WorldWideScience

Sample records for methacrylates polymerization induced

  1. Polymerization of sodium methacrylate induced by irradiation

    International Nuclear Information System (INIS)

    Galvan S, A.

    1998-01-01

    This work has two objectives, first: it is pretended to localize the lines of carbon links in its IR spectra, and second: following the polymerization of sodium methacrylate according to that it is irradiated with gamma rays. (Author)

  2. 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.

  3. Study of radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. VIII. Polymerization of styrene and methyl methacrylate adsorbed on aerosil

    International Nuclear Information System (INIS)

    Fukano, K.; Kageyama, E.

    1976-01-01

    Aerosol is silica having a purity which is very high compared with that of silica gel and having, unlike silica gel, no micropores. To investigate the effects of impurities and micropores on the radiation-induced polymerization of styrene and methyl methacrylate adsorbed on silica gel, the radiation-induced polymerization of styrene and methyl methacrylate adsorbed on Aerosil was carried out. The results of both the styrene--Aerosil 300 system and the methyl methacrylate--Aerosil 300 system were similar to those of the styrene-silica gel and methyl methacrylate-silica gel systems, respectively. This suggests that in the radiation-induced polymerization of both styrene--silica gel and methyl methacrylate--silica gel systems the impurities and the presence of micropores have almost no effect on the reaction mechanism. The effect of aluminum as an impurity was investigated on the styrene--Aerosil MOX 170 system. It was found that aluminum accelerated the cationic polymerization

  4. Polymerization of sodium methacrylate induced by irradiation; Polimerizacion del metacrilato de sodio inducida por la irradiacion

    Energy Technology Data Exchange (ETDEWEB)

    Galvan S, A. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Basicas, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    This work has two objectives, first: it is pretended to localize the lines of carbon links in its IR spectra, and second: following the polymerization of sodium methacrylate according to that it is irradiated with gamma rays. (Author)

  5. Visible Light-Induced Metal Free Surface Initiated Atom Transfer Radical Polymerization of Methyl Methacrylate on SBA-15

    Directory of Open Access Journals (Sweden)

    Liang Ma

    2017-02-01

    Full Text Available Surface-initiated atom transfer radical polymerization (SI-ATRP is one of the most versatile techniques to modify the surface properties of materials. Recent developed metal-free SI-ATRP makes such techniques more widely applicable. Herein photo-induced metal-free SI-ATRP of methacrylates, such as methyl methacrylate, N-isopropanyl acrylamide, and N,N-dimethylaminoethyl methacrylate, on the surface of SBA-15 was reported to fabricate organic-inorganic hybrid materials. A SBA-15-based polymeric composite with an adjustable graft ratio was obtained. The structure evolution during the SI-ATRP modification of SBA-15 was monitored and verified by FT-IR, XPS, TGA, BET, and TEM. The obtained polymeric composite showed enhanced adsorption ability for the model compound toluene in aqueous conditions. This procedure provides a low-cost, readily available, and easy modification method to synthesize polymeric composites without the contamination of metal.

  6. Radiation-induced polymerization monitored in situ by time-resolved fluorescence of probe molecules in methyl methacrylate

    International Nuclear Information System (INIS)

    Frahn, Mark S.; Abellon, Ruben D.; Luthjens, Leonard H.; Vermeulen, Martien J.W.; Warman, John M.

    2003-01-01

    A technique is presented for monitoring radiation-induced polymerizations in situ based on the measurement of the fluorescence lifetime of molecular probes dissolved in the polymerizing medium. This method is illustrated with results on methyl methacrylate (MMA) using two fluorogenic probe molecules; N-(2-anthracene)methacrylamide (AnMA) and maleimido-fluoroprobe (MFP), a molecule which has a highly dipolar excited state

  7. 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)

  8. Characterization of γ-radiation induced polymerization in ethyl methacrylate and methyl acrylate monomers solutions

    Science.gov (United States)

    Baccaro, Stefania; Casieri, Cinzia; Cemmi, Alessia; Chiarini, Marco; D'Aiuto, Virginia; Tortora, Mariagrazia

    2017-12-01

    The present work is focused on the γ-radiation induced polymerization of ethyl methacrylate (EMA) and methyl acrylate (MA) monomers mixture to obtain a co-polymer with specific features. The effect of the irradiation parameters (radiation absorbed dose, dose rate) and of the environmental atmosphere on the features of the final products was investigated. Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Nuclear Magnetic Resonance high-resolution analyses of hydrogen and carbon nuclei (1H and 13C NMR) were applied to follow the γ-induced modifications by monitoring the co-polymerization process and allowed the irradiation parameters optimization. Diffusion-Ordered NMR (DOSY-NMR) data were used to evaluate the co-polymers polydispersity and polymerization degree. Since the last parameter is strongly influenced by the γ radiation and environmental conditions, a comparison among samples prepared and irradiated in air and under nitrogen atmosphere was carried out. In presence of oxygen, higher radiation was required to obtain a full solid co-polymer since a partial amount of energy released to the samples was involved in competitive processes, i.e. oxygen-containing free radicals formation and primary radicals recombination. Irrespectively to the environmental atmosphere, more homogeneous samples in term of polymerization degree dispersion was achieved at lower dose rates. At radiation absorbed doses higher than those needed for the formation of the co-polymer, while in case of samples irradiated in air heavy depolymerization was verified, a sensible increase of the samples stability was attained if the irradiation was performed under nitrogen atmosphere.

  9. 60Co γ-irradiation induced polymerization of methyl methacrylate in imidazolium ionic liquids

    International Nuclear Information System (INIS)

    Qi Mingying; Wu Gongzhong; Liu Yaodong; Chen Shimou; Sha Maolin

    2006-01-01

    Room temperature ionic liquids (RTILs), as a class of novel environmental benign 'green solvents', have been used as reaction media for various polymerizations due to their unique properties of non-volatility, high polarity, ease of recycling and chirality. In radiation polymerization, the energetic photons or electrons result in the formation of solvated electron and radical ions in ionic liquids, which initiate polymerization of monomers without any chemical initiator. In this work, effects of gamma ray irradiation on pure ionic liquid [bmim][PF 6 ] was investigated in detail in a dose range of 5-400 kGy. The ionic liquids were quite stable under low dose irradiations, but underwent notable radiolysis with high doses. With the irradiated [bmim][PF 6 ], the UV-Vis absorbance increased and the fluorescence intensity decreased with increasing doses. Raman spectra proved that gamma radiation induced significant chemical scission of n-butyl group (e.g. C-H and C-C scission), along with damages to the [PF6] - anion. In cooled samples of the irradiated [bmim][PF 6 ] we found two coexist crystal structures, which had suffered a continuous destruction under high dose irradiation. After ensuring stability of the ionic liquids to low dose irradiation, radiation polymerization of methyl methacrylate (MMA) in ionic liquids and IL/organic solutions was performed. By adding the ionic liquids, the monomer conversion and molecular weight (Mw) of the polymer increased significant. Mw of PMMA in neat ionic liquid increased by about 60 times, from 3 x 10 4 with pure organic solvent to about 2 x 10 6 . Molecular weight of the polymer increased with the IL fraction in the IL/organic solutions, and it was dependent on ionic liquids and solvents used, too. It was also found that the polymer obtained in the existence of IL showed multi-modal broadened molecular weight distribution (MWD). A reasonable explanation is the inhomogeneous nature of the ionic liquid in micron scale and the

  10. Radiation processing of polymer emulsion, (4). Radiation-induced emulsion polymerization of methyl methacrylate at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo; Katakai, Akio; Ito, Hiroshi; Hayakawa, Naohiro; Araki, Kunio (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment)

    1983-06-01

    Methyl methacrylate was polymerized in emulsion by Co-60 ..gamma..-rays below 19 deg C in a batch reactor by using sodium lauryl sulfate as emulsifier. The conversion-time curves of the polymerization system showed two rate regions, i.e., a fact conversion rate in early stage, and a much slower rate in latter stage. The change in rate occurred at about 70 % conversion. The molecular weight of product polymer decreased with increasing conversion during the course of polymerization in latter stage, in contrast to the behavior in early stage. The distribution of the monomer in emulsion in latter stage was evaluated by nuclear magnetic resonance technique. The decrease of the molecular weight with conversion is due to the radiation-induced degradation of product polymer accelerated by the monomers absorbed in the polymer particles.

  11. Study on radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. II. Radiation-induced polymerization of methyl methacrylate adsorbed on several inorganic substances

    International Nuclear Information System (INIS)

    Fukano, K.; Kageyama, E.

    1975-01-01

    The radiation-induced polymerization of methyl methacrylate (MMA) adsorbed on such inorganic substances as silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to compare with the case of styrene. The rate of radiation-induced polymerization adsorbed on inorganic substances was high compared with that of radiation-induced bulk state polymerization, as was the case with styrene. Inorganic substrates which contain aluminum as a component element are more likely to be grafted than those which consist of SiO 2 alone, as with styrene. The molecular weight distribution of unextractable polymer and extractable polymer differs, depending on the type of inorganic substance. Experiments by a preirradiation method were carried out in case of silica gel, white carbon, and silicic acid anhydride. GPC spectra of the polymer obtained were different from those of polymer formed by the simultaneous irradiation method. It appears that all the unextractable polymer is grafted to the inorganic surface with chemical bond

  12. Reversible-Deactivation Radical Polymerization of Methyl Methacrylate Induced by Photochemical Reduction of Various Copper Catalysts

    Directory of Open Access Journals (Sweden)

    Jaroslav Mosnáček

    2014-11-01

    Full Text Available Photochemically mediated reversible-deactivation radical polymerization of methyl methacrylate was successfully performed using 50–400 ppm of various copper compounds such as CuSO4·5H2O, copper acetate, copper triflate and copper acetylacetonate as catalysts. The copper catalysts were reduced in situ by irradiation at wavelengths of 366–546 nm, without using any additional reducing agent. Bromopropionitrile was used as an initiator. The effects of various solvents and the concentration and structure of ligands were investigated. Well-defined polymers were obtained when at least 100 or 200 ppm of any catalyst complexed with excess tris(2-pyridylmethylamine as a ligand was used in dimethyl sulfoxide as a solvent.

