of the gold nanoparticles onto the GnPs, with synergistic effects beneficial for the improvement of the electrical conductivity. The formation procedure of the gold nanoparticles, and their arrangement into the composite matrix are studied. We demonstrate that following this straightforward process it is possible to form nanocomposites able to conduct efficiently electric current even at low graphene loadings preserving at the same time the mechanical properties of the polymer matrix.

  12. Anhydric maleic functionalization and polyethylene glycol grafting of lactide-co-trimethylene carbonate copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Díaz, A.; Valle, L.; Franco, L. del [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Sarasua, J.R. [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain); Estrany, F. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J., E-mail: Jordi.Puiggali@upc.es [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain)

    2014-09-01

    Lactide and trimethylene carbonate copolymers were successfully grafted with polyethylene glycol via previous functionalization with maleic anhydride and using N,N′-diisopropylcarbodiimide as condensing agent. Maleinization led to moderate polymer degradation. Specifically, the weight average molecular weight decreased from 36,200 to 30,200 g/mol for the copolymer having 20 mol% of trimethylene carbonate units. Copolymers were characterized by differential scanning calorimetry, thermogravimetry and X-ray diffraction. Morphology of spherulites and lamellar crystals was evaluated with optical and atomic force microscopies, respectively. The studied copolymers were able to crystallize despite the randomness caused by the trimethylene carbonate units and the lateral groups. Contact angle measurements indicated that PEG grafted copolymers were more hydrophilic than parent copolymers. This feature justified that enzymatic degradation in lipase medium and proliferation of both epithelial-like and fibroblast-like cells were enhanced. Grafted copolymers were appropriate to prepare regular drug loaded microspheres by the oil-in-water emulsion method. Triclosan release from loaded microspheres was evaluated in two media. - Highlights: • Pegylated copolymers of lactide and trimethylene carbonate have been synthesized. • Grafting with polyethylene glycol was able via maleic anhydride functionalization. • Drug-loaded microspheres could be prepared from new pegylated copolymers. • Hydrophilicity of lactide/trimethylene carbonate copolymers increased by pegylation. • New pegylated copolymers supported cell adhesion and proliferation.

  13. Surface modification of polypropylene membrane by polyethylene glycol graft polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Abednejad, Atiye Sadat, E-mail: atiyeabednejad@gmail.com [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Amoabediny, Ghasem [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 63894-14179, Tehran (Iran, Islamic Republic of); Ghaee, Azadeh [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of)

    2014-09-01

    Polypropylene hollow fiber microporous membranes have been used in a wide range of applications, including blood oxygenator. The hydrophobic feature of the polypropylene surface causes membrane fouling. To minimize fouling, a modification consisting of three steps: surface activation in H{sub 2} and O{sub 2} plasma, membrane immersion in polyethylene glycol (PEG) and plasma graft polymerization was performed. The membranes were characterized by contact angle measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Oxygen transfer of modified membranes was also tested. The stability of grafted PEG was measured in water and in phosphate buffer saline (PBS) at 37 °C. Blood compatibility of modified surfaces was evaluated by the platelet adhesion method. Water contact angel reduction from 110° to 72° demonstrates the enhanced hydrophilicity, and XPS results verify the presence of oxygenated functional groups due to the peak existence in 286 eV as a result of PEG grafting. The results clearly indicate that plasma graft-polymerization of PEG is an effective way for antifouling improvement of polypropylene membranes. Also, the results show that oxygen transfer changes in PEG grafted membranes are not significant. - Highlights: • H{sub 2} and O{sub 2} plasma graft polymerization of PEG on polypropylene membrane was carried out. • Changes in surface properties were investigated by FTIR, XPS, SEM, and AFM. • Surface wettability enhanced as a result of poly ethylene glycol grafting. • PEG grafting degree increase causes reduction of fouling and adhesion.

  14. Radiolytic stabilization of industrial poly(methyl methacrylate); Estabilizacao radiolitica do poli(metacrilato de metila) industrial

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Katia Aparecida da Silva

    2005-03-15

    Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterilisable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its physical properties. Therefore, radiolytic stabilization of PMMA is important for to become it commercially radio sterilisable. In this work we investigated the radiolytic stabilization of PMMA by using HALS (Hindered Amine Light Stabilizer) additive, commercially used for photo and thermo oxidative stabilization of polymers. The investigation of the radiation-induced main chain scissions was carried out by viscometric method. The additive added to the polymer system at 0.3 % w/w promotes a molecular radioprotection of 61%. That means a reduction of G value (scissions/100 eV) from 2.6 to 1.0. In addition, the glassy transition temperature (Tg) of PMMA (no additive), significantly changed by radiation, does not change when PMMA (with additive) is irradiated. TGA analysis showed that the additive promotes thermal stability to the system, increasing decomposition temperature of PMMA. Spectroscopy analysis, FT-IR and RMN ({sup 1}H), showed that the radioprotector additive added to the system does not change the PMMA structure. Analysis on mechanical (tensile strength and elongation at break) and optical (yellowness index and refractive index) properties showed a good influence of the additive on polymer system. (author)

  15. The antifungal effects and mechanical properties of silver bromide/cationic polymer nano-composite-modified Poly-methyl methacrylate-based dental resin.

    Science.gov (United States)

    Zhang, Yu; Chen, Yin-Yan; Huang, Li; Chai, Zhi-Guo; Shen, Li-Juan; Xiao, Yu-Hong

    2017-05-08

    Poly-methyl methacrylate (PMMA)-based dental resins with strong and long-lasting antifungal properties are critical for the prevention of denture stomatitis. This study evaluated the antifungal effects on Candida albicans ATCC90028, the cytotoxicity toward human dental pulp cells (HDPCs), and the mechanical properties of a silver bromide/cationic polymer nano-composite (AgBr/NPVP)-modified PMMA-based dental resin. AgBr/NPVP was added to the PMMA resin at 0.1, 0.2, and 0.3 wt%, and PMMA resin without AgBr/NPVP served as the control. Fungal growth was inhibited on the AgBr/NPVP-modified PMMA resin compared to the control (P  0.05) between the experimental and control groups. These data indicate that the incorporation of AgBr/NPVP conferred strong and long-lasting antifungal effects against Candida albicans to the PMMA resin, and it has low toxicity toward HDPCs, and its mechanical properties were not significantly affected.

  16. Effect of mixing mode and emulsifying agents on micro/nanoencapsulation of low viscosity self-healing agents in polymethyl methacrylate shell

    Science.gov (United States)

    Ahangaran, Fatemeh; Navarchian, Amir H.; Hayaty, Mehran; Esmailpour, Karim

    2016-09-01

    In this study, epoxy prepolymer (EC 157) and pentaerythritol tetrakis (3-mercaptopropionate) (PETMP) as hardener were encapsulated separately in polymethyl methacrylate (PMMA) shells through an internal phase separation method. Chemical structures, morphologies, and thermal properties of healing agent micro/nanocapsules were characterized by Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), and thermal gravimetric analysis (TGA) respectively. The effects of encapsulation processing conditions such as mechanical mixing rate, ultrasonication, emulsifier type, and co-emulsifier concentration on encapsulation yield, capsule mean diameter and core content were studied using the Taguchi experimental design approach. The results indicated that the main significant factors affecting the yield of encapsulation are emulsifier type and ultrasonication. The most important factors which affect the mean diameter of capsules are emulsifier type and mechanical mixing rate. The core content was influenced by ultrasonication and mechanical mixing rate. The relative optimum condition of encapsulation was also determined using overall evaluation criteria.

  17. Polymethyl methacrylate (PMMA)-bismuth ferrite (BFO) nanocomposite: low loss and high dielectric constant materials with perceptible magnetic properties.

    Science.gov (United States)

    Tamboli, Mohaseen S; Palei, Prakash K; Patil, Santosh S; Kulkarni, Milind V; Maldar, Noormahmad N; Kale, Bharat B

    2014-09-21

    Herein, poly(methyl methacrylate)-bismuth ferrite (PMMA-BFO) nanocomposites were successfully prepared by an in situ polymerization method for the first time. Initially, the as prepared bismuth ferrite (BFO) nanoparticles were dispersed in the monomer, (methyl methacrylate) by sonication. Benzoyl peroxide was used to initiate the polymerization reaction in ethyl acetate medium. The nanocomposite films were subjected to X-ray diffraction analysis (XRD), (1)H NMR, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), infrared spectroscopy (IR), dielectric and magnetic characterizations. The dielectric measurement of the nanocomposites was investigated at a frequency range of 10 Hz to 1 MHz. It was found that the nanocomposites not only showed a significantly increased value of the dielectric constant with an increase in the loading percentage of BFO as compared to pure PMMA, but also exhibited low dielectric loss values over a wide range of frequencies. The values of the dielectric constant and dielectric loss of the PMMA-BFO5 (5% BFO loading) sample at 1 kHz frequency was found be ~14 and 0.037. The variation of the ferromagnetic response of the nanocomposite was consistent with the varying volume percentage of the nanoparticles. The remnant magnetization (Mr) and saturation magnetization (Ms) values of the composites were found to be enhanced by increasing the loading percentage of BFO. The value of Ms for PMMA-BFO5 was found to be ~6 emu g(-1). The prima facie observations suggest that the nanocomposite is a potential candidate for application in high dielectric constant capacitors. Significantly, based on its magnetic properties the composite will also be useful for use in hard disk components.

  18. Preparation of thermo-responsive graft copolymer by using a novel macro-RAFT agent and its application for drug delivery.

    Science.gov (United States)

    Song, Cunfeng; Yu, Shirong; Liu, Cheng; Deng, Yuanming; Xu, Yiting; Chen, Xiaoling; Dai, Lizong

    2016-05-01

    A methodology to prepare thermo-responsive graft copolymer by using a novel macro-RAFT agent was proposed. The macro-RAFT agent with pendant dithioester (ZC(S)SR) was facilely prepared via the combination of RAFT polymerization and esterification reaction. By means of ZC(S)SR-initiated RAFT polymerization, the thermo-responsive graft copolymer consisting of poly(methyl methacrylate-co-hydroxylethyl methacrylate) (P(MMA-co-HEMA)) backbone and hydrophilic poly(N-isopropylacrylamide) (PNIPAAm) side chains was constructed through the "grafting from" approach. The chemical compositions and molecular weight distributions of the synthesized polymers were respectively characterized by (1)H nuclear magnetic resonance ((1)H NMR) and gel permeation chromatography (GPC). Self-assembly behavior of the amphiphilic graft copolymers (P(MMA-co-HEMA)-g-PNIPAAm) was studied by transmission electron microscopy (TEM), dynamic light scattering (DLS) and spectrofluorimeter. The critical micelle concentration (CMC) value was 0.052 mg mL(-1). These micelles have thermo-responsibility and a low critical solution temperature (LCST) of 33.5°C. Further investigation indicated that the guest molecule release property of these micelles, which can be well described by a first-order kinetic model, was significantly affected by temperature. Besides, the micelles exhibited excellent biocompatibility and cellular uptake property. Hence, these micelles are considered to have potential application in controlled drug delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Enhancing both the mechanical and chemical properties of paper sheet by graft co-polymerization with acrylonitrile/methyl methacrylate

    Directory of Open Access Journals (Sweden)

    H.M. Abd El Salam

    2014-09-01

    Full Text Available The chemical graft copolymerization reaction of acrylonitrile (AN and methyl methacrylate (MMA binary mixture onto paper sheet was performed. The effect of initiator concentration, monomer concentration and temperature on the reaction rate was studied. The reaction rate equation of the graft copolymerization reaction is found to be RP = K2 [Initiator]0.795[Monomer]2.007. The apparent activation energy (Ea of the copolymerization reaction is found to be 75.01 kJ/mol. The infrared characteristic absorption bands for cellulosic paper structure and the paper gr-AN-MMA are investigated. Tensile break load, porosity and burst strength were measured for the grafted and pure paper sheet. It was found that the mechanical properties are improved by grafting copolymerization. The chemical resistance of the graft product against a strong acid a strong alkali, polar and nonpolar solvents was investigated. It was found that the resistance to these chemicals is enhanced by grafting.

  20. Radiation graft copolymerization of styrene with m/e and styrene with acrylic acid at highthyl methacryl dose rate

    International Nuclear Information System (INIS)

    Aliev, R.Eh.; Kabanov, B.Ya.

    1984-01-01

    Comparative investigation of radiation graft copolymerization of styrene with methyl methacrylate (MMA) and styrene with acrylic acid (AA) is carried out at considerably differing radiation dose rates. The monomer mixture was grafted to PE low density films at dose rates of 0.16, 0.25 Gy/s (1 MeV electron acceleration). The value of graft was 3-6 and 5-10%, respectively, for the styrene-MMA and styrene-AA systems. An essential difference in the dependences of the formed copolymer composition on initial monomer mixture composition is noticed. Difference in composition of graft polymers prepared at different dose rates is less for the systems with AA, than for systems with MMA. It is shown that at high dose rates in difference with low ones not only radical graft copolymerization of the styrene mixture with AA takes place, but a contribution of the graft styrene polymerization according to cation mechanism as well

  1. Removal of phosphate using copper-loaded polymeric ligand exchanger prepared by radiation grafting of polypropylene/polyethylene (PP/PE) nonwoven fabric

    Science.gov (United States)

    Barsbay, Murat; Kavaklı, Pınar Akkaş; Güven, Olgun

    2010-03-01

    A novel polymeric ligand exchanger (PLE) was prepared for the removal of phosphate ions from water. 2,2'-dipyridylamine (DPA), a bidentate ligand forming compound with high coordination capacity with a variety of metal ions was bound to glycidyl methacrylate (GMA) grafted polypropylene/polyethylene (PP/PE) nonwoven fabric synthesized by radiation-induced grafting technique. DPA attachment on epoxy ring of GMA units was tested in different solvents, i.e. methanol, ethanol, dioxane and dimethylsulfoxide (DMSO). The highest amount of modification was achieved in dioxane. In order to prepare the corresponding PLE for the removal of phosphate, DPA-immobilized fabric was loaded with Cu(II) ions. Phosphate adsorption experiments were performed in batch mode at different pH (5-9) and phosphate concentrations. The fabric was found to be effective for the removal of phosphate ions. At every stage of preparation and use, the nonwoven fabric was characterized by thermal (i.e. DSC and TGA) and spectroscopic (FTIR) methods. Competitive adsorption experiments were also carried out using two solutions with different concentration levels at pH 7 to see the effect of competing ions. Phosphate adsorption was found to be effective and selective from solutions having trace amounts of competitive anions. It is expected that the novel PLE synthesized can be used for the removal of phosphate ions in low concentrations over a large range of pH.

  2. Production of sorption-active polypropylene fibers by radiation-induce grafting of glycidyl methacrylate as a precursor monomer

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.; Kravets, L.I.

    2004-01-01

    Full text: Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 o C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. It was shown that for the samples with GMA grafting degree more than 50% two simultaneous processes take place during the sulfonation reaction, namely the incorporation of the sulfonate groups via opening of the GMA epoxy-rings as well as hydrolysis of the GMA epoxy-rings with the formation of α-glycol groups. Amine groups were incorporated by treatment of GMA-grafted polypropylene fibers with excess of diethylene triamine reagent. The conversion of the epoxy groups into the functional groups was investigated as a function of the degree of GMA grafting and reaction time. The ion-exchange characteristics of obtained sorption-active polypropylene fibers were determined

  3. Production of sorption-active polypropylene fiber by radiation-induce grafting of glycidyl methacrylate as a precursor monomer

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.; Kravets, L.I.

    2004-01-01

    Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 o C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. It was shown that for the samples with GMA grafting degree more than 50% two simultaneous processes take place during the sulfonation reaction, namely the incorporation of the sulfonate groups via opening of the GMA epoxy-rings as well as hydrolysis of the GMA epoxy-rings with the formation of α-glycol groups. Amine groups were incorporated by treatment of GMA-grafted polypropylene fibers with excess of diethylene triamine reagent. The conversion of the epoxy groups into the functional groups was investigated as a function of the degree of GMA grafting and reaction time. The ion-exchange characteristics of obtained sorption-active polypropylene fibers were determined. (author)

  4. Amine functionalization of cellulose surface grafted with glycidyl methacrylate by γ-initiated RAFT polymerization

    International Nuclear Information System (INIS)

    Barsbay, Murat; Güven, Olgun; Kodama, Yasko

    2016-01-01

    This study presents the functionalization of poly(glycidyl methacrylate) (PGMA) grafted cellulose filter paper by a model compound, ethylenediamine (EDA), through the epoxy groups of PGMA. Cellulose based copolymers were prepared via the radiation-induced and RAFT-mediated graft polymerization. The samples were characterized by ATR–FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis, contact angle measurements and scanning electron microscopy (SEM). An efficient modification density of around 1 mmol EDA/mg copolymer was attained within ca. 8 h, indicating that chemical composition of well-defined copolymers may further be tuned by appropriately selecting the reactive agents for use in many emerging fields. - Highlights: • Ethylenediamine (EDA) was immobilized to cellulose-g-PGMA copolymers. • FTIR, XPS, SEM, EA and CA measurements were used for characterization. • The useful qualities of the RAFT were combined with the versatility of PGMA.

  5. One-Pot Hybrid SnO2 /Poly(methyl methacrylate) Nanocomposite Formation through Pulsed Laser Irradiation.

    Science.gov (United States)

    Caputo, Gianvito; Scarpellini, Alice; Palazon, Francisco; Athanassiou, Athanassia; Fragouli, Despina

    2017-06-20

    The localized in situ formation of tin dioxide (SnO 2 ) nanoparticles embedded in poly(methyl methacrylate) (PMMA) films is presented. This is achieved by the photoinduced conversion of the tin acetate precursor included in polymeric films, through controlled UV or visible pulsed laser irradiation at λ=355 and 532 nm, respectively. The evolution of the formation of nanoparticles is followed by UV/Vis spectroscopy and shows that their growth is affected in different ways by the laser pulses at the two applied wavelengths. This, in combination with electron microscopy analysis, reveals that, depending on the irradiation wavelength, the size of the nanoparticles in the final nanocomposites differs. This difference is attributed to distinct mechanistic pathways that lead to the synthesis of small nanoparticles (from 1.5 to 4.5 nm) at λ=355 nm, whereas bigger ones (from 5 to 16 nm) are formed at λ=532 nm. At the same time, structural studies with both X-ray and electron diffraction measurements demonstrate the crystallinity of SnO 2 nanoparticles in both cases, whereas XPS analysis confirms the light-induced oxidation of tin acetate into SnO 2 . Taken all together, it is demonstrated that the pulsed laser irradiation at λ=355 and 532 nm leads to the formation of SnO 2 nanoparticles with defined features highly dispersed in PMMA solid matrices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Recent Advances and Future Perspectives for Reinforcement of Poly(methyl methacrylate Denture Base Materials: A Literature Review

    Directory of Open Access Journals (Sweden)

    Sahar Abdulrazzaq Naji

    2018-03-01

    Full Text Available Poly(methyl methacrylate (PMMA is the most common material used to fabricate complete and partial dentures. Despite its desirable properties, it cannot fulfill all mechanical requirements of prosthesis. Flexural fatigue due to repeated masticatory and high-impact forces caused by dropping are the main causes of denture fractures. In the past, different reinforcing agents such as rubbers, macro fibers, and fillers have been employed to improve the mechanical properties of denture base resins. Development of Nano dentistry has introduced new approaches for reinforcement of dental materials. Interest in nanostructure materials is driven by their high surface area to volume ratio, which enhances interfacial interaction and specific new biological, physical, and chemical properties. Researchers to reinforce PMMA resins have used Nanoparticles (Nps which were comprised of silver, Titania (TiO2, zirconia (ZrO2, alumina, and ceramic. Although different reports describe the use of nanofiber and nanotubes in dental composites, few studies have evaluated the reinforcement potential of nanofiber and nanotubes in PMMA denture base resins. The current article aims to review the different attempts to enhance the mechanical properties of denture base materials. We also focus on recent advances and potential future developments for reinforcement of the PMMA acrylic resins.

  7. Intensifying radiation induced grafting of 4-vinylpyridine/glycidyl methacrylate mixtures onto poly(ethylene-co-tetrafluoroethylene) films using ultrasound

    International Nuclear Information System (INIS)

    Nasef, Mohamed Mahmoud; Sithambaranathan, Paveswari; Ahmad, Arshad; Abouzari-lotf, Ebrahim

    2017-01-01

    A new ultrasound-aided method was used to enhance grafting of 4-vinylpyridine (4-VP) and glycidyl methacrylate (GMA) monomers mixtures onto electron beam (EB) irradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) film for the first time. The effects of reaction parameters such as absorbed dose, monomer concentration, reaction time on both of degree of grafting (DG) and grafting efficiency (GE) were investigated under sonication and conventional grafting at similar temperatures. Fourier transform infrared (FTIR) and atomic force microscopy (AFM) were used to monitor the impact of the applied ultrasound on composition and surfaces of the grafted films whereas 1 H-NMR was used to investigate composition of the grafting residues. The ultrasound-aided grafting of 4-VP/GMA was found to enhance both of DG% and GE remarkably. Moreover, it produced grafted ETFE films having smoother surfaces without homopolymer contamination compared to grafted films obtained from conventional grafting. The results of this study suggest that the use of ultrasound is a promising way for intensifying grafting process and improving its economy. - Highlights: • Grafting of 4-VP/GMA onto ETFE films was carried out with the aid of ultrasound. • Degree of grafting was found to be strongly dependent on reaction parameters. • Sonication remarkably enhanced the reaction kinetics and grafting efficiency. • Grafted films with smoother surfaces without homopolymer contamination were obtained. • Ultrasound aided grafting is superior to conventional one and promotes intensification.

  8. Properties of polymethyl methacrylate-based nanocomposites: Reinforced with ultra-long chitin nanofiber extracted from crab shells

    International Nuclear Information System (INIS)

    Chen, Chuchu; Li, Dagang; Hu, Qinqin; Wang, Ru

    2014-01-01

    Highlights: • Using waste crab shells to develop high-performance composites by simple method. • Combining the anatomic analysis of crab shell with the design of composite. • Introducing a 4-step all-mechanical treatment to prepare ultra-long chitin fiber. • Incorporation of chitin nanofiber improves properties of PMMA/Chitin composite. - Abstract: Ultra-long chitin nanofibers were incorporated into polymethyl methacrylate (PMMA) resin to prepared PMMA/Chitin nanocomposites with improved properties. Transmission electron microscopy (TEM) images showed that through the introduced 4-step all-mechanical treatment, the average aspect ratio of the obtained chitin fiber was up to 1000 with the length at dozens of micron range. Due to the laminated structure formed by “layer-by-layer” effect, tensile strength and Young’s modulus of the prepared composite were significantly enhanced after the filling of chitin nanofibers, as compared with neat PMMA. Light transmittance test indicated that increasing the fiber content causes little light scattering because the nano-scalar network which is smaller enough than the visible wavelength could well preserve the original transparency of PMMA. Furthermore, chitin nanofiber film with extremely low thermal expansion improved the thermal stability of PMMA in a great degree. This could lead to various commercial applications including flexible electronic printing, organic thin-film photovoltaic devices, and is a significantly environmental move towards the sustainable utilization of marine-river crab shell wastes

  9. Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach.

    Science.gov (United States)

    Saeb, Mohammad Reza; Rezaee, Babak; Shadman, Alireza; Formela, Krzysztof; Ahmadi, Zahed; Hemmati, Farkhondeh; Kermaniyan, Tayebeh Sadat; Mohammadi, Yousef

    2017-01-01

    Experimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration, and melt-processing time. An in-house code was developed based on artificial neural network that learns and mimics processing torque and grafting of glycidyl methacrylate (GMA) typical vinylic monomer on high-density polyethylene (HDPE). Application of response surface and desirability function enabled concurrent optimization of processing torque and GMA grafting on HDPE, through which we quantified for the first time competition between parallel reactions taking place during melt processing: (i) desirable grafting of GMA on HDPE; (ii) undesirable cross-linking of HDPE. The proposed robust mathematical modeling approach can precisely learn the behavior of grafting reaction of vinylic monomers on polyolefins and be placed into practice in finding exact operating condition needed for efficient grafting of reactive monomers on polyolefins.

  10. Mammography dosimetry using an in-house developed polymethyl methacrylate phantom

    International Nuclear Information System (INIS)

    Sharma, R.; Sharma, S. D.; Mayya, Y. S.; Chourasiya, G.

    2012-01-01

    Phantom-based measurements in mammography are well-established for quality assurance (QA) and quality control (QC) procedures involving equipment performance and comparisons of X-ray machines. Polymethyl methacrylate (PMMA) is among the best suitable materials for simulation of the breast. For carrying out QA/QC exercises in India, a mammographic PMMA phantom with engraved slots for keeping thermoluminescence dosemeters (TLD) has been developed. The radiation transmission property of the developed phantom was compared with the commercially available phantoms for verifying its suitability for mammography dosimetry. The breast entrance exposure (BEE), mean glandular dose (MGD), percentage depth dose (PDD), percentage surface dose distribution (PSDD), calibration testing of automatic exposure control (AEC) and density control function of a mammography machine were measured using this phantom. MGD was derived from the measured BEE following two different methodologies and the results were compared. The PDD and PSDD measurements were carried out using LiF: Mg, Cu, P chips. The in-house phantom was found comparable with the commercially available phantoms. The difference in the MGD values derived using two different methods were found in the range of 17.5-32.6 %. Measured depth ranges in the phantom lie between 0.32 and 0.40 cm for 75 % depth dose, 0.73 and 0.92 cm for 50 % depth dose, and 1.54 and 1.78 cm for 25 % depth dose. Higher PSDD value was observed towards chest wall edge side of the phantom, which is due to the orientation of cathode-anode axis along the chest wall to the nipple direction. Results obtained for AEC configuration testing shows that the observed mean optical density (O.D) of the phantom image was 1.59 and O.D difference for every successive increase in thickness of the phantom was within ±0.15 O.D. Under density control function testing, at -2 and -1 density settings, the variation in film image O.D was within ±0.15 O.D of the normal density

  11. Thermogravimetric studies on electron beam initiated grafting of triallyl cyanurate onto polyethylene

    International Nuclear Information System (INIS)

    Chaki, T.K.; Bhowmik, A.K.; Mukunda, P.G.; Majali, A.B.; Tikku, V.K.

    1993-01-01

    Low density polyethylene (LDPE) containing different levels of triallyl cyanurate (TAC) have been prepared in a Brabender Plasticorder at 120 degC. The moulded samples in the form of rectangular compression sheet were irradiated under electron beam accelerator with different irradiation doses. Thermogravimetric and derivative thermogravimetric analyses of the irradiated samples grafted with TAC have been carried out in order to explore the decomposition behaviour and kinetics of decomposition under nitrogen atmosphere. Initial decomposition temperature (Ti), temperature at which 50% weight loss takes place (T50), final decomposition temperature (Tf) and the kinetic parameters evaluated from TGA traces of samples at different radiation doses (constant TAC level) and at different levels of TAC (constant radiation dose) have been reported. The effect of radiation dose and TAC level on the grafting of TAC onto polyethylene have been explained on the basis of degradation characteristics of irradiated samples. Kinetic studies show that the degradation of the irradiated samples follow first order reaction kinetics. Activation energies of degradation have been determined using McCarty and Green's method. Activation energy of the irradiated samples increases with the increasing radiation dose and also with increasing level of TAC. (author). 3 tabs

  12. Improved surface hydrophilicity and antifouling property of polysulfone ultrafiltration membrane with poly(ethylene glycol) methyl ether methacrylate grafted graphene oxide nanofillers

    Science.gov (United States)

    Wang, Haidong; Lu, Xiaofei; Lu, Xinglin; Wang, Zhenghui; Ma, Jun; Wang, Panpan

    2017-12-01

    In this study, the GO-g-P(PEGMA) nanoplates were first synthesized by grafting hydrophilic poly (poly (ethylene glycol) methyl ether methacrylate) via surface-initiated atom transfer radical polymerization (SI-ATRP) method. A novel polysulfone (PSF) nanocomposite membrane using GO-g-P(PEGMA) nanoplates as nanofillers was fabricated. FTIR, TGA, 1H NMR, GPC and TEM were applied to verify the successful synthesis of the prepared nanoplates, while SEM, AFM, XPS, contact angle goniometry and filtration experiments were used to characterize the fabricated nanocomposite membranes. It was found that the new prepared nanofillers were well dispersed in organic PSF matrix, and the PSF/GO-g-P(PEGMA) nanocomposite membrane showed significant improvements in water flux and flux recovery rate. Based on the results of resistance-in-series model, the nanocomposite membrane exhibited superior resistance to the irreversible fouling. The excellent filtration and antifouling performance are attributed to the segregation of GO-g-P(PEMGA) nanofillers toward the membrane surface and the pore walls. Notably, the blended nanofillers appeared a stable retention in/on nanocomposite membrane after 30 days of washing time. The demonstrated method of synthesis GO-g-P(PEGMA) in this study can also be extended to preparation of other nanocomposite membrane in future.

  13. Radiation degradation of methyl methacrylate grafted natural rubber

    International Nuclear Information System (INIS)

    Perera, M.C.S.

    1998-01-01

    M G rubber is a mixture consisting of the graft copolymer and two home polymers. Natural rubber is known to undergo crosslinking during exposure to high energy radiation where as poly methyl methacrylate is a polymer where high energy radiation causes chain scission. It is interesting to determine how this partially miscible blend of scission and crosslinking polymers will behave under high energy radiation. Dynamic Mechanical Analysis (DMA) was used to study the variations in the glass transition regions during high energy treatment of the polymers. Another techniques that is available to obtain motional information and miscibility of blends is Nuclear Magnetic Resonance Spectroscopy (NMR).The present study is aimed at understanding the changes in the molecular structure of rubber when exposed to high energy radiation. The changes in the dynamic mechanical properties in the glass transition region and solid state NMR were made used of for this investigation. The data obtained from the DMA results were analysed to calculate the radiation chemical yields. The local dynamics were investigated with measurement of carbon relaxation times and molecular structure was studied with focus on the level of intermolecular mixing by proton relaxation times

  14. Radiolytic stabilization of poly(methyl methacrylate) using commercial additives; Estabilizacao radiolitica do poli(metacrilato de metila) usando aditivos comerciais

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Katia Aparecida da Silva

    2000-04-01

    Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterelizable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its mechanical properties. Therefore, radiolytic of PMMA is important for it to become commercially radiosterizable. In this work some commercial additives, originally used in photo-and thermo-oxidate stabilization of polymers, were tested. Only two additives, type HALS (Hindered Amine Light Stabilizer), denoted Scavenger, showed a good protective quality. The investigation of radiation-induced main scissions was carried out by viscosimetric method. The most effective additive, added to the polymer system at 0.3 w/w%, promotes a great molecular radioprotection of 93%. That means a reduction of G-value (scissions/100 eV) from 0.611 to 0.053. In addition, the glassy transition temperature (T{sub g}) of PMMA (no additive) significantly changed by radiation does not change when PMMA (with additive) is irradiated. The spectroscopy analysis, FT-IR and NMR ({sup 1}H), showed that the radioprotector added to the system does not change the PMMA structure. (author)

  15. Characterization and electrolytic cleaning of poly(methyl methacrylate) residues on transferred chemical vapor deposited graphene

    Science.gov (United States)

    Sun, Jianbo; Finklea, Harry O.; Liu, Yuxin

    2017-03-01

    Poly(methyl methacrylate) (PMMA) residue has long been a critical challenge for practical applications of the transferred chemical vapor deposited (CVD) graphene. Thermal annealing is empirically used for the removal of the PMMA residue; however experiments imply that there are still small amounts of residues left after thermal annealing which are hard to remove with conventional methods. In this paper, the thermal degradation of the PMMA residue upon annealing was studied by Raman spectroscopy. The study reveals that post-annealing residues are generated by the elimination of methoxycarbonyl side chains in PMMA and are believed to be absorbed on graphene via the π-π interaction between the conjugated unsaturated carbon segments and graphene. The post-annealing residues are difficult to remove by further annealing in a non-oxidative atmosphere due to their thermal and chemical stability. An electrolytic cleaning method was shown to be effective in removing these post-annealing residues while preserving the underlying graphene lattice based on Raman spectroscopy and atomic force microscopy studies. Additionally, a solution-gated field effect transistor was used to study the transport properties of the transferred CVD graphene before thermal annealing, after thermal annealing, and after electrolytic cleaning, respectively. The results show that the carrier mobility was significantly improved, and that the p-doping was reduced by removing PMMA residues and post-annealing residues. These studies provide a more in-depth understanding on the thermal annealing process for the removal of the PMMA residues from transferred CVD graphene and a new approach to remove the post-annealing residues, resulting in a residue-free graphene.

  16. Mechanical properties and antibiotic release characteristics of poly(methyl methacrylate)-based bone cement formulated with mesoporous silica nanoparticles.

    Science.gov (United States)

    Letchmanan, Kumaran; Shen, Shou-Cang; Ng, Wai Kiong; Kingshuk, Poddar; Shi, Zhilong; Wang, Wilson; Tan, Reginald B H

    2017-08-01

    The influence of mesoporous silica nanoparticles (MSNs) loaded with antibiotics on the mechanical properties of functional poly(methyl methacrylate)-(PMMA) based bone cements is investigated. The incorporation of MSNs to the bone cements (8.15wt%) shows no detrimental effects on the biomechanical properties of the freshly solidified bone cements. Importantly, there are no significant changes in the compression strength and bending modulus up to 6 months of aging in PBS buffer solution. The preserved mechanical properties of MSN-functionalized bone cements is attributed to the unchanged microstructures of the cements, as more than 96% of MSNs remains in the bone cement matrix to support the cement structures after 6 months of aging. In addition, the MSN-functionalized bone cements are able to increase the drug release of gentamicin (GTMC) significantly as compared with commercially available antibiotic-loaded bone cements. It can be attributed to the loaded nano-sized MSNs with uniform pore channels which build up an effective nano-network path enable the diffusion and extended release of GTMC. The combination of excellent mechanical properties and sustainable drug delivery efficiency demonstrates the potential applicability of MSN-functionalized PMMA bone cements for orthopedic surgery to prevent post-surgery infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A Polymethyl Methacrylate-Based Acrylic Dental Resin Surface Bound with a Photoreactive Polymer Inhibits Accumulation of Bacterial Plaque.

    Science.gov (United States)

    Fukunishi, Miya; Inoue, Yuuki; Morisaki, Hirobumi; Kuwata, Hirotaka; Ishihara, Kazuhiko; Baba, Kazuyoshi

    The aim of this study was to examine the ability of a poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butylmethacrylate-co-2-methacryloyloxyethyloxy-p-azidobenzoate) (PMBPAz) coating on polymethyl methacrylate (PMMA)-based dental resin to inhibit bacterial plaque formation, as well as the polymer's durability against water soaking and chemical exposure. Successful application of PMBPAz on PMMA surfaces was confirmed by x-ray photoelectron spectroscopy (XPS) and measuring the static air contact angle in water. The anti-adhesive effects to bacterial plaque were evaluated using Streptococcus mutans biofilm formation assay. The mechanical and chemical durabilities of the PMBPAz coating on the PMMA surfaces were examined using soaking and immersion tests, respectively. XPS signals for phosphorus and nitrogen atoms and hydrophilic status on PMMA surfaces treated with PMBPAz were observed, indicating the presence of the polymer on the substrates. The treated PMMA surfaces showed significant inhibition of S mutans biofilm formation compared to untreated surfaces. The PMBPAz coating was preserved after water soaking and chemical exposure. In addition, water soaking did not decrease the ability of treated PMMA to inhibit biofilm formation compared to treated PMMA specimens not subjected to water soaking. This study suggests that PMBPAz coating may represent a useful modification to PMMA surfaces for inhibiting denture plaque accumulation.

  18. Thermal and mechanical properties of novel nanocomposites from modified ordered mesoporous carbon FDU-15 and poly(methyl methacrylate)

    Science.gov (United States)

    Mohammadnezhad, Gholamhossein; Dinari, Mohammad; Soltani, Roozbeh; Bozorgmehr, Zahra

    2015-08-01

    With its well-ordered pore structure, high specific surface area and tunable pore diameters, ordered mesoporous carbons are suitable for applications in many areas of modern science and technology. In the present investigation, an ultrasonic irradiation was used for the modification of the mesoporous carbon FDU-15. Three nanocomposite films of the poly(methyl methacrylate) (PMMA) and modified FDU-15 were prepared by solution polymerization technique. The surface morphology and thermal and mechanical properties of the hybrid materials were evaluated by different methods. X-ray diffraction patterns showed that modified mesoporous FDU-15 had an ordered hexagonal mesostructure. Transmission electron microscopy (TEM) and field emission-scanning electron microscopy images confirmed the presence of large pores and a relatively ordered mesostructure for the functionalized materials. Thermogravimetric analysis data also revealed that the onset of decomposition temperature of the nanocomposites was higher than that of pristine PMMA, shifting toward higher temperatures as the amount of modified-FDU was increased. TEM images showed the well-ordered hexagonal arrays of mesopores FDU-15. Mechanical data indicated the improvement in the tensile strength and modulus with the modified FDU-15 loading. The film containing 1 wt.% of modified FDU-15 had a tensile strength of the order of 42 MPa, relative to the 28 MPa of the pristine PMMA.

  19. Adsorption Analysis of Lactoferrin to Titanium, Stainless Steel, Zirconia, and Polymethyl Methacrylate Using the Quartz Crystal Microbalance Method

    Directory of Open Access Journals (Sweden)

    Eiji Yoshida

    2016-01-01

    Full Text Available It is postulated that biofilm formation in the oral cavity causes some oral diseases. Lactoferrin is an antibacterial protein in saliva and an important defense factor against biofilm development. We analyzed the adsorbed amount of lactoferrin and the dissociation constant (Kd of lactoferrin to the surface of different dental materials using an equilibrium analysis technique in a 27 MHz quartz crystal microbalance (QCM measurement. Four different materials, titanium (Ti, stainless steel (SUS, zirconia (ZrO2 and polymethyl methacrylate (PMMA, were evaluated. These materials were coated onto QCM sensors and the surfaces characterized by atomic force microscopic observation, measurements of surface roughness, contact angles of water, and zeta potential. QCM measurements revealed that Ti and SUS showed a greater amount of lactoferrin adsorption than ZrO2 and PMMA. Surface roughness and zeta potential influenced the lactoferrin adsorption. On the contrary, the Kd value analysis indicated that the adsorbed lactoferrin bound less tightly to the Ti and SUS surfaces than to the ZrO2 and PMMA surfaces. The hydrophobic interaction between lactoferrin and ZrO2 and PMMA is presumed to participate in better binding of lactoferrin to ZrO2 and PMMA surfaces. It was revealed that lactoferrin adsorption behavior was influenced by the characteristics of the material surface.

  20. ESR investigations of radiation grafting of methyl methacrylate in aqueous emulsion onto chrome-tanned pig skin

    International Nuclear Information System (INIS)

    Pietrucha, K.; Pekala, W.; Plonka, A.

    1980-01-01

    Upon γ-irradiation at 77 K of the aqueous emulsions of methyl methacrylate embedded into chrome-tanned pig skins there are formed only the radicals of collagen and of 2-el-2-methylopropionic acid methyl ester. The presence of water in the system increases markedly the radiation yield of collagen radicals. During gradual heating up the polymerization reactions start and the macro-radical of growing polymer is observed. Chromium does not participate in the processes of initiation and grafting. (author)

  1. Superparamagnetic poly(methyl methacrylate) nanoparticles surface modified with folic acid presenting cell uptake mediated by endocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Feuser, Paulo Emilio [Federal University of Santa Catarina, Department of Chemical Engineering and Food Engineering (Brazil); Jacques, Amanda Virtuoso [Federal University of Santa Catarina, Department of Clinical Analyses (Brazil); Arévalo, Juan Marcelo Carpio; Rocha, Maria Eliane Merlin [Federal University of Paraná, Department of Biochemistry and Molecular Biology (Brazil); Santos-Silva, Maria Claudia dos [Federal University of Santa Catarina, Department of Clinical Analyses (Brazil); Sayer, Claudia; Araújo, Pedro H. Hermes de, E-mail: pedro.h.araujo@ufsc.br [Federal University of Santa Catarina, Department of Chemical Engineering and Food Engineering (Brazil)

    2016-04-15

    The encapsulation of superparamagnetic nanoparticles (MNPs) in polymeric nanoparticles (NPs) with modified surfaces can improve targeted delivery and induce cell death by hyperthermia. The goals of this study were to synthesize and characterize surface modified superparamagnetic poly(methyl methacrylate) with folic acid (FA) prepared by miniemulsion polymerization (MNPsPMMA-FA) and to evaluate their in vitro cytotoxicity and cellular uptake in non-tumor cells, murine fibroblast (L929) cells and tumor cells that overexpressed folate receptor (FR) β, and chronic myeloid leukemia cells in blast crisis (K562). Lastly, hemolysis assays were performed on human red blood cells. MNPsPMMA-FA presented an average mean diameter of 135 nm and a saturation magnetization (Ms) value of 37 emu/g of iron oxide, as well as superparamagnetic behavior. The MNPsPMMA-FA did not present cytotoxicity in L929 and K562 cells. Cellular uptake assays showed a higher uptake of MNPsPMMA-FA than MNPsPMMA in K562 cells when incubated at 37 °C. On the other hand, MNPsPMMA-FA showed a low uptake when endocytosis mechanisms were blocked at low temperature (4 °C), suggesting that the MNPsPMMA-FA uptake was mediated by endocytosis. High concentrations of MNPsPMMA-FA showed hemocompatibility when incubated for 24 h in human red blood cells. Therefore, our results suggest that these carrier systems can be an excellent alternative in targeted drug delivery via FR.

  2. Superparamagnetic poly(methyl methacrylate) nanoparticles surface modified with folic acid presenting cell uptake mediated by endocytosis

    International Nuclear Information System (INIS)

    Feuser, Paulo Emilio; Jacques, Amanda Virtuoso; Arévalo, Juan Marcelo Carpio; Rocha, Maria Eliane Merlin; Santos-Silva, Maria Claudia dos; Sayer, Claudia; Araújo, Pedro H. Hermes de

    2016-01-01

    The encapsulation of superparamagnetic nanoparticles (MNPs) in polymeric nanoparticles (NPs) with modified surfaces can improve targeted delivery and induce cell death by hyperthermia. The goals of this study were to synthesize and characterize surface modified superparamagnetic poly(methyl methacrylate) with folic acid (FA) prepared by miniemulsion polymerization (MNPsPMMA-FA) and to evaluate their in vitro cytotoxicity and cellular uptake in non-tumor cells, murine fibroblast (L929) cells and tumor cells that overexpressed folate receptor (FR) β, and chronic myeloid leukemia cells in blast crisis (K562). Lastly, hemolysis assays were performed on human red blood cells. MNPsPMMA-FA presented an average mean diameter of 135 nm and a saturation magnetization (Ms) value of 37 emu/g of iron oxide, as well as superparamagnetic behavior. The MNPsPMMA-FA did not present cytotoxicity in L929 and K562 cells. Cellular uptake assays showed a higher uptake of MNPsPMMA-FA than MNPsPMMA in K562 cells when incubated at 37 °C. On the other hand, MNPsPMMA-FA showed a low uptake when endocytosis mechanisms were blocked at low temperature (4 °C), suggesting that the MNPsPMMA-FA uptake was mediated by endocytosis. High concentrations of MNPsPMMA-FA showed hemocompatibility when incubated for 24 h in human red blood cells. Therefore, our results suggest that these carrier systems can be an excellent alternative in targeted drug delivery via FR.

  3. Superparamagnetic poly(methyl methacrylate) nanoparticles surface modified with folic acid presenting cell uptake mediated by endocytosis

    Science.gov (United States)

    Feuser, Paulo Emilio; Jacques, Amanda Virtuoso; Arévalo, Juan Marcelo Carpio; Rocha, Maria Eliane Merlin; dos Santos-Silva, Maria Claudia; Sayer, Claudia; de Araújo, Pedro H. Hermes

    2016-04-01

    The encapsulation of superparamagnetic nanoparticles (MNPs) in polymeric nanoparticles (NPs) with modified surfaces can improve targeted delivery and induce cell death by hyperthermia. The goals of this study were to synthesize and characterize surface modified superparamagnetic poly(methyl methacrylate) with folic acid (FA) prepared by miniemulsion polymerization (MNPsPMMA-FA) and to evaluate their in vitro cytotoxicity and cellular uptake in non-tumor cells, murine fibroblast (L929) cells and tumor cells that overexpressed folate receptor (FR) β, and chronic myeloid leukemia cells in blast crisis (K562). Lastly, hemolysis assays were performed on human red blood cells. MNPsPMMA-FA presented an average mean diameter of 135 nm and a saturation magnetization (Ms) value of 37 emu/g of iron oxide, as well as superparamagnetic behavior. The MNPsPMMA-FA did not present cytotoxicity in L929 and K562 cells. Cellular uptake assays showed a higher uptake of MNPsPMMA-FA than MNPsPMMA in K562 cells when incubated at 37 °C. On the other hand, MNPsPMMA-FA showed a low uptake when endocytosis mechanisms were blocked at low temperature (4 °C), suggesting that the MNPsPMMA-FA uptake was mediated by endocytosis. High concentrations of MNPsPMMA-FA showed hemocompatibility when incubated for 24 h in human red blood cells. Therefore, our results suggest that these carrier systems can be an excellent alternative in targeted drug delivery via FR.

  4. Steric Stabilization of “Charge-Free” Cellulose Nanowhiskers by Grafting of Poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Jun Araki

    2014-12-01

    Full Text Available A sterically stabilized aqueous suspension of “charge-free” cellulose nanowhiskers was prepared by hydrochloric acid hydrolysis of cotton powders and subsequent surface grafting of monomethoxy poly(ethylene glycol (mPEG. The preparation scheme included carboxylation of the terminal hydroxyl groups in mPEG via oxidation with silica gel particles carrying 2,2,6,6-tetramethyl-1-pyperidinyloxyl (TEMPO moieties and subsequent esterification between terminal carboxyls in mPEG and surface hydroxyl groups of cellulose nanowhiskers, mediated by 1,1'-carbonyldiimidazole (CDI in dimethyl sulfoxide or dimethylacetamide. Some of the prepared PEG-grafted samples showed remarkable flow birefringence and enhanced stability after 24 h, even in 0.1 M NaCl, suggesting successful steric stabilization by efficient mPEG grafting. Actual PEG grafting via ester linkages was confirmed by attenuated total reflectance-Fourier transform infrared spectrometry. In a typical example, the amount of grafted mPEG was estimated as ca. 0.3 g/g cellulose by two measurements, i.e., weight increase after grafting and weight loss after alkali cleavage of ester linkages. Transmission electron microscopy indicated unchanged nanowhisker morphology after mPEG grafting.

  5. Using mid-Infrared External Reflectance Spectroscopy to Distinguish Between Different Commercially Produced Poly[Methyl MethAcrylate] (PMMA) Samples - A Null Result

    Science.gov (United States)

    Fajardo, Mario; Neel, Christopher; Lacina, David

    2017-06-01

    We report (null) results of experiments testing the hypothesis that mid-infrared (mid-IR) spectroscopy can be used to distinguish samples of poly[methyl methacrylate] (PMMA) obtained from different commercial suppliers. This work was motivated by the desire for a simple non-destructive and non-invasive test for pre-sorting PMMA samples prior to use in shock and high-strain-rate experiments, where PMMA is commonly used as a standard material. We discuss: our choice of mid-IR external reflectance spectroscopy, our approach to recording reflectance spectra at near-normal (θ = 0 + / - 5 degree) incidence and for extracting the wavelength-weighted absorption spectrum from the raw reflectance data via a Kramers-Krönig analysis. We employ extensive signal, which necessitates adopting a special experimental protocol to mitigate the effects of instrumental drift. Finally, we report spectra of three PMMA samples with different commercial pedigrees, and show that they are virtually identical (+ / - 1 % error, 95% confidence); obviating the use of mid-IR reflectance spectroscopy to tell the samples apart.

  6. Synthesis of polymer hybrid latex poly(methyl methacrylate-co-butyl acrylate) with organo montmorillonite via miniemulsion polymerization method for barrier paper

    Science.gov (United States)

    Chanra, J.; Budianto, E.; Soegijono, B.

    2018-03-01

    Hybrid polymer latex based on combination of organic-inorganic materials, poly(methyl methacrylate-co-butyl acrylate) (PMMBA) and organo-montmorillonite (OMMT) were synthesized via miniemulsion polymerization technique. Modification of montmorillonite (MMT) through the incorporation of myristyltrimethylammonium bromide (MTAB) into the clay’s interlayer spaces were investigated by Small-Angle X-ray Scattering (SAXS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). Barrier property and thermal stability of polymer latex film sample were investigated through its Water Vapor Transmission Rate (WVTR) and Thermogravimetric Analysis (TGA). The results indicated that addition of OMMT as filler in PMMBA increased the barrier property and thermal stability of the latex film. Addition of 8.0% (wt) OMMT increased the barrier property and thermal stability. Miniemusion polymerization process with higher addition (>8.0 wt%) of OMMT resulting in high latex viscosity, particle size, and high amount of coagulum. The utilization of this hybrid polymer could benefits paper and board industries to produce high quality barrier paper for food packaging.

  7. Efficient Functionalization of Polyethylene Fibers for the Uranium Extraction from Seawater through Atom Transfer Radical Polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Neti, Venkata S. [Chemical; Das, Sadananda [Chemical; Brown, Suree [Department; Janke, Christopher J. [Materials; Kuo, Li-Jung [Marine; Gill, Gary A. [Marine; Dai, Sheng [Chemical; Department; Mayes, Richard T. [Chemical

    2017-09-14

    Brush-on-brush structures are proposed as one method to overcome support effects in grafted polymers. Utilizing glycidyl methacrylate (GMA) grafted on polyethylene (PE) fibers using radiation-induced graft polymerization (RIGP) provides a hydrophilic surface on the hydrophobic PE. When integrated with atom transfer radical polymerization (ATRP), the grafting of acrylonitrile (AN) and hydroxyethyl acrylate (HEA) can be controlled and manipulated more easily than with RIGP. Poly(acrylonitrile)-co-poly(hydroxyethyl acrylate) chains were grown via ATRP on PE-GMA fibers to generate an adsorbent for the extraction of uranium from seawater. The prepared adsorbents in this study demonstrated promise (159.9 g- U/kg of adsorbent) in laboratory screening tests using a high uranium concentration brine and 1.24 g-U/Kg of adsorbent in the filtered natural seawater in 21-days. The modest capacity in 21- days exceeds previous efforts to generate brush-on-brush adsorbents by ATRP while manipulating the apparent surface hydrophilicity of the trunk material (PE).

  8. Positronium formation at low temperatures: The role of trapped electrons

    DEFF Research Database (Denmark)

    Hirade, T.; Maurer, F.H.J.; Eldrup, Morten Mostgaard

    2000-01-01

    Measurements have been carried out of electron spin densities (by electron spin resonance technique) and positronium (Ps) formation probability as functions of Co-60 gamma-irradiation dose in poly(methyl methacrylate) and linear poly(ethylene) at 77 K. We observe a linear relationship between...

  9. Precise Measurement of Refractive Index and Absorption Coefficient of Near Millimeter Wave and Far Infrared Materials.

    Science.gov (United States)

    1987-06-01

    polyethylene. The plexiglass is a polymethyl methacrylate and the acrylic is a polymethacrylate . The polyamide(nylon) is made with adipic acid and hexamethylene...are made with acrylic acid . It was not sur- prizing to see both exhibiting similar absorption characteristics atleast 30 times higher than

  10. Average glandular dose in digital mammography and digital breast tomosynthesis: comparison of phantom and patient data

    NARCIS (Netherlands)

    Bouwman, R. W.; van Engen, R. E.; Young, K. C.; den Heeten, G. J.; Broeders, M. J. M.; Schopphoven, S.; Jeukens, C. R. L. P. N.; Veldkamp, W. J. H.; Dance, D. R.

    2015-01-01

    For the evaluation of the average glandular dose (AGD) in digital mammography (DM) and digital breast tomosynthesis (DBT) phantoms simulating standard model breasts are used. These phantoms consist of slabs of polymethyl methacrylate (PMMA) or a combination of PMMA and polyethylene (PE). In the last

  11. Improvement of pesticide adsorption capacity of cellulose fibre by high-energy irradiation-initiated grafting of glycidyl methacrylate

    International Nuclear Information System (INIS)

    Takacs, E.; Wojnarovits, L.; Borsa, J.

    2011-01-01

    Complete text of publication follows. Sustainable development needs renewable raw materials applied wherever possible. Cellulose is the most abundant biopolymer on earth; various modifications of its properties for special uses are important issues of the research. Some contaminations in wastewaters, e.g. pesticides, are hydrophobic materials; their adsorption on hydrophilic cellulose substrates is very limited. Cotton cellulose was grafted by glycidyl methacrylate in simultaneous grafting using gamma irradiation initiation. Water uptake of cellulose significantly decreased while adsorption of phenol and a pesticide molecule (2,4-dichlorophenoxyacetic acid: 2,4-D) increased upon grafting. As the figure shows on untreated sample even negative 2,4-D adsorption occurred, due to the selective adsorption of water from the solution; the adsorption did not approach its saturation value even in a 30 hours time period investigated. Saturation of phenol adsorption was achieved after 5-6 hours; adsorption equilibrium data of phenol fitted the Langmuir isotherm.

  12. Poly(ethylene glycol) and cyclodextrin-grafted chitosan: from methodologies to preparation and potential biotechnological applications

    Science.gov (United States)

    Campos, Estefânia V. R.; Oliveira, Jhones L.; Fraceto, Leonardo F.

    2017-11-01

    Chitosan, a polyaminosaccharide obtained by alkaline deacetylation of chitin, possesses useful properties including biodegradability, biocompatibility, low toxicity, and good miscibility with other polymers. It is extensively used in many applications in biology, medicine, agriculture, environmental protection, and the food and pharmaceutical industries. The amino and hydroxyl groups present in the chitosan backbone provide positions for modifications that are influenced by factors such as the molecular weight, viscosity, and type of chitosan, as well as the reaction conditions. The modification of chitosan by chemical methods is of interest because the basic chitosan skeleton is not modified and the process results in new or improved properties of the material. Among the chitosan derivatives, cyclodextrin-grafted chitosan and poly(ethylene glycol)-grafted chitosan are excellent candidates for a range of biomedical, environmental decontamination, and industrial purposes. This work discusses modifications including chitosan with attached cyclodextrin and poly(ethylene glycol), and the main applications of these chitosan derivatives in the biomedical field.

  13. Toward transparent nanocomposites based on polystyrene matrix and PMMA-grafted CeO2 nanoparticles.

    Science.gov (United States)

    Parlak, Onur; Demir, Mustafa M

    2011-11-01

    The association of transparent polymer and nanosized pigment particles offers attractive optical materials for various potential and existing applications. However, the particles embedded into polymers scatter light due to refractive index (RI) mismatch and reduce transparency of the resulting composite material. In this study, optical composites based on polystyrene (PS) matrix and poly(methyl methacrylate) (PMMA)-grafted CeO(2) hybrid particles were prepared. CeO(2) nanoparticles with an average diameter of 18 ± 8 nm were precipitated by treating Ce(NO(3))·6H(2)O with urea in the presence of a polymerizable surfactant, 3-methacyloxypropyltrimethoxy silane. PMMA chains were grafted on the surface of the nanoparticles upon free radical in situ solution polymerization. While blending of unmodified CeO(2) particles with PS resulted in opaque films, the transparency of the composite films was remarkably enhanced when prepared by PMMA-grafted CeO(2) hybrid particles, particularly those having a PMMA thickness of 9 nm. The improvement in transparency is presumably due to the reduction in RI mismatch between CeO(2) particles and the PS matrix when using PMMA chains at the interface.

  14. Study of microstructure of modified polyethylene films with acrylic and methacrylic acids, by positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Lopez C, R.

    1995-09-01

    Low density polyethylene (LDPE) was preirradiated with γ -rays and after some contact time with the monomers AA and MAA, suitable graft copolymers were obtained at different grafting grades. After their physical-chemistry characterization, the copolymers were studied using the Positron Annihilation Lifetime Spectroscopy (PALS). Owing to its sensitive and non-destructive nature PALS has proven to be very useful in studying free-volume properties -at the molecular level- during phase transitions in molecular solids, such as the graft copolymers of LDPE/AA and LDPE/MAA. Using PALS it was possible to detect the changes in the melting point of the LDPE as a function of the grafting degree, obtaining thus, valuable information about the microstructure of this kind of copolymers. The increase in the values of the o-Ps lifetime, was interpreted as suggesting that the melting transition is followed by a free-volume cavity expansion as the temperature increased. The o-Ps intensity of formation behavior is in accord with the distortions occurring in the electronic density surrounding the o-Ps as well as the changes in the number of cavities available to the formation of o-Ps. (Author)

  15. Synthesis of Well-Defined Polyethylene-Based 3-Miktoarm Star Copolymers and Terpolymers

    KAUST Repository

    Zhang, Zhen

    2016-03-25

    Novel polyethylene (PE)-based 3-miktoarm star copolymers A2B, (AB)2B and terpolymers (AC)2(BC) [A: PE; B, C: polystyrene (PS) or poly(methyl methacrylate) (PMMA)] were synthesized by combining boron chemistry, polyhomologation, and atom transfer radical polymerization (ATRP). 1,4-Pentadiene-3-yl 2-bromo-2-methylpropanoate was first synthesized followed by hydroboration with thexylborane to afford B-thexylboracyclanes, a multi-heterofunctional initiator with two initiating sites for polyhomologation and one for ATRP. After polyhomologation of dimethylsulfoxonium methylide the α,ω-dihydroxyl polyethylene (PE-OH)2-Br produced served as macroinitiator for the ATRP of styrene to afford (PE-OH)2-(PS-Br). Both (PE-OH)2-Br and (PE-OH)2-(PS-Br) were transformed to two new trifunctional macroinitiators (PE-Br)2-Br and (PE-Br)2-(PS-Br) through esterification reactions and used for the synthesis of (AB)2B and (AC)2(BC) 3-miktoarm star co/terpolymers. All intermediates and final products were characterized by 1H NMR, high temperature gel permeation chromatography (HT-GPC), and differential scanning calorimetry (DSC). The synthetic method is a general one and can be used for the synthesis of complex PE-based architectures by combination with other living/living-controlled polymerization techniques. © 2016 American Chemical Society.

  16. Radiation-Induced Grafting with One-Step Process of Waste Polyurethane onto High-Density Polyethylene

    Directory of Open Access Journals (Sweden)

    Jong-Seok Park

    2015-12-01

    Full Text Available The recycling of waste polyurethane (PU using radiation-induced grafting was investigated. The grafting of waste PU onto a high-density polyethylene (HDPE matrix was carried out using a radiation technique with maleic anhydride (MAH. HDPE pellets and PU powders were immersed in a MAH-acetone solution. Finally, the prepared mixtures were irradiated with an electron beam accelerator. The grafted composites were characterized by Fourier transformed infrared spectroscopy (FT-IR, surface morphology, and mechanical properties. To make a good composite, the improvement in compatibility between HDPE and PU is an important factor. Radiation-induced grafting increased interfacial adhesion between the PU domain and the HDPE matrix. When the absorbed dose was 75 kGy, the surface morphology of the irradiated PU/HDPE composite was nearly a smooth and single phase, and the elongation at break increased by approximately three times compared with that of non-irradiated PU/HDPE composite.

  17. Preparation of thermo-responsive graft copolymer by using a novel macro-RAFT agent and its application for drug delivery

    International Nuclear Information System (INIS)

    Song, Cunfeng; Yu, Shirong; Liu, Cheng; Deng, Yuanming; Xu, Yiting; Chen, Xiaoling; Dai, Lizong

    2016-01-01

    A methodology to prepare thermo-responsive graft copolymer by using a novel macro-RAFT agent was proposed. The macro-RAFT agent with pendant dithioester (ZC(S)SR) was facilely prepared via the combination of RAFT polymerization and esterification reaction. By means of ZC(S)SR-initiated RAFT polymerization, the thermo-responsive graft copolymer consisting of poly(methyl methacrylate-co-hydroxylethyl methacrylate) (P(MMA-co-HEMA)) backbone and hydrophilic poly(N-isopropylacrylamide) (PNIPAAm) side chains was constructed through the “grafting from” approach. The chemical compositions and molecular weight distributions of the synthesized polymers were respectively characterized by "1H nuclear magnetic resonance ("1H NMR) and gel permeation chromatography (GPC). Self-assembly behavior of the amphiphilic graft copolymers (P(MMA-co-HEMA)-g-PNIPAAm) was studied by transmission electron microscopy (TEM), dynamic light scattering (DLS) and spectrofluorimeter. The critical micelle concentration (CMC) value was 0.052 mg mL"−"1. These micelles have thermo-responsibility and a low critical solution temperature (LCST) of 33.5 °C. Further investigation indicated that the guest molecule release property of these micelles, which can be well described by a first-order kinetic model, was significantly affected by temperature. Besides, the micelles exhibited excellent biocompatibility and cellular uptake property. Hence, these micelles are considered to have potential application in controlled drug delivery. - Highlights: • A novel macro-RAFT agent with ZC(S)SR was used for preparing graft copolymer. • P(MMA-co-HEMA)-g-PNIPAAm was successful prepared via the “grafting from” approach. • Thermo-responsibility of the P(MMA-co-HEMA)-g-PNIPAAm micelles was investigated. • The drug release behavior of the P(MMA-co-HEMA)-g-PNIPAAm micelles was studied. • These micelles exhibited excellent biocompatibility and cellular uptake property.

  18. Preparation of thermo-responsive graft copolymer by using a novel macro-RAFT agent and its application for drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Song, Cunfeng; Yu, Shirong [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Liu, Cheng; Deng, Yuanming; Xu, Yiting [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen University, Xiamen 361005 (China); Chen, Xiaoling, E-mail: tinachen0628@163.com [Department of Endodontics, Xiamen Stomatology Hospital, Teaching Hospital of Fujian Medical University, Xiamen 361003 (China); Dai, Lizong, E-mail: lzdai@xmu.edu.cn [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen University, Xiamen 361005 (China)

    2016-05-01

    A methodology to prepare thermo-responsive graft copolymer by using a novel macro-RAFT agent was proposed. The macro-RAFT agent with pendant dithioester (ZC(S)SR) was facilely prepared via the combination of RAFT polymerization and esterification reaction. By means of ZC(S)SR-initiated RAFT polymerization, the thermo-responsive graft copolymer consisting of poly(methyl methacrylate-co-hydroxylethyl methacrylate) (P(MMA-co-HEMA)) backbone and hydrophilic poly(N-isopropylacrylamide) (PNIPAAm) side chains was constructed through the “grafting from” approach. The chemical compositions and molecular weight distributions of the synthesized polymers were respectively characterized by {sup 1}H nuclear magnetic resonance ({sup 1}H NMR) and gel permeation chromatography (GPC). Self-assembly behavior of the amphiphilic graft copolymers (P(MMA-co-HEMA)-g-PNIPAAm) was studied by transmission electron microscopy (TEM), dynamic light scattering (DLS) and spectrofluorimeter. The critical micelle concentration (CMC) value was 0.052 mg mL{sup −1}. These micelles have thermo-responsibility and a low critical solution temperature (LCST) of 33.5 °C. Further investigation indicated that the guest molecule release property of these micelles, which can be well described by a first-order kinetic model, was significantly affected by temperature. Besides, the micelles exhibited excellent biocompatibility and cellular uptake property. Hence, these micelles are considered to have potential application in controlled drug delivery. - Highlights: • A novel macro-RAFT agent with ZC(S)SR was used for preparing graft copolymer. • P(MMA-co-HEMA)-g-PNIPAAm was successful prepared via the “grafting from” approach. • Thermo-responsibility of the P(MMA-co-HEMA)-g-PNIPAAm micelles was investigated. • The drug release behavior of the P(MMA-co-HEMA)-g-PNIPAAm micelles was studied. • These micelles exhibited excellent biocompatibility and cellular uptake property.

  19. Effect of barium-coated halloysite nanotube addition on the cytocompatibility, mechanical and contrast properties of poly(methyl methacrylate) cement.

    Science.gov (United States)

    Jammalamadaka, Uday; Tappa, Karthik; Weisman, Jeffery A; Nicholson, James Connor; Mills, David K

    2017-01-01

    Halloysite nanotubes (HNTs) were investigated as a platform for tunable nanoparticle composition and enhanced opacity in poly(methyl methacrylate) (PMMA) bone cement. Halloysite has been widely used to increase the mechanical properties of various polymer matrices, in stark contrast to other fillers such as barium sulfate that provide opacity but also decrease mechanical strength. The present work describes a dry deposition method for successively fabricating barium sulfate nanoparticles onto the exterior surface of HNTs. A sintering process was used to coat the HNTs in barium sulfate. Barium sulfate-coated HNTs were then added to PMMA bone cement and the samples were tested for mechanical strength and tailored opacity correlated with the fabrication ratio and the amount of barium sulfate-coated HNTs added. The potential cytotoxic effect of barium-coated HNTs in PMMA cement was also tested on osteosarcoma cells. Barium-coated HNTs were found to be completely cytocompatible, and cell proliferation was not inhibited after exposure to the barium-coated HNTs embedded in PMMA cement. We demonstrate a simple method for the creation of barium-coated nanoparticles that imparted improved contrast and material properties to native PMMA. An easy and efficient method for coating clay nanotubes offers the potential for enhanced imaging by radiologists or orthopedic surgeons.

  20. Utilization of poly(methyl methacrylate – carbon nanotube and polystyrene – carbon nanotube in situ polymerized composites as masterbatches for melt mixing

    Directory of Open Access Journals (Sweden)

    M. Lahelin

    2012-10-01

    Full Text Available Carbon nanotubes (CNTs were melt mixed directly or by using an in situ polymerized masterbatch into a matrix polymer, polystyrene (PS or poly(methyl methacrylate (PMMA. The mechanical properties of the composites were mostly determined by the amount of CNTs, and not by the use of directly melt mixed CNTs or the use of the masterbatch. In contrast, the electrical resistivity of the composites was dependent on the manner in which the CNTs were added to the matrix polymer. When there was increased interfacial adhesion between the components, as for PS and the CNTs, the use of directly melt mixed CNTs gave better resistivity results. Without strong interactions between the CNTs and the matrix, as with PMMA and CNTs, the use of a tailored masterbatch had a significant effect on properties of the final composites. The molecular weight and viscosity of masterbatches can be varied and when the PMMA-masterbatch had optimized viscosity with respect to the PMMA matrix, electrical resistivity of the final composites decreased noticeably.

  1. Modification of polyetherurethane for biomedical application by radiation-induced grafting. I. Grafting procedure, determination of mechanical properties, and chemical modification of grafted films

    International Nuclear Information System (INIS)

    Jansen, B.; Ellinghorst, G.

    1985-01-01

    Radiation grafting of monomers onto suitable trunk polymers is a useful tool for tailoring new polymers for special purposes. This technique has been used in the past for the development of biocompatible materials, e.g., by grafting hydrogels onto mechanically stable polymers. In this first part of our work, the radiation grafting of hydrophilic or reactive monomers onto a polyetherurethane film using the pre-swelling technique is described. Following this technique the trunk polymer was swollen in the monomer before irradiation. As monomers 2-hydroxyethyl methacrylate (HEMA), 2,3-epoxypropyl methacrylate (GMA), 2,3-dihydroxypropyl methacrylate (GOMA), and acrylamide (AAm) were used. The kinetics of the grafting reactions were examined, and the distribution of the graft component inside the trunk polymer was investigated by means of infrared (IR) spectroscopy. Surface-grafted as well as bulk- and surface-grafted products could be obtained. The mechanical behavior of the grafted films--especially in the water-swollen state--was examined and compared with that of the pure trunk polymer. In nearly all cases it was found that the tensile strength sigma B and the elongation at break epsilon R decreases as the grafting yield increases. Modification of GMA- and AAm-grafted films via chemical reactions was performed to create new functional groups of biomedical interest. In this manner a diol structure, a carboxylic acid structure, and a sulfonic acid group could be introduced in the grafted polymer. The water uptake of such modified films is increased markedly when compared with that of the unmodified samples

  2. Laminin-Coated Poly(Methyl Methacrylate) (PMMA) Nanofiber Scaffold Facilitates the Enrichment of Skeletal Muscle Myoblast Population.

    Science.gov (United States)

    Zahari, Nor Kamalia; Idrus, Ruszymah Binti Haji; Chowdhury, Shiplu Roy

    2017-10-30

    Myoblasts, the contractile cells of skeletal muscle, have been invaluable for fundamental studies of muscle development and clinical applications for muscle loss. A major limitation to the myoblast-based therapeutic approach is contamination with non-contractile fibroblasts, which overgrow during cell expansion. To overcome these limitations, this study was carried out to establish a 3D culture environment using nanofiber scaffolds to enrich the myoblast population during construct formation. Poly(methyl methacrylate) (PMMA) nanofiber (PM) scaffolds were fabricated using electrospinning techniques and coated with extracellular matrix (ECM) proteins, such as collagen or laminin, in the presence or absence of genipin. A mixed population of myoblasts and fibroblasts was isolated from human skeletal muscle tissues and cultured on plain surfaces, as well as coated and non-coated PM scaffolds. PMMA can produce smooth fibers with an average diameter of 360 ± 50 nm. Adsorption of collagen and laminin on PM scaffolds is significantly enhanced in the presence of genipin, which introduces roughness to the nanofiber surface without affecting fiber diameter and mechanical properties. It was also demonstrated that laminin-coated PM scaffolds significantly enhance myoblast proliferation (0.0081 ± 0.0007 h -1 ) and migration (0.26 ± 0.04 μm/min), while collagen-coated PM scaffolds favors fibroblasts proliferation (0.0097 ± 0.0009 h -1 ) and migration (0.23 ± 0.03 μm/min). Consequently, the myoblast population was enriched on laminin-coated PM scaffolds throughout the culture process. Therefore, laminin coating of nanofiber scaffolds could be a potential scaffold for the development of a tissue-engineered muscle substitute.

  3. Synthesis, Characterization, and Aqueous Lubricating Properties of Amphiphilic Graft Copolymers Comprising 2-Methoxyethyl Acrylate

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Røn, Troels; Jankova Atanasova, Katja

    2014-01-01

    Amphiphilic anionic and cationic graft copolymers possessing poly(2-hydroxyethyl methacrylate) (PHEMA) backbone and poly(methacrylic acid), poly(2-methoxyethyl acrylate-co-methacrylic acid), and poly(2-methoxyethyl acrylate-co-2-(dimethylamino)ethyl methacrylate) grafts are constructed by merging...... of the corresponding monomers followed by deblocking reaction leads to well-defined amphiphiles with narrow molecular weight distributions (PDI ≤ 1.29) and varying content of methacrylic acid. The graft copolymers showed effective surface adsorption and lubrication for self-mated poly(dimethylsiloxane) (PDMS) contacts...

  4. Sonochemical synthesis of copper II sulfide nanoparticles and their use as radiolytic stabilizer in poly(methyl methacrylate) matrix

    International Nuclear Information System (INIS)

    Albuquerque, Marilia Cordeiro C. de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S.

    2011-01-01

    Copper (II) sulfide (CuS) was synthesized by sonochemical method. Cu S crystals with hexagonal structure exhibit irregular particles with an average size in the range of 250-900 nm. Commercial Poly(methyl methacrylate) (PMMA) containing CuS nanoparticles (PMMA/Cu) at concentrations of 0.15; 0.30; 0.45 and 0.60 wt% were investigated. The samples were irradiated with gamma radiation ( 60 Co) at room temperature and air atmosphere. The viscosity-average molar mass (Mv) was measured for PMMA systems without nanoparticles and with nanoparticles. Decrease in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of CuS nanoparticles at 0.3 wt% into PMMA matrix decreased the number of main chain scissions at dose of 25 kGy and was calculated a protection of 50% in PMMA matrix. CuS nanoparticles act as free radical scavenger into gamma-irradiated PMMA systems. Changes in the infrared spectra of PMMA systems indicate that polymer molecules interact with CuS nanoparticles. Improvement of mechanical properties was found for PMMA/Cu films. An increase of 38% of Young's modulus value and a decrease of 22% on the elongation at break value were recorded for PMMA/Cu films exposed to gamma irradiation. (author)

  5. Radiation-grafting of 2-hydroxyethylmethacrylate and oligo (ethylene glycol) methyl ether methacrylate onto polypropylene films by one step method

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Jimenez, Alejandro [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, Carmen; Concheiro, Angel [Departamento de Farmacia y Tecnologia Farmaceutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Bucio, Emilio, E-mail: ebucio@nucleares.unam.mx [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)

    2012-01-15

    Polypropylene films were modified with 2-hydroxyethylmethacrylate (HEMA) and oligo (ethylene glycol) methyl ether methacrylate (OEGMA) using the pre-irradiation method with gamma-rays (one step method). The effect of absorbed dose from 10 to 100 kGy, temperature (50, 60, and 70 {sup o}C), monomer concentration between 12.5% and 62.5%, monomers ratio from 10% to 90% and reaction time from 5 to 50 h; on the degree of grafting was determined. The grafted samples were analyzed by FTIR-ATR, TGA, DSC, swelling, and contact angle. Grafts onto polymeric films between 3% and 109% were obtained at doses from 10 to 100 kGy and a dose rate around 7.4 kGy/h. The graft percent increased with the content in HEMA in the HEMA:OEGMA feed mixture, which indicates a lower reactivity of OEGMA compared to HEMA. The hydrogel layer grafted on the polypropylene substrate increases the hydrophilicity of the surface and also provides certain temperature-responsiveness, which may be of interest for biomedical applications. - Highlights: > PP was grafted with a hydrogel layer applying the {gamma}-ray pre-irradiation method. > Effects of radiation dose, time, temperature and monomers concentration were evaluated. > Grafted layer increases the hydrophilicity of PP films. > HEMA and OEGMA grafted onto PP may be of interest for biomedical applications.

  6. A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation.

    Science.gov (United States)

    Wang, Chong-Qing; Wang, Hui; Huang, Luo-Luo

    2017-07-01

    A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO 4 ) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO 4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO 4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO 4 concentration 2mmolL -1 , treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL -1 . Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO 4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO 4 solution is feasible, enabling the process greener. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. The polymerisation of oligo(ethylene glycol methyl ether) methacrylate from a multifunctional poly(ethylene imine) derived amide : a stabiliser for the synthesis and dispersion of magnetite nanoparticles

    NARCIS (Netherlands)

    Kleine, A.; Altan, C.L.; Yarar, U.E.; Sommerdijk, N.A.J.M.; Bucak, S.; Holder, S.J.

    2014-01-01

    A facile synthetic route to poly(ethylene imine)-graft-poly(oligo(ethylene glycol methyl ether)) (PEI-graft-POEGMA) functionalised superparamagnetic magnetite nanoparticles is described. The polymerisation of OEGMA from a model molecular amide demonstrated the feasibility of POEGMA synthesis under

  8. Adhesion mapping of chemically modified and poly(ethylene oxide)-grafted glass surfaces

    OpenAIRE

    Jogikalmath, G.; Stuart, J.K.; Pungor, A.; Hlady, V.

    1999-01-01

    Two-dimensional mapping of the adhesion pull-off forces was used to study the origin of surface heterogeneity in the grafted poly(ethylene oxide) (PEO) layer. The variance of the pull-off forces measured over the μm-sized regions after each chemical step of modifying glass surfaces was taken to be a measure of the surface chemical heterogeneity. The attachment of γ-glycidoxypropyltrimethoxy silane (GPS) to glass decreased the pull-off forces relative to the clean glass and made the surface mo...

  9. A highly selective sorbent for removal of Cr(VI) from aqueous solutions based on Fe₃O₄/poly(methyl methacrylate) grafted Tragacanth gum nanocomposite: optimization by experimental design.

    Science.gov (United States)

    Sadeghi, Susan; Rad, Fatemeh Alavi; Moghaddam, Ali Zeraatkar

    2014-12-01

    In this work, poly(methyl methacrylate) grafted Tragacanth gum modified Fe3O4 magnetic nanoparticles (P(MMA)-g-TG-MNs) were developed for the selective removal of Cr(VI) species from aqueous solutions in the presence of Cr(III). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), a vibrating sample magnetometer (VSM), and thermo-gravimetric analysis (TGA). A screening study on operational variables was performed using a two-level full factorial design. Based on the analysis of variance (ANOVA) with 95% confidence limit, the significant variables were found. The central composite design (CCD) has also been employed for statistical modeling and analysis of the effects and interactions of significant variables dealing with the Cr(VI) uptake process by the developed sorbent. The predicted optimal conditions were situated at a pH of 5.5, contact time of 3.4 h, and 3.0 g L(-1) dose. The Langmuir, Freundlich, and Temkin isotherm models were used to describe the equilibrium sorption of Cr(VI) by the absorbent, and the Langmuir isotherm showed the best concordance as an equilibrium model. The adsorption process was followed by a pseudo-second-order kinetic model. Thermodynamic investigations showed that the biosorption process was spontaneous and exothermic. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Synthesis of block copolymers derived from N-trityl-(S)-serine and pyrene end-labeled poly(methyl methacrylate) or poly(N-isopropylacrylamide) via ATRP

    International Nuclear Information System (INIS)

    Buruiana, Emil C.; Podasca, Viorica; Buruiana, Tinca

    2012-01-01

    A new monomer bearing N-trityl-L-serine methyl ester in structure, methacryloyloxyethyl carbamoyloxy–N-trityl methyl serine (MTS), was prepared to be further polymerized by atom transfer radical polymerization (ATRP) with pyrene-endcapped poly(methyl methacrylate) (Py–PMMA–Br) or poly(N-isopropylacrylamide) (Py–PNIPA–Br). The resulting block copolymers, poly(methyl methacrylate–block–methacryloyloxyethyl carbamoyloxy–N-trityl methyl serine) (Py–PMMA–b–PMTS) and poly(N-isopropylacrylamide–block–methacryloyloxyethyl carbamoyloxy–N-trityl methyl serine (Py–PNIPA–b–PMTS) were characterized by 1 H ( 13 C) NMR, ultraviolet, FTIR and fluorescence spectroscopy, thermal analysis, differential scanning calorimetry (DSC), atomic force microscopy (AFM), scanning electron microscopy (SEM), and gel permeation chromatography (GPC) measurements. The chemical composition in Py–PMMA–b–PMTS was estimated from the 1 H NMR analysis that indicated a ratio of the repeating units of 46:19 (MMA:MTS). For the Py–PNIPA–b–PMTS the composition rate in the copolymer was 61:25 (NIPA:MTS). Quenching of the pyrene species with N,N-diethylaniline, nitrobenzene, nitrophenol, potassium iodide, p-nitrotoluene and tetracyanoquinodimethane (TCNQ) in DMF solution excited at 348 nm was evidenced, more efficiently being nitrophenol and TCNQ. In this case, the monomer emission at 388–409 nm underwent a significant decrease caused of an electron transfer from the electron-reach photoexcited pyrene molecule to the electron-deficient quenchers. - Highlights: ► Diblock copolymers combine the fluorescence of pyrene–PMMA (PNIPA) with the characteristics of PMTS. ► Such copolymers could be used for nitroderivatives detecting. ► UV/vis and fluorescence measurements give a good correlation for LCST of Py–PNIPA–Br.

  11. Influence of amine-grafted multi-walled carbon nanotubes on physical and rheological properties of PMMA-based nanocomposites

    International Nuclear Information System (INIS)

    Kim, Ki-Seok; Park, Soo-Jin

    2011-01-01

    In this work, poly(methyl methacrylate) (PMMA) was grafted onto amine treated multi-walled carbon nanotubes (NH-MWNTs) and the physical and rheological properties of the NH-MWNTs-g-PMMA nanocomposites were investigated. The graft reaction of NH-MWNTs and the PMMA matrix was confirmed from the change of the N 1S peaks, including those of amine oxygen and amide oxygen, by X-ray photoelectron spectroscopy (XPS). The thermal and mechanical properties of the NH-MWNT-g-PMMA nanocomposites were enhanced by the graft reaction between NH-MWNTs and PMMA matrix. In addition, the viscosity of the nanocomposites was increased with the addition of NH-MWNTs. Storage (G') and loss modulus (G'') were significantly increased by increase in the NH-MWNT content compared to acid-treated MWNTs/PMMA nanocomposites. This increase was attributed to the strong interaction by the grafting reaction between NH-MWNTs and the PMMA matrix. - Graphical abstract: This describes the increase of mechanical properties in NH-MWNTs-g-PMMA hybrid composites with different NH-MWNT contents. Highlights: → Aminized carbon nanotubes are used as reinforcement for poly(methylmethacrylate). → Poly(methylmethacrylate) is grafted on aminized carbon nanotubes by thermal reaction. → Grafting of carbon nanotubes and polymer provide enhanced physical properties. → It was due to the strong interaction between carbon nanotubes and polymer matrix.