  13. Photoinitiated Polymerization-Induced Self-Assembly of Glycidyl Methacrylate for the Synthesis of Epoxy-Functionalized Block Copolymer Nano-Objects.

    Science.gov (United States)

    Tan, Jianbo; Liu, Dongdong; Huang, Chundong; Li, Xueliang; He, Jun; Xu, Qin; Zhang, Li

    2017-08-01

    Herein, a novel photoinitiated polymerization-induced self-assembly formulation via photoinitiated reversible addition-fragmentation chain transfer dispersion polymerization of glycidyl methacrylate (PGMA) in ethanol-water at room temperature is reported. It is demonstrated that conducting polymerization-induced self-assembly (PISA) at low temperatures is crucial for obtaining colloidal stable PGMA-based diblock copolymer nano-objects. Good control is maintained during the photo-PISA process with a high rate of polymerization. The polymerization can be switched between "ON" and "OFF" in response to visible light. A phase diagram is constructed by varying monomer concentration and degree of polymerization. The PGMA-based diblock copolymer nano-objects can be further cross-linked by using a bifunctional primary amine reagent. Finally, silver nanoparticles are loaded within cross-linked vesicles via in situ reduction, exhibiting good catalytic properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. 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.

  15. 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.

  16. 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.

  17. Polymerization of methyl methacrylate by diphenylamido bis (methylcyclopentadienyl) ytterbium complex

    Institute of Scientific and Technical Information of China (English)

    WANG, Yao-Rong(王耀荣); SHEN, Qi(沈琪); MA, Jia-Le(马家乐); ZHAO, Qun(赵群)

    2000-01-01

    Methyl methacrylate (MMA) was effectively polymerized by diphenylamido bis(methyicyclopentadienyl) ytterbium complex (MeCp)2YbNPh2(THF). Tne reaction can be carried out over a range of polymerization temperature from - 40℃ to 40℃ and gives the polyMMA with high molecular weights.The initiation mechanism was demonstrated by diphenylamidoterminated methyl methacrylate oligomer.

  18. A New Route for High-Purity Organic Materials: High-Pressure-Ramp-Induced Ultrafast Polymerization of 2-(Hydroxyethyl)Methacrylate

    Science.gov (United States)

    Evlyukhin, E.; Museur, L.; Traore, M.; Perruchot, C.; Zerr, A.; Kanaev, A.

    2015-12-01

    The synthesis of highly biocompatible polymers is important for modern biotechnologies and medicine. Here, we report a unique process based on a two-step high-pressure ramp (HPR) for the ultrafast and efficient bulk polymerization of 2-(hydroxyethyl)methacrylate (HEMA) at room temperature without photo- and thermal activation or addition of initiator. The HEMA monomers are first activated during the compression step but their reactivity is hindered by the dense glass-like environment. The rapid polymerization occurs in only the second step upon decompression to the liquid state. The conversion yield was found to exceed 90% in the recovered samples. The gel permeation chromatography evidences the overriding role of HEMA2•• biradicals in the polymerization mechanism. The HPR process extends the application field of HP-induced polymerization, beyond the family of crystallized monomers considered up today. It is also an appealing alternative to typical photo- or thermal activation, allowing the efficient synthesis of highly pure organic materials.

  19. Immobilization of biomolecules to plasma polymerized pentafluorophenyl methacrylate.

    Science.gov (United States)

    Duque, Luis; Menges, Bernhard; Borros, Salvador; Förch, Renate

    2010-10-11

    Thin films of plasma polymerized pentafluorophenyl methacrylate (pp-PFM) offer highly reactive ester groups throughout the structure of the film that allow for subsequent reactions with different aminated reagents and biological molecules. The present paper follows on from previous work on the plasma deposition of pentafluorophenyl methacrylate (PFM) for optimum functional group retention (Francesch, L.; Borros, S.; Knoll, W.; Foerch, R. Langmuir 2007, 23, 3927) and reactivity in aqueous solution (Duque, L.; Queralto, N.; Francesch, L.; Bumbu, G. G.; Borros, S.; Berger, R.; Förch, R. Plasma Process. Polym. 2010, accepted for publication) to investigate the binding of a biologically active peptide known to induce cellular adhesion (IKVAV) and of biochemically active proteins such as BSA and fibrinogen. Analyses of the films and of the immobilization of the biomolecules were carried out using infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The attachment of the biomolecules on pulsed plasma polymerized pentafluorophenyl methacrylate was monitored using surface plasmon resonance spectroscopy (SPR). SPR analysis confirmed the presence of immobilized biomolecules on the plasma polymer and was used to determine the mass coverage of the peptide and proteins adsorbed onto the films. The combined analysis of the surfaces suggests the covalent binding of the peptide and proteins to the surface of the pp-PFM.

  20. Redox Polymerization of Methyl Methacrylate in the Fluorous Triphasic System

    Institute of Scientific and Technical Information of China (English)

    Shi Zhen CHEN; Yun Peng BAI; Zhao Long LI

    2006-01-01

    Methyl methacrylate (MMA) was polymerized by using of benzoyl peroxide (BPO) and N, N-dimethylaniline (DMA) as an redox initiator in fluorous triphasic system at room temperature.The polymerization was occurred in both initiator layer and monomer layer in a U-tube. It was found that PMMA obtained from the initiator layer with relatively narrow polydispersity.(PDI =1.38)

  1. THE KINETICS OF METHYL METHACRYLATE POLYMERIZATION INITIATED BY THE VOLATILE PRODUCTS OF A METHYL METHACRYLATE PLASMA

    Institute of Scientific and Technical Information of China (English)

    杨梅林; 马於光; 郑莹光; 沈家骢

    1990-01-01

    It is found that the volatile products of methyl methacrylate plasma can very actively initiate the polymerization of the monomer to produce ultrahigh molecular weight polymers. This polymerization of MMA occurs by a livlng free radical mechanism with instantaneous initiation and monomer transfer.

  2. 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.

  3. Polymerization of novel methacrylated anthraquinone dyes

    Directory of Open Access Journals (Sweden)

    Christian Dollendorf

    2013-02-01

    Full Text Available A new series of polymerizable methacrylated anthraquinone dyes has been synthesized by nucleophilic aromatic substitution reactions and subsequent methacrylation. Thereby, green 5,8-bis(4-(2-methacryloxyethylphenylamino-1,4-dihydroxyanthraquinone (2, blue 1,4-bis(4-((2-methacryloxyethyloxyphenylaminoanthraquinone (6 and red 1-((2-methacryloxy-1,1-dimethylethylaminoanthraquinone (12, as well as 1-((1,3-dimethacryloxy-2-methylpropan-2-ylaminoanthraquinone (15 were obtained. By mixing of these brilliant dyes in different ratios and concentrations, a broad color spectrum can be generated. After methacrylation, the monomeric dyes can be covalently emplaced into several copolymers. Due to two polymerizable functionalities, they can act as cross-linking agents. Thus, diffusion out of the polymer can be avoided, which increases the physiological compatibility and makes the dyes promising compounds for medical applications, such as iris implants.

  4. Kinetics and mechanism of polymerization of methyl methacrylate ...

    Indian Academy of Sciences (India)

    Unknown

    Kinetics and mechanism of polymerization of methyl methacrylate initiated by stibonium ylide. A K SRIVASTAVA and AJEY KUMAR CHAURASIA. Department of Chemistry, H B Technological Institute, Kanpur 208 002, India e-mail: akspolym@rediffmail.com. MS received 6 September 2002; revised 25 July 2003. Abstract.

  5. Gamma-radiation induced polymerization of methyl methacrylate in aliphatic hydrocarbons: kinetics and evidence for incorporation of hydrocarbon in the polymer chain

    International Nuclear Information System (INIS)

    Mohan, H.; Iyer, R.M.

    1989-01-01

    On γ-radiolysis, the rate of polymerization of methyl methacrylate in hydrocarbon solvents is observed to decrease. It is explained by hydrocarbon entry into the polymer chains. The hydrocarbon entry into the polymer chains is observed to take place at later stages of polymerization and increases with hydrocarbon chain length. The extent of hydrocarbon entry into the polymer chains is estimated by NMR and GLC analysis. It is observed to be equal to ∼ 12% corresponding to ∼ 97 hexadecane molecules in each polymer chain. The IR, DSC, MW determination and radiation effects on the polymer showed evidences for hydrocarbon entry into the polymer. It is explained by chain transfer from the growing polymer radical to the hydrocarbon molecules. The chain transfer constant is determined to be equal to 1 x 10 -2 . (author)

  6. Gamma radiation-polymerized methacrylates used as heavy metals adsorbents

    International Nuclear Information System (INIS)

    Barrera D, C.; Roa M, G.; Balderas H, P.; Bilyeu, B.; Urena N, F.

    2009-01-01

    Heavy metal removal from aqueous solution is a priority research area since the actual methods are costly and a major drawback is the large amounts of sludge generated when applying traditional techniques. Adsorption is a physiochemical wastewater treatment process, which is gaining prominence as a means of producing high quality effluents, which are low in metal ion concentrations. The development of inexpensive adsorbents for the treatment of wastewater is an important area in environmental sciences. In this work we describe some of the physical and chemical phenomena that take place in the polymerization of methacrylates when gamma radiation is used. We explain how polymeric material characterization equipment are used for obtaining information regarding the material properties. Then we explain how the new polymeric material obtained can be use for the wastewater treatment. Finally, a comparison in the heavy metal removal from aqueous solution with other sorbent materials is presented. (Author)

  7. High temperature initiator-free RAFT polymerization of methyl methacrylate in a microwave reactor

    NARCIS (Netherlands)

    Paulus, R.M.; Becer, C.R.; Hoogenboom, R.; Schubert, U.S.