  12. Post radiation grafting of vinyl acetate onto low density polyethylene films: preparation and properties of membrane

    International Nuclear Information System (INIS)

    Dessouki, A.M.

    1987-01-01

    Reverse osmosis membranes were prepared by the post radiation grafting of vinyl acetate onto low density polyethylene films. The factors affecting the grafting process such as radiation dose, monomer concentration and temperature on the grafting yield were studied. It was found that the dependence of the grafting rate on radiation intensity and monomer concentration was found to be of 0.64 and 1.4 order, respectively. The activation energy for this grafting system was calculated and found to be 4.45 kcal/mol above 30 0 C. Some properties of the grafted films such as specific electric resistance, water uptake, mechanical properties and thermal and chemical stability were investigated. An improvement in these properties was observed which makes possible the use of these membranes in some practical applications. The use of such membranes for reverse osmosis desalination of saline water was tested. The effect of operating time, degree of grafting and applied pressure on the water flux and salt rejection were determined. The results showed salt rejection percent over 90% and a reasonable water flux. A suitable degree of grafting of the membrane was determined as well as the optimum applied pressure. (author)

  13. Preparation and optical properties of indium tin oxide/epoxy nanocomposites with polyglycidyl methacrylate grafted nanoparticles.

    Science.gov (United States)

    Tao, Peng; Viswanath, Anand; Schadler, Linda S; Benicewicz, Brian C; Siegel, Richard W

    2011-09-01

    Visibly highly transparent indium tin oxide (ITO)/epoxy nanocomposites were prepared by dispersing polyglycidyl methacrylate (PGMA) grafted ITO nanoparticles into a commercial epoxy resin. The oleic acid stabilized, highly crystalline, and near monodisperse ITO nanoparticles were synthesized via a nonaqueous synthetic route with multigram batch quantities. An azido-phosphate ligand was synthesized and used to exchange with oleic acid on the ITO surface. The azide terminal group allows for the grafting of epoxy resin compatible PGMA polymer chains via Cu(I) catalyzed alkyne-azide "click" chemistry. Transmission electron microscopy (TEM) observation shows that PGMA grafted ITO particles were homogeneously dispersed within the epoxy matrix. Optical properties of ITO/epoxy nanocomposites with different ITO concentrations were studied with an ultraviolet-visible-near-infrared (UV-vis-NIR) spectrometer. All the ITO/epoxy nanocomposites show more than 90% optical transparency in the visible light range and absorption of UV light from 300 to 400 nm. In the near-infrared region, ITO/epoxy nanocomposites demonstrate low transmittance and the infrared (IR) transmission cutoff wavelength of the composites shifts toward the lower wavelength with increased ITO concentration. The ITO/epoxy nanocomposites were applied onto both glass and plastic substrates as visibly transparent and UV/IR opaque optical coatings.

  14. Adhesion, Growth, and Maturation of Vascular Smooth Muscle Cells on Low-Density Polyethylene Grafted with Bioactive Substances

    Directory of Open Access Journals (Sweden)

    Martin Parizek

    2013-01-01

    Full Text Available The attractiveness of synthetic polymers for cell colonization can be affected by physical, chemical, and biological modification of the polymer surface. In this study, low-density polyethylene (LDPE was treated by an Ar+ plasma discharge and then grafted with biologically active substances, namely, glycine (Gly, polyethylene glycol (PEG, bovine serum albumin (BSA, colloidal carbon particles (C, or BSA+C. All modifications increased the oxygen content, the wettability, and the surface free energy of the materials compared to the pristine LDPE, but these changes were most pronounced in LDPE with Gly or PEG, where all the three values were higher than in the only plasma-treated samples. When seeded with vascular smooth muscle cells (VSMCs, the Gly- or PEG-grafted samples increased mainly the spreading and concentration of focal adhesion proteins talin and vinculin in these cells. LDPE grafted with BSA or BSA+C showed a similar oxygen content and similar wettability, as the samples only treated with plasma, but the nano- and submicron-scale irregularities on their surface were more pronounced and of a different shape. These samples promoted predominantly the growth, the formation of a confluent layer, and phenotypic maturation of VSMC, demonstrated by higher concentrations of contractile proteins alpha-actin and SM1 and SM2 myosins. Thus, the behavior of VSMC on LDPE can be regulated by the type of bioactive substances that are grafted.

  15. Refractive microlenses produced by excimer laser machining of poly(methyl methacrylate)

    DEFF Research Database (Denmark)

    Jensen, Martin Frøhling; Krühne, Ulrich; H., L.

    2005-01-01

    A method has been developed whereby refractive microlenses can be produced in poly (methyl methacrylate) by excimer laser irradiation at λ = 248 nm. The lenses are formed by a combined photochemical and thermal process. The lenses are formed as depressions in the substrate material (negative foca...

  16. Radiation-Induced Graft Polymerization: Gamma Radiation and Electron Beam Technology for Materials Development

    International Nuclear Information System (INIS)

    Madrid, Jordan F.; Cabalar, Patrick Jay; Lopez, Girlie Eunice; Abad, Lucille V.

    2015-01-01

    The formation of functional hybrid materials by attaching polymer chains with advantageous tailored properties to the surface of a base polymer with desirable bulk character is an attractive application of graft copolymerization. Radiation-induced graft polymerization (RIGP) has been a popular approach for surface modification of polymers because of its merits over conventional chemical processes. RIGP, which proceeds primarily via free radical polymerization process, has the advantages such as simplicity, low cost, control over process and adjustment of the materials composition and structure. RIGP can be performed using either electron beam or gamma radiation and it can be applied to both synthetic and natural polymers. These merits make RIGP a popular research topic worldwide. Moreover, the materials synthesized and produced via RIGP has found applications, and were proposed to produce continuous impact, in the fields of medicine, agriculture, pollution remediation, rare earth and valuable metals recovery, fuel cell membrane synthesis and catalysis to name a few. From 2012 our group has performed electron beam and gamma radiation-induced graft polymerization of various monomers onto polymers of natural and synthetic origins (e.g. monomers - glycidyl methacrylate, styrene, acrylonitrile, N,N-dimethylaminoethyl methacrylate; base polymers – polyethylene/polypropylene nonwoven fabric, polypropylene nonwoven fabric pineapple fibers, cellulose nonwoven fabric microcrystalline cellulose). We tested these grafted materials for heavy metals (Pb, Ni, Cu) and organic molecule removal from aqueous solutions and E. coli activity (using reversible addition fragmentation chain transfer RAFT mediated grafting). The results clearly showed the success of materials modified via FIGP in these applications. Currently, we are studying the applications of grafted materials on treatment of waste waters from tanning industry, value addition to abaca nonwoven fabrics cell sheet

  17. Heats of adsorption of Pb on pristine and electron-irradiated poly(methyl methacrylate) by microcalorimetry

    Science.gov (United States)

    Diaz, S. F.; Zhu, J. F.; Harris, J. J. W.; Goetsch, P.; Merte, L. R.; Campbell, Charles T.

    2005-12-01

    The heat of adsorption and sticking probability were measured for Pb gas atoms adsorbing onto clean poly(methyl methacrylate) (PMMA) and electron-irradiated PMMA. The Pb atoms interact very weakly with the outgassed pristine PMMA surface, with a sticking probability of 0.02 ± 0.02. They deposit a heat into the PMMA of 12.7 ± 0.7 kJ/mol of dosed Pb, independent of Pb exposure up to 10 ML. This is slightly less than would be expected even if no Pb atoms stuck to the PMMA, but if they completely thermally accommodated to the substrate temperature during their collision with the surface. This proves that thermal accommodation is incomplete, highlighting the weakness of the Pb-PMMA interaction. Damaging the PMMA surface with electrons causes an increase in reactivity with Pb, as shown by increases in the initial heat of adsorption up to 134.0 ± 0.7 kJ/mol and the initial sticking probability up to 0.51 ± 0.01. These both increase with increasing coverage toward the values expected for Pb adsorption onto a bulk Pb surface with coverage dependences suggesting that metal islands nucleate at electron-induced defects, and grow into large 3D islands of low number density. This is the first calorimetric measurement of any metal adsorption energy onto any polymer surface wherein the sticking probability of the metal also was measured. The PMMA film was spin coated directly onto the heat detector, a pyroelectric polymer foil (polyvinylidene fluoride—PVDF) precoated on both sides with thin metal electrodes. It provides a detector sensitivity of ˜450 V/J with a pulse-to-pulse standard deviation of 1.2 kJ/mol and absolute accuracy within 2%.

  18. Deproteinised natural rubber latex grafted poly(dimethylaminoethyl methacrylate) - poly(vinyl alcohol) blend membranes: Synthesis, properties and application.

    Science.gov (United States)

    Jayadevan, Janisha; Alex, Rosamma; Gopalakrishnapanicker, Unnikrishnan

    2018-02-01

    Natural rubber latex was initially deproteinised (DNRL) and then subjected to physicochemical modifications to make high functional membranes for drug delivery applications. Initially, DNRL was prepared by incubating with urea, sodiumdodecylsulphate and acetone followed by centrifugation. The deproteinisation was confirmed by CHN analysis. The DNRL was then chemically modified by grafting (dimethylaminoethyl methacrylate) onto NR particles by using a redox initiator system viz; cumene hydroperoxide/tetraethylenepentamine, followed by dialysis for purification. The grafting was confirmed by dynamic light scattering, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The grafted system was blended with a hydrophilic adhesive polymer PVA and casted into membranes. The membranes after blending showed enhanced mechanical properties with a threshold concentration of PVA. The moisture uptake, swelling and water contact angle experiments indicated an increased hydrophilicity with an increased PVA content in the blend membranes. The grafted DNRL possessed significant antibacterial property which has been found to be retained in the blended form. A notable decrease in cytotoxicity was observed for the modified DNRL membranes than the bare DNRL membranes. The in-vitro drug release studies using rhodamine B as a model drug, confirmed the utility of the prepared membranes to function as a drug delivery matrix. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Separation of several alcohol-benzene mixtures by pervaporation through styrene graft polyethylene membranes

    International Nuclear Information System (INIS)

    Murata, Kenichi

    1989-01-01

    The permeation of pure liquids, such as methanol, ethanol, 1-propanol, 2-propanol and benzene, and the permeability and selectivity of 50 vol% binary mixtures of these alcohols and benzene were investigated by pervaporation technique. The used membranes (21%, 40%, and 72% graftings) were obtained by graft polymerization of styrene to polyethylene film (thickness 10 μm) by γ-radiation. The permeation rates of each of these alcohols and benzene were measured by pervaporation through the graft membranes. Those of these alcohols were very small as well as those through the original membrane. On the other hand, the permeabilities for benzene through the graft membranes were larger than that through the original membrane. The temperature dependence of the permeation rate for benzene was expressed by Arrhenius-type relationships, and the apparent activation energies were calculated to be 10.7 (21%), 10.2 (40%) and 10.0 (72%) kcal/mol. In the permeation of 50 vol% several alcohol-benzene mixtures, the permeabilities through the graft membranes were also larger than that through the original membrane, and increased with the grafting. The temperature dependence of the permeation for these mixtures was showed by Arrhenius relationships, and the apparent activation energies were calculated to be in the range of 8.4∼11.0 kcal/mol. The separation factors of the graft membranes calculated from composition of the permeates were always smaller than that of the original membrane, but became larger with increase of molecular volume of alcohol in alcohol-benzene mixtures. (author)

  20. Preparation of the copolymer of acrylic acid and acrylamide grafted onto polyethylene and its complexation with samarium ion

    International Nuclear Information System (INIS)

    Kido, Junji; Akiba, Hideto; Nishide, Hiroyuki; Tsuchida, Eishun; Omichi, Hideki; Okamoto, Jiro.

    1986-01-01

    Acrylic acid (AA) and acrylamide (AAm) were graft-copolymerized onto polyethylene (PE) powder by the pre-irradiation method. Complex formation constants of Sm ion with the PE powder grafted with both AA and AAm (PE-g-(AA-co-AAm)) were larger than those with the PE powder grafted with AA (PE-g-AA). Sm ion was efficiently separated from the solution containing both Sm ion and a transition metal ion such as Cu ion. Even after the γ-ray irradiation on PE-g-(AA-co-AAm) and PE-g-AA, the adsorption did not decrease. (author)

  1. Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

    International Nuclear Information System (INIS)

    Al Meslmani, Bassam M.; Mahmoud, Gihan F.; Leichtweiß, Thomas; Strehlow, Boris; Sommer, Frank O.; Lohoff, Michael D.; Bakowsky, Udo

    2016-01-01

    Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm"2, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

  2. Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Al Meslmani, Bassam M., E-mail: almeslmanib@yahoo.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Mahmoud, Gihan F., E-mail: mahmoudg@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Department of Pharmaceutics and Industrial Pharmacy, Helwan University, Ain Helwan, 11795 Cairo (Egypt); Leichtweiß, Thomas, E-mail: Thomas.Leichtweiss@phys.Chemie.uni-giessen.de [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Strehlow, Boris, E-mail: strehlo4@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Sommer, Frank O., E-mail: sommerf@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Lohoff, Michael D., E-mail: lohoff@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Bakowsky, Udo, E-mail: ubakowsky@aol.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany)

    2016-01-01

    Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm{sup 2}, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

  3. Silica-Assisted Nucleation of Polymer Foam Cells with Nanoscopic Dimensions : Impact of Particle Size, Line Tension, and Surface Functionality

    NARCIS (Netherlands)

    Liu, Shanqiu; Eijkelenkamp, Rik; Duvigneau, Joost; Vancso, G. Julius

    2017-01-01

    Core-shell nanoparticles consisting of silica as core and surface-grafted poly(dimethylsiloxane) (PDMS) as shell with different diameters were prepared and used as heterogeneous nucleation agents to obtain CO2-blown poly(methyl methacrylate) (PMMA) nanocomposite foams. PDMS was selected as the shell

  4. Laminin-Coated Poly(Methyl Methacrylate (PMMA Nanofiber Scaffold Facilitates the Enrichment of Skeletal Muscle Myoblast Population

    Directory of Open Access Journals (Sweden)

    Nor Kamalia Zahari

    2017-10-01

    Full Text Available Myoblasts, the contractile cells of skeletal muscle, have been invaluable for fundamental studies of muscle development and clinical applications for muscle loss. A major limitation to the myoblast-based therapeutic approach is contamination with non-contractile fibroblasts, which overgrow during cell expansion. To overcome these limitations, this study was carried out to establish a 3D culture environment using nanofiber scaffolds to enrich the myoblast population during construct formation. Poly(methyl methacrylate (PMMA nanofiber (PM scaffolds were fabricated using electrospinning techniques and coated with extracellular matrix (ECM proteins, such as collagen or laminin, in the presence or absence of genipin. A mixed population of myoblasts and fibroblasts was isolated from human skeletal muscle tissues and cultured on plain surfaces, as well as coated and non-coated PM scaffolds. PMMA can produce smooth fibers with an average diameter of 360 ± 50 nm. Adsorption of collagen and laminin on PM scaffolds is significantly enhanced in the presence of genipin, which introduces roughness to the nanofiber surface without affecting fiber diameter and mechanical properties. It was also demonstrated that laminin-coated PM scaffolds significantly enhance myoblast proliferation (0.0081 ± 0.0007 h−1 and migration (0.26 ± 0.04 μm/min, while collagen-coated PM scaffolds favors fibroblasts proliferation (0.0097 ± 0.0009 h−1 and migration (0.23 ± 0.03 μm/min. Consequently, the myoblast population was enriched on laminin-coated PM scaffolds throughout the culture process. Therefore, laminin coating of nanofiber scaffolds could be a potential scaffold for the development of a tissue-engineered muscle substitute.

  5. Development of an amine-type adsorbent by electron beam-induced emulsion grafting of glycidyl methacrylate onto a nonwoven fabric

    International Nuclear Information System (INIS)

    Madrid, Jordan; Ueki, Yuji; Seko, Noriaki

    2013-01-01

    In the recent years, radiation-induced graft polymerization of various monomers onto different types of trunk polymers have been extensively used for researchers on adsorbents for cations, anions and different compounds, battery separators, antibacterial bandages, protein separators, and fuel cell applications. Some of these technologies were transferred to end-users and eventually commercialized. In most of these studies, a post-grafting reaction is performed to introduced chemical groups that impart functionality to the grafted material. In this paper, pre-irradiation technique was used for emulsion grafting of glycidyl methacrylate (GMA) onto an electron beam irradiated abaca-polyester nonwoven fabric (APNWF). The dependence of degree of grafting (Dg), calculated from the weight of APNWF before and after grafting, on irradiation dose, reaction time and monomer concentration were studies. After 50 kGy irradiation with 2 MeV electron beam and subsequent 3-hour reaction with an emulsion consisting of 5% GMA and 0.5% polyoxyethylene sorbitan monolaurate (Tween 20) surfactant in deionized water at 40 degree centegrade, a grafted APNWF with a Dg greater than 150% was obtained. The GMA grafted APNWF was further modified by reaction with ethylenediamine (EDA) in isopropyl alcohol at 60 degree centegrade to introduce amine functional groups. A 3-hour reaction with 50% EDA resulted to an amine group density of 2.7 mmole/gram-adsorbent. Preliminary batch adsorption experiments using Cu 2+ and Ni 2+ ions in aqueous solutions show that the adsorption capacity of the grafted adsorbent is four times greater for Cu 2+ ions compared to Ni 2+ ions. (author)

  6. Radiation induced graft copolymerization of n-butyl acrylate onto poly(ethylene terephthalate) (PET) films and thermal properties of the obtained graft copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Ping Xiang [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang Mozhen, E-mail: pstwmz@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ge Xuewu, E-mail: xwge@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2011-05-15

    n-Butyl acrylate (BA) was successfully grafted onto poly(ethylene terephthalate) (PET) film using simultaneous radiation induced graft copolymerization with gamma rays. When BA concentration ranges from 20% to 30%, the Degree of Grafting (DG), measured by gravimetry and {sup 1}H NMR, increases with the monomer concentration and absorbed dose, but decreases with dose rate from 0.83 to 2.53 kGy/h. The maximum DG can reach up to 22.1%. The thermal transition temperatures such as glass-transition temperature (T{sub g}) and cold-crystallization temperature (T{sub cc}) of PET in grafted films were little different from those in original PET film, indicating that microphase separation occurred between PBA side chains and PET backbone. This work implied that if PET/elastomers (e.g., acrylate rubber) blends are radiated by high energy gamma rays under a certain condition, PET-g-polyacrylate copolymer may be produced in-situ, which will improve the compatibility between PET and the elastomers so as to improve the integral mechanical properties of PET based engineering plastic.

  7. Pengaruh Konsentrasi Maleat Anhidrat Terhadap Derajat Grafting Maleat Anhidrat Pada High Density Polyethylene ( HDPE ) Dengan Inisiator Benzoil Peroksida

    OpenAIRE

    Iwan Pranata Sitepu

    2009-01-01

    Telah dilakukan penelitian tentang pengaruh konsentrasi maleat anhidrat terhadap derajat grafting maleat anhidrat pada High Density Polyethylene ( HDPE ) dengan inisiator Benzoil Peroksida, dilakukan dengan teknik pengolahan reaktif dalam Internal Mixer pada suhu 1450C dan waktu proses selama 60 menit dengan variasi komposisi HDPE:MA:BPO, 95:3:2, 92:6:2, 89:9:2, 86:12:2 dan 83:15:2. Selanjutnya dilakukan penentuan derajat grafting dengan metode titrasi dan analisis spektra FTIR untuk menen...

  8. Influence of a hindered amine stabilizer (HAS) and inorganic salt mixture on degradation of poly(methyl methacrylate)

    International Nuclear Information System (INIS)

    Silva, Williams B. da; Vasconcelos, Henrique M. de; Aquino, Katia Aparecida da S.; Araujo, Elmo S.

    2009-01-01

    Commercial poly(methyl methacrylate) (PMMA) is used as medical supplies, which is sterilized by gamma irradiation at 25 kGy dose. However, when the PMMA is exposed to gamma rays it undergoes main chain scissions with changes in its properties. Samples of commercial PMMA containing a Hindered Amine Stabilizer (PMMA-HAS) and samples containing a salt mixture of CuCl 2 /KI (PMMA-salt) both at 0.3wt% concentration were investigated. The PMMA samples were purified by re-precipitation in methanol. The samples were irradiated with gamma radiation ( 60 Co) at room temperature in air at dose range of 15-100 kGy. The viscosity- average molecular weight (M v ) was analyzed by viscosity technique. Comparison of viscosity results obtained before and after irradiation of PMMA showed a decrease in Mv values on irradiated samples with the increase in dose, reflecting the random scissions that occurred in the main chain. However the decrease on M v is less in PMMA-HAS samples than control PMMA. The G value (scissions/100 eV of energy transferred to the system) obtained by viscosity analysis were used to calculated the protection value of HAS on PMMA matrix. The HAS showed a protection of 61% on PMMA molecules exposed to gamma irradiation. No efficiency action of salt mixture was observed on radiolytic degradation of PMMA. On the other hand the CuCl 2 /KI mixture influenced the mechanical behavior of PMMA and the HAS additive increased the maximum thermal degradation temperature of PMMA matrix. (author)

  9. Sonochemical synthesis of copper II sulfide nanoparticles and their use as radiolytic stabilizer in poly(methyl methacrylate) matrix

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Marilia Cordeiro C. de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S., E-mail: aquino@ufpe.b [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-07-01

    Copper (II) sulfide (CuS) was synthesized by sonochemical method. Cu S crystals with hexagonal structure exhibit irregular particles with an average size in the range of 250-900 nm. Commercial Poly(methyl methacrylate) (PMMA) containing CuS nanoparticles (PMMA/Cu) at concentrations of 0.15; 0.30; 0.45 and 0.60 wt% were investigated. The samples were irradiated with gamma radiation ({sup 60}Co) at room temperature and air atmosphere. The viscosity-average molar mass (Mv) was measured for PMMA systems without nanoparticles and with nanoparticles. Decrease in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of CuS nanoparticles at 0.3 wt% into PMMA matrix decreased the number of main chain scissions at dose of 25 kGy and was calculated a protection of 50% in PMMA matrix. CuS nanoparticles act as free radical scavenger into gamma-irradiated PMMA systems. Changes in the infrared spectra of PMMA systems indicate that polymer molecules interact with CuS nanoparticles. Improvement of mechanical properties was found for PMMA/Cu films. An increase of 38% of Young's modulus value and a decrease of 22% on the elongation at break value were recorded for PMMA/Cu films exposed to gamma irradiation. (author)

  10. Nonlinear optical properties of poly(methyl methacrylate) thin films doped with Bixa Orellana dye

    Energy Technology Data Exchange (ETDEWEB)

    Zongo, S., E-mail: sidiki@tlabs.ac.za [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, POBox 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 OldFaure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province (South Africa); Kerasidou, A.P. [LUNAM Université, Université d’Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex (France); Sone, B.T.; Diallo, A. [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, POBox 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 OldFaure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province (South Africa); Mthunzi, P. [Council for Scientific and Industrial Research, P O Box 395, Pretoria 0001 (South Africa); Iliopoulos, K. [LUNAM Université, Université d’Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex (France); Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), 26504 Patras (Greece); Nkosi, M. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 OldFaure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province (South Africa); and others

    2015-06-15

    Highlights: • We studied the linear and nonlinear optical properties of hybrid Bixa Orellana dye doped PMMA thin film. • We investigated the linear optical properties by means of UV/Vis, FTIR and Fluorescence. • We used Tauc - Lorentz model to evaluate linear optical parameters (n &k) with relative maximum of 1.456 at 508.5, 523.79 and 511.9 nm for n is observed while the maximum of k varies from 0.070 to 0.080. • We evaluated nonlinear third order susceptibility which was found to be 1.00 × 10{sup −21} m{sup 2} V{sup −2} or 0.72 × 10{sup −13} esu. - Abstract: Natural dyes with highly delocalized π-electron systems are considered as promising organic materials for nonlinear optical applications. Among these dyes, Bixa Orellana dye with extended π-electron delocalization is one of the most attractive dyes. Bixa Orellana dye-doped Poly(methyl methacrylate) (PMMA) thin films were prepared through spin coating process for linear and nonlinear optical properties investigation. Atomic force microscopy (AFM) was used to evaluate the roughness of the thin films. The optical constants n and k were evaluated by ellipsometric spectroscopy. The refractive index had a maximum of about 1.456 at 508.5, 523.79 and 511.9 nm, while the maximum of k varies from 0.070 to 0.080 with the thickness. The third order nonlinear optical properties of the hybrid Bixa Orellana dye-PMMA polymer were investigated under 30 ps laser irradiation at 1064 nm with a repetition rate of 10 Hz. In particular the third-order nonlinear susceptibility has been determined by means of the Maker Fringes technique. The nonlinear third order susceptibility was found to be 1.00 × 10{sup −21} m{sup 2} V{sup −2} or 0.72 × 10{sup −13} esu. Our studies provide concrete evidence that the hybrid-PMMA composites of Bixa dye are prospective candidates for nonlinear material applications.

  11. Properties of electrospun CdS and CdSe filled poly(methyl methacrylate) (PMMA) nanofibres

    Energy Technology Data Exchange (ETDEWEB)

    Mthethwa, T.P. [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa); Moloto, M.J., E-mail: mmoloto@uj.ac.za [University of Johannesburg, Department of Chemical Technology, P.O. Box 17011, Doornfontein 2028 (South Africa); De Vries, A.; Matabola, K.P. [CSIR Materials Science and Manufacturing, 4 Gomery avenue, Summerstrand, Port Elizabeth 6000 (South Africa)

    2011-04-15

    Graphical abstract: SEM images of CdS/PMMA showing coiling as loading of CdS nanoparticles is increased. Thermal stability is increased with increase in %loading of both CdS and CdSe nanoparticles. Research highlights: {yields} TOPO-capped CdS and HDA-capped CdSe nanoparticles were synthesized and fully characterized. {yields} The nanoparticles were mixed with the polymer, PMMA using electrospinning technique using 2, 5 and 10% weight loadings. {yields} The mixture was spun to produce fibres with optical and thermal properties showing significant change and also the increase in loading causing bending or spiraling. {yields} Both TEM images for nanoparticles and SEM for fibres shows the morphology and sizes of the particles. -- Abstract: Electrospinning technique was used to fabricate poly(methyl methacrylate) (PMMA) fibres incorporating CdS and CdSe quantum dots (nanoparticles). Different nanoparticle loadings (2, 5 and 10 wt% with respect to PMMA) were used and the effect of the quantum dots on the properties of the fibres was studied. The optical properties of the hybrid composite fibres were investigated by photoluminescence and UV-vis spectrophotometry. Scanning electron microscopy (SEM), X-ray diffraction and FTIR spectrophotometry were also used to investigate the morphology and structure of the fibres. The optical studies showed that the size-tunable optical properties can be achieved in the polymer fibres by addition of quantum dots. SEM images showed that the morphologies of the fibres were dependent on the added amounts of quantum dots. A spiral type of morphology was observed with an increase in the concentration of CdS and CdSe nanoparticles. Less beaded structures and bigger diameter fibres were obtained at higher quantum dot concentrations. X-ray diffractometry detected the amorphous peaks of the polymer and even after the quantum dots were added and the FTIR analysis shows that there was no considerable interaction between the quantum dots and the

  12. Properties of electrospun CdS and CdSe filled poly(methyl methacrylate) (PMMA) nanofibres

    International Nuclear Information System (INIS)

    Mthethwa, T.P.; Moloto, M.J.; De Vries, A.; Matabola, K.P.

    2011-01-01

    Graphical abstract: SEM images of CdS/PMMA showing coiling as loading of CdS nanoparticles is increased. Thermal stability is increased with increase in %loading of both CdS and CdSe nanoparticles. Research highlights: → TOPO-capped CdS and HDA-capped CdSe nanoparticles were synthesized and fully characterized. → The nanoparticles were mixed with the polymer, PMMA using electrospinning technique using 2, 5 and 10% weight loadings. → The mixture was spun to produce fibres with optical and thermal properties showing significant change and also the increase in loading causing bending or spiraling. → Both TEM images for nanoparticles and SEM for fibres shows the morphology and sizes of the particles. -- Abstract: Electrospinning technique was used to fabricate poly(methyl methacrylate) (PMMA) fibres incorporating CdS and CdSe quantum dots (nanoparticles). Different nanoparticle loadings (2, 5 and 10 wt% with respect to PMMA) were used and the effect of the quantum dots on the properties of the fibres was studied. The optical properties of the hybrid composite fibres were investigated by photoluminescence and UV-vis spectrophotometry. Scanning electron microscopy (SEM), X-ray diffraction and FTIR spectrophotometry were also used to investigate the morphology and structure of the fibres. The optical studies showed that the size-tunable optical properties can be achieved in the polymer fibres by addition of quantum dots. SEM images showed that the morphologies of the fibres were dependent on the added amounts of quantum dots. A spiral type of morphology was observed with an increase in the concentration of CdS and CdSe nanoparticles. Less beaded structures and bigger diameter fibres were obtained at higher quantum dot concentrations. X-ray diffractometry detected the amorphous peaks of the polymer and even after the quantum dots were added and the FTIR analysis shows that there was no considerable interaction between the quantum dots and the polymer fibres at low

  13. Poly(ethylene glycol) grafted chitosan as new copolymer material for oral delivery of insulin

    International Nuclear Information System (INIS)

    Ho, Thanh Ha; Thanh Le, Thi Nu; Nguyen, Tuan Anh; Dang, Mau Chien

    2015-01-01

    A new scheme of grafting poly (ethylene glycol) onto chitosan was proposed in this study to give new material for delivery of insulin over oral pathway. First, methoxy poly(ethylene glycol) amine (mPEGa MW 2000) were grafted onto chitosan (CS) through multiples steps to synthesize the grafting copolymer PEG-g-CS. After each synthesis step, chitosan and its derivatives were characterized by FTIR, "1H NMR Then, insulin loaded PEG-g-CS nanoparticles were prepared by cross-linking of CS with sodium tripolyphosphate (TPP). Same insulin loaded nanoparticles using unmodified chitosan were also prepared in order to compare with the modified ones. Results showed better protecting capacity of the synthesized copolymer over original CS. CS nanoparticles (10 nm of size) were gel like and high sensible to temperature as well as acidic environment while PEG-g-CS nanoparticles (200 nm of size) were rigid and more thermo and pH stable. (paper)

  14. Swelling, ion uptake and biodegradation studies of PE film modified through radiation induced graft copolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Inderjeet, E-mail: ij_kaur@hotmail.com [Department Chemistry, HPU Shimla 171005 (India); Gupta, Nitika; Kumari, Vandna [Department Chemistry, HPU Shimla 171005 (India)

    2011-09-15

    An attempt to develop biodegradable polyethylene film grafting of mixture of hydrophilic monomers methacrylic acid (MAAc) and acrylamide (AAm) onto PE film has been carried out by preirradiation method using benzoyl peroxide as the radical initiator. Since ether linkages are susceptible to easy cleavage during degradation process, PE film was irradiated before the grafting reactions by {gamma}-rays to introduce peroxidic linkages (PE-OO-PE) that offer sites for grafting. The effect of irradiation dose, monomer concentration, initiator concentration, temperature, time and amount of water on the grafting percent was determined. Maximum percentage of grafting of binary mixture (MAAc+AAm), (1792%) was obtained at a total concentration of binary monomer mixture=204.6x10{sup -2} mol/L ([MAAc]=176.5x10{sup -2} mol/L, [AAm]=28.1x10{sup -2} mol/L), [BPO]=8.3x10{sup -2} mol/L at 100 deg. C in 70 min. The grafted PE film was characterized by the Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopic (SEM) methods. Some selective properties of grafted films such as swelling studies, ion uptake and biodegradation studies have been investigated. The grafted films show good swelling in water, ion uptake studies shows promising results for desalination of brackish water and the soil burial test shows that PE film grafted with binary monomer mixture degrades up to 47% within 50 days. - Highlights: > Binary mixture of methacrylic acid (MAAc) and acrylamide (AAm) onto PE film by preirradiation method was carried out. > Graft copolymers of MAAc+AAm and PE film were characterized by FTIR, TGA and SEM studies and was found to be thermally stable. > Grafting of MAAc+AAm improved swelling behavior giving maximum swelling (485.71%) in water as against PE with 0% swelling. > The grafted PE-g-poly (MAAc-co-AAm) behaves as an excellent material for ion separation. > Biodegradation studies by soil burial test showed 47.19% of

  15. External Electric Field Effects on Excited-State Intramolecular Proton Transfer in 4'-N,N-Dimethylamino-3-hydroxyflavone in Poly(methyl methacrylate) Films.

    Science.gov (United States)

    Furukawa, Kazuki; Hino, Kazuyuki; Yamamoto, Norifumi; Awasthi, Kamlesh; Nakabayashi, Takakazu; Ohta, Nobuhiro; Sekiya, Hiroshi

    2015-09-17

    The external electric field effects on the steady-state electronic spectra and excited-state dynamics were investigated for 4'-N,N-(dimethylamino)-3-hydroxyflavone (DMHF) in a poly(methyl methacrylate) (PMMA) film. In the steady-state spectrum, dual emission was observed from the excited states of the normal (N*) and tautomer (T*) forms. Application of an external electric field of 1.0 MV·cm(-1) enhanced the N* emission and reduced the T* emission, indicating that the external electric field suppressed the excited-state intramolecular proton transfer (ESIPT). The fluorescence decay profiles were measured for the N* and T* forms. The change in the emission intensity ratio N*/T* induced by the external electric field is dominated by ESIPT from the Franck-Condon excited state of the N* form and vibrational cooling in potential wells of the N* and T* forms occurring within tens of picoseconds. Three manifolds of fluorescent states were identified for both the N* and T* forms. The excited-state dynamics of DMHF in PMMA films has been found to be very different from that in solution due to intermolecular interactions in a rigid environment.

  16. Radiation-assisted grafting of vinylidene chloride onto high-density polyethylene

    Science.gov (United States)

    Nagesh, N.; Dokhale, P. A.; Bhoraskar, V. N.

    1999-06-01

    6 MeV electrons and Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays were used for grafting vinylidene chloride (VDC) onto high-density polyethylene (HDPE) samples. The HDPE samples were immersed in vinylidene chloride and irradiated either with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays or with 6 MeV electrons. In both cases, the radiation dose was varied in the range 1.25-7.5 kGy. The grafted samples were characterized by IR spectroscopy to obtain information about the chemical bonds and with the 14 MeV neutron activation analysis technique for estimating the number of chlorine atoms. The formation of stable bonds between the VDC molecules and the polymer chains could be achieved either with 6 MeV electrons or with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays. Both the number of chlorine atoms and the sample-surface conductivity increased with the radiation dose but the increases achieved with 6 MeV electrons were greater than those achieved with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays.

  17. EFFECTS OF ω-ACRYLOYL POLY(ETHYLENE OXIDE) MACROMONOMER ON EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE AND n-BUTYL ACRYLATE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macromonomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxide with diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction terminating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emulsion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containing various concentrations of PEO-A was studied. In all cases stable emulsion coplymerizations of MMA and BA were obtained. The stabilizing effect was found to be dependent on the molecular weight and the feed amount of the macromonomer.

  18. Synthesis of graft copolymers onto starch and its semiconducting properties

    Directory of Open Access Journals (Sweden)

    Nevin Çankaya

    Full Text Available Literature review has revealed that, although there are studies about grafting on natural polymers, especially on starch, few of them are about electrical properties of graft polymers. Starch methacrylate (St.met was obtained by esterification of OH groups on natural starch polymer for this purpose. Grafting of synthesized N-cyclohexyl acrylamide (NCA and commercial methyl methacrylate (MMA monomers with St.met was done by free radical polymerization method. The graft copolymers were characterized with FT-IR spectra, thermal and elemental analysis. Thermal stabilities of the graft copolymers were determined by TGA (thermo gravimetric analysis method and thermal stability of the copolymers is decreased via grafting. The electrical conductivity of the polymers was measured as a function of temperature and it has been observed that electrical conductivity increases with increasing temperature. The absorbance and transmittance versus wavelength of the polymers have been measured. Keywords: Starch, Graft copolymer, Semiconducting, Thermal stability, Starch methacrylate

  19. Graft copolymers of ethyl methacrylate on waxy maize starch derivatives as novel excipients for matrix tablets: physicochemical and technological characterisation.

    Science.gov (United States)

    Marinich, J A; Ferrero, C; Jiménez-Castellanos, M R

    2009-05-01

    Nowadays, graft copolymers are being used as an interesting option when developing a direct compression excipient for controlled release matrix tablets. New graft copolymers of ethyl methacrylate (EMA) on waxy maize starch (MS) and hydroxypropylstarch (MHS) were synthesised by free radical polymerization and alternatively dried in a vacuum oven (OD) or freeze-dried (FD). This paper evaluates the performance of these new macromolecules and discusses the effect of the carbohydrate nature and drying process on their physicochemical and technological properties. Grafting of EMA on the carbohydrate backbone was confirmed by IR and NMR spectroscopy, and the grafting yields revealed that graft copolymers present mainly a hydrophobic character. The graft copolymerization also leads to more amorphous materials with larger particle size and lower apparent density and water content than carbohydrates (MS, MHS). All the products show a lack of flow, except MHSEMA derivatives. MSEMA copolymers underwent much plastic flow and less elastic recovery than MHSEMA copolymers. Concerning the effect of drying method, FD derivatives were characterised by higher plastic deformation and less elasticity than OD derivatives. Tablets obtained from graft copolymers showed higher crushing strength and disintegration time than tablets obtained from raw starches. This behaviour suggests that these copolymers could be used as excipients in matrix tablets obtained by direct compression and with a potential use in controlled release.

  20. Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

    Science.gov (United States)

    Wang, Jingjing; Wei, Jun

    2016-09-01

    Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

  1. Enhancement of stiffness, strength, ductility and toughness of poly(ethylene oxide) using phenoxy-grafted multiwalled carbon nanotubes

    International Nuclear Information System (INIS)

    Yang Bingxing; Shi Jiahua; Pramoda, K P; Goh, Suat Hong

    2007-01-01

    Phenoxy (poly(hydroxyether of bisphenol-A), also known as poly(bisphenol-A-co-epichlorohydrin)) was grafted onto multiwalled carbon nanotubes (MWNTs) by a reactive blending process. Reactions between terminal glycidyl groups of phenoxy and carboxylic acid groups of acidified MWNTs resulted in the grafting of phenoxy chains onto MWNTs. The mechanical properties of composites of poly(ethylene oxide) (PEO) and phenoxy-grafted MWNTs were studied. The miscibility between PEO and phenoxy enabled the good dispersion of nanotubes in the PEO matrix as evidenced by polarized optical microscopy and transmission electron microscopy. The spherulite size of PEO progressively decreased with increasing amount of phenoxy-grafted MWNTs added. At an optimal MWNT content of 1.5 wt%, the addition of phenoxy-grafted MWNTs led to increases of storage modulus, Young's modulus, yield stress, tensile strength, ultimate strain, and toughness of PEO by 113, 228, 166, 442, 1240, and 4080%, respectively. Such simultaneous increases in stiffness, strength, ductility and toughness of a polymer by an additive are rather uncommon

  2. Nanoscale mechanical and tribological properties of fluorocarbon films grafted onto plasma-treated low-density polyethylene surfaces

    International Nuclear Information System (INIS)

    Cheng, Q; Komvopoulos, K

    2012-01-01

    Fluorocarbon (FC) films were grafted onto Ar plasma-treated low-density polyethylene (LDPE) surfaces by plasma polymerization and deposition. The evolution of the surface morphology of the grafted FC films was investigated at different scales with an atomic force microscope. Nanoscale sliding experiments performed with a surface force microscope provided insight into the nanotribological properties of Ar plasma-treated LDPE, with and without grafted FC films, in terms of applied normal load and number of sliding cycles. The observed trends are explained in the context of microstructure models accounting for morphological and structure changes at the LDPE surface due to the effects of plasma treatment (e.g., selective etching of amorphous phase, chain crosslinking and FC film grafting) and surface sliding (e.g., crystalline lamellae alignment along the sliding direction). Nanoindentation experiments elucidated the effect of plasma treatment on surface viscoelasticity and global contact stiffness. The results of this study demonstrate that plasma-assisted grafting of FC films is an effective surface modification method for tuning the nanomechanical/tribological properties of polymers. (paper)

  3. Simple introduction of sulfonic acid group onto polyethylene by radiation-induced cografting of sodium styrenesulfonate with hydrophilic monomers

    International Nuclear Information System (INIS)

    Tsuneda, Satoshi; Saito, Kyoichi; Furusaki, Shintaro; Sugo, Takanobu; Makuuchi, Keizo

    1993-01-01

    The sulfonic acid (SO 3 H) group was readily introduced into a polyethylene (PE) membrane by radiation-induced cografting of sodium styrenesulfonate (SSS) with hydrophilic monomers such as acrylic acid (AAc) and hydroxyethyl methacrylate (HEMA). The density of SSS grafted onto the PE membrane was determined as a function of molar ratio of hydrophilic monomer to SSS in the monomer mixture. Immersion of the electron-beam-irradiated PE membrane into the mixture of SSS and HEMA for 5 h at 323 K provided to the SO 3 H density of 2.5 mol/kg of the H-type product

  4. Polyethylene and methyl methacrylate particle-stimulated inflammatory tissue and macrophages up-regulate bone resorption in a murine neonatal calvaria in vitro organ system.

    Science.gov (United States)

    Ren, Weiping; Wu, Bin; Mayton, Lois; Wooley, Paul H

    2002-09-01

    There is considerable evidence that orthopaedic wear debris plays a crucial role in the pathology of aseptic loosening of joint prostheses. This study examined the effect of inflammatory membranes stimulated with methyl methacrylate and polyethylene on bone resorption, using the murine air pouch model. The capacity of RAW 264.7 mouse macrophages exposed to polymer particles to produce factors affecting bone metabolism was also studied. Neonatal calvaria bones were co-cultured with either pouch membranes or conditioned media from activated macrophages. Bone resorption was measured by the release of calcium from cultured bones, and the activity of tartrate-resistant acid phosphatase in both bone sections and culture medium was also assayed. Results showed that inflammatory pouch membrane activated by methyl methacrylate and polyethylene enhanced osteoclastic bone resorption. Conditioned media from particles stimulated mouse macrophages also stimulated bone resorption, although this effect was weaker than resorption induced by inflammatory pouch membranes. The addition of the particles directly into the medium of cultured calvaria bones had little effect on bone resorption. Our observations indicate that both inflammatory tissue and macrophages provoked by particles can stimulate bone resorption in cultured mouse neonatal calvaria bones. This simple in vitro bone resorption system allows us to investigate the fundamental cellular and molecular mechanism of wear debris induced bone resorption and to screen potential therapeutic approaches for aseptic loosening.

  5. Synthesis and characterization of radiation grafted films for removal of arsenic and some heavy metals from contaminated water

    International Nuclear Information System (INIS)

    Chowdhury, M.N.K.; Khan, M.W.; Mina, M.F.; Beg, M.D.H.; Khan, Maksudur R.; Alam, A.K.M.M.

    2012-01-01

    Grafting of styrene/maleic anhydride and methyl methacrylate/maleic anhydride binary monomers onto the low density polyethylene film was performed using the γ-ray irradiation technique. Then, the synthesized grafted films were treated with different ammonia derivatives for developing chelating functionalization. These chelating products were characterized by the gravimetric method as well as by the Fourier transformed infrared spectroscopic method, and were used for removal of arsenic and some heavy metals from aqueous solutions. The optimum absorbed dose of 30 kGy reveals the graft yielding of about 325% in the films. Uptake of arsenic and some heavy-metal ions (Cr(III), Mn(II), Fe(III), Ni(II), Cu(II) and Pb(II)) from contaminated water by the chelating functionalized films (CFF) was examined by an atomic absorption spectrophotometer. The maximum arsenic removal capacity of 5062 mg/kg has been observed for the film treated with hydroxylamine hydrochloride. The CFF prepared by semicarbazide and thiol analogs show affinity toward the metal ions with an order: Cu(II)>Fe(III)>Mn(II) etc. The results obtained from this study indicate that the functionalized films show good chelating and ion-exchange property for metal ions. - Highlights: ► Optimization of radiation dose for grafting reaction of polyethylene with binary monomers. ► Chelating functionalization of grafted film with various amine compounds. ► Characterization of both grafted and chelating functionalized films. ► Proposed mechanism for both grafting and chelating functionalization reaction. ► Application of the synthesized films for the removal of arsenic and some heavy metals from contaminated water.

  6. Mineralogical and Thermal Properties of Poly(methyl methacrylate) Alite Composite

    International Nuclear Information System (INIS)

    Ismail, M.R.; El-Fass, M.M.; Abd-El-Rahman, H.A.; El-Miligy, A.A.

    1999-01-01

    The X-ray diffraction (XRD) characteristics and thermal stability of PMMA alite composite have been studied. The dried alite samples were impregnated by methyl methacrylate monomer and then subjected to gamma irradiation. The mineralogical and thermal properties of the PMMA alite composite materials were investigated by using XRD, DTA, and TGA techniques. The results indicate that, a markedly reduction of the peaks intensities of XRD for tricalcium silicate and calcium hydroxide. TGA data showed that PMMA alite composite has a high thermal stability as compared to PMMA

  7. Color formation on irradiated polymethyl methacrylate by electrons beam; Formacao de cor no polimetil metacrilato (PMMA) irradiado com feixes de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Nardi, Daniela T.; Guedes, Selma M.L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: smguedes@ipen.br

    2005-07-01

    The color formation on national and commercial polymethyl methacrylate (PMMA) irradiated by electrons beam was investigated in function of dose (0-150 kGy), post-irradiation time (0-31 days) and heating (110 deg C/1 h) by colorimetry (CIELab), electron spectroscopy resonance (RPE) and photoacoustic infrared spectroscopy (FTIRPAS). The irradiation promoted the formation of unstable color centers responsible by changing of colorimetric and optical properties. Visually or by colorimetric parameters the radiation became the PMMAS yellow and darkening which intensified by increase the dose and disappeared after the post-irradiation time. The yellow color disappeared and darkening increased when the irradiated PMMA (150 kGy) was heated. It was impossible to see the green and red colors however the colorimetric parameters showed a little decreasing of the Da value in function of the increased dose and a little increasing in function of post-irradiation time. The FTIR-PAS spectra did not show the presence of different functional groups after irradiation however the correlation among the Db values and RPE spectra suggested that the radicals could be responsible by unstable and yellow color centers. The radiosterilized PMMA (25 kGy) showed significant colorimetric changes that decreased but continued visible yet after 31 days. (author)

  8. Custom CAD-CAM healing abutment and impression coping milled from a poly(methyl methacrylate) block and bonded to a titanium insert.

    Science.gov (United States)

    Proussaefs, Periklis

    2016-11-01

    This article describes a technique in which a custom-made computer-aided design and computer-aided manufacturing (CAD-CAM) healing abutment milled from a poly(methyl methacrylate) (PMMA) block is fabricated and bonded to a titanium metal insert. An impression is made during dental implant surgery, and the CAD-CAM custom-made healing abutment is fabricated before second-stage surgery while appropriate healing time is allowed for the dental implant to osseointegrate. The contours of the healing abutment are based on the contours of a tentatively designed definitive prosthesis. The healing tissue obtains contours that will be compatible with the contours of the definitive prosthesis. After the milling process is complete, a titanium metal insert is bonded to the healing abutment. Placement of the custom-made CAD-CAM healing abutment at second-stage surgery allows the tissue to obtain contours similar to those of the definitive prosthesis. A custom-made CAD-CAM impression coping milled from a PMMA block and with a titanium insert is used for the definitive impression after the soft tissue has healed. This technique allows guided soft tissue healing by using a custom-made CAD-CAM healing abutment and impression coping. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Low-loss integrated electrical surface plasmon source with ultra-smooth metal film fabricated by polymethyl methacrylate ‘bond and peel’ method

    Science.gov (United States)

    Liu, Wenjie; Hu, Xiaolong; Zou, Qiushun; Wu, Shaoying; Jin, Chongjun

    2018-06-01

    External light sources are mostly employed to functionalize the plasmonic components, resulting in a bulky footprint. Electrically driven integrated plasmonic devices, combining ultra-compact critical feature sizes with extremely high transmission speeds and low power consumption, can link plasmonics with the present-day electronic world. In an effort to achieve this prospect, suppressing the losses in the plasmonic devices becomes a pressing issue. In this work, we developed a novel polymethyl methacrylate ‘bond and peel’ method to fabricate metal films with sub-nanometer smooth surfaces on semiconductor wafers. Based on this method, we further fabricated a compact plasmonic source containing a metal-insulator-metal (MIM) waveguide with an ultra-smooth metal surface on a GaAs-based light-emitting diode wafer. An increase in propagation length of the SPP mode by a factor of 2.95 was achieved as compared with the conventional device containing a relatively rough metal surface. Numerical calculations further confirmed that the propagation length is comparable to the theoretical prediction on the MIM waveguide with perfectly smooth metal surfaces. This method facilitates low-loss and high-integration of electrically driven plasmonic devices, thus provides an immediate opportunity for the practical application of on-chip integrated plasmonic circuits.

  10. Modification of polyetherurethane for biomedical application by radiation induced grafting. II. Water sorption, surface properties, and protein adsorption of grafted films

    International Nuclear Information System (INIS)

    Jansen, B.; Ellinghorst, G.

    1984-01-01

    A series of polyetherurethane films grafted by means of gamma radiation with hydrophilic or reactive monomers (2-hydroxyethyl methacrylate, 2,3-epoxypropyl methacrylate, 2,3-dihydroxypropyl methacrylate, and acrylamide) and partially chemically modified were subjected to various physico-chemical investigation methods involving water sorption, contact angle, and protein adsorption measurements. From contact angle data the interfacial free energy gamma sw between grafted films and water was calculated. It was found that the water uptake of grafted films increases with grafting yield or, in the case of grafted and afterwards chemically modified films, with reaction yield; the diffusion coefficient of water in the modified films also increases with grafting yield. Contact angle studies revealed all grafted films to have surfaces more hydrophilic than the ungrafted trunk polymer. The degree of hydrophilicity--especially of HEMA-grafted films--strongly depends on grafting conditions. For some grafted samples with high surface hydrophilicity very low interfacial free energies approaching zero were measured. The study of the competitive adsorption of bovine serum albumin, gamma-globulin, and fibrinogen from a synthetic protein solution onto modified films showed that the adsorption of albumin increases markedly with increasing grafting yields, whereas the fibrinogen and gamma-globulin adsorption only slightly increases. A correlation between interfacial free energy and protein adsorption in the sense of the minimum interfacial free energy hypothesis was found only for samples with grafting yields below 5%. At higher grafting yields the increased surface area complicates the analysis

  11. Highly hydrophilic ultra-high molecular weight polyethylene powder and film prepared by radiation grafting of acrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Honglong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xu, Lu; Li, Rong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Pang, Lijuan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Hu, Jiangtao; Wang, Mouhua [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Wu, Guozhong, E-mail: wuguozhong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-09-30

    Highlights: • Hydrophilic UHMWPE powder and film were obtained by γ-ray pre-irradiation grafting of AA. • A low concentration of AA solution was used for surface modification of UHMWPE. • A small grafting yield of AA sufficiently improved hydrophilicity of UHMWPE powder and film. - Abstract: The surface properties of ultra-high molecular weight polyethylene (UHMWPE) are very important for its use in engineering or composites. In this work, hydrophilic UHMWPE powder and film were prepared by γ-ray pre-irradiation grafting of acrylic acid (AA) and further neutralization with sodium hydroxide solution. Variations in the chemical structure, grafting yield and hydrophilicity were investigated and compared. FT-IR and XPS analysis results showed that AA was successfully grafted onto UHMWPE powder and film; the powder was more suitable for the grafting reaction in 1 wt% AA solution than the film. Given a dose of 300 kGy, the grafting yield of AA was ∼5.7% for the powder but ∼0.8% for the film under identical conditions. Radiation grafting of a small amount of AA significantly improved the hydrophilicity of UHMWPE. The water contact angle of the UHMWPE-g-PAA powder with a grafting yield of AA at ∼5.7% decreased from 110.2° to 68.2°. Moreover, the grafting powder (UHMWPE-g-PAA) exhibited good dispersion ability in water.

  12. Preparation of Oleyl Phosphate-Modified TiO2/Poly(methyl methacrylate Hybrid Thin Films for Investigation of Their Optical Properties

    Directory of Open Access Journals (Sweden)

    Masato Fujita

    2015-01-01

    Full Text Available TiO2 nanoparticles (NPs modified with oleyl phosphate were synthesized through stable Ti–O–P bonds and were utilized to prepare poly(methyl methacrylate- (PMMA- based hybrid thin films via the ex situ route for investigation of their optical properties. After surface modification of TiO2 NPs with oleyl phosphate, IR and 13C CP/MAS NMR spectroscopy showed the presence of oleyl groups. The solid-state 31P MAS NMR spectrum of the product revealed that the signal due to oleyl phosphate (OP shifted upon reaction, indicating formation of covalent Ti–O–P bonds. The modified TiO2 NPs could be homogeneously dispersed in toluene, and the median size was 16.1 nm, which is likely to be sufficient to suppress Rayleigh scattering effectively. The TEM images of TiO2/PMMA hybrid thin films also showed a homogeneous dispersion of TiO2 NPs, and they exhibited excellent optical transparency even though the TiO2 content was 20 vol%. The refractive indices of the OP-modified TiO2/PMMA hybrid thin films changed higher with increases in TiO2 volume fraction, and the hybrid thin film with 20 vol% of TiO2 showed the highest refractive index (n = 1.86.

  13. Phase behavior for the poly(alkyl methacrylate)+supercritical CO2+DME mixture at high pressures

    International Nuclear Information System (INIS)

    Choi, Yong-Seok; Chio, Sang-Won; Byun, Hun-Soo

    2016-01-01

    The phase behavior curves of binary and ternary system were measured for poly(alkyl methacrylate) in supercritical CO 2 , as well as for the poly(alkyl methacrylate)+dimethyl ether (DME) (or 1-butene) in CO 2 . The solubility curves are reported for the poly(alkyl methacrylate)+DME in supercritical CO 2 at temperature from (300 to 465) K and a pressure from (3.66 to 248) MPa. Also, The high-pressure static-type apparatus of cloud-point curve was tested by comparing the measured phase behavior data of the poly(methyl methacrylate) [PMMA]+CO 2 +20.0 and 30.4 wt% methyl methacrylate (MMA) system with literature data of 10.4, 28.8 and 48.4 wt% MMA concentration. The phase behavior data for the poly(alkyl methacrylate)+CO 2 +DME mixture were measured in changes of the pressure-temperature (p, T) slope and with DME concentrations. Also, the cloud-point pressure for the poly(alkyl methacrylate)+1- butene solution containing supercritical CO 2 shows from upper critical solution temperature (UCST) region to lower critical solution temperature (LCST) region at concentration range from (0.0 to 95) wt% 1-butene at below 455 K and at below 245MPa.

  14. Influence of temperature on radiation-induced graft polymerization of styrene onto poly(ethylene terephthalate) nuclear membranes and films

    International Nuclear Information System (INIS)

    Zhitaryuk, N.I.; Shtan'ko, N.I.

    1989-01-01

    Temperature effect on kinetics of radiation-induced graft polymerization of styrene onto poly(ethylene terephthalate) (PETP) nuclear membranes with various parameters (pore diameter, the average distance between the pores) as well as onto PETP films with different thickness has been studied. Graft polymerization has been carried out by the methods of preirradiation in air and in vacuum. The overall activation energy of grafting as well as the activation energy of swelling of PETP in toluene has been obtained. It was found that in the method of preirradiation in vacuum the initial grafting rate in Arrhenius plot has two linear ranges. Activation energy in low temperature range correlates with activation energy of PETP swelling. Activation energy in high temperature range is determined by kinetics of graft polymerization in the method of preirradiation in air. Arrhenius plot of the initial grafting rate gives the activation energy that approximately corresponds to the initiation of grafting with oxyradicals. Dependence of PETP matrix critical thickness on temperature has also been obtained. The form of this dependence is identical to the one of the rate of graft polymerization. 33 refs.; 6 figs.; 2 tabs

  15. Development of form stable Poly(methyl methacrylate) (PMMA) coated thermal phase change material for solar water heater applications

    Science.gov (United States)

    Munusamy, Y.; Shanmugam, S.; Shi-Ying, Kee

    2018-04-01

    Phase change material (PCM) is one of the most popular and widely used thermal energy storage material in solar water heater because it able to absorb and release a large amount of latent heat during a phase change process over a narrow temperature range. However the practical application of PCM is limited by two major issues; 1) leakage which leads to material loss and corrosion of tank and 2) large volume change during phase change process which cause pressure build up in the tank. In this work, form-stable PCM was prepared by coating myristic acid with Poly(methyl methacrylate) (PMMA) to prevent leakage of PCM. PMMA was mixed with different weight percentage (0.1, 0.2, 0.3, 0.4 and 0.5 wt%) of dicumyl peroxide (DCP). The purpose of adding DCP to PMMA is to crosslink the polymer and to increase the mechanical strength of PMMA to hold the myristic acid content inside the coating during the phase change process. Leakage test results showed that PMMA mixed with 0.1% DCP exhibit 0% leakage. This result is further supported by Field Emission Scanning Electron Microscopy (FESEM) images and Fourier transform infrared spectroscopy (FTIR) analysis results, where a compact and uniform coating without cracks were formed for PCM coated with PMMA with 0.1% DCP. Differential scanning calorimetry (DSC) results shows that the melting point of form-stable PCM is 55°C, freezing point is 50°C, the latent heat of melting and freezing is 67.59 J/g.

  16. Synthesis and Characterization of Metal Sulfides Nanoparticles/Poly(methyl methacrylate) Nanocomposites

    OpenAIRE

    Ajibade, Peter A.; Mbese, Johannes Z.

    2014-01-01

    Metal sulfides nanoparticles in poly(methyl methacrylate) matrices were prepared and characterized by infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). The FTIR confirms the dispersion of the nanoparticles in PMMA matrices with the C=O and C–O–C bonds of the PMMA shifting slightly which may be attributed to the interactions between the nanoparticles and PMMA. The ZnS nanoparticles in PMM...

  17. Production of sorption-active polypropylene fibers by radiation-induced grafting of glycidyl methacrylate as a precursor monomer

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.

    2006-01-01

    The design and development of sorption-active natural and synthetic polymer fibers and textile materials is of great scientific and practical interest. The advantages of that type of polymeric adsorbents, as their highly developed specific surface, excellent ion-exchange and adsorption parameters and ease of their use especially under continuous conditions, allow them to find a great application in the chemical, biomedical, ecological and industrial fields. To obtain functional polymer materials with the desired performance, the non-active polymer surface have to be modified. Among different innovative techniques used for the introduction of graft chains, the radiation-chemical method of initiation has some economical and ecological preferences over others. It allows to introduce into inert polymeric matrix chains of a monomer already containing a desirable functional group, or to graft chains of a precursor-monomer and subsequently its chemical modification to form required functional groups. At present an epoxy-group containing monomer, glycidyl methacrylate (GMA), is successfully used as a precursor-monomer for production of polymeric adsorbents of variety applications on the base of membranes, films, fibers and fabrics. Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of GMA, with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 deg C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. Amine groups were incorporated by treatment of the GMA-grafted

  18. Fabrication of 3D Microfluidic Devices by Thermal Bonding of Thin Poly(methyl methacrylate) Films

    KAUST Repository

    Perez, Paul

    2012-07-01

    The use of thin-film techniques for the fabrication of microfluidic devices has gained attention over the last decade, particularly for three-dimensional channel structures. The reasons for this include effective use of chip volume, mechanical flexibility, dead volume reduction, enhanced design capabilities, integration of passive elements, and scalability. Several fabrication techniques have been adapted for use on thin films: laser ablation and hot embossing are popular for channel fabrication, and lamination is widely used for channel enclosure. However, none of the previous studies have been able to achieve a strong bond that is reliable under moderate positive pressures. The present work aims to develop a thin-film process that provides design versatility, speed, channel profile homogeneity, and the reliability that others fail to achieve. The three building blocks of the proposed baseline were fifty-micron poly(methyl methacrylate) thin films as substrates, channel patterning by laser ablation, and device assembly by thermal-fusion bonding. Channel fabrication was characterized and tuned to produce the desired dimensions and surface roughness. Thermal bonding was performed using an adapted mechanical testing device and optimized to produce the maximum bonding strength without significant channel deformation. Bonding multilayered devices, incorporating conduction lines, and integrating various types of membranes as passive elements demonstrated the versatility of the process. Finally, this baseline was used to fabricate a droplet generator and a DNA detection chip based on micro-bead agglomeration. It was found that a combination of low laser power and scanning speed produced channel surfaces with better uniformity than those obtained with higher values. In addition, the implemented bonding technique provided the process with the most reliable bond strength reported, so far, for thin-film microfluidics. Overall, the present work proved to be versatile

  19. Preparation of poly(polyethylene glycol methacrylate-co-acrylic acid) hydrogels by radiation and their physical properties

    International Nuclear Information System (INIS)

    Park, S.-E.; Nho, Y.-C.; Kim, H.-I.

    2004-01-01

    The pH-responsive copolymer hydrogels were prepared with the monomers of polyethylene glycol methacrylate and acrylic acid based on γ-ray irradiation technique. The gel content of these copolymer hydrogels varied depending on both the composition of monomers and the radiation dose. Maximum gel percent and degree of crosslinking were obtained at the composition of equal amount of comonomers. These copolymer hydrogels did not show any noticeable change in swelling at lower pH range. However they showed an abrupt increase in swelling at higher pH range due to the ionization of carboxyl groups. This pH-responsive swelling behavior was applied for the insulin carrier via oral delivery. Insulin-loaded copolymer hydrogels released most of their insulin in the simulated intestinal fluid which had a pH of 6.8 but not in the simulated gastric fluid which had a pH of 1.2

  20. Rapid synthesis of graft copolymers from natural cellulose fibers.

    Science.gov (United States)

    Thakur, Vijay Kumar; Thakur, Manju Kumari; Gupta, Raju Kumar

    2013-10-15

    Cellulose is the most abundant natural polysaccharide polymer, which is used as such or its derivatives in a number of advanced applications, such as in paper, packaging, biosorption, and biomedical. In present communication, in an effort to develop a proficient way to rapidly synthesize poly(methyl acrylate)-graft-cellulose (PMA-g-cellulose) copolymers, rapid graft copolymerization synthesis was carried out under microwave conditions using ferrous ammonium sulfate-potassium per sulfate (FAS-KPS) as redox initiator. Different reaction parameters such as microwave radiation power, ratio of monomer, solvent and initiator concentrations were optimized to get the highest percentage of grafting. Grafting percentage was found to increase with increase in microwave power up to 70%, and maximum 36.73% grafting was obtained after optimization of all parameters. Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA/DTA/DTG) analysis were used to confirm the graft copolymerization of poly(methyl acrylate) (PMA) onto the mercerized cellulose. The grafted cellulosic polymers were subsequently subjected to the evaluation of different physico-chemical properties in order to access their application in everyday life, in a direction toward green environment. The grafted copolymers demonstrated increased chemical resistance, and higher thermal stability. Published by Elsevier Ltd.

  1. Study on grafting of different types of acrylic monomers onto natural rubber by γ-rays

    International Nuclear Information System (INIS)

    Dafader, N.C.; Haque, M.E.; Akhtar, F.; Ahmad, M.U.

    2006-01-01

    A comparative study of various acrylic monomers for grafting onto natural rubber was done. The stability of natural rubber latex (NRL) against coagulum with monomer, mechanical properties of grafted rubbers and percent of grafting were investigated. The NRL with monomers, methylacrylate (MA), ethylacrylate (EA) and n-butylacrylate (n-BA), is unstable but it is stable with methyl methacrylate (MMA), n-butyl methacrylate (BMA) and cyclohexyl methacrylate (CHMA). The mechanical properties and degree of grafting attained a maximum at a total radiation dose of 4 kGy. The values of tensile properties of MMA and CHMA grafted rubbers are almost similar, and higher than those of BMA grafted rubbers. On the other hand, the degree of grafting for CHMA is higher than those of MMA and BMA grafted rubbers. The infrared (IR) spectra of monomer grafted natural rubber were also studied

  2. Preparation of poly (methyl methacrylate)/nanometer calcium carbonate composite by in-situ emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    史建明; 包永忠; 黄志明; 翁志学

    2004-01-01

    Methyl methacrylate (MMA) emulsion polymerization in the presence of nanometer calcium carbonate (nano-CaCO3) surface modified with (-methacryloxypropyltrimethoxysilane (MPTMS) was carried out to prepare poly (methyl methacrylate) (PMMA)/nano-CaCO3 composite. The reaction between nano-CaCO3 and MPTMS, and the grafting of PMMA onto nano-CaCO3 were confirmed by infrared spectrum. The grafting ratio and grafting efficiency of PMMA on nano-CaCO3 modified with MPTMS were much higher than that on nano-CaCO3 modified with stearic acid. The grafting ratio of PMMA increased as the weight ratio between MMA and nano-CaCO3 increased, while the grafting efficiency of PMMA decreased. Transmission electron micrograph showed that nano-CaCO3 covered with PMMA was formed by in-situ emulsion polymerization.

  3. Osteo-odonto-keratoprosthesis (OOKP) and the testing of three different adhesives for bonding bovine teeth with optical poly-(methyl methacrylate) (PMMA) cylinder.

    Science.gov (United States)

    Weisshuhn, K; Berg, I; Tinner, D; Kunz, C; Bornstein, M M; Steineck, M; Hille, K; Goldblum, D

    2014-07-01

    Preparation of the lamina during osteo-odonto-keratoprosthesis (OOKP) design is complex, and its longevity and watertightness important. To date, only acrylic bone cements have been used for bonding the optical cylinder to the tooth dentine. Our aim was to evaluate different dental adhesives for OOKP preparation. Specimens of bovine teeth were produced by preparing 1.5-mm thick dentine slices with holes having a diameter of 3.5 mm. Each group (n=10 per group) was luted with either classic poly-(methyl methacrylate) (PMMA) bone cement, universal resin cement or glass ionomer cement. All specimens underwent force measurement using a uniaxial traction machine. The highest mean force required to break the bond was measured for PMMA bone cement (128.2 N) followed by universal resin cement (127.9 N), with no statistically significant difference. Glass ionomer cement showed significantly lower force resistance (78.1 N). Excellent bonding strength combined with easy application was found for universal resin cement, and thus, it is a potential alternative to acrylic bone cement in OOKP preparation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Grafting of copolymer styrene maleic anhydride on poly(ethylene terephthalate) film by chemical reaction and by plasma method

    Energy Technology Data Exchange (ETDEWEB)

    Bigan, Muriel; Bigot, Julien [Laboratoire de Chimie Organique et Macromoleculaire (UMR 8009), Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France); Mutel, Brigitte [Laboratoire de Genie des Procedes d' Interactions Fluides reactifs-Materiaux (UPRES-EA 3751), Batiment C5, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France)], E-mail: Brigitte.mutel@univ-lille1.fr; Coqueret, Xavier [Laboratoire Reactions Selectives et Applications (UMR-CNRS 6519) Universite de Reims Champagne-Ardennes, B.P. 1039, 51687 Reims Cedex 2 (France)

    2008-02-15

    This work deals with the chemical grafting of a styrene maleic anhydride copolymer on the surface of a previously hydrolyzed polyethylene terephthalate (PET) film 12 {mu}m thick via covalent bond. Two different ways are studied. The first one involves an activation of the hydrolyzed PET by the triethylamine before the grafting step. In the second one, the copolymer reacts with the 4-dimethylaminopyridine in order to form maleinyl pyridinium salt which reacts with alcohol function of the hydrolyzed PET. Characterization and quantification of the grafting are performed by Fourier transform infrared spectroscopy. Factorial experiment designs are used to optimize the process and to estimate experimental parameters effects. The opportunity to associate the chemical process to a cold remote nitrogen plasma one is also examined.

  5. Durable grafting of silkworm pupa protein onto the surface of polyethylene terephthalate fibers

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jianfeng, E-mail: 584884673@qq.com [College of Textiles & Garments, Southwest University, Chongqing 400716 (China); Chongqing Engineering Research Center of Biomaterial Fiber and Modern Textile, 400716 (China); Zheng, Dandan, E-mail: 183737543@qq.com [College of Textiles & Garments, Southwest University, Chongqing 400716 (China); Chongqing Engineering Research Center of Biomaterial Fiber and Modern Textile, 400716 (China); Zhang, Fengxiu, E-mail: zhangfx656472@sina.com.cn [School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Zhang, Guangxian, E-mail: zgx656472@sina.com [College of Textiles & Garments, Southwest University, Chongqing 400716 (China); Chongqing Engineering Research Center of Biomaterial Fiber and Modern Textile, 400716 (China)

    2016-12-01

    In this paper, reactive –NH{sub 2} groups (8.36 × 10{sup −6} mol/g fabric) were introduced to the surface of polyethylene terephthalate (PET) fabrics by a nitration and reduction method, and epoxy groups were introduced to silkworm pupa protein (SPP) by reaction with epoxy chloropropane. PET-SPP composite fabrics were then prepared by reaction of these two precursors. The results showed that the SPP was firmly grafted onto the PET fabric surface and that the hydrophilicity of the fabric was markedly improved by the grafting of SPP. SEM images revealed a layer of substance covering the surface of the PET fibers, and XPS investigation showed that the nitrogen content of the PET-SPP fabric was higher than that of the original PET fabric (2.32% vs 0%). ATR-FTIR adsorption bands at 1653 and 1543 cm{sup −1} suggested the successful grafting of SPP onto the PET fabric surface. The DSC and TG of the PET fibers demonstrated that the thermal stability of the original PET fibers was maintained well by the SPP-grafted PET fibers. The breaking strength, bending rigidity, air permeability, and crease recovery angle of the original PET fabric were also retained by the SPP-grafted PET fabric. - Highlights: • Reactive –NH{sub 2} groups were introduced to PET fibers by nitration and reduction method. • Reactive epoxy groups were introduced to silkworm pupa protein by reacting with epoxy chloropropane. • The silkworm pupa protein could be grafted firmly on the PET fabric surface through covalent bond. • The skin-friendly property and hydrophilicity of PET-SPP fabric were improved greatly. • The wearability of PET-SPP composite fabric kept well.

  6. Adhesion mapping of chemically modified and poly(ethylene oxide)-grafted glass surfaces.

    Science.gov (United States)

    Jogikalmath, G; Stuart, J K; Pungor, A; Hlady, V

    1999-08-01

    Two-dimensional mapping of the adhesion pull-off forces was used to study the origin of surface heterogeneity in the grafted poly(ethylene oxide) (PEO) layer. The variance of the pull-off forces measured over the μm-sized regions after each chemical step of modifying glass surfaces was taken to be a measure of the surface chemical heterogeneity. The attachment of γ-glycidoxypropyltrimethoxy silane (GPS) to glass decreased the pull-off forces relative to the clean glass and made the surface more uniform. The subsequent hydrolysis of the terminal epoxide groups resulted in a larger surface heterogeneity which was modeled by two populations of the terminal hydroxyl groups, each with its own distribution of adhesion forces and force variance. The activation of the hydroxyls with carbonyldiimmidazole (CDI) healed the surface and lowered its adhesion, however, the force variance remained rather large. Finally, the grafting of the α,ω-diamino poly(ethyleneoxide) chains to the CDI-activated glass largely eliminated adhesion except at a few discrete regions. The adhesion on the PEO grafted layer followed the Poisson distribution of the pull-off forces. With the exception of the glass surface, a correlation between the water contact angles and the mean pull-off forces measured with the Si(3)N(4) tip surfaces was found for all modified glass surfaces.

  7. Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder. Part II: Thermal, FTIR and morphological characterisation

    Science.gov (United States)

    Aydınlı, Bahattin; Tin c̡er, Teoman

    2001-10-01

    Radiation induced grafted polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamide (PAAm), poly N,N-dimethyl acrylamide (PNDAAm) and poly 1-vinyl-2 pyrrolidone (PVP) on ultra-high molecular weight polyethylene (UHMWPE) were characterised by DSC, FTIR and SEM analysis. While the effect of irradiation on pure UHMWPE was found to increase crystallinity and cause higher enthalpy of crystallisation, grafted UHMWPE powders showed lower crystallinity and enthalpy of crystallisation. In all grafted UHMWPE there existed secondary transitions corresponding to grafting polymers in the first run of DSC above 60°C and they became clearer at a higher grafting level. In the second run of DSC some Tg values appeared to shift to higher temperatures while some were not detected. FTIR analysis indicated the presence of water-soluble polymers in the grafted UHMWPE. The characteristic peaks of water-soluble polymers became sharper in the grafted UHMWPE. SEM analysis revealed that the grafting occurs both on fiber and microparticles of UHMWPE while flowing characteristic of powder is retained.

  8. Modulation of friction dynamics in water by changing the combination of the loop- and graft-type poly(ethylene glycol) surfaces.

    Science.gov (United States)

    Seo, Ji-Hun; Tsutsumi, Yusuke; Kobari, Akinori; Shimojo, Masayuki; Hanawa, Takao; Yui, Nobuhiko

    2015-02-07

    A Velcro-like poly(ethylene glycol) (PEG) interface was prepared in order to control the friction dynamics of material surfaces. Graft- and loop-type PEGs were formed on mirror-polished Ti surfaces using an electrodeposition method with mono- and di-amine functionalized PEGs. The friction dynamics of various combinations of PEG surfaces (i.e., graft-on-graft, loop-on-loop, graft-on-loop, and loop-on-graft) were investigated by friction testing. Here, only the Velcro-like combinations (graft-on-loop and loop-on-graft) exhibited a reversible friction behavior (i.e., resetting the kinetic friction coefficient and the reappearance of the maximum static friction coefficient) during the friction tests. The same tendency was observed when the molecular weights of loop- and graft-type PEGs were tested at 1 k and 10 k, respectively. This indicates that a Velcro-like friction behavior could be induced by simply changing the conformation of PEGs, which suggests a novel concept of altering polymer surfaces for the effective control of friction dynamics.

  9. Effect of block composition on thermal properties and melt viscosity of poly[2-(dimethylaminoethyl methacrylate], poly(ethylene oxide and poly(propylene oxide block co-polymers

    Directory of Open Access Journals (Sweden)

    2011-09-01

    Full Text Available To modify the rheological properties of certain commercial polymers, a set of block copolymers were synthesized through oxyanionic polymerization of 2-(dimethylaminoethyl methacrylate to the chain ends of commercial prepolymers, namely poly(ethylene oxide (PEO, poly(ethylene oxide-block-poly(propylene oxide-block-poly(ethylene oxide (PEO-PPO-PEO, and poly(propylene oxide (PPO. The formed block copolymers were analysed with size exclusion chromatography and nuclear magnetic resonance spectroscopy in order to confirm block formation. Thermal characterization of the resulting polymers was done with differential scanning calorimetry. Thermal transition points were also confirmed with rotational rheometry, which was primarily used to measure melt strength properties of the resulting block co-polymers. It was observed that the synthesised poly[2-(dimethylaminoethyl methacrylate]-block (PDM affected slightly the thermal transition points of crystalline PEO-block but the influence was stronger on amorphous PPO-blocks. Frequency sweeps measured above the melting temperatures for the materials confirmed that the pre-polymers (PEO and PEO-PPO-PEO behave as Newtonian fluids whereas polymers with a PDM block structure exhibit clear shear thinning behaviour. In addition, the PDM block increased the melt viscosity when compared with that one of the pre-polymer. As a final result, it became obvious that pre-polymers modified with PDM were in entangled form, in the melted state as well in the solidified form.

  10. Synthesis and Properties of High Strength Thin Film Composites of Poly(ethylene Oxide and PEO-PMMA Blend with Cetylpyridinium Chloride Modified Clay

    Directory of Open Access Journals (Sweden)

    Mohammad Saleem Khan

    2015-01-01

    Full Text Available Ion-conducting thin film composites of polymer electrolytes were prepared by mixing high MW poly(ethylene oxide (PEO, poly(methyl methacrylate (PMMA as a polymer matrix, cetylpyridinium chloride (CPC modified MMT as filler, and different content of LiClO4 by using solution cast method. The crystallinity, ionic conductivity (σ, and mechanical properties of the composite electrolytes and blend composites were evaluated by using XRD, AC impedance, and UTM studies, respectively. The modification of clay by CPC showed enhancement in the d-spacing. The loading of clay has effect on crystallinity of PEO systems. Blend composites showed better mechanical properties. Young’s modulus and elongation at break values showed increase with salt and clay incorporation in pure PEO. The optimum composition composite of PEO with 3.5 wt% of salt and 3.3 wt% of CPMMT exhibited better performance.

  11. Radiation-Induced Grafting for the Synthesis of Adsorbents for Phosphate and Chromate Removal from Aqueous Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kavakli, P A; Kavakli, C; Guven, O [Department of Chemistry, Hacettepe University, Beytepe, 06800, Ankara (Turkey)

    2012-09-15

    Nonwoven fabrics made of PE coated PP fibres were irradiated by accelerated electrons in inert atmospheres for grafting of two different monomers, glycidyl methacrylate and dimethylaminoethyl methacrylate. Grafting conditions were optimized by a systematic investigation of the effects of absorbed dose, monomer concentration, grafting reaction temperature and duration. 150% grafted copolymers were later modified by protonation and quaternization of poly(dimethylaminoethyl methacrylate) chains and by Cu(II) loading of dipyridyl amine modified poly(glycidyl methacrylate) graft chains. The PE/PP based adsorbents thus prepared were used for their suitability of removing phosphate and chromate ions from aqueous systems. Adsorption/removal studies were carried out in both batch and continuous flow type systems. The selectivity of adsorption of phosphate ions in the presence of other competing anions were also checked showing the enhanced selectivity for phosphate ions. (author)

  12. Effect of barium-coated halloysite nanotube addition on the cytocompatibility, mechanical and contrast properties of poly(methyl methacrylate cement

    Directory of Open Access Journals (Sweden)

    Jammalamadaka U

    2017-06-01

    Full Text Available Uday Jammalamadaka,1 Karthik Tappa,1 Jeffery A Weisman,1 James Connor Nicholson,2 David K Mills1,3 1Center for Biomedical Engineering and Rehabilitation Science, 2Nanosystems Engineering, 3The School of Biological Sciences, Louisiana Tech University, Ruston, LA, USA Abstract: Halloysite nanotubes (HNTs were investigated as a platform for tunable nanoparticle composition and enhanced opacity in poly(methyl methacrylate (PMMA bone cement. Halloysite has been widely used to increase the mechanical properties of various polymer matrices, in stark contrast to other fillers such as barium sulfate that provide opacity but also decrease mechanical strength. The present work describes a dry deposition method for successively fabricating barium sulfate nanoparticles onto the exterior surface of HNTs. A sintering process was used to coat the HNTs in barium sulfate. Barium sulfate-coated HNTs were then added to PMMA bone cement and the samples were tested for mechanical strength and tailored opacity correlated with the fabrication ratio and the amount of barium sulfate-coated HNTs added. The potential cytotoxic effect of barium-coated HNTs in PMMA cement was also tested on osteosarcoma cells. Barium-coated HNTs were found to be completely cytocompatible, and cell proliferation was not inhibited after exposure to the barium-coated HNTs embedded in PMMA cement. We demonstrate a simple method for the creation of barium-coated nanoparticles that imparted improved contrast and material properties to native PMMA. An easy and efficient method for coating clay nanotubes offers the potential for enhanced imaging by radiologists or orthopedic surgeons. Keywords: barium, bone cement, halloysite, imaging, PMMA, sintering

  13. Synthesis of Isotactic-block-Syndiotactic Poly(methyl Methacrylate via Stereospecific Living Anionic Polymerizations in Combination with Metal-Halogen Exchange, Halogenation, and Click Reactions

    Directory of Open Access Journals (Sweden)

    Naoya Usuki

    2017-12-01

    Full Text Available Isotactic (it- and syndiotactic (st- poly(methyl methacrylates (PMMAs form unique crystalline stereocomplexes, which are attractive from both fundamental and application viewpoints. This study is directed at the efficient synthesis of it- and st-stereoblock (it-b-st- PMMAs via stereospecific living anionic polymerizations in combination with metal-halogen exchange, halogenation, and click reactions. The azide-capped it-PMMA was prepared by living anionic polymerization of MMA, which was initiated with t-BuMgBr in toluene at –78 °C, and was followed by termination using CCl4 as the halogenating agent in the presence of a strong Lewis base and subsequent azidation with NaN3. The alkyne-capped st-PMMA was obtained by living anionic polymerization of MMA, which was initiated via an in situ metal-halogen exchange reaction between 1,1-diphenylhexyl lithium and an α-bromoester bearing a pendent silyl-protected alkyne group. Finally, copper-catalyzed alkyne-azide cycloaddition (CuAAC between these complimentary pairs of polymers resulted in a high yield of it-b-st-PMMAs, with controlled molecular weights and narrow molecular weight distributions. The stereocomplexation was evaluated in CH3CN and was affected by the block lengths and ratios.