    2009-01-01

    The reversible additionfragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) was investigated under microwave irradiation. At first, a comparison was made between microwave and thermal heating for the RAFT polymerization of MMA with azobis(isobutyronitrile) (AIBN) as

  8. Synthesis and characterization of poly (n-butyl acrylate)-poly (methyl methacrylate) latex interpenetrating polymer networks by radiation-induced seeded emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Yu Haibo [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Peng Jing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)], E-mail: jpeng@pku.edu.cn; Zhai Maolin; Li Jiuqiang; Wei Genshuan [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Qiao Jinliang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); SINOPEC Beijing Research Institute of Chemical Industry, Beijing 100013 (China)

    2007-11-15

    A series of latex interpenetrating polymer networks (LIPNs) were prepared via a two-stage emulsion polymerization of methyl methacrylate (MMA) or mixture of MMA and n-butyl acrylate (n-BA) on crosslinked poly(n-butyl acrylate)(PBA) seed latex using {sup 60}Co {gamma}-ray radiation. The particles of resultant latex were produced with diameters between 150 and 250 nm. FTIR spectra identified the formation of crosslinked copolymers of PMMA or P(MMA-co-BA). Dynamic light scattering (DLS) showed that with increasing n-BA concentration in second-stage monomers, the particle size of LIPN increased. Transmission electron microscope(TEM) photographs showed that the morphology of resultant acrylate interpenetrating polymer network (IPN) latex varied from the distinct core-shell structure to homogenous particle structure with the increase of n-BA concentration, and the morphology was mainly controlled by the miscibility between crosslinked PBA seed and second-stage copolymers and polarity of P(MMA-co-BA)copolymers. In addition, differential scanning calorimeter (DSC) measurements indicated the existence of reinforced miscibility between PBA seed and P(MMA-co-BA)copolymer in prepared LIPNs.

  9. 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.

  10. 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

  11. Neural Network Models for Free Radical Polymerization of Methyl Methacrylate

    International Nuclear Information System (INIS)

    Curteanu, S.; Leon, F.; Galea, D.

    2003-01-01

    In this paper, a neural network modeling of the batch bulk methyl methacrylate polymerization is performed. To obtain conversion, number and weight average molecular weights, three neural networks were built. Each was a multilayer perception with one or two hidden layers. The choice of network topology, i.e. the number of hidden layers and the number of neurons in these layers, was based on achieving a compromise between precision and complexity. Thus, it was intended to have an error as small as possible at the end of back-propagation training phases, while using a network with reduced complexity. The performances of the networks were evaluated by comparing network predictions with training data, validation data (which were not uses for training), and with the results of a mechanistic model. The accurate predictions of neural networks for monomer conversion, number average molecular weight and weight average molecular weight proves that this modeling methodology gives a good representation and generalization of the batch bulk methyl methacrylate polymerization. (author)

  12. Modeling of a Buss-Kneader as a Polymerization Reactor for Acrylates. Part II: Methyl Methacrylate Based Resins

    NARCIS (Netherlands)

    Troelstra, E.J; van Dierendonck, L.L.; Janssen, L.P.B.M.; Renken, A.

    2002-01-01

    The Buss-Kneader has proven to be a suitable reactor for the polymerization of acrylates. In this second part, the polymerization of methyl methacrylate and the ter-polymerization of methyl methacrylate (MMA), hydroxyethyl methacrylate and n-butylmethacrylate is carried out in a pilot Buss-Kneader.

  13. In situ stabilizer formation from methacrylic acid macromonomers in emulsion polymerization

    NARCIS (Netherlands)

    Schreur-Piet, Ingeborg; Heuts, Johan P.A.

    2017-01-01

    Oligomers of methacrylic acid containing a propenyl ω-endgroup (i.e. MAA-macromonomers) were synthesized by cobalt-mediated catalytic chain transfer polymerization and used as precursors to stabilizers in emulsion polymerization. It was found that only in those polymerizations in which these

  14. 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)

  15. Preparation of polymer microspheres by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Naka, Y.; Yamamoto, Y.; Yoshida, Y.; Tagawa, S.

    1995-01-01

    Cross-liking monomer, diethylene glycol dimethacrylate gives microspheres from organic solution by radiation-induced polymerization. /One of the remarkable result is that the number of the microspheres is not changing during the polymerization. Ethyl methacrylate, maleic anhydride, styrene and acrylamide are used as comonomers. These comonomers give the microspheres in the range of 0 to 0.4 as mol fractions. (author)

  16. Pyrogallol-imprinted polymers with methyl methacrylate via precipitation polymerization

    Science.gov (United States)

    Mehamod, Faizatul Shimal; Othman, Nor Amira; Bulat, Ku Halim Ku; Suah, Faiz Bukhari Mohd

    2018-06-01

    Molecular simulation techniques are important to study the understanding of chemical and physical properties of any material. Computational modeling is considered as time reducer in finding the best recipes for Molecularly-Imprinted Polymers (MIPs). In this study, Pyrogallol-imprinted polymers (PIP) and non-imprinted polymers (NIPs) were synthesized via precipitation polymerization using Pyrogallol (Py), methyl methacrylate (MMA), divinylbenzene (DVB) as template, functional monomer and cross-linker, respectively. The recipe was according to the results from computational techniques. The synthesized PIP and NIPs were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and UV-visible spectroscopy (UV-vis). Studies on adsorption isotherm showed that PIP and NIPs follow Scatchard isotherm models. Sorption kinetic study found that PIP and NIPs follow pseudo-second order which indicates the rate-limiting step is the surface adsorption. The imprinting factor of PIP was determined by selectivity study and showed the value of k >1, which proved that PIP was selective toward Pyrogallol compared to NIP.

  17. The effect of reducing monosaccharides on the atom transfer radical polymerization of butyl methacrylate

    NARCIS (Netherlands)

    Vries, de Andrew; Klumperman, B.; Wet-Roos, de D.; Sanderson, R.D.

    2001-01-01

    The effect of various reducing monosaccharides on the rate of atom transfer radical polymerization (ATRP) of butyl methacrylate is reported in this study. The addition of reducing sugars affects the rate of ATRP positively with a 100% increase in the rate of polymerization in some cases. In

  18. Polymerization of Methyl Methacrylate with Samarocene Complex Supported on Mesoporous Silica

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Samarocene complex was supported on a series of mesoporous silica with various pore sizes. Polymerization of methyl methacrylate (MMA) by these catalysts provide highly syndiotactic PMMAs with higher molecular weights compared with those obtained by solution polymerization with homogeneous catalyst system.

  19. ANIONIC POLYMERIZATION OF ALKYL METHACRYLATES INITIATED BY nBuCu(NCy2)Li

    Institute of Scientific and Technical Information of China (English)

    Bing-yong Han; Jian-guo Liang; Jian-min Lu; Feng An; Wan-tai Yang

    2009-01-01

    Anionic polymerization of methyl methacrylate (MMA), n-butyl methacrylate (nBMA) and glycidyl methacrylate (GMA) initiated by nBuCu(NCy2)Li (1) in tetrahydrofuran (THF) at -50℃ to -10℃ was investigated. It was found that the polymerization of MMA and nBMA initiated by 1 proceeded quantitatively in THF to afford PMMA and PBMA with polydispersity index 1.15-1.30 and nearly 100% initiator efficiencies at -10℃. The molecular weights increased linearly with the ratio of [monomer]/[1]. However, a post-polymerization experiment carried out on this system revealed a double polymer peak by GPC when fresh monomer was added after an interval of 10 rain. Polymerization of styrene could be initiated by 1, but the initiator efficiency was low.

  20. ATOM TRANSFER RADICAL POLYMERIZATION OF N-BUTYL METHACRYLATE IN AQUEOUS DISPERSED SYSTEMS: A MINIEMULSION APPROACH. (R826735)

    Science.gov (United States)

    Ultrasonication was applied in combination with a hydrophobe for the copper-mediated atom transfer radical polymerization of n-butyl methacrylate in an aqueous dispersed system. A controlled polymerization was successfully achieved, as demonstrated by a linear correlation between...

  1. 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.

  2. 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.

  3. A novel process for ultrasound-induced radical polymerization in CO2-expanded fluids

    NARCIS (Netherlands)

    Kemmere, M.F.; Kuijpers, M.W.A.; Prickaerts, R.M.H.; Keurentjes, J.T.F.

    2005-01-01

    A strong viscosity increase upon polymerization hinders cavitation and subsequent radical formation during an ultrasound-induced bulk polymerization. In this work, ultrasound-induced radical polymerizations of methyl methacrylate (MMA) have been performed in CO2-expanded MMA in order to reduce the

  4. Influence of CO2 on ultrasound-induced polymerizations in high-pressure fluids

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; Jacobs, L.J.M.; Kemmere, M.F.; Keurentjes, J.T.F.

    2005-01-01

    A strong viscosity increase upon polymerization hinders cavitation and subsequent radical formation during an ultrasound-induced bulk polymerization. Ultrasound-induced radical polymerizations of methyl methacrylate (MMA) have been performed in CO2-expanded MMA, as well as in bulk MMA. For this

  5. TEMPLATE POLYMERIZATION OF N-VINYLIMIDAZOLE ALONG POLY(METHACRYLIC ACID) IN WATER .2. KINETICS OF THE TEMPLATE POLYMERIZATION

    NARCIS (Netherlands)

    VANDEGRAMPEL, HT; TAN, YY; CHALLA, G

    1991-01-01

    The template polymerization of N-vinylimidazole (VIm) along poly(methacrylic acid) (PMAA) in water at 50-degrees-C with 2,2'-azobis(2-amidinopropane).2HCl (AAP) as initiator was studied by using variable initiator and monomer concentrations at constant [PMAA]/[VIm]0. From the order in [VIm] it was

  6. Dynamic void behavior in polymerizing polymethyl methacrylate cement.

    Science.gov (United States)

    Muller, Scott D; McCaskie, Andrew W

    2006-02-01

    Cement mantle voids remain controversial with respect to survival of total hip arthroplasty. Void evolution is poorly understood, and attempts at void manipulation can only be empirical. We induced voids in a cement model simulating the constraints of the proximal femur. Intravoid pressure and temperature were recorded throughout polymerization, and the initial and final void volumes were measured. Temperature-dependent peak intravoid pressures and void volume increases were observed. After solidification, subatmospheric intravoid pressures were observed. The magnitude of these observations could not be explained by the ideal gas law. Partial pressures of the void gas at peak pressures demonstrated a dominant effect of gaseous monomer, thereby suggesting that void growth is a pressure-driven phenomenon resulting from temperature-dependent evaporation of monomer into existing trapped air voids.