  14. Effect of Reinforcement Using Stainless Steel Mesh, Glass Fibers, and Polyethylene on the Impact Strength of Heat Cure Denture Base Resin - An In Vitro Study.

    Science.gov (United States)

    Murthy, H B Mallikarjuna; Shaik, Sharaz; Sachdeva, Harleen; Khare, Sumit; Haralur, Satheesh B; Roopa, K T

    2015-06-01

    The impact strength of denture base resin is of great concern and many approaches have been made to strengthen acrylic resin dentures. The objective of this study was to compare the impact strength of the denture base resin with and without reinforcement and to evaluate the impact strength of denture base resin when reinforced with stainless steel mesh, glass fiber, and polyethylene fibers in the woven form. The specimens (maxillary denture bases) were fabricated using a standard polyvinylsiloxane mold with conventional heat cured polymethyl methacrylate resin. The specimens were divided into four groups (n = 10). Group I specimens or control group were not reinforced. Group II specimens were reinforced with stainless steel mesh and Group III and Group IV specimens were reinforced with three percent by weight of glass fibers and polyethylene fibers in weave form respectively. All the specimens were immersed in water for 1-week before testing. The impact strength was measured with falling weight impact testing machine. One-way analysis of variance and Tukey's post-hoc test were used for statistical analysis. Highest impact strength values were exhibited by the specimens reinforced with polyethylene fibers followed by glass fibers, stainless steel mesh, and control group. Reinforcement of maxillary complete dentures showed a significant increase in impact strength when compared to unreinforced dentures. Polyethylene fibers exhibit better impact strength followed by glass fibers and stainless steel mesh. By using pre-impregnated glass and polyethylene fibers in woven form (prepregs) the impact strength of the denture bases can be increased effectively.

  15. Making continuous bubble type polyethylene foam incombustible

    International Nuclear Information System (INIS)

    Kaji, Kanako; Hatada, Motoyoshi; Yoshizawa, Iwao; Komai, Kuniaki; Kohara, Choji.

    1989-01-01

    Since continuous bubble type plastic foam has excellent compression characteristics and sound absorption characteristics, it has been widely used as cushion material, sealing material, sound insulating material and so on. However, the most part of plastic foam is taken by air, therefore at the time of fires, it becomes a very dangerous material. At present, the material used mostly as the seat cushions for airliners, railroad coaches, automobiles and others is polyurethane foam, but since it contains C-N couples in its molecules, it is feared to generate cyanic gas according to the condition of combustion. As the plastic foam that does not generate harmful gas at the time of fires, there is continuous bubble type polyethylene which is excellent in its weathering property and chemical resistance. A reactive, phosphorus-containing oligomer has large molecular weight and two or more double couplings in a molecule, therefore, it does not enter the inside of polyethylene, and polymerizes and crosslinks on the surfaces of bubble walls in the foam, accordingly it is expected that the apparent graft polymerization is carried out, and it is very effective for making polyethylene foam incombustible. The method of making graft foam, the properties of graft foam and so on are reported. When the graft polymerization of this oligomer to continuous bubble type polyethylene foam was tried, highly incombustible polyethylene foam was obtained. (K.I.)

  16. Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingjing, E-mail: jjwang1@hotmail.com; Wei, Jun

    2016-09-30

    Highlights: • Crosslinked hydrogel brushes were grafted from SS surfaces for marine antifouling. • All brush-coated SS surfaces could effectively reduce the adhesion of biofouling. • The antifouling efficacy increased with the crosslinking density of hydrogels. - Abstract: Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

  17. Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

    International Nuclear Information System (INIS)

    Wang, Jingjing; Wei, Jun

    2016-01-01

    Highlights: • Crosslinked hydrogel brushes were grafted from SS surfaces for marine antifouling. • All brush-coated SS surfaces could effectively reduce the adhesion of biofouling. • The antifouling efficacy increased with the crosslinking density of hydrogels. - Abstract: Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

  18. Phase behavior for the poly(alkyl methacrylate)+supercritical CO{sub 2}+DME mixture at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong-Seok; Chio, Sang-Won; Byun, Hun-Soo [Chonnam National University, Yeosu (Korea, Republic of)

    2016-01-15

    The phase behavior curves of binary and ternary system were measured for poly(alkyl methacrylate) in supercritical CO{sub 2}, as well as for the poly(alkyl methacrylate)+dimethyl ether (DME) (or 1-butene) in CO{sub 2}. The solubility curves are reported for the poly(alkyl methacrylate)+DME in supercritical CO{sub 2} at temperature from (300 to 465) K and a pressure from (3.66 to 248) MPa. Also, The high-pressure static-type apparatus of cloud-point curve was tested by comparing the measured phase behavior data of the poly(methyl methacrylate) [PMMA]+CO{sub 2}+20.0 and 30.4 wt% methyl methacrylate (MMA) system with literature data of 10.4, 28.8 and 48.4 wt% MMA concentration. The phase behavior data for the poly(alkyl methacrylate)+CO{sub 2}+DME mixture were measured in changes of the pressure-temperature (p, T) slope and with DME concentrations. Also, the cloud-point pressure for the poly(alkyl methacrylate)+1- butene solution containing supercritical CO{sub 2} shows from upper critical solution temperature (UCST) region to lower critical solution temperature (LCST) region at concentration range from (0.0 to 95) wt% 1-butene at below 455 K and at below 245MPa.

  19. Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder. Part II: Thermal, FTIR and morphological characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Aydinli, Bahattin; Tincer, Teoman E-mail: teotin@metu.edu.tr

    2001-10-01

    Radiation induced grafted polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamide (PAAm), poly N,N-dimethyl acrylamide (PNDAAm) and poly 1-vinyl-2 pyrrolidone (PVP) on ultra-high molecular weight polyethylene (UHMWPE) were characterised by DSC, FTIR and SEM analysis. While the effect of irradiation on pure UHMWPE was found to increase crystallinity and cause higher enthalpy of crystallisation, grafted UHMWPE powders showed lower crystallinity and enthalpy of crystallisation. In all grafted UHMWPE there existed secondary transitions corresponding to grafting polymers in the first run of DSC above 60 deg. C and they became clearer at a higher grafting level. In the second run of DSC some T{sub g} values appeared to shift to higher temperatures while some were not detected. FTIR analysis indicated the presence of water-soluble polymers in the grafted UHMWPE. The characteristic peaks of water-soluble polymers became sharper in the grafted UHMWPE. SEM analysis revealed that the grafting occurs both on fiber and microparticles of UHMWPE while flowing characteristic of powder is retained.

  20. Encapsulation of Piper cabralanum (Piperaceae) nonpolar extract in poly(methyl methacrylate) by miniemulsion and evaluation of increase in the effectiveness of antileukemic activity in K562 cells.

    Science.gov (United States)

    Mendes, Anderson Nogueira; Filgueiras, Lívia Alves; Siqueira, Monica Regina Pimentel; Barbosa, Gleyce Moreno; Holandino, Carla; de Lima Moreira, Davyson; Pinto, José Carlos; Nele, Marcio

    2017-01-01

    This study aimed to synthesize and characterize nanoparticles (NPs) of poly(methyl methacrylate) (PMMA) and evaluate their ability to incorporate plant extracts with antitumor activity and low dissolution in aqueous media. The extract used was n -hexane partition of the methanol extract of Piper cabralanum (PCA-HEX). PMMA NPs were obtained using the mini-emulsion method, which was able to encapsulate almost 100% of PCA-HEX. The synthesized polymeric particles presented with a size of 200 nm and a negative charge. Cytotoxicity tests by MTT and trypan blue assays showed that NPs without PCA-HEX did not kill leukemic cells (K562 cells). NPs containing PCA-HEX were able to enhance cell death when compared to pure extract. The results showed that PMMA NPs could be useful as a drug delivery system as they can enhance the antitumor activity of the PCA-HEX extract by more than 20-fold. PMMA NPs containing plant extracts with antitumor activities may be an alternative to control the evolution of diseases such as leukemia.

  1. Effects of alumina nanoparticles on the microstructure, strength and wear resistance of poly(methyl methacrylate)-based nanocomposites prepared by friction stir processing.

    Science.gov (United States)

    Aghajani Derazkola, Hamed; Simchi, Abdolreza

    2018-03-01

    In this study, alumina-reinforced poly(methyl methacrylate) nanocomposites (PMMA/Al 2 O 3 ) containing up to 20vol% nanoparticles with an average diameter of 50nm were prepared by friction stir processing. The effects of nanoparticle volume fraction on the microstructural features and mechanical properties of PMMA were studied. It is shown that by using a frustum pin tool and employing an appropriate processing condition, i.e. a rotational speed of 1600rpm/min and transverse velocity of 120mm/min, defect free nanocomposites at microscale with fine distribution of the nanoparticles can successfully been prepared. Mechanical evaluations including tensile, flexural, hardness and impact tests indicate that the strength and toughness of the material gradually increases with the nanoparticle concentration and reach to a flexural strength of 129MPa, hardness of 101 Shore D, and impact energy 2kJ/m 2 for the nanocomposite containing 20vol% alumina. These values are about 10% and 20% better than untreated and FSP-treated PMMA (without alumina addition). Fractographic studies indicate typical brittle features with crack deflection around the nanoparticles. More interestingly, the sliding wear rate in a pin-on-disk configuration and the friction coefficient are reduced up to 50% by addition of alumina nanoparticles. The worn surfaces exhibit typical sliding and ploughing features. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Photografting of perfluoroalkanes onto polyethylene surfaces via azide/nitrene chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Siegmann, Konstantin, E-mail: konstantin.siegmann@zhaw.ch [Institute of Materials and Process Engineering (IMPE), School of Engineering (SoE), Zurich University of Applied Sciences - ZHAW, Technikumstrasse 9, CH-8401 Winterthur (Switzerland); Inauen, Jan, E-mail: jan.inauen@zhaw.ch [Institute of Materials and Process Engineering (IMPE), School of Engineering (SoE), Zurich University of Applied Sciences - ZHAW, Technikumstrasse 9, CH-8401 Winterthur (Switzerland); Villamaina, Diego, E-mail: diego.villamaina@gmail.com [Visiting scientist at IMPE, Permanent address: Rapidplatz 3, CH-8953 Dietikon (Switzerland); Winkler, Martin, E-mail: martin.winkler@zhaw.ch [Institute of Materials and Process Engineering (IMPE), School of Engineering (SoE), Zurich University of Applied Sciences - ZHAW, Technikumstrasse 9, CH-8401 Winterthur (Switzerland)

    2017-02-28

    The purpose of this study is to render polyethylene surfaces strongly and permanently hydrophobic. Polyethylene is a common plastic and, because of its inertness, difficult to graft. We chose polyethylene as example because of its ubiquity and model character. As graft chains linear perfluoroalkyl residues (−C{sub 4}F{sub 9}, −C{sub 6}F{sub 13}, −C{sub 8}F{sub 17} and −C{sub 10}F{sub 21}) were chosen, and photografting was selected as grafting method. Photolytically generated nitrenes can insert into carbon–hydrogen bonds and are therefore suited for binding to polyethylene. Hydrophobic photo reactive surface modifiers based on azide/nitrene chemistry are designed, synthesized in high yield and characterized. Four new molecules are described. Water contact angles exceeding 110° were achieved on grafted polyethylene. One problem is to demonstrate that the photografted surface modifiers are bound covalently to the polyethylene. Abrasion tests show that all new molecules, when photografted to polyethylene, have a higher abrasion resistance than a polyethylene surface coated with a long-chain perfluoroalkane. Relative abrasion resitances of 1.4, 2.0, 2.1 and 2.5 compared to the fluoroalkane coating were obtained for the four compounds. An abrasion model using ice is developed. Although all four compounds have the same λ{sub max} of 266 nm in acetonitrile solution, their molar extincition coefficients increase from 1.6·10{sup 4} to 2.2·10{sup 4} with increasing length of the fluorotelomer chain. Exitonic coupling of the chromophores of the surface modifiers is observed for specific molecules in the neat state. A linear correlation of water contact angle with fluorine surface content, as measured by photoelectron spectroscopy, in grafted polyethylene surfaces is established.

  3. Radiation-grafted hydrogels for biomaterial applications as studied by the ESCA technique

    International Nuclear Information System (INIS)

    Ratner, B.D.; Weathersby, P.K.; Hoffman, A.S.; Kelly, M.A.; Schrapen, L.H.

    1978-01-01

    Electron spectroscopy for chemical analysis (ESCA) was used to study the surface composition of several radiation-grafted polymers in both the dry and hydrated (frozen at 160 0 K) states. Poly(2-hydroxyethyl methacrylate) (HEMA) and polyacrylamide, both hydrophilic polymers, were readily detected in the hydrated or dehydrated states when grafted to polethylene substrates. For silicone rubber substrates, both grafts were observed on the hydrated surface but were significantly decreased in surface concentration upon dehydration. For grafts on a polyester-urethane, acrylamide was not a major constituent of either the dry or hydrated surface, while HEMA appeared to increase in abundance upon drying. The amount of the hydrophobic poly(ethyl methacrylate) found on the graft surface depended upon the substrate polymer used, but the surface abundance of poly(ethyl methacrylate) was not affected by drying. These results were considered in terms of polar group orientation, polymer chain mobility, substrate permeability, and the limitations of the ESCA technique. The implications of these results with respect to the use of radiation-grafted hydrophilic polymers for biomedical applications are also discussed

  4. Preparation and characterization of PVDF separators for lithium ion cells using hydroxyl-terminated polybutadiene grafted methoxyl polyethylene glycol (HTPB-g-MPEG) as additive

    Science.gov (United States)

    Li, Hao; Niu, Dong-Hui; Zhou, Hui; Chao, Chun-Ying; Wu, Li-Jun; Han, Pei-Lin

    2018-05-01

    Hydroxyl-terminated polybutadiene grafted methoxyl polyethylene glycol (HTPB-g-MPEG) with different arm length were synthesized by grafting methoxyl poly(ethylene glycol)s (MPEGs, Mn = 350, 750, 1900 and 5000, respectively) to the hydroxyl-terminated polybutadiene (HTPB) molecule using isophorone diisocyanate (IPDI) as the coupling agent, and blended with PVDF to fabricate porous separators via phase inversion process. By measuring the composition, morphology and ion conductivity etc., the influence of HTPB-g-MPEG on structure and property of blend separators were discussed. Compared with pure PVDF separator with comparable porous structure, the adoption of HTPB-g-MPEG could not only decrease the crystallinity, but also enhance the stability of entrapped liquid electrolyte and corresponding ion conductivity. The cells assembled with such separators showed good initial discharge capacity and cyclic stability.

  5. Thermal and mechanical properties of novel nanocomposites from modified ordered mesoporous carbon FDU-15 and poly(methyl methacrylate)

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadnezhad, Gholamhossein, E-mail: mohammadnezhad@cc.iut.ac.ir; Dinari, Mohammad, E-mail: dinari@cc.iut.ac.ir; Soltani, Roozbeh; Bozorgmehr, Zahra

    2015-08-15

    Graphical abstract: - Highlights: • The surface of mesoporous carbon, FDU-15, was modified by 3-mercaptopropyl-trimethoxysilane. • Nanocomposites of PMMA and modified FDU-15 were prepared by solution polymerization. • XRD shows that modified mesoporous FDU-15 has an ordered hexagonal mesostructure. • TEM and SEM images confirm the presence of large pores and ordered mesostructure. • Mechanical data indicated improvement in the tensile strength and modulus. - Abstract: With its well-ordered pore structure, high specific surface area and tunable pore diameters, ordered mesoporous carbons are suitable for applications in many areas of modern science and technology. In the present investigation, an ultrasonic irradiation was used for the modification of the mesoporous carbon FDU-15. Three nanocomposite films of the poly(methyl methacrylate) (PMMA) and modified FDU-15 were prepared by solution polymerization technique. The surface morphology and thermal and mechanical properties of the hybrid materials were evaluated by different methods. X-ray diffraction patterns showed that modified mesoporous FDU-15 had an ordered hexagonal mesostructure. Transmission electron microscopy (TEM) and field emission-scanning electron microscopy images confirmed the presence of large pores and a relatively ordered mesostructure for the functionalized materials. Thermogravimetric analysis data also revealed that the onset of decomposition temperature of the nanocomposites was higher than that of pristine PMMA, shifting toward higher temperatures as the amount of modified-FDU was increased. TEM images showed the well-ordered hexagonal arrays of mesopores FDU-15. Mechanical data indicated the improvement in the tensile strength and modulus with the modified FDU-15 loading. The film containing 1 wt.% of modified FDU-15 had a tensile strength of the order of 42 MPa, relative to the 28 MPa of the pristine PMMA.

  6. Thermal and mechanical properties of novel nanocomposites from modified ordered mesoporous carbon FDU-15 and poly(methyl methacrylate)

    International Nuclear Information System (INIS)

    Mohammadnezhad, Gholamhossein; Dinari, Mohammad; Soltani, Roozbeh; Bozorgmehr, Zahra

    2015-01-01

    Graphical abstract: - Highlights: • The surface of mesoporous carbon, FDU-15, was modified by 3-mercaptopropyl-trimethoxysilane. • Nanocomposites of PMMA and modified FDU-15 were prepared by solution polymerization. • XRD shows that modified mesoporous FDU-15 has an ordered hexagonal mesostructure. • TEM and SEM images confirm the presence of large pores and ordered mesostructure. • Mechanical data indicated improvement in the tensile strength and modulus. - Abstract: With its well-ordered pore structure, high specific surface area and tunable pore diameters, ordered mesoporous carbons are suitable for applications in many areas of modern science and technology. In the present investigation, an ultrasonic irradiation was used for the modification of the mesoporous carbon FDU-15. Three nanocomposite films of the poly(methyl methacrylate) (PMMA) and modified FDU-15 were prepared by solution polymerization technique. The surface morphology and thermal and mechanical properties of the hybrid materials were evaluated by different methods. X-ray diffraction patterns showed that modified mesoporous FDU-15 had an ordered hexagonal mesostructure. Transmission electron microscopy (TEM) and field emission-scanning electron microscopy images confirmed the presence of large pores and a relatively ordered mesostructure for the functionalized materials. Thermogravimetric analysis data also revealed that the onset of decomposition temperature of the nanocomposites was higher than that of pristine PMMA, shifting toward higher temperatures as the amount of modified-FDU was increased. TEM images showed the well-ordered hexagonal arrays of mesopores FDU-15. Mechanical data indicated the improvement in the tensile strength and modulus with the modified FDU-15 loading. The film containing 1 wt.% of modified FDU-15 had a tensile strength of the order of 42 MPa, relative to the 28 MPa of the pristine PMMA

  7. Effect of Storage in Distilled Water for Three Months on the Antimicrobial Properties of Poly(methyl methacrylate Denture Base Material Doped with Inorganic Filler

    Directory of Open Access Journals (Sweden)

    Grzegorz Chladek

    2016-04-01

    Full Text Available The colonization of poly(methyl methacrylate (PMMA denture base materials by pathogenic microorganisms is a major problem associated with the use of prostheses, and the incorporation of antimicrobial fillers is a method of improving the antimicrobial properties of these materials. Numerous studies have demonstrated the initial in vitro antimicrobial effectiveness of this type of material; however, reports demonstrating the stability of these fillers over longer periods are not available. In this study, silver sodium hydrogen zirconium phosphate was introduced into the powder component of a PMMA denture base material at concentrations of 0.25%, 0.5%, 1%, 2%, 4%, and 8% (w/w. The survival rates of the gram-positive bacterium Staphylococcus aureus, gram-negative bacterium Escherichia coli and yeast-type fungus Candida albicans were established after fungal or bacterial suspensions were incubated with samples that had been previously stored in distilled water. Storage over a three-month period led to the progressive reduction of the initial antimicrobial properties. The results of this study suggest that additional microbiological tests should be conducted for materials that are treated with antimicrobial fillers and intended for long-term use. Future long-term studies of the migration of silver ions from the polymer matrix and the influence of different media on this ion emission are required.

  8. Biocompatible and Biodegradable Ultrafine Nanoparticles of Poly(Methyl Methacrylate-co-Methacrylic Acid Prepared via Semicontinuous Heterophase Polymerization: Kinetics and Product Characterization

    Directory of Open Access Journals (Sweden)

    Henned Saade

    2016-01-01

    Full Text Available Ultrafine nanoparticles, less than 10 nm in mean diameter, of the FDA approved copolymer methyl methacrylate- (MMA- co-methacrylic acid (MAA, 2/1 (mol/mol, were prepared. The method used for the preparation of these particles stabilized in a latex containing around 11% solids includes the dosing of the monomers mixture on a micellar solution preserving monomer starved conditions. It is thought that the operation at these conditions combined with the hydrophilicity of MMA and MAA units favors the formation of ultrafine particles; the propagation reaction carried out within so small compartments renders copolymer chains rich in syndiotactic units very likely as consequence of the restricted movements of the end propagation of the chains. Because of their biocompatibility and biodegradability as well as their extremely small size these nanoparticles could be used as vehicles for improved drug delivery in the treatment of chronic-degenerative diseases.

  9. Polymerization by radiation. Application

    International Nuclear Information System (INIS)

    Romero, M.; Fernandez Miranda, J.

    1997-01-01

    Achieved results of the research work done in the field of radiation polymerization are summarized. Developing new chromatographic matrices, the radiation grafting of Glycidyl methacrylate on the surface of Low Density Polyethylene beads was studied. The dependence of both, the grafted degree and width of the grafted layer, with the radiation dose applied, is presented

  10. Functionalization of polypropylene by radiation grafting of acryloyl chloride and sterification with disperse red

    International Nuclear Information System (INIS)

    Bucio, E.; Burillo, G.; Carreon, M.P.; Ogawa, T.

    2002-01-01

    Complete text of publication follows. A practical method for obtaining films containing functional groups on the surface, is the gamma ray-induced grafting of acryloyl or methacryloyl chloride on the films, followed by the reaction of hydroxy or amino groups of the functional compounds. Direct grafting of acrylates or methacrylates with bulky functional groups onto films of polyethylene, polypropylene, polycarbonate, etc, is often encounter difficulty in polymerization of bulky monomers, loss due to homopolymerization, etc. In this work, polypropylene (PP) films were irradiated by gamma rays of Co-60 (Gamma Beam 651 PT source) and grafted with acryloyl chloride; grafting was carried out by direct and phase vapor direct method, at a dose rate of 5.1 kGy/h, different acryloyl concentration on toluene, and doses from 1 to 5 kGy, at room temperature. The unreacted acryloyl chloride and its homopolymer were removed by chloroform extraction. The grafted poly(acryloyl chloride) was then reacted with Disperse Red 1,2-[4-(4-nitrophenylazo)-N-ethylphenylamino] ethanol. The grafted films were characterized by NMR, FTIR-ATR, Visible Spectroscopy, DSC, X-ray diffractometry, SEM, AFM, NMR of solids and Elemental Analysis. Scanning electron micrographs of fractured surfaces indicated that grafting took place not only on the surface of PP film, but the grafted polymer penetrated into the PP films. Thermochromic properties of the films were observed by FTIR and UV-VIS spectrophotometers at different temperatures. AFM showed depth profiles and average rough for samples with different percentage of graft

  11. Polymethyl methacrylate and polystyrene with layered double hydroxide nano composites: In situ synthesis, morphology and thermal properties; Nanocompositos de polimetacrilato de metila e poliestireno com hidroxido duplo lamelar: sintese in situ, morfologia e propriedades termicas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Over the past decade, polymer nanocomposites have attracted interest, both in industry and in academia, because they often exhibit remarkable improvement in their properties when compared with pure polymer or conventional micro and macro-composites using low levels of reinforcements. In this work polymethyl methacrylate and polystyrene reinforced with layered double hydroxide, which was intercalated with sodium dodecyl sulfate were synthesized by in situ bulk polymerization. The nanocomposites were characterized and compared by X-ray diffraction, thermogravimetric analysis and flammability test. The X-ray diffraction demonstrated that synthesized nanocomposites showed a high global dispersion of layered double hydroxide, suggesting exfoliated morphology. The result of thermogravimetric analysis and flammability test for synthesized polystyrene/ layered double hydroxide nanocomposite presented a significant improvement in thermal stability and flammability property when compared with pure polymer. (author)

  12. Study and Optimization on graft polymerization under normal pressure and air atmospheric conditions, and its application to metal adsorbent

    International Nuclear Information System (INIS)

    Ueki, Yuji; Chandra Dafader, Nirmal; Hoshina, Hiroyuki; Seko, Noriaki; Tamada, Masao

    2012-01-01

    Radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto non-woven polyethylene (NWPE) fabric was achieved under normal pressure and air atmospheric conditions, without using unique apparatus such as glass ampoules or vacuum lines. To attain graft polymerization under normal pressure and air atmospheric conditions, the effects of the pre-irradiation dose, pre-irradiation atmosphere, pre-irradiation temperature, de-aeration of GMA-emulsion, grafting atmosphere in a reactor, and dissolved oxygen (DO) concentration in GMA-emulsion on the degree of grafting (Dg) were investigated in detail. It was found that the DO concentration had the strongest influence, the pre-irradiation dose, de-aeration of emulsion and grafting atmosphere had a relatively strong impact, and the pre-irradiation atmosphere and pre-irradiation temperature had the least effect on Dg. The optimum DO concentration before grafting was 2.0 mg/L or less. When a polyethylene bottle was used as a reactor instead of a glass ampoule, graft polymerization under normal pressure and air atmospheric conditions could be achieved under the following conditions; the pre-irradiation dose was more than 50 kGy, the volume ratio of GMA-emulsion to air was 50:1 or less, and the DO concentration in GMA-emulsion during grafting was below 2.0 mg/L. Under these grafting conditions, Dg was controlled within a range of up to 362%. The prepared GMA–grafted NWPE (GMA–g-NWPE) fabric was modified with a phosphoric acid to obtain an adsorbent for heavy metal ions. In the column-mode adsorption tests of Pb(II), the adsorption performance of the produced phosphorylated GMA–g-NWPE fabric (fibrous metal adsorbent) was not essentially dependent on the flow rate of the feed. The breakthrough points of 200, 500, and 1000 h −1 in space velocity were 483, 477 and 462 bed volumes, and the breakthrough capacities of the three flow rates were 1.16, 1.15 and 1.16 mmol-Pb(II)/g-adsorbent.

  13. Study and Optimization on graft polymerization under normal pressure and air atmospheric conditions, and its application to metal adsorbent

    Science.gov (United States)

    Ueki, Yuji; Chandra Dafader, Nirmal; Hoshina, Hiroyuki; Seko, Noriaki; Tamada, Masao

    2012-07-01

    Radiation-induced graft polymerization of glycidyl methacrylate (GMA) onto non-woven polyethylene (NWPE) fabric was achieved under normal pressure and air atmospheric conditions, without using unique apparatus such as glass ampoules or vacuum lines. To attain graft polymerization under normal pressure and air atmospheric conditions, the effects of the pre-irradiation dose, pre-irradiation atmosphere, pre-irradiation temperature, de-aeration of GMA-emulsion, grafting atmosphere in a reactor, and dissolved oxygen (DO) concentration in GMA-emulsion on the degree of grafting (Dg) were investigated in detail. It was found that the DO concentration had the strongest influence, the pre-irradiation dose, de-aeration of emulsion and grafting atmosphere had a relatively strong impact, and the pre-irradiation atmosphere and pre-irradiation temperature had the least effect on Dg. The optimum DO concentration before grafting was 2.0 mg/L or less. When a polyethylene bottle was used as a reactor instead of a glass ampoule, graft polymerization under normal pressure and air atmospheric conditions could be achieved under the following conditions; the pre-irradiation dose was more than 50 kGy, the volume ratio of GMA-emulsion to air was 50:1 or less, and the DO concentration in GMA-emulsion during grafting was below 2.0 mg/L. Under these grafting conditions, Dg was controlled within a range of up to 362%. The prepared GMA-grafted NWPE (GMA-g-NWPE) fabric was modified with a phosphoric acid to obtain an adsorbent for heavy metal ions. In the column-mode adsorption tests of Pb(II), the adsorption performance of the produced phosphorylated GMA-g-NWPE fabric (fibrous metal adsorbent) was not essentially dependent on the flow rate of the feed. The breakthrough points of 200, 500, and 1000 h-1 in space velocity were 483, 477 and 462 bed volumes, and the breakthrough capacities of the three flow rates were 1.16, 1.15 and 1.16 mmol-Pb(II)/g-adsorbent.

  14. Radiation grafting of hydrophilic monomers on to plasticized poly(vinyl chloride) sheets: Pt. 1

    International Nuclear Information System (INIS)

    Kalliyana Krishnan, V.; Jayakrishnan, A.; Francis, J.D.

    1990-01-01

    Medical-grade plasticized polyvinyl chloride (PVC) sheets were surface modified using gamma-radiation grafting of a combination of hydrophilic monomers based on 2-hydroxyethyl methacrylate (HEMA) and N-vinyl pyrrolidone (NVP). The properties of the modified surfaces were evaluated using contact angle measurements, phase-contrast photomicroscopy and scanning electron microscopy. Surface energy calculations indicated that the surfaces became highly hydrophilic when grafted with even a 1% (v/v) solution of HEMA-NVP combination in the presence of 0.005 M CuSO 4 . Migration of the plasticizer di(2-ethylhexyl phthalate) from the grafted sheets was examined in hydrocarbon solvents such as n-hexane, n-heptane and n-octane and in extractant media such as cotton seed oil and polyethylene glycol-400 (PEG-400). The migration was found to be 0 C over a period of 5 h. Accelerated leaching studies in cotton seed oil and PEG-400 demonstrated that virtually no plasticizer migrated out in the former over a period of 96 h whereas the rate of migration in the latter medium showed only a mild reduction. The migration behaviour was Fickian in nature for grafted sheets. The method described may be useful as a simple, versatile technique for preventing plasticizer migration from plasticized PVC for medical applications. (author)

  15. Gelation of photopolymerized hyaluronic acid grafted with glycidyl methacrylate

    International Nuclear Information System (INIS)

    Prado, S.S.; Weaver, J.M.; Love, B.J.

    2011-01-01

    Experiments have tracked the ambient gelation of a series of hydrophilic hyaluronic acid (HA) resins grafted with glycidyl methacrylate (GM) and photopolymerized as a function of dose. The resin mixtures range in GMHA concentration between 0.5 and 1.5% w/w in phosphate buffered saline (PBS). Illuminated at 20 mW/cm 2 , the dynamic viscosity (η(t)) has been tracked and characterized using the Boltzmann log-sigmoidal model. A gelled viscosity of ∼ 10 Pa s was determined at 0.5% w/w which rose to ∼ 50 Pa s at or above 1% w/w. More curing agent marginally increased the gel viscosity at each concentration. Time constants associated with viscosity advancement were shortest at [GMHA] = 1.0%; higher concentrations are attributed with lower quantum efficiency when illuminated. Subsequent frequency sweeps replicated already published work using similar GHMA concentrations in PBS. G' values ranged from 100 to 500 Pa over the formulation range with expected sensitivity to GMHA and curing agent concentration. Overall, the sigmoidal model represented this advancing viscosity data well, and further analysis of the physical significance of these model parameters may help in understanding photopolymerization of this complicated formulation more broadly. Highlights: → The ambient dynamic viscosity of photopolymerized GMHA gels has been measured. → 2 physical parameters and two time constants were extracted from the sigmoidal model. → Higher crosslinker content for a fixed GMHA concentration led to higher gel viscosity. → The time to toggle between the initial and final viscosity ranged between 5 and 10 s. → Dynamic frequency sweep tests on cured gels also revealed G' values between 100 and 500 Pa.

  16. KINETICS OF SUSPENDED EMULSION POLYMERIZATION OF METHYL METHACRYLATE

    Institute of Scientific and Technical Information of China (English)

    Yong-zhong Bao; Cheng-xi Wang; Zhi-ming Huang; Zhi-xue Weng

    2004-01-01

    The kinetics of suspended emulsion polymerization of methyl methacrylate (MMA), in which water acted as the dispersed phase and the mixture of MMA and cyclohexane as the continuous phase, was investigated. It showed that the initial polymerization rate (Rp0) and steady-state polymerization rate (Rp) were proportional to the mass ratio between water and oil phase, and increased as the polymerization temperature, the potassium persulphate concentration ([I]) and the Tween20 emulsifier concentration ([S]) increased. The relationships between the polymerization rate and [I] and [S] were obtained as follows: Rp0 ∝ [I]0.73[S]0.32 and Rp ∝ [I]0.71[S]0.23. The above exponents were close to those obtained from normal MMA emulsion polymerization. It also showed that the average molecular weight of the resulting poly(methyl methacrylate) decreased as the polymerization temperature, [I] and [S] increased. Thus, MMA suspended emulsion polymerization could be considered as a combination of many miniature emulsion polymerizations proceeding in water drops and obeyed the classical kinetics of MMA emulsion polymerization.

  17. New membranes obtained by grafted irradiated PVDF foils

    International Nuclear Information System (INIS)

    Mazzei, R.; García Bermúdez, G.; Camporotondi, D.E.; Arbeitman, C.

    2012-01-01

    The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar + beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid–glycidyl methacrylate (AAc–GMA); acrylic acid–styrene (AAc–S), acrylic acid-N-isopropyl acrylamide (AAc–NIPAAm) and acrylic acid-N-isopropyl acrylamide–glycidyl methacrylate (AAc-NIPAAm–GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

  18. Synthesis of Monodispersed Gold Nanoparticles with Exceptional Colloidal Stability with Grafted Polyethylene Glycol-g-polyvinyl Alcohol

    Directory of Open Access Journals (Sweden)

    Alaaldin M. Alkilany

    2015-01-01

    Full Text Available Herein, we report the synthesis of spherical gold nanoparticles with tunable core size (23–79 nm in the presence of polyethylene glycol-g-polyvinyl alcohol (PEG-g-PVA grafted copolymer as a reducing, capping, and stabilizing agent in a one-step protocol. The resulted PEG-g-PVA-capped gold nanoparticles are monodispersed with an exceptional colloidal stability against salt addition, repeated centrifugation, and extensive dialysis. The effect of various synthesis parameters and the kinetic/mechanism of the nanoparticle formation are discussed.

  19. Allylthioketone Mediated Free Radical Polymerization of Methacrylates

    Directory of Open Access Journals (Sweden)

    Feng Zhong

    2017-11-01

    Full Text Available By combination of high trapping free radical efficiency of the thioketone and resonance of the allylic radical, a new type of mediating agent, 1,3,3-triphenylprop-2-ene-1-thione (TPPT has been successfully synthesized, and then is used to study controlled free radical polymerization of methacrylates. Very stable TPPT radicals at the end of poly(methyl methacrylate (PMMA are detected in the polymerization of MMA using TPPT and AIBN as the control agent and initiator. The MALDI-TOF MS spectra are used to identify terminal groups of the resultant poly(glycidyl methacrylate (PGMA, and major component of the obtained polymer has the structure, (CH32(CNC-PGMA-C7H9O3. Chain extension reaction tests ascertain formation of the dead polymers during the polymer storage and purification process of the polymers. Owing to very slow fragmentation reaction of the TPPT-terminated polymethacrylate radical and addition reaction of this radical with a primary radical, the growing chain radicals are difficult to be regenerated, leading to an unobvious change of the molecular weight with monomer conversion. The molecular weights of polymers can be controlled by the ratios of monomer/initiator and TPPT/initiator. However, the first order kinetics of the polymerization and the polymers with narrow polydispersity are obtained, and these phenomena are discussed. This study provides useful information on how to design a better controlling agent.

  20. Random laser based on Rhodamine 6G (Rh6G doped poly(methyl methacrylate (PMMA films coating on ZnO nanorods synthesized by hydrothermal oxidation

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    Full Text Available Random laser based on Rh6G doped PMMA thin films coating on ZnO nanorods synthesized by a simple hydrothermal oxidation method has been demonstrated. This kind of random laser medium is based on waveguide structure consisting of ZnO nanorods, Rh6G doped PMMA film and air. By controlling the time of hydrothermal oxidation reaction, wheat-like and hexagonal prism ZnO nanorods have been successfully fabricated. The emission spectra of these gain mediums based on different ZnO nanorods are different. The one based on wheat-like ZnO nanorods mainly exhibits amplified spontaneous emission, and the other one based on hexagonal prism ZnO nanorods shows random laser emission. The threshold of the random laser medium is about 73.8 μJ/pulse, and the full width at half maximum (FWHM is around 2.1 nm. The emission spectra measured at different detecting angles reveal that the output direction is strongly confined in ±30° by the waveguide effect. Our experiments demonstrate a promising method to achieve organic random laser medium. Keywords: Random laser, ZnO nanorods, Hydrothermal oxidation, Rhodamine 6G (Rh6G, Poly(methyl methacrylate (PMMA

  1. PEG Grafted-Nanodiamonds for the Delivery of Gemcitabine.

    Science.gov (United States)

    Lu, Mingxia; Wang, Yu-Kai; Zhao, Jiacheng; Lu, Hongxu; Stenzel, Martina H; Xiao, Pu

    2016-12-01

    Carboxyl end-functionalized poly[poly(ethylene glycol) methyl ether methacrylate] [P(PEGMEMA)] and its block copolymer with gemcitabine substituted poly(N-hydroxysuccinimide methacrylate) [PGem-block-P(PEGMEMA)] are synthesized via reversible addition-fragmentation transfer (RAFT) polymerization. Then, two polymers are grafted onto the surface of amine-functionalized nanodiamonds to obtain [P(PEGMEMA)]-grafted nanodiamonds (ND-PEG) and [PGem-block-P(PEGMEMA)]-grafted nanodiamonds (ND-PF). Gemcitabine is physically absorbed to ND-PEG to produce ND-PEG (Gem). Two polymer-grafted nanodiamonds (i.e., with physically absorbed gemcitabine ND-PEG (Gem) and with chemically conjugated gemcitabine ND-PF) are characterized using attenuated total reflectance infrared spectroscopy, dynamic light scattering, and thermogravimetric analysis. The drug release, cytotoxicity (to seed human pancreatic carcinoma AsPC-1 cells), and cellular uptake of ND-PEG (Gem) and ND-PF are also investigated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. New membranes obtained by grafted irradiated PVDF foils

    Energy Technology Data Exchange (ETDEWEB)

    Mazzei, R. [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Universidad Tecnologica Nacional Facultad Regional, Buenos Aires (Argentina); Garcia Bermudez, G. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad Nacional de General San Martin, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Camporotondi, D.E., E-mail: camporotondi@cae.cnea.gov.ar [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Arbeitman, C. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); and others

    2012-09-15

    The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar{sup +} beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid-glycidyl methacrylate (AAc-GMA); acrylic acid-styrene (AAc-S), acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid-N-isopropyl acrylamide-glycidyl methacrylate (AAc-NIPAAm-GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

  3. A sustained release system using porous cellulose spheres modified by grafting as matrices

    International Nuclear Information System (INIS)

    Hosoi, Fumio; Makuuchi, Keizo; Saito, Kenji; Koishi, Masumi.