  7. Radiation polymerization of 2-hydroxyethyl methacrylate-vinyl pyrrolidone-water system

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1988-01-01

    Polymerization was studied using mixtures of 2-hydroxyethyl methacrylate(HEMA)-water, vinyl pyrrolidone(NVP)-water and 2-hydroxyethyl methacrylate-vinyl pyrrolidone-water. The mixtures were irradiated with gamma radiation from a 60 Co source. Irradiation was carried out at temperatures of 0, -24, -45, -63, -78, and -196 degC. The dependence was studied of the polymerization rate on temperature during irradiation for the individual mixtures, as were the effect of monomer composition on the polymerization of the HEMA-NVP-water system at 0 degC, the effect of water on NVP polymerization and the relationship between water absorption and the composition of the monomer. (E.S.). 4 figs., 6 refs

  8. Ultrasound-induced polymerization of methyl methacrylate in liquid carbon dioxide : a clean and safe route to produce polymers with controlled molecular weight

    NARCIS (Netherlands)

    Kemmere, M.F.; Kuijpers, M.W.A.; Jacobs, L.J.M.; Keurentjes, J.T.F.

    2004-01-01

    Ultrasound-induced cavitation is known to enhance chemical reactions as well as mass transfer at ambient pressures. Ultrasound is rarely studied at higher pressures, since a high static pressure hampers the growth of cavities. Recently, we have shown that pressurized carbon dioxide can be used as a

  9. Olefin copolymerization via controlled radical polymerization : copolymerization of methyl methacrylate and 1-octene

    NARCIS (Netherlands)

    Venkatesh, R.; Klumperman, B.

    2004-01-01

    The atom transfer radical (co)polymerization (ATRP) of methyl methacrylate (MMA) with 1-octene was investigated. Well controlled homopolymer of MMA was obtained with 2,2,2-trichoroethanol (TCE) and p-toluenesulfonyl chloride (pTsCl), although, uncontrolled copolymerization occurred when pTsCl was

  10. KINETICS OF POLYMERIZATION OF METHYL METHACRYLATE INITIATED BY COPPER POLYPROPYLENE-BASED POLYAMIDOXIME-SODIUM SULFITE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Yiguang; YANG Chaoxiong

    1992-01-01

    The aqueous polymerization of methyl methacrylate initiated by copper polypropylene-based polyamidoxime ( PPAO - Cu ) - sodium sulfite system was investigated . The overall rate of polymerization (Rp) is Rp=9.7 × 1012 e-21, 200/RT [MMA]0.88 [ Na2 SO 3 ]0.50 The length of the induction period (τ) is inversely proportional to the concentration of sodium sulfite and independent of the amount of polymer supported copper and the concentration of monomer. It could be expressed as follows:1τ=1.2× 1012e-15,600/RT[ Na2SO3] =KτRi The polymerization is initiated by a primary radical generated from the redox reaction rather than induced by "coordination-proton transfer" mechanism.

  11. Kinetics and mechanism of polymerization of methyl methacrylate ...

    Indian Academy of Sciences (India)

    Homopolymerization of methyl methacrylate (MMA) was carried out in the presence of triphenylstibonium 1,2,3,4-tetraphenyl-cyclopentadienylide as an initiator in dioxane at 65°C ± 0·1°C. The system follows non-ideal radical kinetics ( ∝ [M]1.4 [I]0.44) due to primary radical termination as well as degradative ...

  12. INITIATION EFFICIENCY f OF METHYL METHACRYLATE BULK RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    沈家骢; 田元; 王国斌; 杨梅林

    1990-01-01

    The values of the initiation efficiency f at various conversions in the bulk polymerization of MMA initiated by AIBME have first been determined according to a strict unsteady-state formula and based on the data of radical concentration and the termination rate constant determined using ESR method. A model of diffusion control initiation is proposed. The theory is well in agreement with the experiments during the whole process of polymerization.

  13. Antimicrobial bacterial cellulose nanocomposites prepared by in situ polymerization of 2-aminoethyl methacrylate.

    Science.gov (United States)

    Figueiredo, Ana R P; Figueiredo, Andrea G P R; Silva, Nuno H C S; Barros-Timmons, Ana; Almeida, Adelaide; Silvestre, Armando J D; Freire, Carmen S R

    2015-06-05

    Antimicrobial bacterial cellulose/poly(2-aminoethyl methacrylate) (BC/PAEM) nanocomposites were prepared by in situ radical polymerization of 2-aminoethyl methacrylate, using variable amounts of N,N-methylenebis(acrylamide) (MBA) as cross-linker. The obtained nanocomposites were characterized in terms of their structure, morphology, thermal stability, mechanical properties and antibacterial activity. The ensuing composite membranes were significantly more transparent than those of pure BC and showed improved thermal and mechanical properties. The antibacterial activity of the obtained nanocomposites was assessed towards a recombinant bioluminescent Escherichia coli and only the non-crosslinked nanocomposite (BC/PAEM) proved to have antibacterial activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. A New Initiator Cholesteryl Chloroformate for Cupper-Based Atom Transfer Radical Polymerization of Methyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    曹健; 楚娟; 张可达

    2004-01-01

    The polymerization of metyl methacrylate (MMA) was studied in detail by use of CuCl/L as a catalyst and cholesteryl chloroformate (CC) as an initiator. It was found that the atom transfer radical polymerization of MMA could proceed when L equals to a multidentate aliphatic amine ligand, N,N,N',N",N"-penta(methyl acrylate)diethylenetriamine (MA5-DETA), and no polymerization was occurred while L=2,2'-bipyridine and 1,10-phenanthroline. The linear proportionality of the molecular weights to the conversions and straight lines observed in ln[M]0/[M] versus time plots indicated that the present polymerization system had the typical controlled polymerization characteristics.

  15. 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.

  16. 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...

  17. CONCERNING CHAIN GROWTH SPECIFIC REACTION RATE AS A PART OF THE PROCESS OF METHYL METHACRYLATE MASS RADICAL POLYMERIZATION

    Directory of Open Access Journals (Sweden)

    A. A. Sultanova

    2017-02-01

    Full Text Available It is the chain growth specific reaction rate that was determined for the process of methyl methacrylate mass radical polymerization within the temperature range of 40–900 С in quasi-steady approximation by means of Monte Carlo method. The theoretical model of radical polymerization was developed taking the gel effect into account. Computer software was developed that enables to imitate radical polymerization process taking gel effect into account within the minimum run time. The programme was tested on asymptotic examples as well as was applied for methyl methacrylate mass radical polymerization. The programme makes it possible to calculate monomer conversion, molecular mass variation, molecular-mass distribution, etc.

  18. Synthesis of indenyllanthanide amides: the effective initiators for polymerization of methyl methacrylate

    Institute of Scientific and Technical Information of China (English)

    赵群; 姚英明; 沈琪

    2000-01-01

    Diisopropylamido bisindenyl lanthanides ( C9H7)2LnN( i-Pr)2(Ln=Gd (1), Y(2), Er (3)) were successfully synthesized in satisfied yield by the reaction of Ln(N(i-Pr)2)3(THF) with indene in 1:2 molar ratio in toluene. All of the complexes exhibit very high catalytic activity in the polymerization of methyl methacrylate. The resulting polymers have narrow molecular weight distributions and syndiotacticity.

  19. Property improvement by gamma polymerization of methyl methacrylate impregnated local Thai wood Yang (Dipterocarpus Sp.)

    International Nuclear Information System (INIS)

    Saisomboon, S.; Sumitra, T.

    1990-01-01

    Property improvement of a local Thai wood (Yang-Dipterocarpus Sp.) was studied by impregnating with methyl methacrylate before polymerizing with gamma ray. The polymer loading were 126 and 68 percent for sapwood and heart wood, respectively. Significant improvements in impact, compressive and bending strength were observed in the wood polymer composite (WPC). In addition, the microstructure and the impact fractured-surfaces of WPC were also carried with a scanning electron-microscope

  20. N-Chlorosuccinimide (NCS): A Novel Initiator for Atom Transfer Radical Polymerization of Methyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    WANG,Xia-Yan; CHANG,Li-Qun; ZHOU,Hong; ZHANG,Ke-Da

    2006-01-01

    Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was achieved, using N-chlorosuccinimide (NCS) as an initiator together with catalytic system CuCl/PMDETA (N,N,N',N',N"-pentamethyldiethyl-enetriamine), CuCl/MA5-DETA (N,N,N',N',N"-penta(methylacrylate)diethylenetriamine), and CuCl/bipy (bipy=2,2'-bipyridyl) respectively. The results indicated that the polymerization possessed typical controlled/living radical polymerization characteristics. The analysis for terminal group of obtained polymer by 1H NMR proved that NCS is an initiator for ATRP. In comparison with NBS, the polymerization rate was slower and the resulted polymer had narrower molecular weight distribution (MWD) when NCS was employed as the initiator.

  1. STUDIES ON RADICAL POLYMERIZATION OF METHYL METHACRYLATE INITIATED WITH ORGANIC PEROXIDE-AMINE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    QIU Kunyuan; SHUI Li; FENG Xinde

    1984-01-01

    Radical polymerization of methyl methacrylate (MMA) initiated with various diacyl peroxideamine systems was studied. Benzoyl peroxide (BPO) and lauroyl peroxide (LPO) were used as diacyl peroxide component, N,N-dimethyl aniline (DMA) and its para substituted derivatives, i.e., N,N-dimethyl-p-toluidine (DMT), p-hydroxymethyl-N,N-dimethyl aniline (HDMA), p-nitro-N,N-dimethyl aniline (NDMA) and p-dimethylamino benzaldehyde (DMAB) were used as amine components. It was found that the peroxide-DMT systems give higher rates of bulk polymerization Rp of MMA than the organic hydroperoxide-DMT systems with the following descending order BPO-DMT>LPO-DMT>CHP (cumene hydroperoxide)-DMT>TBH (tert-butyl hydroperoxide)-DMT.The aromatic tertiary amines possess obvious structural effect on the Rp values in the diacyl peroxideamine system. The overall activation energy of MMA polymerization was determined and the kinetics of polymerization of MMA initiated with BPO-DMT system was investigated.

  2. Kinetics of Vinyl Polymerization of Methyl Methacrylate Initiated by Ce(IV-Vanillin Redox System

    Directory of Open Access Journals (Sweden)

    M. Palanivelu

    2012-01-01

    Full Text Available The kinetics of polymerization of methyl methacrylate initiated by Ce(IV-Vanillin redox system was studied in aqueous solution of sulfuric acid at 40°C. The rate of polymerization (Rp and the reaction orders with respect to monomer, initiator and ligand have been determined and found to be 1.5, 0.5 and 0.5 respectively. The effect of concentration of sulfuric acid on the polymerization was also studied. The rate of polymerization was found to increase with increasing temperature 30–60°C and decreases at higher temperature (>60°C. The overall activation energy (Ea was found to be 36.7 kJ/mol. A suitable kinetic scheme has been proposed.

  3. Synthesis and characterization of the silver methacrylate and its polymerization with gamma radiation

    International Nuclear Information System (INIS)

    Figueroa de Paz, Y. M.

    2014-01-01

    One of the traditional objectives in research has been the development of new and useful materials that combine the properties of polymers with metals. Synthesis of monomers containing metal, followed by a polymerization process, is a method to introduce metal ions in the structure of a polymer, and the gamma radiation was easily applied to initiate polymerization. The coordination polymers have high insolubility, which is a general problem of these materials, besides the lack of structural information available. Also, due to the difficulty of obtaining single crystals, it has hindered the identification of the structures of some coordination polymers, requiring the use of indirect methods for structural characterization. In this work the synthesis of silver poly-methacrylate (PMAAg), was performed using the gamma radiation as polymerization initiator, having as precursor to silver methacrylate monomer (MAAg). The combination of spectroscopic methods revealed structural changes in the coordination polymers. With scanning electron microscopy, it was observed that the morphology of the monomer and its polymers is fiber, which grows with increasing radiation dose; furthermore, this increase in size is related to Bet analysis result, since the monomer has a bigger superficial area to the irradiated polymers. In monomer and irradiated polymers the crystalline structure CCC was observed by X-ray diffraction. By thermogravimetric analysis the decomposition temperature of the products was determined, finding around 150 degrees C. The infrared spectroscopy confirmed the silver methacrylate polymerization, as with increasing radiation dose, also increases the degree of polymerization; likewise the form of coordination of the monomer was determined and its irradiated polymers which corresponds to a bi-dentate chelate, confirmed by X-ray photoelectron spectroscopy. (Author)

  4. 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.

  5. 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...

  6. Radiation-induced polymerization of glass-forming systems. VII. Polymerization in supercooled state under high pressure

    International Nuclear Information System (INIS)

    Kaetsu, I.; Yoshii, F.; Watanabe, Y.

    1978-01-01

    Radiation-induced polymerization of glass-forming monomers such as 2-hydroxyethyl methacrylate and glycidyl methacrylate under high pressure was studied. The glass transition temperature of these monomers was heightened by increased pressure. The temperature dependence of polymerizability showed a characteristic relation, similar to those in supercooled-phase polymerization under normal pressure, that had a maximum at T/sub ν/ which shifted to higher levels of temperature as well as to T/sub g/ under high pressure. Polymerizability in the supercooled state also increased under increased pressure

  7. In situ self-polymerization of unsaturated metal methacrylate and its dispersion mechanism in rubber-based composites

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Shipeng; Zhou, Yao; Yao, Lu [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang, Liqun [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Chan, Tung W. [Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, VA 24061 (United States); Liang, Yongri [Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Li, E-mail: LiuL@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2013-11-10

    Highlights: • In situ self-polymerization of unsaturated metal methacrylate was investigated mainly by the thermal effect. • UMM with low melting point can self-polymerize to a large extent. • The fine dispersion phase is composed of poly(UMM) nanoparticles formed by in situ self-polymerization in the rubber matrix. • The UMM crystals in the presence of peroxide and rubber undergo the processes of melting, diffusion, polymerization, and phase separation in this order. - Abstract: Unsaturated metal methacrylate (UMM) as one kind of functional filler has played an important role in reinforcing rubber materials. The in situ self-polymerization of UMM in UMM/rubber composite leads to the uniform dispersion of poly(UMM) in the rubber matrix, while the crosslinking of rubber and grafting between UMM and rubber chains occur simultaneously, making it difficult to clarify the effect of the in situ polymerization on the dispersion of poly(UMM) in the rubber matrix. In this work, we investigated the dispersion mechanism of UMM without rubber matrix for the first time using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. Three types of UMMs including zinc methacrylate (Zn(MA){sub 2}), sodium methacrylate (Na(MA)) and samarium methacrylate (Sm(MA){sub 3}) were chosen to investigate the in situ self-polymerization of UMM. Based on DSC results, we conclude that the crystals with low melting point tend to self-polymerize first and generate a large amount of heat in the presence of peroxide. The high heat of reaction can melt the crystals with high melting point, and more UMM molecules are dissolved in the rubber matrix, thus increasing the extent of the in situ polymerization. Hence, the UMM with low melting point can self-polymerize to a large extent. Our findings provide in-depth understanding of the dispersion mechanism of UMM in rubber.

  8. In situ self-polymerization of unsaturated metal methacrylate and its dispersion mechanism in rubber-based composites

    International Nuclear Information System (INIS)

    Wen, Shipeng; Zhou, Yao; Yao, Lu; Zhang, Liqun; Chan, Tung W.; Liang, Yongri; Liu, Li

    2013-01-01

    Highlights: • In situ self-polymerization of unsaturated metal methacrylate was investigated mainly by the thermal effect. • UMM with low melting point can self-polymerize to a large extent. • The fine dispersion phase is composed of poly(UMM) nanoparticles formed by in situ self-polymerization in the rubber matrix. • The UMM crystals in the presence of peroxide and rubber undergo the processes of melting, diffusion, polymerization, and phase separation in this order. - Abstract: Unsaturated metal methacrylate (UMM) as one kind of functional filler has played an important role in reinforcing rubber materials. The in situ self-polymerization of UMM in UMM/rubber composite leads to the uniform dispersion of poly(UMM) in the rubber matrix, while the crosslinking of rubber and grafting between UMM and rubber chains occur simultaneously, making it difficult to clarify the effect of the in situ polymerization on the dispersion of poly(UMM) in the rubber matrix. In this work, we investigated the dispersion mechanism of UMM without rubber matrix for the first time using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. Three types of UMMs including zinc methacrylate (Zn(MA) 2 ), sodium methacrylate (Na(MA)) and samarium methacrylate (Sm(MA) 3 ) were chosen to investigate the in situ self-polymerization of UMM. Based on DSC results, we conclude that the crystals with low melting point tend to self-polymerize first and generate a large amount of heat in the presence of peroxide. The high heat of reaction can melt the crystals with high melting point, and more UMM molecules are dissolved in the rubber matrix, thus increasing the extent of the in situ polymerization. Hence, the UMM with low melting point can self-polymerize to a large extent. Our findings provide in-depth understanding of the dispersion mechanism of UMM in rubber

  9. 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.

  10. 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.

  11. Influence of wood extractives in the polymerization of methyl methacrylate by gamma irradiation

    International Nuclear Information System (INIS)

    Burillo de V, G.; Loyola V, V.M.; Albarran S, G.; Candelas, J.

    1975-01-01

    Those materials that can be extracted from pine or oak by ether, ethanol, methyl methacrylate (MMA), or benzene--alcohol all act as inhibitors in the γ polymerization of MMA--wood composites. It was found that preirradiation of either the wood or of the wood--monomer combination reduces or eliminates the inhibitory effect. The most practical industrial solution to this problem is to increase the dose, thereby achieving high molecular polymer in the composite. However, the presence of a maximum in the molecular weight--dose curves means that each wood--monomer pair may have a different optimum dose

  12. Influence Of Initiator Types And Emulsion Polymerization Techniques To Particle Size Of Copolymerization Styrene-Butyl Acrylate-Methyl Methacrylate

    Directory of Open Access Journals (Sweden)

    Ariyanti Sarwono

    2008-11-01

    Full Text Available Influence of initiator types and emulsion polymerization techniques to particle size of copolymerization styrene-butyl acrylate-methyl methacrylate. Copoly(styrene/butyl acrylic/methyl methacrylic was prepared by emulsion polymerization method. This paper describes effect of insiator types i.e. ammonium persulfate (APS, hydrogen peroxide, ters-butyl peroxide (TBHP, initiator redox (H2O2/ascorbic acid and polymerization techniques i.e. batch and semicontinue to particle size distribution of copoly(styrene/butyl acrylic/methyl methacrylic. Initiator TBHP and H2O2 could not initiate copolymerization properly, but initiator APS and redox initiate copolymerization with batch and semi continue techniques could well perform. The higher concentration of APS, the greater particle size of the copolymer, but the copolymer is polymodal. Initiator redox (H2O2/ascorbic acid produced greater particle size than initiator redox (ascorbic acid/ H2O2.