    1987-01-01

    Polymer-coated spheres, obtained by the graft polymerization of methyl methacrylate (MMA) onto porous spheres based on cellulose by the pre-irradiation method, were used as matrices for the drug sustained release system for salicylic acid. The adsorption of salicylic acid was carried out by dipping the grafted spheres in a 50% aqueous ethanol solution containing salicylic acid. The amount of salicylic acid adsorbed (Q) increased proportionately with the percent graft of MMA (G) to the power of 2.9. Adsorption mechanism of salicylic acid could be expressed in term of Langmuir's adsorption isotherm. The ratio of constants for adsorption and desorption (k) and the saturated amount of salicylic acid adsorbed (Q 0 ) were expressed as k = k 1 G and Q 0 = k 2 G 2.4 , respectively. These results indicate that the number of adsorption sites increased proportionately with the nth power of G as a results of the interaction of grafted poly (methyl methacrylate)(PMMA) and cellulose. Similar results were obtained with grafting of MMA, MMA-styrene (St), and MMA-methacrylic acid (MAc) in the presence of salicylic acid. (author)

  4. Protective properties of radiation-modified polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Surnina, N.N.; Saltykova, L.A.; Strochkova, E.M.; Tatarenko, O.F.

    1986-09-01

    A study was made of the mass transfer of corrosive liquids and gases through polyethylene films modified by radiation surface grafting. Studies were performed on an unstabilized type A film with graft adhesion-active layer based on polymethacrylic acid. The protective properties of the polymer coating in corrosive fluids with low vapor tension were estimated by impedance measurements. Steel specimens with a protective coating of radiation-modified polyethylene film were exposed to 10% sulfuric acid at room temperature. The results indicated that the acid did not penetrate through to the metal surface. The films retain their protective properties and protect the metal from the acid. Radiation modification significantly improves the adhesion of polyethylene to metals without reducing physical and mechanical properties of the polymers. 50 references, 1 figure.

  5. pH-sensitive membranes for lithium separation

    International Nuclear Information System (INIS)

    Smolinska, Katarzyna; Bryjak, Marek; Wolska, Joanna; Kujawski, Wojciech

    2014-01-01

    Dielectric barrier discharge plasma was used to modify track etched poly(ethylene terephthalate) membranes followed by grafting of poly(acrylic acid) and copolymers of acrylic acid and di(ethylene glycol)methyl ether methacrylate. The evaluation by IR and XPS spectroscopies showed that both polymers were successfully grafted to the porous membranes. Determination of permeate fluxes pointed the membranes to have excellent responses to pH changes when grafting yield was not so high. When grafting exceeded 0.1 mg cm −2 stimuli response gel-filled membranes were formed that could be used for transport of alkaline ions. The best permselectivity was observed for poly(ethylene terephthalate) membranes grafted with 1:2 copolymer of acrylic acid and di(ethylene glycol)methyl ether methacrylate. The dialysis was more effectively facilitated for lithium than for potassium or sodium salts at solution of pH = 5.5. - Highlights: • Preparation of pore-filled stimuli response membranes that facilitate transport of alkaline salts. • pH controlled transport of alkaline salts. • Facilitation of lithium transport over sodium and potassium

  6. Preparation of well-defined erythromycin imprinted non-woven fabrics via radiation-induced RAFT-mediated grafting

    Science.gov (United States)

    Söylemez, Meshude Akbulut; Barsbay, Murat; Güven, Olgun

    2018-01-01

    Radiation-induced RAFT polymerization technique was applied to synthesize well-defined molecularly imprinted polymers (MIPs) of erythromycin (ERY). Methacrylic acid (MAA) was grafted onto porous polyethylene (PE)/polypropylene (PP) nonwoven fabrics, under γ-irradiation by employing 2-pheny-2-propyl benzodithioate as the RAFT agent and ethylene glycol dimethacrylate (EGDMA) as the crosslinker. MAA/erythromycin ratios of 2/1, 4/1, 6/1 were tested to optimize the synthesis of MIPs. The highest binding capacity was encountered at a MAA/ERY ratio of 4/1. Non-imprinted polymers (NIPs) were also synthesized in the absence of ERY. The MIPs synthesized by RAFT method presented a better binding capacity compared to those prepared by conventional method where no RAFT agent was employed.

  7. Mechanical and thermal properties of hydroxyapatite filled poly(methyl methacrylate) heat processed denture base material

    International Nuclear Information System (INIS)

    Mohamed, S.H.; Arifin, A.; Mohd Ishak, Z.A.; Nizam, A.; Samsudin, A.R.

    2004-01-01

    The aim of this study was to evaluate the effect of powder-to-liquid ratio on the glass transition temperature (Tg) and the tensile properties of denture base material prepared from poly (methyl methacrylate) (PMMA) and hydroxyapatite (HA) previously treated with 3-trimethoxysilylpropyl methacrylate (γ-MPS). Specimens for, mechanical testing were prepared by adding composites powder (PMMA, BPO and RA) to the monomer (MMA and EGDMA) followed by hand mixing as in dental laboratory description usage. The glass transition temperature was studied by using differential scanning calorimetry (DSQ. It was observed that the tensile properties and the Tg were affected by the powder-to-liquid ratio. The mechanical characterization of the materials were performed by using single edge notch-tension (SEN-T) specimens; the fracture toughness was slightly higher in formulation which contained RA filler compared to commercial denture base material. (Author)

  8. Radiation Induced Crosslinking of Polyethylene in the Presence of Bifunctional Vinyl Monomers

    DEFF Research Database (Denmark)

    Joshi, M. S.; Singer, Klaus Albert Julius; Silverman, J.

    1977-01-01

    Several reports have been published showing that the radiation induced grafting of bifunctional vinyl monomers to low density polyethylene results in a product with an unusually high density of crosslinks. The same grafting reactions are shown to reduce the incipient gel dose by more than a factor...... of fifty. This paper is concerned with the apparent crosslinking produced by the radiation grafting of two monomers to polyethylene: acrylic acid and acrylonitrile....

  9. Molecular dynamics modeling of polymer flammability

    International Nuclear Information System (INIS)

    Nyden, M.R.; Brown, J.E.; Lomakin, S.M.

    1992-01-01

    Molecular dynamic simulations were used to identify factors which promote char formation during the thermal degradation of polymers. Computer movies based on these simulations, indicate that cross-linked model polymers tend to undergo further cross-linking when burned, eventually forming a high molecular weight, thermally stable char. This paper reports that the prediction was confirmed by char yield measurements made on γ and e - -irradiated polyethylene and chemically cross-linked poly(methyl methacrylate)

  10. Morphological study and thermal analysis of surface modified α-FeOOH via in situ polymerization of methyl methacrylate

    International Nuclear Information System (INIS)

    Han Yaoxing; Ma Xinsheng; Cao Hongming; Zhang Haiying; Wu Qiufang

    2004-01-01

    Considering the interfacial characteristics of goethite (α-FeOOH, iron oxide yellow), the in situ polymerization of methyl methacrylate was employed to modify the surfaces of α-FeOOH pigments in aqueous slurry. The scanning electron micrographs indicated that the poly(methyl methacrylate) anchored on the surfaces of the particle homogeneously. From this study, it was found that one of the key requirements in the synthesis of the α-FeOOH-PMMA composite was to enhance interfacial compatibility between inorganic particles and organic monomer. Moreover, polymer-treated α-FeOOH particles were easily dispersed in organic medium to form a stable colloid and the heat resistance of α-FeOOH particles was improved

  11. Development of semi- and grafted interpenetrating polymer networks based on poly(ethylene glycol) diacrylate and collagen.

    Science.gov (United States)

    Madaghiele, Marta; Marotta, Francesco; Demitri, Christian; Montagna, Francesco; Maffezzoli, Alfonso; Sannino, Alessandro

    2014-12-30

    The objective of this work was to develop composite hydrogels based on poly(ethylene glycol) diacrylate (PEGDA) and collagen (Coll), potentially useful for biomedical applications. Semi-interpenetrating polymer networks (semi-IPNs) were obtained by photo-stabilizing aqueous solutions of PEGDA and acrylic acid (AA), in the presence of collagen. Further grafting of the collagen macromolecules to the PEGDA/poly(AA) network was achieved by means of a carbodiimide-mediated crosslinking reaction. The resulting hydrogels were characterized in terms of swelling capability, collagen content and mechanical properties. The grafting procedure was found to significantly improve the mechanical stability of the IPN hydrogels, due to the establishment of covalent bonding between the PEGDA/poly(AA) and the collagen networks. The suitability of the composite hydrogels to be processed by means of stereolithography (SLA) was also investigated, toward creating biomimetic constructs with complex shapes, which might be useful either as platforms for tissue engineering applications or as tissue mimicking phantoms.

  12. Correlation between molecular structure and self healing in a series of anthraquinone derivatives doped in poly(methyl methacrylate)

    Science.gov (United States)

    Dhakal, Prabodh

    Using absorbance spectroscopy and fluorescence spectroscopy as a probe, we studied photodegradation and recovery of a series of anthraquinone derivatives doped in (poly)methyl methacrylate (PMMA) thin films. We observed that many anthraquinone derivatives recover their optical properties after they are photodamaged. The mechanism that is responsible for their recovery is not well understood. Previous research, which uses non-linear methods such as Amplified spontaneous emission (ASE), two photon absorption, and indirect linear methods such as transmittance imaging, have focussed on one of the derivatives of the anthraquinone class named dispersed orange 11 (DO11) dye doped in PMMA. Since no direct measurements have yet been reported on a variety of anthraquinone derivatives, we have extended our research on a series of anthraquinone derivatives using direct measurement techniques such as linear absorption spectroscopy, fluorescence spectroscopy and photochroism measurements as a function of dye concentration and sample temperature. The data obtained from temperature-dependent photodecay and recovery as well as concentration-dependent photodecay are found to be in qualitative agreement with the Correlated Chromophore Domain Model (CCrDM). We also applied the depth dependent absorption model to estimate the degree of self-absorption of the fluorescence signal emitted by the sample. This analysis allows us to determine the depth dependent damage profile and time dependence of the damage profile. Our results show that damage decreases as a function of depth into the sample and increases as a function of time of exposure of the pump beam. The degree of self-absorption is found to increase with sample thickness. We also did a numerical analysis to find the intensity dependent decay rate constant alpha and the recovery rate beta for fluorescence. We then used the data to test the CCrDM to find the average number of molecules in a domain, number density of molecules and

  13. Electrical double layer capacitor using poly(methyl methacrylate)–C4BO8Li gel polymer electrolyte and carbonaceous material from shells of mata kucing (Dimocarpus longan) fruit

    International Nuclear Information System (INIS)

    Arof, A.K.; Kufian, M.Z.; Syukur, M.F.; Aziz, M.F.; Abdelrahman, A.E.; Majid, S.R.

    2012-01-01

    Poly(methyl methacrylate), PMMA based gel polymer electrolytes (GPE) containing immobilized lithium bis(oxalato)borate, C 4 BO 8 Li or LiBOB dissolved in a propylene carbonate–ethylene carbonate binary solvent were prepared by heating the cast solution between 70 and 80 °C for 20 min. The electrolyte composition with 5 wt.% PMMA exhibited the highest conductivity of 3.27 and 7.46 mS cm −1 at 298 and 343 K respectively. Cyclic voltammetry studies on the GPE containing 15 wt.% PMMA and 85 wt.% (0.6 M LiBOB) dissolved in equal weight of ethylene and propylene carbonates showed that the electrochemical potential stability window of the electrolyte lies in the range between −1.7 to +1.7 V. Linear sweep voltammetry indicates the gel polymer electrolyte is stable up to 1.7 V. The electrical double layer capacitor (EDLC) using the highest conducting GPE and activated carbon derived from shells of the mata kucing (Dimocarpus longan) fruit has capacitance of ∼685 mF g −1 on the first cycle. The EDLC performance was also characterized using cyclic voltammetry and charge–discharge processes at constant current.

  14. Gold nanorod linking to control plasmonic properties in solution and polymer nanocomposites.

    Science.gov (United States)

    Ferrier, Robert C; Lee, Hyun-Su; Hore, Michael J A; Caporizzo, Matthew; Eckmann, David M; Composto, Russell J

    2014-02-25

    A novel, solution-based method is presented to prepare bifunctional gold nanorods (B-NRs), assemble B-NRs end-to-end in various solvents, and disperse linked B-NRs in a polymer matrix. The B-NRs have poly(ethylene glycol) grafted along its long axis and cysteine adsorbed to its ends. By controlling cysteine coverage, bifunctional ligands or polymer can be end-grafted to the AuNRs. Here, two dithiol ligands (C6DT and C9DT) are used to link the B-NRs in organic solvents. With increasing incubation time, the nanorod chain length increases linearly as the longitudinal surface plasmon resonance shifts toward lower adsorption wavelengths (i.e., red shift). Analogous to step-growth polymerization, the polydispersity in chain length also increases. Upon adding poly(ethylene glycol) or poly(methyl methacrylate) to chloroform solution with linked B-NR, the nanorod chains are shown to retain end-to-end linking upon spin-casting into PEO or PMMA films. Using quartz crystal microbalance with dissipation (QCM-D), the mechanism of nanorod linking is investigated on planar gold surfaces. At submonolayer coverage of cysteine, C6DT molecules can insert between cysteines and reach an areal density of 3.4 molecules per nm(2). To mimic the linking of Au NRs, this planar surface is exposed to cysteine-coated Au nanoparticles, which graft at 7 NPs per μm(2). This solution-based method to prepare, assemble, and disperse Au nanorods is applicable to other nanorod systems (e.g., CdSe) and presents a new strategy to assemble anisotropic particles in organic solvents and polymer coatings.

  15. Research of Polylactic Acid Modiifed by Polymethyl Acrylate-Methyl Methacrylate Copolymer%聚丙烯酸甲酯-甲基丙烯酸甲酯共聚物改性聚乳酸的研究

    Institute of Scientific and Technical Information of China (English)

    苏桂仙; 李光辉; 和芹; 李德玲

    2015-01-01

    为了提高聚乳酸(PLA)的韧性,采用聚丙烯酸甲酯-甲基丙烯酸甲酯(PMA-MMA)对PLA进行共混改性。采用悬浮聚合法,以丙烯酸甲酯(MA)、甲基丙烯酸甲酯(MMA)为共聚单体,制备珠粒状的PMA-MMA共聚物。通过熔融共混法,分别以PMA-MMA共聚物为增韧剂,聚乙二醇为增塑剂,聚乙烯蜡为润滑剂,对PLA进行改性,对改性后的PLA复合材料的热性能和力学性能进行研究。结果表明,随着PMA-MMA共聚物用量的增加,PLA复合材料的拉伸强度呈先增大后减小的趋势,而断裂伸长率和冲击强度不断增大。当PMA-MMA共聚物用量为15份时, PLA复合材料的拉伸强度达到最大值,为52.2 MPa;当PMA-MMA共聚物用量为25份时,PLA复合材料冲击强度为53.26 kJ/m2,是纯PLA的4.4倍,断裂伸长率为54.9%。PMA-MMA共聚物与PLA的相容性好,有明显的增韧作用。PMA-MMA共聚物的加入并未降低PLA复合材料的热性能。%In order to improve the toughness of poly(lactic acid)(PLA),polymethyl acrylate-methyl methacrylate(PMA-MMA) copolymer was used to mix with PLA. Methyl acrylate (MA) and methyl methacrylate(MMA) were used as the monomers for the preparation of PMA-MMA copolymer by means of suspention polymerization. PLA and PMA-MMA copolymer were melt-blended with polyethylene glycol(PEG) as a plasticizer and polyethylene as a lubricant. The modified PLA composites were studied by means of heat resistance and mechanical properties. The results show that with the increase of PMA-MMA copolymer content, the elongation at break and impact strength of the composites are improved,and its tensile strength increases first and then decreases. While the content of PMA-MMA copolymer is 15 phr,the tensile strength of the composite has the best tensile strength of 52.2 MPa. While the content of PMA-MMA copolymer is 25 phr,the impact strength of the composite is 53.26 kJ/m2,which is the 4.4 times of the pure PLA

  16. A novel functionalisation process for glucose oxidase immobilisation in poly(methyl methacrylate) microchannels in a flow system for amperometric determinations.

    Science.gov (United States)

    Cerqueira, Marcos Rodrigues Facchini; Grasseschi, Daniel; Matos, Renato Camargo; Angnes, Lucio

    2014-08-01

    Different materials like glass, silicon and poly(methyl methacrylate) (PMMA) are being used to immobilise enzymes in microchannels. PMMA shows advantages such as its low price, biocompatibility and attractive mechanical and chemical properties. Despite this, the introduction of reactive functional groups on PMMA is still problematic, either because of the complex chemistry or extended reaction time involved. In this paper, a new methodology was developed to immobilise glucose oxidase (GOx) in PMMA microchannels, with the benefit of a rapid immobilisation process and a very simple route. The new procedure involves only two steps, based on the reaction of 5.0% (w/w) polyethyleneimine (PEI) with PMMA in a dimethyl sulphoxide medium, followed by the immobilisation of glucose oxidase using a solution containing 100U enzymes and 1.0% (v/v) glutaraldehyde. The reactors prepared in this way were evaluated by a flowing system with amperometric detection (+0.60V) based on the oxidation of the H2O2 produced by the reactor. The microreactor proposed here was able to work with high bioconversion and a frequency of 60 samples h(-1), with detection and quantification limits of 0.50 and 1.66µmol L(-1), respectively. Michaelis-Menten parameters (Vmax and KM) were calculated as 449±47.7nmol min(-1) and 7.79±0.98mmol. Statistical evaluations were done to validate the proposed methodology. The content of glucose in natural and commercial coconut water samples was evaluated using the developed method. Comparison with spectrophotometric measurements showed that both methodologies have a very good correlation (tcalculated, 0.05, 4=1.35

  17. Synthesis and characterization of poly(methyl methacrylate-co-vinyl acetate) and its evaluation as filtrate reducer; Sintese e caracterizacao de poli(metacrilato de metila-co-acetato de vinila) e sua avaliacao como redutor de filtrado

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Rita de Cassia P.; Pires, Renata V.; Segtovich, Iuri V.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro, Instituto de Macromoleculas, Laboratorio de Macromoleculas e Coloides na Industria de Petroleo, (UFRJ), RJ (Brazil)], e-mail: repires@ima.ufrj.br

    2011-07-01

    The drilling of petroleum well is extremely important and requires the use of suitable drilling fluids in order to ensure an efficient operation without causing rock damage. Specific polymers have been used in controlling infiltration during drilling, ensuring the operation success. In this work, spherical microparticles of poly(methyl methacrylate-co-vinyl acetate) (PMMA-VAc), prepared by suspension polymerization, were evaluated in terms of their performance in controlling filtrate loss of aqueous fluids. A filter press test with ceramic disc, simulating the rock, was used. The performance of the synthesized materials was compared to that of commercial polymers. It was observed that the performance of the material is directly associated to the relation between particle size and pore size of rock specimen. Furthermore, when the particle size is suitable, the rubbery characteristic of the material produces a more efficient filter cake, for filtrate control. (author)

  18. Influence of the way of synthesis of poly(methyl methacrylate in the presence of surface modified TiO2 nanoparticles on the properties of obtained nanocomposites

    Directory of Open Access Journals (Sweden)

    Džunuzović Enis S.

    2010-01-01

    Full Text Available Incorporation of inorganic nanoparticles can significantly affect the properties of the polymer matrix. The properties of polymer nanocomposites depend on the type of incorporated nanoparticles, their size and shape, their concentration, and interactions with the polymer matrix. Homogeneity of polymer nanocomposites is influenced very much by the preparation method. In this study, TiO2 nanoparticles surface modified with 6-palmitate ascorbic acid (6-PAA were incapsulated in poly(methyl methacrylate (PMMA by in situ radical polymerization of methyl methacrylate initiated by 2,2'-azobisisobutyronitrile (AIBN. The surface modification of the TiO2 nanoparticles was achieved by the formation of a charge transfer complex between TiO2 nanoparticles and 6-palmitate ascorbic acid. The radical polymerization of MMA in the presence of TiO2-PAA nanoparticles was conducted in solution (PMMA/TiO2-PAA-R, in bulk (PMMA/TiO2-PAA-M or in suspension (PMMA/TiO2-PAA-S. The main purpose of this study was to investigate the influence of the preparation method on the molar masses and thermal properties of PMMA/TiO2-PAA nanocomposite. It was obtained that molar masses of PMMA extracted from the composites had smaller values compared to molar masses of pure PMMA synthesized in the same manner, which indicated that TiO2-PAA nanoparticles affected the reaction of termination. Thermal properties were investigated by DSC and TGA. The values of glass transition temperature, Tg, were influenced by the way the radical polymerization was conducted, even in the case of the pure PMMA. The Tg of composite samples was always smaller than the value of the corresponding PMMA sample and the smallest value was obtained for PMMA/TiO2-PAA-M since they contained the largest amount of low molar mass residue. The TGA results showed that thermal and thermooxidative stability of polymer composites obtained in solution and in suspension was better than for the pure PMMA obtained in the same way.

  19. Immobilization of catalase on poly(acrylonitrile)-g.co-hydroxyethyl methacrylate

    International Nuclear Information System (INIS)

    Cavaco, M.C.; Andrade, M.E.

    1991-01-01

    Various poly(acrylonitrile)-g.co-hydroxyethyl methacrylate graft copolymers were prepared by using gamma irradiation at 400 Gy.h -1 . The influence of monomer concentration and time of irradiation on the level of grafting were analysed. The hydrophilicity of the polymeric supports was calculated by determining the water sorption. From the results obtained, we could conclude that the hydrophilicity was dependent on the yield of grafting. Some of the graft copolymers prepared were used for the immobilization of catalase. This enzyme was covalently coupled to the hydroxyl groups of the support after activation either with epichlorohydrin or with p-toluene sulphonyl chloride. The yield of enzyme coupling increases when hexamethylenediamine was used as a 'spacer'. (author) 5 refs.; 3 figs.; 2 tabs

  20. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by methacrylic acid

    International Nuclear Information System (INIS)

    Guo Baochun; Lei Yanda; Chen Feng; Liu Xiaoliang; Du Mingliang; Jia Demin

    2008-01-01

    Methacrylic acid (MAA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed interaction mechanisms of MAA and the in situ formed zinc methacrylate (ZDMA) were revealed by X-ray diffraction (XRD), surface area and porosity analysis, X-ray photoelectron spectroscopy (XPS) together with crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through ZDMA and MAA intermediated linkages. ZDMA connects SBR and HNTs via grafting/complexation mechanism. MAA bonds SBR and HNTs through grafting/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and MAA or ZDMA was achieved. Effects of MAA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of MAA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and MAA or ZDMA and the largely improved dispersion of HNTs

  1. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by methacrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baochun [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)], E-mail: psbcguo@scut.edu.cn; Lei Yanda; Chen Feng; Liu Xiaoliang; Du Mingliang; Jia Demin [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2008-12-30

    Methacrylic acid (MAA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed interaction mechanisms of MAA and the in situ formed zinc methacrylate (ZDMA) were revealed by X-ray diffraction (XRD), surface area and porosity analysis, X-ray photoelectron spectroscopy (XPS) together with crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through ZDMA and MAA intermediated linkages. ZDMA connects SBR and HNTs via grafting/complexation mechanism. MAA bonds SBR and HNTs through grafting/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and MAA or ZDMA was achieved. Effects of MAA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of MAA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and MAA or ZDMA and the largely improved dispersion of HNTs.

  2. The effect of polystyrene sodium sulfonate grafting on polyethylene terephthalate artificial ligaments on in vitro mineralisation and in vivo bone tissue integration

    Science.gov (United States)

    Vaquette, Cédryck; Viateau, Véronique; Guérard, Sandra; Anagnostou, Fani; Manassero, Mathieu; Castner, David G.; Migonney, Véronique

    2013-01-01

    This study investigates the impact of polystyrene sodium sulfonate (PolyNaSS) grafting onto the osseointegration of a polyethylene terephthalate artificial ligament (Ligament Advanced Reinforcement System, LARS™) used for Anterior Cruciate Ligament (ACL). The performance of grafted and non-grafted ligaments was assessed in vitro by culturing human osteoblasts under osteogenic induction and this demonstrated that the surface modification was capable of up-regulating the secretion of ALP and induced higher level of mineralisation as measured 6 weeks post-seeding by Micro-Computed Tomography. Grafted and non-grafted LARS™ were subsequently implanted in an ovine model for ACL reconstruction and the ligament-to-bone interface was evaluated by histology and biomechanical testing 3 and 12 months post-implantation. The grafted ligaments exhibited more frequent direct ligament-to-bone contact and bone formation in the core of the ligament at the later time point than the nongrafted specimens, the grafting also significantly reduced the fibrous encapsulation of the ligament 12 months post-implantation. However, this improved osseo-integration was not translated into a significant increase in the biomechanical pull-out loads. These results provide evidences that PolyNaSS grafting improved the osseo-integration of the artificial ligament within the bone tunnels. This might positively influence the outcome of the surgical reconstructions, as higher ligament stability is believed to limit micro-movement and therefore permits earlier and enhanced healing. PMID:23790438

  3. Poly(glycidyl methacrylate) grafted CdSe quantum dots by surface-initiated atom transfer radical polymerization: Novel synthesis, characterization, properties, and cytotoxicity studies

    Energy Technology Data Exchange (ETDEWEB)

    Bach, Long Giang; Islam, Md. Rafiqul [Department of Imaging System Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Lee, Doh Chang [Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury (KINC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Lim, Kwon Taek, E-mail: ktlim@pknu.ac.kr [Department of Imaging System Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2013-10-15

    A novel approach for the synthesis of poly(glycidyl methacrylate) grafted CdSe quantum dot (QDs) (PGMA-g-CdSe) was developed. The PGMA-g-CdSe nanohybrids were synthesized by the surface-initiated atom transfer radical polymerization of glycidyl methacrylate from the surface of the strategic initiator, CdSe-BrIB QDs prepared by the interaction of 2-bromoisobutyryl bromide (BrIB) and CdSe-OH QDs. The structure, morphology, and optical property of the PGMA-g-CdSe nanohybrids were analyzed by FT-IR, XPS, TGA, XRD, TEM, and PL. The as-synthesized PGMA-g-CdSe nanohybrids having multi-epoxide groups were employed for the direct coupling of biotin via ring-opening reaction of the epoxide groups to afford the Biotin-f-PGMA-g-CdSe nanobioconjugate. The covalent immobilization of biotin onto PGMA-g-CdSe was confirmed by FT-IR, XPS, and EDX. Biocompatibility and imaging properties of the Biotin-f-PGMA-g-CdSe were investigated by MTT bioassay and PL analysis, respectively. The cell viability study suggested that the biocompatibility was significantly enhanced by the functionalization of CdSe QDs by biotin and PGMA.

  4. Poly(glycidyl methacrylate) grafted CdSe quantum dots by surface-initiated atom transfer radical polymerization: Novel synthesis, characterization, properties, and cytotoxicity studies

    International Nuclear Information System (INIS)

    Bach, Long Giang; Islam, Md. Rafiqul; Lee, Doh Chang; Lim, Kwon Taek

    2013-01-01

    A novel approach for the synthesis of poly(glycidyl methacrylate) grafted CdSe quantum dot (QDs) (PGMA-g-CdSe) was developed. The PGMA-g-CdSe nanohybrids were synthesized by the surface-initiated atom transfer radical polymerization of glycidyl methacrylate from the surface of the strategic initiator, CdSe-BrIB QDs prepared by the interaction of 2-bromoisobutyryl bromide (BrIB) and CdSe-OH QDs. The structure, morphology, and optical property of the PGMA-g-CdSe nanohybrids were analyzed by FT-IR, XPS, TGA, XRD, TEM, and PL. The as-synthesized PGMA-g-CdSe nanohybrids having multi-epoxide groups were employed for the direct coupling of biotin via ring-opening reaction of the epoxide groups to afford the Biotin-f-PGMA-g-CdSe nanobioconjugate. The covalent immobilization of biotin onto PGMA-g-CdSe was confirmed by FT-IR, XPS, and EDX. Biocompatibility and imaging properties of the Biotin-f-PGMA-g-CdSe were investigated by MTT bioassay and PL analysis, respectively. The cell viability study suggested that the biocompatibility was significantly enhanced by the functionalization of CdSe QDs by biotin and PGMA.

  5. Unique effects of microwave heating on polymerization kinetics of poly(methyl methacrylate) composites

    Energy Technology Data Exchange (ETDEWEB)

    Spasojević, Pavle [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Jovanović, Jelena, E-mail: jelenaj@ffh.bg.ac.rs [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11001 Belgrade (Serbia); Adnadjevic, Borivoj [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11001 Belgrade (Serbia)

    2013-09-16

    The effects of heating mode (conventional and microwave) on the kinetics of isothermal polymerization of MMA composite materials were investigated. Isothermal kinetics curves at temperature range from 343 K to 363 K for both conventional (CH) and microwave heating (MWH) were determined. It was found that the polymerization of MMA composite materials was kinetically elementary reaction for both CH and MWH. The kinetics of CH polymerization can be described by the model of phase-boundary controlled process (contracting volume), whereas the kinetics of MWH polymerization can be described by the model of first-order chemical reaction. The kinetics parameters (E{sub a} and ln A) of the polymerization under microwave heating are lower than for conventional heating. The established decreases in the activation energy and pre-exponential factor under the MWH compared to the CH is explained with the increase in the energy of ground vibrational level of the C–O valence vibrations (ν = 987 cm{sup −1}) in methyl methacrylate molecule and with the decrease in its anharmonicity factor which is caused with the selective resonant transfer of energy from the energetic reservoir to the oscillators in methyl methacrylate molecules. - Graphical abstract: Display Omitted - Highlights: • The MWH speeds the MMA material polymerization and changes the kinetics model. • A novel concept of MWH action based on activation complexes formation is presented. • The Selective Energy Transfer model is used to explain the effects of MWH. • The kinetics parameters under MWH are lower than for CH. • The activation energy for both MWH and CH polymerization is quantized.

  6. Hemocompatibility and oxygenation performance of polysulfone membranes grafted with polyethylene glycol and heparin by plasma-induced surface modification.

    Science.gov (United States)

    Wang, Weiping; Zheng, Zhi; Huang, Xin; Fan, Wenling; Yu, Wenkui; Zhang, Zhibing; Li, Lei; Mao, Chun

    2017-10-01

    Polyethylene glycol (PEG) and heparin (Hep) were grafted onto polysulfone (PSF) membrane by plasma-induced surface modification to prepare PSF-PEG-Hep membranes used for artificial lung. The effects of plasma treatment parameters, including power, gas type, gas flow rate, and treatment time, were investigated, and different PEG chains were bonded covalently onto the surface in the postplasma grafting process. Membrane surfaces were characterized by water contact angle, PEG grafting degree, attenuated total reflectance-Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry, X-ray photoelectron spectroscopy, critical water permeability pressure, and scanning electron microscopy. Protein adsorption, platelet adhesion, and coagulation tests showed significant improvement in the hemocompatibility of PSF-PEG-Hep membranes compared to pristine PSF membrane. Gas exchange tests through PSF-PEG6000-Hep membrane showed that when the flow rate of porcine blood reached 5.0 L/min, the permeation fluxes of O 2 and CO 2 reached 192.6 and 166.9 mL/min, respectively, which were close to the gas exchange capacity of a commercial membrane oxygenator. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1737-1746, 2017. © 2016 Wiley Periodicals, Inc.

  7. Cranioplasty using presurgically fabricated presterilised polymethyl methacrylate plate by a simple, cost-effective technique on patients with and without original bone flap: study on 29 patients.

    Science.gov (United States)

    Sharavanan, G M; Jayabalan, Suresh; Rajasukumaran, K; Veerasekar, Ganesh; Sathya, G

    2015-06-01

    The purpose of the study was to assess the clinical effectiveness of presurgically fabricated pre-sterilized polymethyl methacrylate (PMMA) plate as a cranioplasty material. The study group consisted of 29 patients with skull defect following decompressive craniectomy. Some patients had their original bone flap preserved and some were without it. In either group pre-sterilized prefabricated PMMA plate was used. On each visit, patients were clinically assessed; CT scans were taken in immediate follow up period but if needed more films were taken in subsequent follow ups. Post-op complications that include infection, post-op hematoma, chronic pain, aesthetic, biocompatibility, post-op dimensional changes of prosthesis were evaluated. Mean follow up was 7 1/2 months. Five patients developed swelling and pain in the subsequent follow ups. One patient was treated conservatively with antibiotics. Tapping was performed in couple of patients. Surgical evacuation of hematoma was performed in one patient. Of the five infected plates, one demanded removal from the patient. One complained of chronic pain. Post-op follow up assessed clinically and by CT scan confirmed good aesthetic result, biocompatibility and dimensional stability of prosthesis. The result of this study support the view that the use of prefabricated pre-sterilized PMMA plate as cranioplasty material is a simple, reliable, convenient way that brings acceptable function and aesthetics to patients who underwent decompressive craniectomy, in an inexpensive way.

  8. Surface grafting of poly(ethylene glycol) onto poly(acrylamide-co-vinyl amine) cross-linked films under mild conditions.

    Science.gov (United States)

    Yamamoto, Y; Sefton, M V

    1998-01-01

    Poly(ethylene glycol) (PEG) was grafted onto poly(acrylamide-co-vinyl amine) (poly(AM-co-VA)) film using tresylated PEG (TPEG) at 37 degrees C in aqueous buffers (pH 7.4) with a view to surface-modifying microencapsulated mammalian cells. Poly(AM-co-VA) film was synthesized by Hofmann degradation of a cross-linked poly(acrylamide) film. Conversion to vinyl amine on the surface of the film was approximately 50%, but bulk conversion was not observed; surface specificity was thought to be the result of cleavage of aminated polymer chains at the surface due to chain scission. Reaction between primary amine and TPEG gave a graft yield of 2 mol% (based on XPS) with respect to available surface amine groups, equivalent to 54 mol% ethylene oxide based on monomer units. Physical adsorption of non-activated polymer was done under identical conditions as a control and the difference in oxygen content was significant compared to TPEG. The type of buffer agent and buffer concentration did not influence graft yields. This graft reaction, which was completed in as little as 2 h was considered to be mild enough to be used for a surface modification of microcapsules containing cells without affecting their viability. Such a surface modification technique may prove to be a useful means of enhancing the biocompatibility of microcapsules (or any tissue engineering construct) even after cell encapsulation or seeding.

  9. Facile phase transfer of hydrophobic nanoparticles with poly(ethylene glycol) grafted hyperbranched poly(amido amine)

    International Nuclear Information System (INIS)

    Ji Minglei; Yang Wuli; Ren Qingguang; Lu Daru

    2009-01-01

    In order to enhance the dispersion ability of hydrophobic nanoparticles in water while maintaining their unique properties, we utilized poly(ethylene glycol) grafted hyperbranched poly(amido amine) (h-PAMAM-g-PEG) to modify three types of hydrophobic nanoparticle, CdSe, Au, and Fe 3 O 4 , and transferred them into water to extend their applications in biology. Considering the large amounts of amino groups in hyperbranched poly(amido amine) (h-PAMAM) polymer, complexation interaction between h-PAMAM-g-PEG copolymer and nanoparticles was achieved and ligand exchange between the copolymers and original small molecules ligands occurred. The transferred nanoparticles could be easily dispersed in water with better stability, and their unique properties, such as fluorescence, surface plasmon resonance, and superparamagnetism, were well maintained in the ligand exchange process. In addition, increasing the number of grafted PEG showed a negative effect on the ligand exchange process. Due to the existence of h-PAMAM-g-PEG ligands, the stabilized nanoparticles have improved stability in aqueous and ionic solutions. In the case of CdSe nanoparticles, the h-PAMAM-g-PEG layer leads to a lower cytotoxicity when compared with bare CdSe particles, and they could be directly used in bioimaging.

  10. Micro/nanoencapsulated n-nonadecane with poly(methyl methacrylate) shell for thermal energy storage

    International Nuclear Information System (INIS)

    Sarı, Ahmet; Alkan, Cemil; Biçer, Alper; Altuntaş, Ayşe; Bilgin, Cahit

    2014-01-01

    Graphical abstract: This paper was aimed to prepare, characterize and determinate of thermal energy storage properties of PMMA/C19 micro/nanocapsules as a novel encapsulated phase change material (M/N-EPCM). The chemical structure of the prepared M/N-EPCM was verified using FTIR spectroscopy method. The analysis results obtained from POM and SEM indicated that the synthesized capsules had virtually spherical-shape. The PSD analysis indicated that the M/N-EPCM capsules had mean diameter of 8.18 μm and the percentage of the capsules with nanosize was 4.90 (v/v). The DSC results showed that the synthesized M/N-PCM had a melting temperature and total latent heat value as 31.23 °C and 139.20 J/g, respectively. It can be also deduced from all results that the synthesized M/N-EPCM had promising thermal energy storage potential due to its good latent heat thermal energy storage properties, thermal durability, thermal reliability, chemical stability, thermal conductivity and phase change reversibility properties. - Highlights: • The chemical structure of the prepared M/N-EPCM was verified using FTIR spectroscopy method. • POM and SEM results indicated that the M/N-EPCM had virtually spherical shape-appearance. • The M/N-EPCM had mean diameter of 8.18 μm and the percentage of the capsules with nanosize was 4.90 (v/v). • The M/N-PCM had a melting temperature and total latent heat value as 31.23 °C and 139.20 J/g, respectively. • The M/N-EPCM had promising thermal energy storage potential. - Abstract: This paper was aimed to prepare, characterize and determine the thermal energy storage properties of poly(methyl methacrylate) (PMMA)/n-nonadecane (C19) capsules as a novel micro/nanoencapsulated phase change material (M/N-EPCM). The M/N-EPCM was fabricated via emulsion polymerization reaction of methylmethacrylate (MMA) monomer occurred around C19 used as core material. The chemical structure of the prepared M/N-EPCM was verified using Fourier transform infrared

  11. Poly(methacrylic) Acid and g-methacryloxypropyltrimethoxy Silane/Clay Nanocomposites Prepared by In-Situ Polymerization

    OpenAIRE

    GÜLTEK, Ahmet; SEÇKİN, Turgay

    2002-01-01

    Poly(methacrylic acid) and poly(acrylic acid) nanocomposites were prepared by in-situ polymerization of g-methacryloxypropyltrimethoxysilane (A174)/clay nanocomposites in which the macromonomer was generated by grafting A-174 onto activated clay samples via hydroxyl groups or via intercalation. In- situ polymerization was carried out in the presence of an initiator. It was found that the structural affinity between the methacrylic or acrylic acid monomers and the amount of clay playe...

  12. Controlling Foam Morphology of Poly(methyl methacrylate via Surface Chemistry and Concentration of Silica Nanoparticles and Supercritical Carbon Dioxide Process Parameters

    Directory of Open Access Journals (Sweden)

    Deniz Rende

    2013-01-01

    Full Text Available Polymer nanocomposite foams have received considerable attention because of their potential use in advanced applications such as bone scaffolds, food packaging, and transportation materials due to their low density and enhanced mechanical, thermal, and electrical properties compared to traditional polymer foams. In this study, silica nanofillers were used as nucleating agents and supercritical carbon dioxide as the foaming agent. The use of nanofillers provides an interface upon which CO2 nucleates and leads to remarkably low average cell sizes while improving cell density (number of cells per unit volume. In this study, the effect of concentration, the extent of surface modification of silica nanofillers with CO2-philic chemical groups, and supercritical carbon dioxide process conditions on the foam morphology of poly(methyl methacrylate, PMMA, were systematically investigated to shed light on the relative importance of material and process parameters. The silica nanoparticles were chemically modified with tridecafluoro-1,1,2,2-tetrahydrooctyl triethoxysilane leading to three different surface chemistries. The silica concentration was varied from 0.85 to 3.2% (by weight. The supercritical CO2 foaming was performed at four different temperatures (40, 65, 75, and 85°C and between 8.97 and 17.93 MPa. By altering the surface chemistry of the silica nanofiller and manipulating the process conditions, the average cell diameter was decreased from 9.62±5.22 to 1.06±0.32 μm, whereas, the cell density was increased from 7.5±0.5×108 to 4.8±0.3×1011 cells/cm3. Our findings indicate that surface modification of silica nanoparticles with CO2-philic surfactants has the strongest effect on foam morphology.

  13. Industrial application of electron beams for grafting and vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1994-12-31

    The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber.