  13. γ-Diimine palladium(II based complexes mediated polymerization of methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Mahmoud Sunjuk

    2017-02-01

    Full Text Available The synthesis of new palladium(II complexes of the type [Pd(A–NC–ph–CN–ACl2] (4a–e (A = cyclohexyl (a, 2-isoprpropyl (b, pyrenyl (c, naphthyl (d, and 2,6-diisopropyl (e is described. The isolated γ-diimine ligands and their corresponding palladium(II complexes were characterized by their physical properties, elemental analysis, 1H NMR-, 13C NMR, and infrared spectroscopy. The palladium(II complexes (4a–e were employed successfully as catalysts for atom transfer radical polymerization (ATRP of methyl methacrylate (MMA in the presence of ethyl-2-bromoisobutyrate (EBIB as initiator at 90 °C. Polymerization with these catalyst systems afforded polymers with low molecular weight distribution (Mw/Mn and syndio-rich atactic poly (MMA with relatively higher [rr] diads.

  14. Stereocontrol of Methyl Methacrylate during Photoinduced Nitroxide-Mediated Polymerization in the Presence of Photosensitive Alkoxyamine

    Directory of Open Access Journals (Sweden)

    Juahui Su

    2016-01-01

    Full Text Available Photosensitive alkoxyamine 2,2,6,6-tetramethyl-1-(1-phenylethoxypiperidin-4-yl quinoline-2-carboxylate (PE-TEMPO-Q was synthesized. Photochemical properties of PE-TEMPO-Q were studied to develop photoinduced nitroxide-mediated polymerization of methyl methacrylate (MMA. Rapid and facile polymerization at ambient temperature with PE-TEMPO-Q as an initiator was confirmed to proceed in a controlled mechanism based on the linear growth in molecular weight combined with relative narrow polydispersity index (1.4–1.8 of the resulting polymers. The stereochemistry of obtained polymers was also investigated, and the syndiotacticity slightly increased compared with the typical photopolymerization. Dual-controlled photopolymerization of MMA was achieved in the presence of synthesized alkoxyamine.

  15. Radiation induced emulsion polymerization

    International Nuclear Information System (INIS)

    Stannett, V.T.; Stahel, E.P.

    1990-01-01

    High energy radiation is particularly favored for the initiation of emulsion polymerization. The yield of free radicals, for example, from the radiolysis of the aqueous phase, is high; G(radical) values of 5-7. In addition, the rather special kinetics associated with emulsion polymerization lead, in general, to very large kinetic chain lengths, even with 'non-ideal' monomers such as vinyl acetate. Together, high polymerization rates at low doses become possible. There are some important advantages of radiation polymerization compared with chemical initiators, such as potassium persulfate. Perhaps the most important among them is the temperature independence of the initiation step. This makes low temperature polymerization very accessible. With monomers such as vinyl acetate, where chain termination to monomer is predominant, low temperatures lead to often highly desirable higher molecular weights. With styrene, the classical ideally behaved monomer, there are the advantages such as, for example, the feasibility of using cationic monomers. These and some attendant disadvantages are discussed in detail, including pilot plant studies

  16. Syringyl Methacrylate, a Hardwood Lignin-Based Monomer for High-Tg Polymeric Materials.

    Science.gov (United States)

    Holmberg, Angela L; Reno, Kaleigh H; Nguyen, Ngoc A; Wool, Richard P; Epps, Thomas H

    2016-05-17

    As viable precursors to a diverse array of macromolecules, biomass-derived compounds must impart wide-ranging and precisely controllable properties to polymers. Herein, we report the synthesis and subsequent reversible addition-fragmentation chain-transfer polymerization of a new monomer, syringyl methacrylate (SM, 2,6-dimethoxyphenyl methacrylate), that can facilitate widespread property manipulations in macromolecules. Homopolymers and heteropolymers synthesized from SM and related monomers have broadly tunable and highly controllable glass transition temperatures ranging from 114 to 205 °C and zero-shear viscosities ranging from ∼0.2 kPa·s to ∼17,000 kPa·s at 220 °C, with consistent thermal stabilities. The tailorability of these properties is facilitated by the controlled polymerization kinetics of SM and the fact that one vs two o -methoxy groups negligibly affect monomer reactivity. Moreover, syringol, the precursor to SM, is an abundant component of depolymerized hardwood (e.g., oak) and graminaceous (e.g., switchgrass) lignins, making SM a potentially sustainable and low-cost candidate for tailoring macromolecular properties.

  17. Atom-transfer radical polymerization of methyl methacrylate (MMA) using CuSCN as the catalyst

    NARCIS (Netherlands)

    Singha, N.K.; Klumperman, B.

    2000-01-01

    The effect of CuSCN as a catalyst in atom-transfer radical polymerization (ATRP) was investigated. CuSCN can successfully be used for the ATRP of MMA. Substituted bipyridines as well as imines can be used to stabilize the copper complex in solution. CuSCN induces faster polymerization compared to

  18. STUDIES ON THE INITIATION MECHANISM OF ORGANIC PEROXIDE AND N-METHACRYLOYLOXYETHYL-N-METHYL ANILINE IN METHYL METHACRYLATE POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    QIU Kunyuan; GUO Dajie; GUO Xinqiu; FENG Xinde

    1990-01-01

    The initiation mechanism of methyl methacrylate (MMA) polymerization by organic peroxide and polymerizable aromatic tertiary amine such as N-methacryloyloxyethyl-N-methyi aniline (MEMA) binary system has been studied. The kinetics of polymerization of MMA and the ESR spectra of organic peroxide/MEMA system were determined. Based on the ESR study and the end-group analysis by UV spectra of the polymer formed, the initiation mechanism is proposed.

  19. KINETICS OF POLYMERIZATION OF METHYL METHACRYLATE INITIATED BY COPPER POLYPROPYLENE—BASED POLY(OXIME—IMIDODIACETATE)—SODIUM SULFITE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WUJinyuan; YANGChaoxiong; 等

    1992-01-01

    The aqueous polymerization of methyl methacrylate intiated by copper polypropylene-based poly(oxime-imidodiacetate)(P-Cu)-sodium sulfite system has been investigated.The overall rate of polymerization(Rp) was found to be Rp=5.8×1012e-84.1KJ/RT[MMA]1.4[P-Cu]0[Na2SO3]0.50 A mechanism of “coordination-proton transfer”for the production of initiating species was proposed and discussed.

  20. Iron halide mediated atom transfer radical polymerization of methyl methacrylate with N-Alkyl-2-pyridylmethanimine as the ligand

    NARCIS (Netherlands)

    Zhang, H.; Schubert, U.S.

    2004-01-01

    The controlled atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) catalyzed by iron halide/N-(n-hexyl)-2-pyridylmethanimine (NHPMI) is described. The ethyl 2-bromoisobutyrate (EBIB)-initiated ATRP with [MMA]0/[EBIB]0/[iron halide]0/[NHPMI]0 = 150/1/1/2 was better controlled in

  1. Lipase catalyzed HEMA initiated ring-opening polymerization: In situ formation of mixed polyester methacrylates by transesterification

    NARCIS (Netherlands)

    Takwa, M.; Xiao, Y.; Simpson, N.; Malmstrom, E.; Hult, K.; Koning, C.E.; Heise, A.; Martinelle, M.

    2008-01-01

    2-Hydroxyethyl methacrylate (HEMA) was used as initiator for the enzymatic ring-opening polymerization (ROP) of ¿-pentadecalactone (PDL) and e-caprolactone (CL). The lipase B from Candida antarctica was found to catalyze the cleavage of the ester bond in the HEMA end group of the formed polyesters,

  2. Magnetic poly(glycidyl methacrylate) microspheres prepared by dispersion polymerization in the presence of electrostatically-stabilized ferrofluids

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Benedyk, N.

    2004-01-01

    Roč. 42, č. 22 (2004), s. 5827-5837 ISSN 0887-624X R&D Projects: GA ČR GA525/02/0287 Institutional research plan: CEZ:AV0Z4050913 Keywords : magnetic * glycidyl methacrylate * dispersion polymerization Subject RIV: CE - Biochemistry Impact factor: 2.773, year: 2004

  3. Photocatalysed (Methacrylate Polymerization by (Antimony-Doped Tin Oxide Nanoparticles and Photoconduction of Their Crosslinked Polymer Nanoparticle Composites

    Directory of Open Access Journals (Sweden)

    J. C. M. Brokken-Zijp

    2010-01-01

    Full Text Available In the absence of another (photoradical initiator Sb:SnO2 nanoparticles (0≤Sb≤13 at % photocatalyze during irradiation with UV light the radical polymerization of (methacrylate monomers. When cured hard and transparent (>98% films with a low haze (0 at % nanoparticles can be attractive fillers for other photocatalytic applications photorefractive materials, optoelectronic devices and sensors.

  4. 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

  5. Radiation Induced Polymerization of Pyrrole

    International Nuclear Information System (INIS)

    Sarada Idris; Ratnam, C.T.; Ahmad Ashrif Abu Bakar

    2016-01-01

    We demonstrate the polymerization of pyrrole by gamma irradiation. The pyrrole films were exposed to gamma ray from cobalt 60 source at doses ranging from 0 to 150 kGy. The films were subjected to structural and morphological analyses by using FTIR, SEM and AFM techniques. Similar studies were also made on pristine pyrrole film which serve as control. Results revealed that pyrrole has been successfully polymerized through irradiation induced reactions. The SEM images depicted the formation of cauliflower shape upon gamma irradiation. The structural changes of pyrrole also evidenced by FTIR spectra. Surface topography and roughness of pyrrole before and after gamma irradiation found to show significant differences. (author)

  6. Morphological, elemental, and optical characterization of plasma polymerized n-butyl methacrylate thin films

    Science.gov (United States)

    Nasrin, Rahima; Hossain, Khandker S.; Bhuiyan, A. H.