  14. Industrial application of electron beams for grafting and vulcanization

    International Nuclear Information System (INIS)

    Keizo Makuuchi

    1994-01-01

    The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber

  15. Equilibrium and kinetics study on hexavalent chromium adsorption onto diethylene triamine grafted glycidyl methacrylate based copolymers

    International Nuclear Information System (INIS)

    Maksin, Danijela D.; Nastasović, Aleksandra B.; Milutinović-Nikolić, Aleksandra D.; Suručić, Ljiljana T.; Sandić, Zvjezdana P.; Hercigonja, Radmila V.; Onjia, Antonije E.

    2012-01-01

    Highlights: ► Methacrylate based copolymers grafted with diethylene triamine as Cr(VI) sorbents. ► Chemisorption and pore diffusion are characteristics of this sorption system. ► Langmuir isotherm provided best fit and maximum adsorption capacity was 143 mg g −1 . ► Cr(VI) sorption onto amino-functionalized copolymer was endothermic and spontaneous. ► A simple, efficient and cost-effective hexavalent chromium removal method. - Abstract: Two porous and one non-porous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [abbreviated PGME] were prepared by suspension copolymerization and functionalized with diethylene triamine [abbreviated PGME-deta]. Samples were characterized by elemental analysis, mercury porosimetry, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and transmission electron microscopy. Kinetics of Cr(VI) sorption by PGME-deta were investigated in batch static experiments, in the temperature range 25–70 °C. Sorption was rapid, with the uptake capacity higher than 80% after 30 min. Sorption behavior and rate-controlling mechanisms were analyzed using five kinetic models (pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion and Bangham model). Kinetic studies showed that Cr(VI) adsorption adhered to the pseudo-second-order model, with definite influence of pore diffusion. Equilibrium data was tested with Langmuir, Freundlich and Tempkin adsorption isotherm models. Langmuir model was the most suitable indicating homogeneous distribution of active sites on PGME-deta and monolayer sorption. The maximum adsorption capacity from the Langmuir model, Q max , at pH 1.8 and 25 °C was 143 mg g −1 for PGME2-deta (sample with the highest amino group concentration) while at 70 °C Q max reached the high value of 198 mg g −1 . Thermodynamic parameters revealed spontaneous and endothermic nature of Cr(VI) adsorption onto PGME-deta.

  16. The Effect of Polymethyl Methacrylate Augmentation on the Primary Stability of Cannulated Bone Screws in an Anterolateral Plate in Osteoporotic Vertebrae: A Human Cadaver Study.

    Science.gov (United States)

    Rüger, Matthias; Sellei, Richard M; Stoffel, Marcus; von Rüden, Christian

    2016-02-01

    Study Design Cohort study. Objective Expandable anterolateral plates facilitate the reduction of posttraumatic deformities of thoracolumbar spine injuries and are commonly used in cases of unstable injuries or compromised bone quality. In this in vitro study, the craniocaudal yield load of the osseous fixation of an anterior angular stable plate fixation system and the effect of polymethyl methacrylate (PMMA) screw augmentation on the primary stability of the screw-bone interface during kyphosis reduction was evaluated in 12 osteoporotic human thoracolumbar vertebrae. Methods The anterolateral stabilization device used for this study is comprised of two swiveling flanges and an expandable midsection. It facilitates the controlled reduction of kyphotic deformities in situ with a geared distractor. Single flanges were attached to 12 thoracolumbar vertebrae. Six specimens were augmented with PMMA by means of cannulated bone screws. The constructs were subjected to static, displacement-controlled craniocaudal loading to failure in a servohydraulic testing machine. Results The uncemented screws cut out at a mean 393 ± 66 N, whereas the cemented screws showed significantly higher yield load of 966 ± 166 N (p augmentation is an effective method to increase two- to threefold the primary stability of the screw-bone interface of an anterolateral spine stabilization system in osteoporotic bone. We recommend it in cases of severely compromised bone quality to reduce the risk of screw loosening during initial kyphosis correction and to increase long-term construct stability.

  17. Crystallization of calcium carbonate on radiation-grafted polyethylene films

    International Nuclear Information System (INIS)

    Hou Zhengchi; Zhang Fengying; Deng Bo; Yang Haijun; Chen Shuang; Sheng Kanglong

    2006-01-01

    In biomineralization processes, nucleation and growth of inorganic crystals can be regulated by organic template molecules. This has inspired great interest in studying mimic biomineralization. In our study, growing CaCO 3 crystals on PE films functionalized through radiation-induced grafting was attempted. PE films grafted with different functional groups of different distributions and densities were used as substrates for CaCO 3 nucleation and crystal growth from Ca(HCO 3 ) 2 supersaturated solution under different environmental conditions (e.g. additives and temperature) to study the effects and mechanisms. The grafted PE films were analyzed by ATR-FTIR and AFM, and the evolution of CaCO 3 crystal formation on the grafted PE film was characterized by SEM, FTIR, and XRD. The results indicated that heterogeneous nucleation of CaCO 3 crystals was significantly facilitated by the functional groups grafted on the surface of PE films, that the morphology of CaCO 3 crystals could be controlled by distribution and density of the grafted functional groups, and that polymorphism of CaCO 3 crystal could be regulated by selection of grafting functional groups. We believe that studying the effects of chemical structures on inorganic crystallization is of great importance since radiation-induced grafting is an effective method to graft desirable functional groups onto different polymers by selected monomers, in the endeavor of developing advanced organic/inorganic composites with high performance, with a wide availability of polymers, monomers and inorganic solutions. (authors)

  18. Stable Poly(methacrylic acid Brush Decorated Silica Nano-Particles by ARGET ATRP for Bioconjugation

    Directory of Open Access Journals (Sweden)

    Marcello Iacono

    2015-08-01

    Full Text Available The synthesis of polymer brush decorated silica nano-particles is demonstrated by activator regeneration by electron transfer atom transfer radical polymerization (ARGET ATRP grafting of poly(tert-butyl methacrylate. ATRP initiator decorated silica nano-particles were obtained using a novel trimethylsiloxane derivatised ATRP initiator obtained by click chemistry. Comparison of de-grafted polymers with polymer obtained from a sacrificial initiator demonstrated good agreement up to 55% monomer conversion. Subsequent mild deprotection of the tert-butyl ester groups using phosphoric acid yielded highly colloidal and pH stable hydrophilic nano-particles comprising approximately 50% methacrylic acid groups. The successful bio-conjugation was achieved by immobilization of Horseradish Peroxidase to the polymer brush decorated nano-particles and the enzyme activity demonstrated in a conversion of o-phenylene diamine dihydrochloride assay.

  19. The Mechanical Properties of Recycled Polyethylene-Polyethylene Terephthalate Composites

    Directory of Open Access Journals (Sweden)

    Ehsan Avazverdi

    2015-02-01

    Full Text Available Polyethylene terephthalate (PET, one of the thermoplastic polymers, is encountered with arduous problems in its recycling. After recycling, its mechanical properties drop dramatically and therefore it cannot be used to produce the products as virgin PET does. Polyethylene is a thermoplastic polymer which can be easily recycled using the conventional recycling processes. The decreased mechanical properties of virgin polyethylene due to the environmental factors can be improved by reinforcing fillers. In this paper, we studied the effects of adding recycled polyethylene terephthalate (rPET as a filler, in various amounts with different sizes, on the physical and mechanical properties of recycled polyethylene. Composite samples were prepared using an internal mixer at temperature 185°C, well below rPET melting point (250°C, and characterized by their mechanical properties. To improve the compatibility between different components, PE grafted with maleic anhydride was added as a coupling agent in all the compositions under study. The mechanical properties of the prepared samples were performed using the tensile strength, impact strength, surface hardness and melt flow index (MFI tests. To check the dispersity of the polyethylene terephthalate powder in the polyethylene matrix, light microscopy was used. The results showed that the addition of rPET improved the tensile energy, tensile modulus and surface hardness of the composites while reduced the melt flow index, elongation-at-yield, tensile strength and fracture energy of impact test. We could conclude that with increasing rPET percentage in the recycled polyethylene matrix, the composite became brittle, in other words it decreased the plastic behavior of recycled polyethylene. Decreasing particle size led to higher surface contacts, increased the mechanical properties and made the composite more brittle. The light microscopy micrographs of the samples showed a good distribution of small r

  20. Synthesis and properties of silane-fluoroacrylate grafted starch.

    Science.gov (United States)

    Qu, Jia; He, Ling

    2013-10-15

    The latex of silane-fluoroacrylate grafted starch for coating materials, VTMS-starch/P(MMA/BA/3FMA), is obtained by two step grafting reactions. Vinyltrimethoxysilane (VTMS) is primarily grafted onto starch by condensation between Si-OH and C-OH at 120 °C, and then the copolymer of methyl methacrylate (MMA), butyl acrylate (BA) and 2,2,2-trifluoroethyl methacrylate (3FMA) is grafted onto the VTMS-starch by emulsion polymerization. Fourier transform infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS) have been used to confirm the chemically grafting reactions in every step. The conversion percent, grafting percent and grafting efficiency for VTMS-starch/p(MMA/BA/3FMA) latex indicate that the optimum conditions should be controlled at 75 °C for 1h as VTMS-starch/P(MMA/BA/3FMA) in 1/3 weight ratio. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis have revealed that the latexes exhibit the uniform spherical particles of 40-60 nm in a narrow size distribution. The latex films perform the obvious hydrophobic (107°) property, lower surface free energy (25-35 mN/m) and the higher thermostability (330-440 °C) than starch (51°, 51.32 mN/m, 100-330 °C). Dynamic thermomechanical analysis (DMA) shows that the latex film could gain considerable toughness and strength with an elongation at break of 39.45% and a tensile strength of 11.97 MPa. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Radiation induced deposition of copper nanoparticles inside the nanochannels of poly(acrylic acid)-grafted poly(ethylene terephthalate) track-etched membranes

    Science.gov (United States)

    Korolkov, Ilya V.; Güven, Olgun; Mashentseva, Anastassiya A.; Atıcı, Ayse Bakar; Gorin, Yevgeniy G.; Zdorovets, Maxim V.; Taltenov, Abzal A.

    2017-01-01

    Poly(ethylene terephthalate) PET, track-etched membranes (TeMs) with 400 nm average pore size were UV-grafted with poly(acrylic acid) (PAA) after oxidation of inner surfaces by H2O2/UV system. Carboxylate groups of grafted PAA chains were easily complexed with Cu2+ ions in aqueous solutions. These ions were converted into metallic copper nanoparticles (NPs) by radiation-induced reduction of copper ions in aqueous-alcohol solution by gamma rays in the dose range of 46-250 kGy. Copper ions chelating with -COOH groups of PAA chains grafted on PET TeMs form polymer-metal ion complex that prevent the formation of agglomerates during reduction of copper ions to metallic nanoparticles. The detailed analysis by X-Ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed the deposition of copper nanoparticles with the average size of 70 nm on the inner surface of nanochannels of PET TeMs. Samples were also investigated by FTIR, ESR spectroscopies to follow copper ion reduction.

  2. Surface modification of polyethylene by radiation-induced grafting for adhesive bonding. IV. Improvement in wet peel strength

    International Nuclear Information System (INIS)

    Yamakawa, S.; Yamamoto, F.

    1980-01-01

    Adhesive joints of hydrolyzed methyl acrylate grafts, bonded with epoxy adhesives, yield extremely high peel strength (adherend failure) in dry conditions. However, when the joints are exposed to humid environments, the peel strength rapidly decreases with exposure time and then reaches a constant value (wet peel strength). Since the locus of failure changes from the adherend to the homopolymer layer with decreasing peel strength, the decrease is due to a decrease in mechanical strength of the homopolymer layer itself, which results from its swelling by water absorption. Many attempts to reduce the swelling of the homopolymer layer or to strengthen the swollen homopolymer layer were unsuccessful except (1) priming with epoxy solutions consisting of a base epoxy resin and organic solvents which can dissolve not only epoxy resins but also hydrolyzed poly(methyl acrylate) and (2) partial etching of the homopolymer layer by photo-oxidative degradation. All the results on the improvement in wet peel strength can be explained in terms of the penetration of epoxy resins into the homopolymer layer and subsequent curing of the penetrated epoxy resin. 15 figures, 1 table

  3. Cytocompatibility of amine functionalized carbon nanoparticles grafted on polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Žáková, Pavlína, E-mail: pavlina.zakova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Slepičková Kasálková, Nikola [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Kolská, Zdeňka [Faculty of Science, J. E. Purkyně University, Ústí nad Labem (Czech Republic); Leitner, Jindřich [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Karpíšková, Jana; Stibor, Ivan [Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec (Czech Republic); Slepička, Petr; Švorčík, Václav [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic)

    2016-03-01

    Five types of amide–amine Carbon Nano-Particles (CNPs) were prepared by functionalization of CNPs and characterized by several analytical methods. The successful grafting of amines on CNPs was verified by X-ray photoelectron spectroscopy (XPS), organic elemental analysis and electrokinetic analysis. The size and morphology of CNPs were determined from transmission electron microscopy. The surface area and porosity of CNPs were examined by adsorption and desorption isotherms. Differential scanning calorimetry was used to investigate thermal stability of CNPs. The amount of bonded amine depends on its dimensionality arrangement. Surface area and pore volumes of CNPs decrease several times after individual amino-compound grafting. Selected types of functionalized CNPs were grafted onto a plasma activated surface of HDPE. The successful grafting of CNPs on the polymer surface was verified by XPS. Wettability was determined by contact angle measurements. Surface morphology and roughness were studied by atomic force microscopy. A dramatic decrease of contact angle and surface morphology was observed on CNP grafted polymer surface. Cytocompatibility of modified surfaces was studied in vitro, by determination of adhesion, proliferation and viability of vascular smooth muscle cells (VSMCs). Grafting of CNPs onto the polymer surface has a positive effect on the adhesion, proliferation and viability of VSMCs. - Highlights: • Amine functionalized CNPs were successfully grafted on HDPE surface. • Significant change to the positive zeta potential for grafted CNPs was induced. • Grafting of CNPs significantly enhanced cell cytocompatibility and viability. • Homogeneous distribution of cells with correct size was achieved.

  4. Radiation induced grafting of monomers onto natural rubber : processes and applications

    International Nuclear Information System (INIS)

    Sunny Sebastian, M.

    2001-01-01

    Full text: Certain inherent mechanical properties of natural rubber (NR) can be modified by grafting vinyl monomers onto the polymer backbone. This paper described the gamma radiation induced graft copolymerization of methyl methacrylate (MMA), styrene and acrylonitrile (AN) onto NR. The graft copolymers can be crosslinked by sulphur and organic accelerators. The crosslinked graft copolymers show improved modulus and hardness in their films compared to NR. However the tensile strength of the films is reduced by grafting. The methods for preparing the graft copolymers, their properties and applications are briefly described

  5. Polymer Brush Grafted Nanoparticles and Their Impact on the Morphology Evolution of Polymer Blend Films

    Science.gov (United States)

    Chung, Hyun-Joong; Ohno, Kohji; Composto, Russell

    2013-03-01

    We present an novel pathway to control the location of nanoparticles (NPs) in phase-separating polymer blend films containing poly(methyl methacrylate) (PMMA) and poly(styrene-ran-acrylonitrile) (SAN). Because hydrophobic polymer phases have a small interfacial energy, ~1 mJ/m2, subtle changes in the NP surface functionality can be used to guide NPs to either the interface between immiscible polymers or into one of the phases. Based on this idea, we designed a class of NPs grafted with PMMA brushes. These PMMA brushes were grown from the NP surface by atom transfer radical polymerization (ATRP), which results in chains terminated with chlorine atoms. The chain end can be substituted with protons (H) by dehalogenation. As a result, the NPs are strongly segregated at the interface when grafted PMMA chains are short (Mn =1.8K) and the end group is Cl, whereas NPs partition into PMMA-rich phase when chains are long (Mn =160K) and/or when chains are terminated with hydrogen. The Cl end groups and shorter chain length cause an increase in surface energy for the NPs. The increase in surface energy of short-chained NPs can be attributed to (i) an extended brush conformation (entropic) and/or (ii) a high density of ``unfavorable'' end groups (enthalpic). Finally, the impact of NPs on the morphological evolution of the polymer blend films will be discussed. Ref: H.-J.Chung et al., ACS Macro Lett. 1(1), 252-256 (2012).

  6. Well-defined polyethylene-based graft terpolymers by combining nitroxide-mediated radical polymerization, polyhomologation and azide/alkyne “click” chemistry†

    KAUST Repository

    Alkayal, Nazeeha

    2016-03-30

    Novel well–defined polyethylene–based graft terpolymers were synthesized via the “grafting onto” strategy by combining nitroxide-mediated radical polymerization (NMP), polyhomologation and copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) “click” chemistry. Three steps were involved in this approach: (i) synthesis of alkyne-terminated polyethylene-b-poly(ε-caprolactone) (PE-b-PCL-alkyne) block copolymers (branches) by esterification of PE-b-PCL-OH with 4-pentynoic acid; the PE-b-PCL-OH was obtained by polyhomologation of dimethylsulfoxonium methylide to afford PE-OH, followed by ring opening polymerization of ε-caprolactone using the PE-OH as macroinitiator, (ii) synthesis of random copolymers of styrene (St) and 4-chloromethylstyrene (4-CMS) with various CMS contents, by nitroxide-mediated radical copolymerization (NMP), and conversion of chloride to azide groups by reaction with sodium azide (NaN3) (backbone) and (iii) “click” linking reaction to afford the PE-based graft terpolymers. All intermediates and final products were characterized by high-temperature size exclusion chromatography (HT-SEC), Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR) and differential scanning calorimetry (DSC).

  7. Efficacy of citric acid denture cleanser on the Candida albicans biofilm formed on poly(methyl methacrylate): effects on residual biofilm and recolonization process.

    Science.gov (United States)

    Faot, Fernanda; Cavalcanti, Yuri Wanderley; Mendonça e Bertolini, Martinna de; Pinto, Luciana de Rezende; da Silva, Wander José; Cury, Altair Antoninha Del Bel

    2014-06-23

    It is well known that the use of denture cleansers can reduce Candida albicans biofilm accumulation; however, the efficacy of citric acid denture cleansers is uncertain. In addition, the long-term efficacy of this denture cleanser is not well established, and their effect on residual biofilms is unknown. This in vitro study evaluated the efficacy of citric acid denture cleanser treatment on C. albicans biofilm recolonization on poly(methyl methacrylate) (PMMA) surface. C. albicans biofilms were developed for 72 h on PMMA resin specimens (n = 168), which were randomly assigned to 1 of 3 cleansing treatments (CTs) overnight (8 h). CTs included purified water as a control (CTC) and two experimental groups that used either a 1:5 dilution of citric acid denture cleanser (CT5) or a 1:8 dilution of citric acid denture cleanser (CT8). Residual biofilms adhering to the specimens were collected and quantified at two time points: immediately after CTs (ICT) and after cleaning and residual biofilm recolonization (RT). Residual biofilms were analyzed by quantifying the viable cells (CFU/mL), and biofilm architecture was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Denture cleanser treatments and evaluation periods were considered study factors. Data were analyzed using two-way ANOVA and Tukey's Honestly Significant Difference (HSD) test (α = 0.05). Immediately after treatments, citric acid denture cleansing solutions (CT5 and CT8) reduced the number of viable cells as compared with the control (p recolonization (p recolonization was also detected by CLSM and SEM analysis, which revealed a higher biomass and average biofilm thickness for the CT8 group (p recolonization.

  8. Engineering of poly(ethylene glycol) chain-tethered surfaces to obtain high-performance bionanoparticles

    International Nuclear Information System (INIS)

    Nagasaki, Yukio

    2010-01-01

    A poly(ethylene glycol)-b-poly[2-(N,N-dimethylamino)ethyl methacrylate] block copolymer possessing a reactive acetal group at the end of the poly(ethylene glycol) (PEG) chain, that is, acetal-PEG-b-PAMA, was synthesized by a proprietary polymerization technique. Gold nanoparticles (GNPs) were prepared using the thus-synthesized acetal-PEG-b-PAMA block copolymer. The PEG-b-PAMA not only acted as a reducing agent of aurate ions but also attached to the nanoparticle surface. The GNPs obtained had controlled sizes and narrow size distributions. They also showed high dispersion stability owing to the presence of PEG tethering chains on the surface. The same strategy should also be applicable to the fabrication of semiconductor quantum dots and inorganic porous nanoparticles. The preparation of nanoparticles in situ, i.e. in the presence of acetal-PEG-b-PAMA, gave the most densely packed polymer layer on the nanoparticle surface; this was not observed when coating preformed nanoparticles. PEG/polyamine block copolymer was more functional on the metal surface than PEG/polyamine graft copolymer, as confirmed by angle-dependent x-ray photoelectron spectroscopy. We successfully solubilized the C 60 fullerene into aqueous media using acetal-PEG-b-PAMA. A C 60 /acetal-PEG-b-PAMA complex with a size below 5 nm was obtained by dialysis. The preparation and characterization of these materials are described in this review. (topical review)

  9. Rheological, mechanical and morphological properties of poly(methyl methacrylate/poly(ethylene terephthalate blend with dual reactive interfacial compatibilization

    Directory of Open Access Journals (Sweden)

    Juciklécia da Silva Reinaldo

    2015-10-01

    Full Text Available Abstract In this work, the rheological, mechanical and morphological behavior of immiscible blend poly (methyl methacrylate with elastomeric particles (PMMAelast and post-consumer poly (ethylene terephthalate (PET with and without the use of the interfacial compatibilizer poly (methyl methacrylate-co-glycidyl methacrylate-co-ethyl acrylate (MGE was studied. The significant increase in torque presented in rheological analyses has shown a indication of chemical reactions between the epoxy group of MGE with end groups of PET chains and also with the elastomeric phase of PMMAelast. The increased concentration of PET yielded an increase in maximum strength and elasticity modulus and a decrease in elongation at break. The PMMAelast/PET binary blend (50/50 wt% and PMMAelast/PET/MGE compatibilized blend (65/30/5 wt% showed pronounced results in elongation at break compared to PMMAelast, whereas, in the first results were due to the evidence of a co-continuous morphological structure and in the second, due to the efficiency of the dual reactive interfacial compatibilization of PMMAelast/PET blends. Scanning electron microscopy (SEM and transmission electron microscopy (TEM analyses showed that PMMAelast/PET/MGE blends exhibit complex phase morphology due to the presence of elastomeric particles in the PMMAelast copolymer and in the use of MGE terpolymer.

  10. Poly(methyl methacrylate) Composites with Size-selected Silver Nanoparticles Fabricated Using Cluster Beam Technique

    DEFF Research Database (Denmark)

    Muhammad, Hanif; Juluri, Raghavendra R.; Chirumamilla, Manohar

    2016-01-01

    based on cluster beam technique allowing the formation of monocrystalline size-selected silver nanoparticles with a ±5–7% precision of diameter and controllable embedment into poly (methyl methacrylate). It is shown that the soft-landed silver clusters preserve almost spherical shape with a slight...... tendency to flattening upon impact. By controlling the polymer hardness (from viscous to soft state) prior the cluster deposition and annealing conditions after the deposition the degree of immersion of the nanoparticles into polymer can be tuned, thus, making it possible to create composites with either...

  11. Study on dosimetry characteristics of polymer–CNT nanocomposites: Effect of polymer matrix

    Energy Technology Data Exchange (ETDEWEB)

    Malekie, Shahryar [Radiation Application Research School, Nuclear Science & Technology Research Institute, PO Box 11365-3486, Tehran (Iran, Islamic Republic of); Ziaie, Farhood, E-mail: fziaie@aeoi.org.ir [Radiation Application Research School, Nuclear Science & Technology Research Institute, PO Box 11365-3486, Tehran (Iran, Islamic Republic of); Esmaeli, Abdolreza [Plasma and Fusion Research School, Nuclear Science & Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2016-04-21

    In this research work, the current density of polymer–carbon nanotube nanocomposite in different weight percentages of nanotubes, over the radiation absorbed dose under a fixed DC voltage for different polymer matrices such as high density polyethylene, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, and polystyrene was investigated via finite element method. The predicted electrical percolation threshold values in different composites were validated by experimental results published by other scientists. The absorbed dose value was considered as multiplying of heat capacity and temperature rise of the composite, regarding the calorimetric approach. Results show that the polymer type having different characteristics of relative permittivity and heat capacity could affect the sensitivity and working dose range of the composite as a dosimeter.

  12. Radiation-induced grafting of TMPM onto polypropylene

    International Nuclear Information System (INIS)

    Wang Huiliang; Li Hong; Chen Wenxiu

    1995-01-01

    The gamma radiation-induced graft copolymerization of 2,2,6,6-tetramethyl-4-piperidinyl-methacrylate (TMPM), a very effective hindered amine light stabilizer (HALS), onto polypropylene was investigated by simultaneous- irradiation technique. The various synthesis conditions on the graft content was studied. It was found that benzene, CCl 4 and petroleum ether are more effective than other solvents, the percent grafting reached 7.1% for benzene. The percent grafting is higher when graft copolymerization is carried out in argon atmosphere than those in air. For all the grafting copolymerization carried out in benzene and CCl 4 , percent grafting increase linearly from 1 to 5 Mrad and beyond 5 Mrad, a tendency to level off appeared. At a constant dose, the percent grafting was found to be higher at high dose rate until 228 rad/s. Percent grafting also increased continuously with increasing monomer concentration up to 2.85 mol/L, but significant increase in grafting was observed only up to 1.14 mol/L

  13. Surface modification and characterization of magnesium hydroxide sulfate hydrate nanowhiskers

    Energy Technology Data Exchange (ETDEWEB)

    Gao Chuanhui [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Li Xianguo, E-mail: chuanhuigao@foxmail.com [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Feng Lijuan; Lu Shaoyan; Liu Jinyan [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China)

    2010-03-01

    In order to enhance the compatibility with plastic polymers, magnesium hydroxide sulfate hydrate (MHSH) nanowhiskers were modified through grafting methyl methacrylate (MMA) on the surface of the nanowhiskers by emulsion polymerization. The influences of the reaction time, MMA monomer content, adding speed of monomer and the reaction temperature on the grafting ratio were investigated. Thermogravimetry (TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy and surface contact angle measurement were used to characterize the effect of surface modification. The results showed that the MHSH nanowhiskers were uniformly coated by polymethyl methacrylate (PMMA), and a well-defined core-shell hybrid structure of MHSH/PMMA was obtained. The surface contact angle of the hybrid whiskers increased to 87.32 deg. from 12.71 deg. and the whiskers surface was changed from hydrophilic to lipophilic.

  14. Radiolytic stabilization of poly(methyl methacrylate) in blends with polystyrene; Estabilizacao radiolitica do poli(metacrilato de metila) em misturas fisicas com poliestireno

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Ivania Soares de

    2002-04-01

    In this work the radiolytic stabilization of poly(methyl methacrylate) was analyzed by three radioprotective agents: polystyrene (PS) and hindered amine light stabilizers (HEALS), respectively, PMMA/PS systems, so a called polymeric blends were prepared with different compositions, where the miscibility of these blends were studied using viscometric, microscopy (SEM) and spectroscopy (FT-IR) techniques. The results show that PMMA/PS blends in the compositions below 10 wt% of PS are miscible, on films casting from solution of toluene and methyl-ethyl-ketone (1;1) mixture. On the other hand, in the composition above 10 wt% of PS, PMMA/PS blends show imminiscibility behavior. These polymer solutions were irradiated with gamma rays ({sup 60} Co) and viscometric, microscopic and spectroscopic experiments show gamma radiation-induced compatibilization on PMMA/PS blends on proportion 50/50 and 30/70 take place. Viscometric interaction parameters of miscible and compatibilized PMMA/PS bends were calculated in the range of - 50 kGy, with the goal to find out the polymeric interactions after irradiation of the films. G values of PMMA, PMMA/PS and PMMA+St systems were calculated in order to analyze the radioprotection of PS and St into PMMA matrix. The results show that (90/10) PMMA/PS and PMMA+1,5%St systems promote protection against the gamma the radiation-induced scissions, effect that leads to polymer degradation. Moreover, a small amount of crosslinking observed in irradiated blends has contributed to stabilize mechanical properties of PMMA films. PMMA+0,3% HALS system irradiated in doses above 60 kGy showed little stabilization of the mechanical properties of PMMA, since it was observed mechanical degradation this system. Based on these results, PS and St showed to be the best radioprotective agents to PMMA. (author)

  15. Controlling fungal biofilms with functional drug delivery denture biomaterials.

    Science.gov (United States)

    Wen, Jianchuan; Jiang, Fuguang; Yeh, Chih-Ko; Sun, Yuyu

    2016-04-01

    Candida-associated denture stomatitis (CADS), caused by colonization and biofilm-formation of Candida species on denture surfaces, is a significant clinical concern. We show here that modification of conventional denture materials with functional groups can significantly increase drug binding capacity and control drug release rate of the resulting denture materials for potentially managing CADS. In our approach, poly(methyl methacrylate) (PMMA)-based denture resins were surface grafted with three kinds of polymers, poly(1-vinyl-2-pyrrolidinone) (PNVP), poly(methacrylic acid) (PMAA), and poly(2-hydroxyethyl methacrylate) (PHEMA), through plasma-initiated grafting polymerization. With a grafting yield as low as 2 wt%, the three classes of new functionalized denture materials showed significantly higher drug binding capacities toward miconazole, a widely used antifungal drug, than the original PMMA denture resin control, leading to sustained drug release and potent biofilm-controlling effects against Candida. Among the three classes of functionalized denture materials, PNVP-grafted resin provided the highest miconazole binding capability and the most powerful antifungal and biofilm-controlling activities. Drug binding mechanisms were studied. These results demonstrated the importance of specific interactions between drug molecules and functional groups on biomaterials, shedding lights on future design of CADS-managing denture materials and other related devices for controlled drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The effect of layer-by-layer chitosan-hyaluronic acid coating on graft-to-bone healing of a poly(ethylene terephthalate) artificial ligament.

    Science.gov (United States)

    Li, Hong; Ge, Yunsheng; Zhang, Pengyun; Wu, Lingxiang; Chen, Shiyi

    2012-01-01

    Surface coating with an organic layer-by-layer self-assembled template of chitosan and hyaluronic acid on a poly(ethylene terephthalate) (PET) artificial ligament was designed for the promotion and enhancement of graft-to-bone healing after artificial ligament implantation in a bone tunnel. The results of in vitro culturing of MC3T3-E1 mouse osteoblastic cells supported the hypothesis that the layer-by-layer coating of chitosan and hyaluronic acid could promote the cell compatibility of grafts and could promote osteoblast proliferation. A rabbit extra-articular tendon-to-bone healing model was used to evaluate the effect of this kind of surface-modified stainless artificial ligament in vivo. The final results proved that this organic compound coating could significantly promote and enhance new bone formation at the graft-bone interface histologically and, correspondingly, the experimental group with coating had significantly higher biomechanical properties compared with controls at 8 weeks (P < 0.05).

  17. Viscoelastic Analysis of Thermally Stiffening Polymer Nanocomposites

    Science.gov (United States)

    Ehlers, Andrew; Rende, Deniz; Senses, Erkan; Akcora, Pinar; Ozisik, Rahmi

    Poly(ethylene oxide), PEO, filled with silica nanoparticles coated with poly(methyl methacrylate), PMMA, was shown to present thermally stiffening behavior above the glass transition temperature of both PEO and PMMA. In the current study, the viscoelastic beahvior of this nanocomposite system is investigated via nanoindenation experiments to complement on going rheological studies. Results were compared to neat polymers, PEO and PMMA, to understand the effect of coated nanoparticles. This material is based upon work supported by the National Science Foundation under Grant No. CMMI-1538730.

  18. Biodegradation of starch–graft–polystyrene and starch–graft–poly(methacrylic acid copolymers in model river water

    Directory of Open Access Journals (Sweden)

    Nikolić Vladimir

    2013-01-01

    Full Text Available In this paper the biodegradation study of grafted copolymers of polystyrene (PS and corn starch and poly(methacrylic acid and corn starch in model river water is described. These copolymers were obtained in the presence of different amine activators. The synthesized copolymers and products of degradation were characterized by Fourier Transform Infrared Spectroscopy (FTIR and Scanning Electron Microscopy (SEM. Biodegradation was monitored by mass decrease and number of microorganisms by Koch’s method. Biodegradation of both copolymers advanced with time, poly(methacrylic acid-graft-starch copolymers completely degraded after 21 day, and polystyrene-graft-starch partially degraded (45.78-93.09 % of total mass after 27 days. Differences in the degree of biodegradation are consequences of different structure of the samples, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. The grafting degree of PS necessary to prevent biodegradation was 54 %. Based on experimental evidence, mechanisms of both biodegradation processes are proposed, and influence of degree of starch and synthetic component of copolymers on degradation were established. [Projekat Ministarstva nauke Republike Srbije, br. 172001 i br. 172062

  19. Photoluminescence spectral study of single cadmium selenide/zinc sulfide colloidal nanocrystals in poly(methyl methacrylate) and quantum dots molecules

    Science.gov (United States)

    Shen, Yaoming

    Quantum dots (QDs)and Nano-crystals (NCs) have been studies for decades. Because of the nanoscale quantum confinement, delta shape like energy density states and narrowband emitters properties, they hold great promise for numerous optoelectronics and photonics applications. They could be used for tunable lasers, white LED, Nano-OLED, non-volatile memory and solar cells. They are also the most promising candidates for the quantum computing. The benefits for NCs over QDs is that NCs can be incorporated into a variety of polymers as well as thin films of bulk semiconductors. These exceptional flexibility and structural control distinguish NCs from the more traditional QD structures fabricated using epitaxial growth techniques. In my research of work, I studied the photoluminescence (PL) and absorption character of ensemble NCs incorporated in Polymethyl methacrylate (PMMA). To understand the behavior of the NCs in PMMA, it is important to measure a singe NC to avoid the inhomogenous broading of many NCs. So I particularly studied the behavior of a single NC in PMMA matrix. A microphotoluminescence setup to optically isolate a single nanocrystal is used. Random spectral shift and blinking behavior (on and off) are found. Addition to that, two color spectral shifting, is a major phenomena found in the system. Other interesting results such as PL intensity changes (decreasing or increasing with time) and quenching effect are observed and explained too. From the correlation function, we can distinguish the phonon replicas. The energy of these phonons can be calculated very accurately from the experiment result. The Huang-Rhys factors can be estimated too. Self-assembled semiconductor quantum dots (QDs), from highly strained-layer heteroepitaxy in the Stranski-Krastanow (S-K) growth mode, have been intensively studied because of the delta-function-like density of states, which is significant for optoelectronic applications. Spontaneous formation of semiconductor quantum

  20. Graft-copolymerization of polyethersulfone microporous membrane with electron beam simultaneous irradiation method

    International Nuclear Information System (INIS)

    Han Zhaolei; Meng Fanxia; Wang Yongxia; Liu Xiaoguang; Wang Rong

    2010-01-01

    Polyethersulfone(PES) microporous membrane was grafted with methacrylic acid under electron beam irradiation. Controlling the monomer concentration or the absorbed dose, the relationships of the degree of grafting with the monomer concentration and the absorbed dose were obtained for optimum the monomer concentration and absorbed dose. The grafted membrane was characterized by FT-IR and SEM, and the hydrophilicity contact angle of the membrane was tested. (authors)

  1. Adsorption of UO2+2 by polyethylene adsorbents with amidoxime, carboxyl, and amidoxime/carboxyl group

    International Nuclear Information System (INIS)

    Choi, Seong-Ho; Nho, Young Chang

    2000-01-01

    The polyethylene (PE) adsorbents were prepared by a radiation-induced grafting of acrylonitrile (AN), acrylic acid (AA), and the mixture of AN/AA onto PE film, and by subsequent amidoximation of cyano groups of poly-AN graft chains. With an increase of AA composition in AN/AA monomer mixture, the water uptake of the grafted polyethylene film increased. In AN/AA mixture, the maximum adsorption of UO 2+ 2 was observed in the adsorbent with a ratio of AN/AA (50/50, mol%) in copolymer. The amidoxime, carboxyl, and amidoxime/carboxyl groups onto PE acted as a chelating site for the selected UO 2+ 2 . The complex structure of polyethylene with three functional groups and UO 2+ 2 was confirmed by Fourier Transform Infrared (FTIR) spectroscopy. (author)

  2. Mesoscopic Iron-Oxide Nanorod Polymer Nanocomposite Films

    Science.gov (United States)

    Ferrier, Robert; Ohno, Kohji; Composto, Russell

    2012-02-01

    Dispersion of nanostructures in polymer matrices is required in order to take advantage of the unique properties of the nano-sized filler. This work investigates the dispersion of mesoscopic (200 nm long) iron-oxide rods (FeNRs) grafted with poly(methyl methacrylate) (PMMA) brushes having molecular weights (MWs) of 3.7K, 32K and 160K. These rods were then dispersed in either a poly(methyl methacrylate) or poly(oxyethylene) (PEO) matrix film so that the matrix/brush interaction is either entropic (PMMA matrix) or enthalpic and entropic (PEO matrix). Transmission electron microscopy (TEM) was used to determine the dispersion of the FeNRs in the polymer matrix. The results show that the FeNRs with the largest brush were always dispersed in the matrix, whereas the rods with the shorter brushes always aggregated in the matrix. This suggests that the brush MW is a critical parameter to achieve dispersion of these mesoscopic materials. This work can be extended to understand the dispersion of other types of mesocopic particles

  3. Poly(2-hydroxyethyl methacrylate) grafted halloysite nanotubes as a molecular host matrix for luminescent ions prepared by surface-initiated RAFT polymerization and coordination chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Md. Rafiqul; Bach, Long Giang; Lim, Kwon Taek, E-mail: ktlim@pknu.ac.kr

    2013-07-01

    A fluorescent nanohybrid complex comprising of halloysite nanotubes (HNTs), poly(2-hydroxyethyl methacrylate) (PHEMA), and europium ions (Eu{sup 3+}) was synthesized by the combination of surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization and coordination chemistry. Initially, PHEMA was grafted from the HNTs by SI-RAFT and then reacted with succinic anhydride to provide carboxyl acid groups on the external layers of HNTs-g-PHEMA nanohybrids. The subsequent coordination of the nanohybrids with Eu{sup 3+} ions afforded photoluminescent Eu{sup 3+} tagged HNTs-g-PHEMA nanohybrid complexes (HNTs-g-PHEMA-Eu{sup 3+}). The structure, morphology, and fluorescence properties of the Eu{sup 3+} coordinated nanohybrid complexes were investigated by respective physical and spectral studies. FT-IR, XPS, and EDS analyses suggested the formation of the HNTs-g-PHEMA-Eu{sup 3+} nanohybrids. FE-SEM images indicated the immobilization of polymer layers on HNTs. TGA scans further demonstrated the grafting of PHEMA onto HNTs surface. The optical properties of HNTs-g-PHEMA-Eu{sup 3+} nanohybrid complexes were investigated by photoluminescence spectroscopy.

  4. Some Limitations in the Use of Plastic and Dyed Plastic Dosimeters

    DEFF Research Database (Denmark)

    Miller, Arne; Bjergbakke, Erling; McLaughlin, W. L.

    1975-01-01

    Several practical plastic and dyed plastic dosimeters were examined under irradiation conditions similar to those used for radiation processing of materials. Cellulose triacetate, polymethyl methacrylate, polyvinyl chloride, dyed polymethyl methacrylate, dyed Cellophane and dyed Nylon were given...

  5. Homogeneous cation exchange membrane by radiation grafting

    International Nuclear Information System (INIS)

    Kolhe, Shailesh M.; G, Agathian; Ashok Kumar

    2001-01-01

    Preparation of a strong cation exchange membrane by radiation grafting of styrene on to polyethylene (LDPE) film by mutual irradiation technique in the presence of air followed by sulfonation is described. The grafting has been carried out in the presence of air and without any additive. Low dose rate has been seen to facilitate the grafting. Further higher the grafting percentage more is the exchange capacity. The addition of a swelling agent during the sulfonation helped in achieving the high exchange capacity. The TGA-MASS analysis confirmed the grafting and the sulfonation. (author)

  6. Evaluation of the Thermophysical Properties of Poly(MethylMethacrylate): A Reference Material for the Development of a flammability Test for Micro-Gravity Environments

    OpenAIRE

    Steinhaus, Thomas

    1999-01-01

    A study has been conducted using PMMA (Poly(methyl methacrylate)) as a reference material in the development process of the Forced Flow and flame Spread Test (FIST). This test attempts to establish different criteria for material flammability for micro-gravity environments. The FIST consists of two tests, ignition and flame spread tests, that provide a series of material “fire” properties that jointly provide important information on the flammability of a material. This work de...

  7. Magnetic poly(glycidyl methacrylate) microspheres for protein capture.

    Science.gov (United States)

    Koubková, Jana; Müller, Petr; Hlídková, Helena; Plichta, Zdeněk; Proks, Vladimír; Vojtěšek, Bořivoj; Horák, Daniel

    2014-09-25

    The efficient isolation and concentration of protein antigens from complex biological samples is a critical step in several analytical methods, such as mass spectrometry, flow cytometry and immunochemistry. These techniques take advantage of magnetic microspheres as immunosorbents. The focus of this study was on the development of new superparamagnetic polymer microspheres for the specific isolation of the tumor suppressor protein p53. Monodisperse macroporous poly(glycidyl methacrylate) (PGMA) microspheres measuring approximately 5 μm and containing carboxyl groups were prepared by multistep swelling polymerization of glycidyl methacrylate (GMA), 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) and ethylene dimethylacrylate (EDMA) as a crosslinker in the presence of cyclohexyl acetate as a porogen. To render the microspheres magnetic, iron oxide was precipitated within their pores; the Fe content in the particles received ∼18 wt%. Nonspecific interactions between the magnetic particles and biological media were minimized by coating the microspheres with poly(ethylene glycol) (PEG) terminated by carboxyl groups. The carboxyl groups of the magnetic PGMA microspheres were conjugated with primary amino groups of mouse monoclonal DO-1 antibody using conventional carbodiimide chemistry. The efficiency of protein p53 capture and the degree of nonspecific adsorption on neat and PEG-coated magnetic microspheres were determined by western blot analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Additives in UV and ionising radiation grafting and curing processes

    International Nuclear Information System (INIS)

    Garnett, J.L.; Ng, L.T.; Viengkhou, V.

    1998-01-01

    Full text: Curing of polymers induced by both UV and ionising radiation are now established technologies. Currently both systems are predominantly based on acrylate chemistry. UV processes use photoinitiators to achieve fast polymerisation. In the proposed paper the significance of the occurrence of concurrent grafting with cure will be examined. particularly with respect to the recycling of finished product. Basic studies on grafting initiated by UV and ionising radiation will be discussed. Polar methyl methacrylate (MMA) and non-polar styrene will be used as representative monomers with cellulose and propylene typifying the backbone polymers. The additives chosen for examination in this study are predominantly components used in radiation curing formulations since grafting and curing are known to be mechanically related. The additives used were mineral acid, photoinitiators, vinyl ethers, oligomers, polyfunctional monomers including multifunctional acrylates (MFAs) and methacrylates (MFMAs). For the first time the use of charge transfer complexes in the Mulliken sense as additives in radiation grafting will be discussed. The CT complexes themselves, being monomers, have also been grafted to the above polymers. Recent developments with excimer laser sources for initiating these processes will be discussed, especially the use of non-acrylate chemistry. Excimer laser sources are shown to complement conventional UV and ionising radiation and are photoinitiator free. Mechanisms for the above grafting and curing processes will be outlined

  9. Evidence on unusual way of cocaine smuggling: cocaine-polymethyl methacrylate (PMMA) solid solution--study of clandestine laboratory samples.

    Science.gov (United States)

    Gostic, T; Klemenc, S

    2007-07-04

    An abandoned clandestine laboratory was seized in Slovenia. All confiscated exhibits were analysed in a forensic laboratory, where the following analytical methods were applied: capillary gas chromatography coupled with mass spectrometry (GC-MS) combined also by solid-phase micro extraction (SPME) and pyrolysis (Py) technique, Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy with energy dispersive X-ray detector (SEM-EDX). The most interesting analytical findings can be summarised as follows: at the crime scene some plastic pieces, which contained cocaine dissolved (as solid solution) in polymethyl methacrylate-plexiglass (PMMA), were found. The highest cocaine concentration measured in the plastic sample was about 15% by weight. Two larger lumps of material (12 and 3 kg) were composed mainly of PMMA and CaCO3 and contained only 0.4 and 0.5% of cocaine, respectively. As for the low cocaine concentration, we assume that those two lumps of material represent discarded waste product--residue after the isolation of cocaine from plastic. Higher quantities of pure solvents (41 l) and solvent mixtures (87 l) were seized. We identified three types of pure solvents (acetone, gasoline and benzine) and two different types of solvent mixtures (benzine/acetone and gasoline/acetone). The total seized volume (87 l) of solvent mixtures holds approximately 395 g of solid residue formed mainly of PMMA and cocaine. Obviously solvent mixtures were used for isolation of cocaine from the plastic. Small quantities of relatively pure cocaine base were identified on different objects. There were two cotton sheets, most probably used for filtration. One sheet had traces of cocaine base (76% purity) on the surface, while cocaine in hydrochloride form (96%) was identified on the other sheet. GC-MS analyses of micro traces isolated from analytical balances showed the presence of cocaine and some common adulterants: phenacetine, lidocaine and procaine. A cocaine

  10. Effect of zirconium oxide nanoparticles addition on the optical and tensile properties of polymethyl methacrylate denture base material.

    Science.gov (United States)

    Gad, Mohammed M; Abualsaud, Reem; Rahoma, Ahmed; Al-Thobity, Ahmad M; Al-Abidi, Khalid S; Akhtar, Sultan

    2018-01-01

    Polymethyl methacrylate (PMMA) is widely used for the fabrication of removable prostheses. Recently, zirconium oxide nanoparticles (nano-ZrO 2 ) have been added to improve some properties of PMMA, but their effect on the optical properties and tensile strength are neglected. The aim of this study was to investigate the effect of nano-ZrO 2 addition on the translucency and tensile strength of the PMMA denture base material. Eighty specimens (40 dumbbell-shaped and 40 discs) were prepared out of heat-polymerized acrylic resin and divided into four groups per test (n=10). The control group for each test included unreinforced acrylic, while the test groups were reinforced with 2.5, 5, and 7.5 wt% nano-ZrO 2 . Acrylic resin was mixed according to manufacturer's instructions, packed, and processed by conventional method. After polymerization, all specimens were finished, polished, and stored in distilled water at 37°C for 48±2 hours. Tensile strength (MPa) was evaluated using the universal testing machine while the specimens' translucency was examined using a spectrophotometer. Statistical analysis was carried out by SPSS using the paired sample t -test ( p ≤0.05). A scanning electron microscope was used to analyze the morphological changes and topography of the fractured surfaces. This study showed that the mean tensile strength of the PMMA in the test groups of 2.5%NZ, 5%NZ, and 7.5%NZ was significantly higher than the control group. The tensile strength increased significantly after nano-ZrO 2 addition, and the maximum increase seen was in the 7.5%NZ group. The translucency values of the experimental groups were significantly lower than those of the control group. Within the reinforced groups, the 2.5%NZ group had significantly higher translucency values when compared to the 5%NZ and 7.5%NZ groups. The addition of nano-ZrO 2 increased the tensile strength of the denture base acrylic. The increase was directly proportional to the nano-ZrO 2 concentration. The

  11. Polyethyleneglycol grafting of γ-alumina membranes for solvent resistant nanofiltration

    NARCIS (Netherlands)

    Tanardi, Cheryl; Catana, Romina; Barboiu, Mihai; Ayral, André; Vankelecom, Ivo F.J.; Nijmeijer, Arian; Winnubst, Aloysius J.A.

    2016-01-01

    A method is presented for grafting mesoporous g-alumina (pore size 5 nm), supported on an a-alumina ceramic membrane, with polyethylene glycols (PEG). The grafting performance of g-Al2O3 powders with various PEG grafting agents, having different molecular weights, alkoxy groups, and ureido

  12. Development of a water purifier for radioactive cesium removal from contaminated natural water by radiation-induced graft polymerization

    Science.gov (United States)

    Seko, Noriaki; Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya; Saiki, Seiichi; Ueki, Yuji

    2018-02-01

    Six years after the Fukushima-nuclear accident, the dissolved radioactive cesium (Cs) is now hardly detected in environmental natural waters. These natural waters are directly used as source of drinking and domestic waters in disaster-stricken areas in Fukushima. However, the possibility that some radioactive Cs adsorbed on soil or leaves will contaminate these natural waters during heavy rains or typhoon is always present. In order for the returning residents to live with peace of mind, it is important to demonstrate the safety of the domestic waters that they will use for their daily life. For this purpose, we have synthesized a material for selective removal of radioactive Cs by introducing ammonium 12-molybdophosphate (AMP) onto polyethylene nonwoven fabric through radiation-induced emulsion graft polymerization technique. Water purifiers filled with the grafted Cs adsorbent were installed in selected houses in Fukushima. The capability of the grafted adsorbent to remove Cs from domestic waters was evaluated for a whole year. The results showed that the tap water filtered through the developed water purifier contained no radioactive Cs, signifying the very effective adsorption performance of the developed grafted adsorbent. From several demonstrations, we have commercialized the water purifier named "KranCsair®". Furthermore, we have also developed a method for the mass production of the grafted nonwoven fabric. Using a 30 L grafting reactor, it was possible to produce the grafted nonwoven fabric with a suitable range of degree of grafting. When an irradiated roll of nonwoven trunk fabric with a length of 10 m and a width of 30 cm was set in the reactor filled with glycidyl methacrylate (GMA), AMP, Tween 80 monomer emulsion solution at 40 °C for 1 h, the difference of Dgs in the length and the width on roll of fabrics was negligible.

  13. Characterization and Some Properties of Functionalized Graft Copolymer

    International Nuclear Information System (INIS)

    Hegazy El-Sayed, A.; Kamal, H.; Mahmoud, Gh.A.; Khalifa, N.A.

    2000-01-01

    The study involved the investigation and characterization of membranes prepared by graft copolymerization of acrylonitrile (AN) and vinyl acetate (VAc) binary monomers onto low density polyethylene (LDPE) and isotactic polypropylene (IPP). The mutual gamma-irradiation method was used as a grafting technique. The effects of grafting and chemical treatments on the thermal properties and crystallinity of prepared graft copolymer have been investigated using DSC, TGA and XRD. IR spectra recorded before and after grafting and also for the chemically treated membranes to elucidate the structural changes occurred due to grafting and chemical treatments

  14. Synthesis, Characterization and Bulk Properties of Amphiphilic Copolymers Containing Fluorinated Methacrylates from Sequential Copper-Mediated Radical Polymerization

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Gerstenberg, Michael; Haddleton, David M.

    2008-01-01

    acrylate (MEA), and poly(ethylene glycol) methyl ether methacrylate (PEGMA) by Atom Transfer Radical Polymerization. A kinetic study of the 3FM homopolymerization initiated with ethyl bromoisobutyrate and Cu(I)Br/N-(n-propyl)-2-pyridylmethanimine reveals a living/ controlled polymerization in the range 80...

  15. Preparation, properties and biological application of pH-sensitive poly(ethylene oxide) (PEO) hydrogels grafted with acrylic acid(AAc) using gamma-ray irradiation

    International Nuclear Information System (INIS)

    Nho, Y.C.; Mook Lim, Youn; Moo Lee, Young

    2004-01-01

    pH-sensitive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing it in the small intestine. In this study, hydrogels based on poly(ethylene oxide) (PEO) networks grafted with acrylic acid (AAc) were prepared via a two-step process. PEO hydrogels were prepared by γ-ray irradiation, and then grafting by AAc monomer onto the PEO hydrogels with the subsequent irradiation (radiation dose: 5-20 kGy, dose rate: 2.15 kGy/h). These grafted hydrogels showed a pH-sensitive swelling behavior. The grafted hydrogels were used as a carrier for the drug delivery systems for the controlled release of insulin. The in vitro drug release behaviors of these hydrogels were examined by quantification analysis with a UV/VIS spectrophotometer. Insulin was loaded into freeze-dried hydrogels (7 mmx3 mmx2.5 mm) and administrated orally to healthy and diabetic Wistar rats. The oral administration of insulin-loaded hydrogels to Wistar rats decreased the blood glucose levels obviously for at least 4 h due to the absorption of insulin in the gastrointestinal tract

  16. Characterization of polymethyl methacrylate/polyethylene glycol/aluminum nitride composite as form-stable phase change material prepared by in situ polymerization method

    International Nuclear Information System (INIS)

    Zhang, Lei; Zhu, Jiaoqun; Zhou, Weibin; Wang, Jun; Wang, Yan

    2011-01-01

    Highlights: → Form-stable PMMA/PEG/AlN PCMs were prepared by in situ polymerization method. → AlN additive effectively enhanced the heat transfer property of composite PCMs. → The composites exhibited desirable thermal performance and electric insulativity. → The composites were available for the thermal management of electronic device. - Abstract: This work was focused on the preparation and characterization of a new type of form-stable phase change material (PCM) employed in thermal management. Using the method of in situ polymerization, polyethylene glycol (PEG) acting as the PCM and aluminum nitride (AlN) serving as the thermal conductivity promoter were uniformly encapsulated and embedded inside the three-dimensional network structure of PMMA matrix. When the mass fraction of PEG was below 70%, the prepared composite PCMs remained solid without leakage above the melting point of the PEG. XRD and FT-IR results indicated that the PEG was physically combined with PMMA matrix and AlN additive and did not participate in the polymerization. Thermal analysis results showed that the prepared composite PCMs possess available latent heat capacity and thermal stability, and the AlN additive was able to effectively enhance the heat transfer property of organic PCM. Moreover, the volume resistivity of composite achieved (5.92 ± 0.16) x 10 10 Ω cm when the mass ratio of AlN was 30%. To sum up, the prepared form-stable PCMs were competent for the thermal management of electronic device due to their acceptable thermal performance and electric insulativity.

  17. Poly(vinyl chloride)-g-poly(2-(dimethylamino)ethyl methacrylate) graft copolymers templated synthesis of mesoporous TiO{sub 2} thin films for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Rajkumar; Ahn, Sung Hoon; Seo, Jin Ah; Kim, Sang Jin; Kim, Jong Hak, E-mail: jonghak@yonsei.ac.kr [Yonsei University, Department of Chemical and Biomolecular Engineering (Korea, Republic of)

    2012-07-15

    A poly(vinyl chloride) (PVC) main chain was grafted with poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) containing a quaternary amine group using atom transfer radical polymerization. The successful synthesis of a PVC-g-PDMAEMA graft copolymer was confirmed by Fourier transform infrared, nuclear magnetic resonance, thermogravimetric analysis, and transmission electron microscopy. The PVC-g-PDMAEMA graft copolymer was used as a structure-directing agent (SDA) for the fabrication of a mesoporous thin film containing a titanium dioxide (TiO{sub 2}) layer. To control the porosity of the resultant inorganic layer, the ratio of SDA to TTIP as well as the concentration of the sol-gel was varied. The structure and porosity of the mesoporous film were characterized by XRD and SEM analysis. The mesoporous TiO{sub 2} film fabricated on the FTO surface was used as a photoanode for the dye-sensitized solar cell (DSSC). DSSC performance was the greatest when using TiO{sub 2} film with a higher porosity and lower interfacial resistance. The highest energy conversion efficiency reached 3.2 % at 100 mW/cm{sup 2}, which was one of the highest reported values for a quasi-solid-state DSSC with 600-nm-thick TiO{sub 2} film.

  18. Grafted Cellulose Based Adsorbents for Selective Separation Purposes

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, E; Wojnarovits, L [Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary)

    2012-09-15

    The effect of high energy ionizing radiation on cotton-cellulose was studied. It was found that degradation of cellulose started at low doses, below 5 kGy, resulting in decrease in the degree of polymerization. However, the mechanical properties of cotton-cellulose samples only slightly changed with the dose up to 40 kGy. Acrylate type monomers were successfully grafted to cellulose by mutual and by pre-irradiation grafting technique. With both techniques the grafting yield increased with increasing dose and monomer concentration. In the case of pre-irradiation grafting the increase in grafting time also resulted in an increase in grafting percentage. Cotton-cellulose was functionalized using pre-irradiation grafting (PIG) and simultaneous grafting (SG) of glycidyl methacrylate (GMA). The adsorption properties of this material were further enhanced by {beta}-cyclodextrin (CD) immobilization. This molecule is known for its unique ability to form inclusion complexes among others with aromatic compounds like phenols, pesticide, dyes, etc. (author)

  19. Graft polymerization of vynil monomers at carbon black surface (1)

    International Nuclear Information System (INIS)

    Haryono Arumbinang.

    1976-01-01

    Effect of aromatic condensates containing functional group on carbon black surface, effect of pH condensates on carbon black chemisorption, analysis and configuration of functional group, the crystal structure, property measurement standard, particle diameter measurement, oil adsorption, colour capacity, volatile acid content, electric resistence and the volume of the granular or carbon black dust, are given. Electron paramagnetic resonance determination of the amount of free radicals on carbon black surface, its oxidation and effects on the surface and inner structure of carbon black, and graft polymerization by radiation copolymerization, are discussed. Experiments on radiation graft copolymerization by acrylic acid, methacrylate, and glycidol methacrylate, in a vacuum condition, have been carried out. It is concluded that further research on the modification and configuration of carbon black should be developed. (author)

  20. Effect of γ-ray irradiation on polystyrene, poly (methyl methacrylate), and their copolymer prepared by cast polymerization

    International Nuclear Information System (INIS)

    Tsukame, Takahiro; Kutsuzawa, Michio; Saitoh, Hideki; Shibasaki, Yoshio

    1998-01-01

    Effect of γ-ray irradiation on polystyrene (PS), poly(methyl methacrylate) (PMMA), and their copolymer prepared by cast polymerization was studied using size exclusion chromatography. The main chemical reactions in irradiated polymers were crosslinking and scission. Conversion of all irradiated samples increased regardless of the concentration of initiator (AIBN) used for cast polymerization. On γ-ray irradiation, the molecular weight of PS increased and its distribution broadened, whereas the molecular weight of PMMA decreased. These phenomena should be attributable to the competitive occurrence of scission and crosslinking in PS by γ-ray irradiation, whereas scission occurred mainly in PMMA. (author)

  1. Synthesis of transparent ZnO/PMMA nanocomposite films through free-radical copolymerization of asymmetric zinc methacrylate acetate and in-situ thermal decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lin [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Li Fan, E-mail: lfan@ncu.edu.cn [Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Chen Yiwang, E-mail: ywchen@ncu.edu.cn [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wang Xiaofeng [Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China)

    2011-08-15

    In this paper, a new and simple approach for in-situ preparation of transparent ZnO/poly(metyl methacrylate) (ZnO/PMMA) nanocomposite films was developed. Poly(methyl methacrylate)-co-poly(zinc methacrylate acetate) (PMMA-co-PZnMAAc) copolymer was synthesized via free-radical polymerization between methyl methacrylate (MMA) and zinc methacrylate acetate (ZnMAAc), where asymmetric ZnMAAc with only one terminal double bond (C=C) was applied to act as the precursor for ZnO nanocrystals and could avoid cross-link. Subsequently, transparent ZnO/PMMA nanocomposite films were obtained by in-situ thermal decomposition. Scanning electron microscope (SEM) image revealed that ZnO nanocrystals were homogeneously dispersed in PMMA matrix. With thermal decomposition time increasing, the absorption intensity in UV region and photoluminescence intensity of ZnO/PMMA nanocomposite films enhanced. However, the optical properties diminished when the thermal decomposition temperature increased. The TGA measurement displayed ZnO/PMMA nanocomposite films prepared by the in-situ synthesis method possessed better thermal stability compared with those prepared by the physical blending method and pristine PMMA films. - Highlights: > ZnO/PMMA hybrid films were prepared via free-radical polymerization and in-situ thermal decomposition. > ZnO NCs are homogeneously dispersed in the PMMA matrix and these films have good optical properties. > Thermal stability of these films is improved compared with those of physically blending ones.

  2. Synthesis of transparent ZnO/PMMA nanocomposite films through free-radical copolymerization of asymmetric zinc methacrylate acetate and in-situ thermal decomposition

    International Nuclear Information System (INIS)

    Zhang Lin; Li Fan; Chen Yiwang; Wang Xiaofeng

    2011-01-01

    In this paper, a new and simple approach for in-situ preparation of transparent ZnO/poly(metyl methacrylate) (ZnO/PMMA) nanocomposite films was developed. Poly(methyl methacrylate)-co-poly(zinc methacrylate acetate) (PMMA-co-PZnMAAc) copolymer was synthesized via free-radical polymerization between methyl methacrylate (MMA) and zinc methacrylate acetate (ZnMAAc), where asymmetric ZnMAAc with only one terminal double bond (C=C) was applied to act as the precursor for ZnO nanocrystals and could avoid cross-link. Subsequently, transparent ZnO/PMMA nanocomposite films were obtained by in-situ thermal decomposition. Scanning electron microscope (SEM) image revealed that ZnO nanocrystals were homogeneously dispersed in PMMA matrix. With thermal decomposition time increasing, the absorption intensity in UV region and photoluminescence intensity of ZnO/PMMA nanocomposite films enhanced. However, the optical properties diminished when the thermal decomposition temperature increased. The TGA measurement displayed ZnO/PMMA nanocomposite films prepared by the in-situ synthesis method possessed better thermal stability compared with those prepared by the physical blending method and pristine PMMA films. - Highlights: → ZnO/PMMA hybrid films were prepared via free-radical polymerization and in-situ thermal decomposition. → ZnO NCs are homogeneously dispersed in the PMMA matrix and these films have good optical properties. → Thermal stability of these films is improved compared with those of physically blending ones.

  3. Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

    International Nuclear Information System (INIS)

    Saliza Jam; Mansor Ahmad; Wan Md Zin Wan Yunus; Khairul Zaman Mohd Dahlan

    2001-01-01

    Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

  4. Hydrophilicity improvement of polyethersulfone membranes by grafting methacrylic acid with γ-ray irradiation

    International Nuclear Information System (INIS)

    Li Jing; Hou Zhengchi; Xie Leidong; Zhang Fengying; Deng Bo

    2005-01-01

    Grafting methyacrylic acid onto poly(ether sulfone) membranes was realized by means of simultaneous irradiation in liquids. The modified membranes with different grafting ratios were obtained by changing the concentration of methyacrylic acid. It was shown that the grafting ratio increased lineally as the monomer concentration was less than 10% and hydrophilicity of the membranes was improved with increasing grafting ratios. (authors)

  5. Synthesis and characterization of organometallic copolymers of acrylic acid g-polyethylene, with Mo, Fe, Co, Zn and Ni

    International Nuclear Information System (INIS)

    Dorantes R, G.L.

    1997-01-01

    In this study, the preparation of a series of low density polyethylenes grafted with acrylic acid is presented. The grafting reactions were initiated by different doses of γ radiation; it was observed that grafting increased with the doses of radiation. The prepared copolymers were coordinated with different metals, as Mo, Fe, Co, Zn and Ni. The amount of metal supported on the polymer was determined by atomic absorption. Infrared spectroscopy and thermogravimetric analysis confirmed the metal chelation on the graft copolymer. The film surfaces were observed by scanning electron microscopy. positron annihilation spectroscopy revealed a decrease on the free volume in the low density polyethylene after the grafting with acrylic acid. (Author)

  6. Current status of grafts and implants in rhinoplasty: Part II. Homologous grafts and allogenic implants.

    Science.gov (United States)

    Sajjadian, Ali; Naghshineh, Nima; Rubinstein, Roee

    2010-03-01

    After reading this article, the participant should be able to: 1. Understand the challenges in restoring volume and structural integrity in rhinoplasty. 2. Identify the appropriate uses of various homologous grafts and allogenic implants in reconstruction, including: (a) freeze-dried acellular allogenic cadaveric dermis grafts, (b) irradiated cartilage grafts, (c) hydroxyapatite mineral matrix, (d) silicone implants, (e) high-density polyethylene implants, (f) polytetrafluoroethylene implants, and (g) injectable filler materials. 3. Identify the advantages and disadvantages of each of these biomaterials. 4. Understand the specific techniques that may aid in the use these grafts or implants. This review specifically addresses the use of homologous grafts and allogenic implants in rhinoplasty. It is important to stress that autologous materials remain the preferred graft material for use in rhinoplasty, owing to their high biocompatibility and low risk of infection and extrusion. However, concerns of donor-site morbidity, graft availability, and graft resorption have motivated the development and use of homologous and allogenic implants.

  7. Modification of natural leather by grafting emulsion copolymerization technique

    International Nuclear Information System (INIS)

    Badran, A.S.; Nasr, H.E.; El-Halawany, N.R.; Mohamed, W.S.

    2005-01-01

    Grafting emulsion copolymerization of methyl methacrylate (MMA) with butyl acrylate of different molar ratios onto natural leather with different molar ratios was carried out using developed redox initiation system of potassium persulphate (PPS) as an oxidizing agent and some sodium bisulphite adducts as reducing agent, as well as sodium dodecyl sulphate (SDS) was used as an anionic emulsifier. The grafted leather was characterized via FTIR, SEM and thermal gravimetric analysis. Moreover, the grafted leather was evaluated through water absorption, tensile strength, dyeing performance and hardness measurements. The obtained results revealed that the physical and mechanical properties of the modified leather were enhanced

  8. Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE Addition

    Directory of Open Access Journals (Sweden)

    Yun Lu

    2013-06-01

    Full Text Available This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs. The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%–8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

  9. Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE) Addition.

    Science.gov (United States)

    Chen, Jinxiang; Wang, Yong; Gu, Chenglong; Liu, Jianxun; Liu, Yufu; Li, Min; Lu, Yun

    2013-06-18

    This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE) enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs). The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%-8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

  10. Initiated chemical vapor deposition of pH responsive poly(2-diisopropylamino)ethyl methacrylate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Karaman, Mustafa, E-mail: karamanm@selcuk.edu.tr [Department of Chemical Engineering, Selcuk University (Turkey); Advanced Technology Research and Application Center, Selcuk University (Turkey); Cabuk, Nihat [Department of Chemical Engineering, Selcuk University (Turkey)

    2012-08-31

    Poly(2-(diisopropylamino)ethyl methacrylate) (PDPAEMA) thin films were deposited on low temperature substrates by initiated chemical vapor deposition (iCVD) method using tertbutyl peroxide as an initiator. Very high deposition rates up to 38 nm/min were observed at low filament temperatures due to the use of the initiator. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy show the formation of PDPAEMA films with high retention of tertiary amine functionality which is responsible for pH induced changes in the wetting behavior of the surfaces. As-deposited PDPAEMA thin films on flat Si surface showed a reversible switching of water contact angle values between 87 Degree-Sign and 28 Degree-Sign ; after successive treatments of high and low pH water solutions, respectively. Conformal and non-damaging nature of iCVD allowed to functionalize fragile and rough electrospun poly(methyl methacrylate) fiber mat surfaces by PDPAEMA, which creates a surface with a switching behavior between superhydrophobic and approaching superhydrophilic with contact angle values of 155 {+-} 3 Degree-Sign and 22 {+-} 5 Degree-Sign , respectively. - Highlights: Black-Right-Pointing-Pointer Poly(2-diisopropylaminoethyl methacrylate) thin films were deposited by a dry process. Black-Right-Pointing-Pointer Initiated chemical vapor deposition can produce thin films on fragile substrates. Black-Right-Pointing-Pointer We report a reversible pH-induced transition from hydrophilic to super-hydrophobic.

  11. Location of radiation-induced grafted chains in polymers studied by solid-state NMR

    International Nuclear Information System (INIS)

    Whittacker, A.; Liu, H.

    1998-01-01

    In this study styrene and N-phenyl maleimide monomers were grafted onto poly(ethylene) (PE) chains using gamma radiation. Of main interest is the distribution of grafted chains within the polymer matrix, as this will determine the efficacy of mixing with the glassy polymers. It is expected that grafting will occur within the amorphous regions, and especially near the interface of the crystalline and amorphous regions. A suitable method for characterising the location of the grafted chains is solid-state 13 C NMR spectroscopy. The 13 C CPMAS spectrum of the blend of PE and N-phenyl maleimide mixed in the melt at 150 deg C , prior to reaction, is shown above. The spectrum shows the typical peaks for poly(ethylene) due to the amorphous and crystalline phase at 30.5 and 32.5 ppm, respectively. Peaks are also seen in the aromatic and carbonyl region due to the maleimide (not plotted). Experiments will be described where the NMR magnetisation is prepared in either the crystalline and amorphous regions of the poly(ethylene) prior to spin diffusion to the maleimide and styrene fractions. The location of the grafted monomers can then be determined by monitoring the changes in signal of polymer and graft with time

  12. Acrylique acid grafted polyolefines. Thermoadhesive applications

    International Nuclear Information System (INIS)

    Guimon, Claude

    1979-01-01

    Radiochemical grafting of polyolefines by peroxidation has been industrialized in France for about 10 years by irradiation of these polymers with an electron accelerator and then treated by acrylic acid. Products obtained show a high adhesivity on metallic surfaces above their melting point. The main application of acrylic acid grafted high density polyethylene is composite film with aluminum foil for thermosealing of plastic bottle caps of sterilized milk. Acrylic acid grafted polypropylene is used in suspension in a volatile liquid for aluminum foil coating satisfying food packaging regulations [fr

  13. Ph responsive permeability and Ion- exchange characteristics of (PE/EPDM)-g-PMAA membranes

    International Nuclear Information System (INIS)

    El- Awady, M.M.; El-Awady, N.I.; Eissa, A.M.

    2005-01-01

    Chemical grafting of methacrylic acid (MAA) on low density exchange membranes for recovery of different cations from their solutions was investigated. When the dialysis permeability of two solutes (glucose + urea) through the membrane were tested at different ph values and compared, glucose was found to be less efficient than urea for permeation through the membrane. The permeability response of such solute was noticed only at higher ph value (ph 8). The grafted film (membrane) with graft yield of 185% is experimentally adequate to permeate all molecules with radius of lower than 4.3 x 10 polyethylene blended with EPDM with a ratio (90/10) films was carried out using sodium bisulphite as initiator. Factors affecting grafting and the properties of the grafted films were studied in details and showed improved hydrophilic properties, good thermal stability and nearly unaffected strength properties which make them acceptable for practical uses.In the present work, the possibility of practical uses of such grafted films as ph-responsive membranes in a dialysis process and as ion--7 mm. Grafted membranes in different forms (COOH-form), (Na-methacrylate form) and (K methacrylate- form) were prepared to evaluate the membranes uptake selectivity to different mono, di-and trivalent cations from their solutions. The results obtained showed very good efficiency of the prepared membranes as compared with the values obtained for the commercial cation exchange resin (Dowex)

  14. Development of Highly Efficient Grafting Technique and Synthesis of Natural Polymer-Based Graft Adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Ueki, Y; Seko, N; Tamada, M [Japan Atomic Energy Agency, Quantum Beam Science Directorate, Takasaki (Japan)

    2012-09-15

    In the framework of the CRP, Japan has focused on the development of fibrous adsorbents for removal of toxic metal ions and recovery of significant metal ions from industrial wastewater and streaming water. Graft polymerization was carried out by using gamma irradiation facility and electron beam accelerator. Emulsion grafting is a novel topic for synthesis of metal ion adsorbents which are prepared from fibrous trunk polymers such as polyethylene fibre and biodegradable nonwoven fabrics. The emulsion grafting, where monomer micelles are dispersed in water in the presence of surfactant, is a highly efficient and economic grafting technique as compared to general organic solvent system. The resultant cotton-based adsorbent has high adsorption efficiency and high adsorption capacity for Hg, besides, it is biodegradable. Polylactic acid can also be used as a trunk material for the grafting. (author)

  15. Study by dispersed light photometry of the polymerization of methacrylates by gamma radiation

    International Nuclear Information System (INIS)

    Isaurralde, Haidee; Molinari, M.A.

    1976-04-01

    Determinations of molecular weights of methyl methacrylate irradiated in presence and in absence of oxygen were made at different exposure times exponential function of the time of irradiation. The molecular weight of polymethyl metacrilate obtained by irradiating the monomer in presence of nitrogen or oxygen was determined, and the value 4,4 x 10 6 was obtained in both cases, for total polymerization. Different experiments were made to determine the yield of polimerization, by precipitation and recuperation of the precipitate, and with dilatometer, and we saw that in presence of nitrogen the yield is much larger than in presence of oxygen, being in the first case 100% at 4 hs. 45 min., and in the second 4% for the same exposure time. (author) [es

  16. Influence of incorporation of ZrO2 nanoparticles on the repair strength of polymethyl methacrylate denture bases

    Directory of Open Access Journals (Sweden)

    Gad MM

    2016-10-01

    Full Text Available Mohammed M Gad,1 Ahmed Rahoma,2,3 Ahmad M Al-Thobity,1 Aws S ArRejaie4 1Department of Substitutive Dental Sciences, 2Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Dammam, Saudi Arabia; 3Department of Dental Materials, College of Dentistry, Al-Azhar University, Assiut, Egypt; 4Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia Background: Repeated fracture of the denture base is a common problem in prosthodontics, and it represents a nuisance and a time sink for the clinician. Therefore, the possibility of increasing repair strength using new reinforcement materials is of great interest to prosthodontists.Aim of the study: This study aimed to evaluate the effects of incorporation of zirconia nanoparticles (nano-ZrO2 on the flexural strength and impact strength of repaired polymethyl methacrylate (PMMA denture bases.Materials and methods: One hundred eighty specimens of heat-polymerized acrylic resin were fabricated (90 for each test and divided into three main groups: one control group (intact specimens and two groups divided according to surface design (45° bevels and butt joints, in which specimens were prepared in pairs to create 2.5 mm gaps. Nano-ZrO2 was added to repair resin in 2.5 wt%, 5 wt%, and 7.5 wt% concentrations of acrylic powder. A three-point bending test was used to measure flexural strength, and a Charpy-type test was used to measure impact strength. Scanning electron microscopy was used to analyze the fracture surfaces and nano-ZrO2 distribution. The results were analyzed with a paired sample t-test and an unpaired t-test, with a P-value of ≤0.05 being significant.Results: Incorporation of nano-ZrO2 into the repair resin significantly increased flexural strength (P<0.05. The highest value was found in the bevel group reinforced with 7.5% nano-ZrO2, whereas the lowest value was found in the butt group reinforced with 2.5% nano

  17. The primary report of percutaneous polymethyl methacrylate cementoplasty in osteolytic metastases of the pelvis and peripheral bone

    International Nuclear Information System (INIS)

    Sun Gang; Jin Peng; Yi Yuhai; Xie Zhiyong; Zhang Xuping; Li Guoying

    2005-01-01

    Objective: To propose a technique and treatment of percutaneous polymethyl methacrylate (PMMA) cementoplasty for painful metastatic lesions of the pelvis, humerus, and tibia. Methods: Percutaneous PMMA cementoplasty was performed in 24 cases, including the lesions of S1 in 9 cases, acetabulum in 7 cases, ischium in 5 cases, humerus in 2 cases, and tibia in 1 case. There were 26 local lesions. The puncture approach was performed under fluoroscopic guidance. The S1 vertebral body puncture was performed with lateral transsacroiliac joint approach. The needle progression was controlled in the anteroposterior projection with a needle course above the level of the S1 foramen. With the needle adjacent to the S1 vertebral body edge, the needle tip should center just in front of the spinal canal in the lateral fluoroscopic projection. The acetabular roof puncture was performed with lateral approach. The needle progression was controlled in the anteroposterior and lateral projections alternately with a needle course parallel to the body axial plane. The puncture needle arrived directly at the lesions. The puncture to the ischium was from ischium tubercle to the lesions. The puncture progression to the internal compartment of the acetabulum was with the trajectory of the needle from the ischium tubercle to the lesion. The puncture progression to the humerus should avoid conflicting with the radial nerve and upper extremity vessels. The needle course should be from the dorsal upper arm to the lesions. As for the lesions of the tibia, the needle was punctured from the front of tibia to the lesion. After the needle tip placement in the lesions, PMMA in paste condition was injected with the precession injector pressure device under continuous visual control with adequate filling and avoidance of important PMMA leakage. Results: Partial or complete pain relief was obtained in all 24 patients (CR in 10 cases, PR in 14 cases) within 7 days after the operation. Clinical improvement

  18. Comparison of Wear Resistance of Hawley and Vacuum Formed Retainers: An in-vitro Study

    Directory of Open Access Journals (Sweden)

    Moshkelgosha V

    2016-06-01

    Full Text Available Statement of Problem: As a physical property, wear resistance of the materials used in the fabrication of orthodontic retainers play a significant role in the stability and long term use of the appliances. Objectives: To evaluate the wear resistance of two commonly used materials for orthodontic retainers: Acropars OP, i.e. a polymethyl methacrylate based material, and 3A-GS060, i.e. a polyethylene based material. Materials and Methods: For each material, 30 orthodontic retainers were made according to the manufacturers’ instructions and a 30×30×2 mm block was cut out from the mid- palatal area of each retainer. Each specimen underwent 1000 cycles of wear stimulation in a pin on disc machine. The depth of wear of each specimen was measured using a Nano Wizard II atomic force microscope in 3 random points of each specimen’s wear trough. The average of these three measurements was calculated and considered as mean value wear depth of each specimen (µm. Results: The mean wear depth was 6.10µm and 2.15µm for 3A-GS060 and Acropars OP groups respectively. Independent t-test showed a significant difference between the two groups (p < 0.001. The results show Polymethyl methacrylate base (Acropars is more wear resistance than the polyethylene based material (3A-GS060. Conclusions: As the higher wear resistance of the fabrication material can improve the retainers’ survival time and its cost-effectiveness, VFRs should be avoided in situations that the appliance needs high wear resistance such as bite blocks opposing occlusal forces.

  19. Comparison of Wear Resistance of Hawley and Vacuum Formed Retainers: An in-vitro Study.

    Science.gov (United States)

    V, Moshkelgosha; M, Shomali; M, Momeni

    2016-06-01

    As a physical property, wear resistance of the materials used in the fabrication of orthodontic retainers play a significant role in the stability and long term use of the appliances. To evaluate the wear resistance of two commonly used materials for orthodontic retainers: Acropars OP, i.e. a polymethyl methacrylate based material, and 3A-GS060, i.e. a polyethylene based material. For each material, 30 orthodontic retainers were made according to the manufacturers' instructions and a 30×30×2 mm block was cut out from the mid- palatal area of each retainer. Each specimen underwent 1000 cycles of wear stimulation in a pin on disc machine. The depth of wear of each specimen was measured using a Nano Wizard II atomic force microscope in 3 random points of each specimen's wear trough. The average of these three measurements was calculated and considered as mean value wear depth of each specimen (µm). The mean wear depth was 6.10µm and 2.15µm for 3A-GS060 and Acropars OP groups respectively. Independent t-test showed a significant difference between the two groups ( p < 0.001). The results show Polymethyl methacrylate base (Acropars) is more wear resistance than the polyethylene based material (3A-GS060). As the higher wear resistance of the fabrication material can improve the retainers' survival time and its cost-effectiveness, VFRs should be avoided in situations that the appliance needs high wear resistance such as bite blocks opposing occlusal forces.

  20. Iodinated glycidyl methacrylate copolymer as a radiopaque material for biomedical applications.

    Science.gov (United States)

    Dawlee, S; Jayabalan, M

    2013-07-01

    Polymeric biomaterial was synthesized by copolymerizing 50:50 mol% of monomers, glycidyl methacrylate and methyl methacrylate. Iodine atoms were then grafted to the epoxide groups of glycidyl methacrylate units, rendering the copolymer radiopaque. The percentage weight of iodine in the present copolymer was found to be as high as 23%. The iodinated copolymer showed higher glass transition temperature and thermal stability in comparison with unmodified polymer. Radiographic analysis showed that the copolymer possessed excellent radiopacity. The iodinated copolymer was cytocompatible to L929 mouse fibroblast cells. The in vivo toxicological evaluation by intracutaneous reactivity test of the copolymer extracts has revealed that the material was nontoxic. Subcutaneous implantation of iodinated copolymer in rats has shown that the material was well tolerated. Upon explantation and histological examination, no hemorrhage, infection or necrosis was observed. The samples were found to be surrounded by a vascularized capsule consisting of connective tissue cells. The results indicate that the iodinated copolymer is biocompatible and may have suitable applications as implantable materials.