    2018-05-01

    Plasma polymerized n-butyl methacrylate (PPnBMA) thin films of varying thicknesses were prepared at room temperature by AC plasma polymerization system using a capacitively coupled parallel plate reactor. Field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy-dispersive X-ray (EDX) analysis, and ultraviolet-visible (UV-Vis) spectroscopic investigation have been performed to study the morphological, elemental, and optical properties of the PPnBMA thin films, respectively. The flat and defect-free nature of thin films were confirmed by FESEM and AFM images. With declining plasma power, average roughness and root mean square roughness increase. Allowed direct transition ( E gd) and indirect transition ( E gi) energy gaps were found to be 3.64-3.80 and 3.38-3.45 eV, respectively, for PPnBMA thin films of different thicknesses. Values of E gd as well as E gi increase with the increase of thickness. The extinction coefficient, Urbach energy, and steepness parameter were also determined for these thin films.

  7. Methacrylic Zwitterionic, Thermoresponsive, and Hydrophilic (Co)Polymers via Cu(0)-Polymerization: The Importance of Halide Salt Additives.

    Science.gov (United States)

    Simula, Alexandre; Anastasaki, Athina; Haddleton, David M

    2016-02-01

    The synthesis of hydrophilic, thermoresponsive, and zwitterionic polymethacrylates is reported by Cu(0)-mediated reversible deactivation radical polymerization in water and/or water/alcohol mixtures. The predisproportionation of [Cu(I) (PMDETA)Cl] in water prior to initiator and monomer addition is exploited to yield well-defined polymethacrylates with full monomer conversions in 30 min. The addition of supplementary halide salts (NaCl) enables the synthesis of various molecular weight poly[poly(ethylene glycol) methyl ether methacrylate] (PEGMA475) (DPn = 10-80, Mn ≈ 10,000-40 000 g mol(-1)) with full monomer conversion and narrow molecular weight distributions attained in all cases (Đ ≈ 1.20-1.30). A bifunctional PEG initiator (average Mn ≈ 1000 g mol(-1)) is utilized for the polymerization of a wide range of methacrylates including 2-dimethylaminoethyl methacrylate, 2-morpholinoethyl methacrylate, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, and 2-methacryloyloxyethyl phosphorylcholine. Despite the high water content, high end group fidelity is demonstrated by in situ chain extensions and block copolymerizations with PEGMA475 yielding well-defined functional telechelic pentablock copolymers within 2.5 h. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Influence of Emulsion Polymerization Techniques to Particle Size of Copoly(styrene/butyl acrylate/methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Tresye Utari

    2008-04-01

    Full Text Available In the majority of applications, particle size and particle size distribution are highly significant factors that determine the properties of a polymer dispersion, such as its flow behavior or its stability. For example, a coating material with small particle size will give smooth coating result, good adhesive strength, good water resistance and latex stability. This article describes influence of various emulsion polymerization techniques to particle size of copoly(styrene/butyl acrylate/methyl methacrylate with mix surfactant SDBS linear chain and nonyl fenol (EO10 and initiator ammonium persulphate. DSC data, solid content and IR spectrum showed that copoly(styrene/butyl acrylate/methyl methacrylate was produced. Batch emulsion polymerization technique gave the highest particle size i.e. 615 nm and also the highest % conversion of monomer i.e. 97%. The more concentration of monomer was seeded to initial charge gave greater particle size and greater poly dispersity index.

  9. Synthesis, characterization and polymerization of methacrylates of copper (II), cobalt (II) and molybdenum (II). Generation of new materials

    International Nuclear Information System (INIS)

    Rojas Bolanos, Omar

    2006-01-01

    Coordination compounds of the species copper (II), cobalt (II) and molybdenum (II) with methacrylic acid were synthesized and characterized. Besides, it realized reactions of bromine addition to the doubles links of the species obtained previously, also too like reactions with dry HCl. Finally, it got hybrids materials by polymerization of the first compounds in an acrylic matrix. Research concluded with the characterization of all the products. (author) [es

  10. SYNTHESIS OF CHIRAL BINAPHTHYL CROWN ETHERS AND THEIR USE IN ANIONIC POLYMERIZATION OF METHYL METHACRYLATE AS INITIATOR LIGANDS

    Institute of Scientific and Technical Information of China (English)

    Hong-wei Liu; Chuan-fu Chen; Fu Xi

    2004-01-01

    Some chiral binaphthyl crown ethers were synthesized. The anionic polymerization of methyl methacrylate (MMA) was carried out in the presence of t-BuOK, Ph2CHK or Ph2CHNa (RM), and RM coordination initiator by using chiral binaphthyl crown ethers as ligands, respectively. The results showed that in the former case the PMMA obtained has mainly isotactic structure but without optical activity, while in the later case the PMMA produced predominately has syndiotactic suucture also without optical activity.

  11. 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)

  12. 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

  13. Radiation-induced graft polymerization of amphiphilic monomers with different polymerization characteristics onto hydrophobic polysilane

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Hidenori; Iwasaki, Isao; Kunai, Yuichiro [Research Reactor Institute, Kyoto University, Asashironishi 2-1010, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Sato, Nobuhiro, E-mail: sato-n@rri.kyoto-u.ac.j [Research Reactor Institute, Kyoto University, Asashironishi 2-1010, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Matsuyama, Tomochika [Research Reactor Institute, Kyoto University, Asashironishi 2-1010, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)

    2011-08-15

    The structures of poly(methyl-n-propylsilane) (PMPrS) amphiphilically modified through {gamma}-ray-induced graft polymerization were investigated with {sup 1}H NMR measurement. By the use of methyl methacrylate (MMA) or diethyl fumarate (DEF) as monomers for the graft polymerization, grafting yield rose with increasing total absorption dose and monomer concentrations, but decreased with increasing dose rate. This result means that grafting yield of modified PMPrS can be controlled by changing irradiation conditions. However, the number of PMMA or PDEF graft chains per PMPrS chain was estimated to be less than 1.0 by analysis of {sup 1}H NMR spectra, and this value was lower than that we had expected. To improve graft density, maleic anhydride (MAH), which is known as a non-homopolymerizable monomer in radical polymerization, was used as a monomer for grafting. As a result, high density grafting (one MAH unit for 4.2 silicon atoms) was attained. It demonstrates that the structure of {gamma}-ray-modified polysilane strongly depends on the polymerization characteristics of grafted monomers.

  14. Synthesis and Characterization of Poly(hydroxyethyl methacrylate-co-methacrylic acid) Cross Linked Polymeric Network for the Delivery of Analgesic Agent

    International Nuclear Information System (INIS)

    Rashid, H.; Ahmad, M.; Minhas, M. U.; Aamir, M. F.; Sohail, M.

    2015-01-01

    Objective of the study was to synthesize a chemically cross-linked poly(hydroxyethylmethacrylate-co-methacrylic acid) hydrogel (p(HEMA-co-MAA hydrogel)) for pH-responsive, controlled drug delivery of Flurbiprofen. pH-sensitive hydrogel drug delivery system was synthesized with the help of poly hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA) by using ethylene glycol dimethacrylate (EGDMA) as crosslinker. The monomers (HEMA and MAA) were successfully cross linked through free radical polymerization process, initiated by benzoyl peroxide in an aqueous medium. All formulations were loaded with Flurbiprofen as a model drug and evaluated at pH 1.2 and pH 7.4 to investigate pH-responsive nature of the system. Fourier transform infrared spectroscopy (FTIR) was performed to confirm the cross-linking of copolymer while thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed to evaluate the thermal stability of the system. Swelling studies and in-vitro release studies were carried out to evaluate pH-responsive nature of the hydrogels. FTIR confirmed that monomers were successfully cross-linked to form a copolymer. Hydrogel system showed less swelling at lower pH while at higher pH, it showed higher swelling, releasing drug in the same fashion. It was concluded that a stable hydrogel network was chemically cross-linked showing pH-responsive nature and thus, synthesized p(HEMA-co-MAA) hydrogels can be successfully employed as potential candidate for controlled drug delivery. (author)

  15. 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.

  16. 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

  17. THE EFFECTS OF N-2-HYDROXYETHYL-N-METHYL-P-TOLUIDINE ON METHYL METHACRYLATE RADICAL POLYMERIZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    QIU Kunyuan; ZHANG Zhanghua; FENG Xinde

    1992-01-01

    The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polymerization and the overall activation energy of polymerization were determined. Based on kinetics study and the end group analysis of the polymer obtained by UV spectrum method, the initiation mechanism is proposed.

  18. 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

  19. N-Heterocyclic Olefins as Initiators for the Polymerization of (Meth)Acrylic Monomers: A Combined Experimental and Theoretical Approach

    KAUST Repository

    Naumann, Stefan

    2017-08-25

    The zwitterionic organopolymerization of four different acrylic monomers (N,N-dimethylacrylamide, methyl acrylate, methyl methacrylate and tert-butyl methacrylate) based on neutral initiators, so-called N-heterocyclic olefins (NHOs), is presented. Scope and underlying (deactivation-)mechanisms where studied in a combined experimental and computational effort. From a range of differently structured NHOs it emerged that imidazole-, in contrast to imidazoline- and benzimidazole-derivatives, readily polymerize the selected monomers. While the additive-free reactions proceed with a relatively low degree of control to yield largely atactic material, for the acrylamide the addition of LiCl as µ-type ligand has been shown to result in a rapid and quantitative monomer consumption. The thus generated poly(N,N-dimethyl acrylamide) was found to be highly isotactic (>90% isotactic dyads) with high molecular weight (Mn = 250 000 – 650 000 g/mol, ÐM = 1.3- 1.6). Complementing DFT calculations considered the zwitterionic chain growth with respect to competing side reactions, namely spirocycles and enamine formation. It was found that NHOs with unsaturated backbone better support the zwitterionic chain growth, with the spirocycles acting as dormant species that slow down but do not quench the polymerization process. Contrasting this, enamine formation irreversibly terminates the polymerization and is found to be energetically favored. This pathway can be blocked by introduction of substituents on the exocyclic carbon of the NHO, resulting in structures like 2-isopropylidene-1,3,4,5-tetramethylimidazoline (4) which consequently deliver the most controlled polymerizations. Finally, a good correlation of the initiation energy barrier with the buried volume (%VBur) and the Parr electrophilicity index is described, allowing for a quick and reliable screening of potential monomers based on these two readily accessible parameters.

  20. 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.

  1. 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.

  2. 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.

  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. Synthesis, Characterization and Application of A Novel Carbon Bridged Half-metallocene Chromium Catalyst for Methyl Methacrylate Polymerization

    Institute of Scientific and Technical Information of China (English)

    CHENG Zhengzai; GONG Kai; WANG Yang; ZHOU Xue; ZHANG Weixing; LI Yin; SUN Junquan; LI Wenbing

    2014-01-01

    A new carbon bridged cyclopentadienyl chromium complex of the type [(C5H4)C(CH3)2 CH2(C5H4N)]CrCl2 was prepared by treatment of CrCl3•(THF)3 in THF solution with the lithium salt of ligand containing cyclopentadienyl and pyridyl groups. The chromium complex was characterized by 1H NMR and elemental analysis(EA), and the crystal structure was determined by X-ray diffraction analysis. Activated by Al(i-Bu)3, the chromium complex displayed a very high activity for methyl methacrylate (MMA) polymerization. After 24 hours,more than 95.5%MMA was converted to polymethyl methacrylate (PMMA) with a viscosity average molecular weight (Wη) of 416000 g•mol-1 at 60℃for MMA/Al(i-Bu)3/chromium catalyst molar ratio of up to 2000:20:1. Effects of temperature, molar ratios of MMA/catalyst and catalyst/cocatalyst on the polymerization have been studied. The high conversion of MMA and high molecular weight of PMMA with narrow molecular weight distribution is caused by the unique stable active site formed by the new chromium complex and aluminum cocatalyst.

  6. Better flocculants by radiation induced polymerization

    International Nuclear Information System (INIS)

    Laizier, J.; Gaussens, G.

    1978-01-01

    The use of radiation induced polymerization should theoritically allow to prepare better flocculants. The testings of several products prepared by such a process shows that better properties are indeed obtained: better efficiencies, lower amounts needed, better overall properties [fr

  7. Chromatographic assessment of two hybrid monoliths prepared via epoxy-amine ring-opening polymerization and methacrylate-based free radical polymerization using methacrylate epoxy cyclosiloxane as functional monomer.

    Science.gov (United States)

    Wang, Hongwei; Ou, Junjie; Lin, Hui; Liu, Zhongshan; Huang, Guang; Dong, Jing; Zou, Hanfa

    2014-11-07

    Two kinds of hybrid monolithic columns were prepared by using methacrylate epoxy cyclosiloxane (epoxy-MA) as functional monomer, containing three epoxy moieties and one methacrylate group. One column was in situ fabricated by ring-opening polymerization of epoxy-MA and 1,10-diaminodecane (DAD) using a porogenic system consisting of isopropanol (IPA), H2O and ethanol at 65°C for 12h. The other was prepared by free radical polymerization of epoxy-MA and ethylene dimethacrylate (EDMA) using 1-propanol and 1,4-butanediol as the porogenic solvents at 60°C for 12h. Two hybrid monoliths were investigated on the morphology and chromatographic assessment. Although two kinds of monolithic columns were prepared with epoxy-MA, their morphologies looked rather different. It could be found that the epoxy-MA-DAD monolith possessed higher column efficiencies (25,000-34,000plates/m) for the separation of alkylbenzenes than the epoxy-MA-EDMA monolith (12,000-13,000plates/m) in reversed-phase nano-liquid chromatography (nano-LC). Depending on the remaining epoxy or methacrylate groups on the surface of two pristine monoliths, the epoxy-MA-EDMA monolith could be easily modified with 1-octadecylamine (ODA) via ring-opening reaction, while the epoxy-MA-DAD monolith could be modified with stearyl methacrylate (SMA) via free radical reaction. The chromatographic performance for the separation of alkylbenzenes on SMA-modified epoxy-MA-DAD monolith was remarkably improved (42,000-54,000 plates/m) when compared with that on pristine epoxy-MA-DAD monolith, while it was not obviously enhanced on ODA-modified epoxy-MA-EDMA monolith when compared with that on pristine epoxy-MA-EDMA monolith. The enhancement of the column efficiency of epoxy-MA-DAD monolith after modification might be ascribed to the decreased mass-transfer resistence. The two kinds of hybrid monoliths were also applied for separations of six phenols and seven basic compounds in nano-LC. Copyright © 2014 Elsevier B.V. All

  8. Radiation-induced polymerization for the immobilization of penicillin acylase

    International Nuclear Information System (INIS)

    Boccu, E.; Carenza, M.; Lora, S.; Palma, G.; Veronese, F.M.

    1987-01-01

    The immobilization of Escherichia coli penicillin acylase was investigated by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperature. A leak-proof composite that does not swell in water was obtained by adding the cross-linking agent trimethylolpropane trimethacrylate to the monomer-aqueous enzyme mixture. Penicillin acylase, which was immobilized with greater than 70% yield, possessed a higher Km value toward the substrate 6-nitro-3-phenylacetamidobenzoic acid than the free enzyme form (Km = 1.7 X 10(-5) and 1 X 10(-5) M, respectively). The structural stability of immobilized penicillin acylase, as assessed by heat, guanidinium chloride, and pH denaturation profiles, was very similar to that of the free-enzyme form, thus suggesting that penicillin acylase was entrapped in its native state into aqueous free spaces of the polymer matrix

  9. Design rules for carbazole derivatized n-alkyl methacrylate polymeric memristors

    Czech Academy of Sciences Publication Activity Database

    McFarlane, T. M.; Zdyrko, B.; Bandera, Y.; Worley, D.; Klep, O.; Jurča, M.; Tonkin, C.; Foulger, S. H.; Vilčáková, J.; Sáha, P.; Pfleger, Jiří

    2018-01-01

    Roč. 6, č. 10 (2018), s. 2533-2545 ISSN 2050-7526 Institutional support: RVO:61389013 Keywords : n-alkyl methacrylate polymers * charge transport * composites Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 5.256, year: 2016

  10. In situ AFM investigation of electrochemically induced surface-initiated atom-transfer radical polymerization.

    Science.gov (United States)

    Li, Bin; Yu, Bo; Zhou, Feng

    2013-02-12

    Electrochemically induced surface-initiated atom-transfer radical polymerization is traced by in situ AFM technology for the first time, which allows visualization of the polymer growth process. It affords a fundamental insight into the surface morphology and growth mechanism simultaneously. Using this technique, the polymerization kinetics of two model monomers were studied, namely the anionic 3-sulfopropyl methacrylate potassium salt (SPMA) and the cationic 2-(metharyloyloxy)ethyltrimethylammonium chloride (METAC). The growth of METAC is significantly improved by screening the ammonium cations by the addition of ionic liquid electrolyte in aqueous solution. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Redox-Initiated Poly(methyl methacrylate) Emulsion Polymerizations Stabilized with Block Copolymers Based on Methoxy-Poly(ethylene glycol), epsilon-Caprolactone, and Linoleic Acid

    NARCIS (Netherlands)

    Tan, Boonhua; Nabuurs, Tijs; Feijen, Jan; Grijpma, Dirk W.

    2009-01-01

    A redox initiating system, consisting of t-butyl hydroperoxide (tBHPO), isoascorbic acid (iAA), and ethylenediaminetetraacetic acid ferric-sodium salt (FeEDTA) was employed in emulsion polymerizations of methyl methacrylate (MMA) at high solids contents of 30 wt % in water. The system was stabilized

  12. CAMPHORQUINONE AS A PHOTOINITIATOR IN THE POLYMERIZATION OF 2-HYDROXYETHYL METHACRYLATE IN AQUEOUS SOLUTION: A KINETIC STUDY

    Directory of Open Access Journals (Sweden)

    Iqbal Ahmad

    2017-06-01

    Full Text Available The photoinitiated polymerization of 2-hydroxyethyl methacrylate (HEMA (1-3 M using camphorquinone (CQ \\ triethanolamine (TEOHA system has been studied in the pH range 6.0-9.0. The kinetics of the reaction has been evaluated during the initial stages causing about 5% HEMA conversion to avoid the effects of any variation in the volume of the solution. The change in the concentration of HEMA during polymerization has been determined by a UV spectrometric method at 208 nm with a precision of 3%. The apparent first-order rate constants (kobs for the polymerization of HEMA by CQ in the presence of 0.01 M TEOHA, carried out up to 100 s, range from 3.35-7.78 (1 M, 2.72-6.78 (2 M and 2.33`5.89x104 s-1(3 M. The second-order rate constants for the interaction of TEOHA radicals with HEMA (1-3 M range from 2.33-7.78x10-2 M 1 s-lat pH 6.0-9.0 indicating an increase in the reactivity of TEOHA radicals with an increase in the pH of the solution. There is a linear relation between kobs (1-3 M HEMA and inverse of solution viscosity suggesting the quenching of CQ excited state with an increase in the viscosity of the medium.

  13. 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.

  14. 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.

  15. Effect of leaching residual methyl methacrylate concentrations on in vitro cytotoxicity of heat polymerized denture base acrylic resin processed with different polymerization cycles

    Directory of Open Access Journals (Sweden)

    Canan Bural

    2011-08-01

    Full Text Available OBJECTIVES: Residual methyl methacrylate (MMA may leach from the acrylic resin denture bases and have adverse effects on the oral mucosa. This in vitro study evaluated and correlated the effect of the leaching residual MMA concentrations ([MMA]r on in vitro cytotoxicity of L-929 fibroblasts. MATERIAL AND METHODS: A total of 144 heat-polymerized acrylic resin specimens were fabricated using 4 different polymerization cycles: (1 at 74ºC for 9 h, (2 at 74ºC for 9 h and terminal boiling (at 100ºC for 30 min, (3 at 74ºC for 9 h and terminal boiling for 3 h, (4 at 74ºC for 30 min and terminal boiling for 30 min. Specimens were eluted in a complete cell culture medium at 37ºC for 1, 2, 5 and 7 days. [MMA]r in eluates was measured using high-performance liquid chromatography. In vitro cytotoxicity of eluates on L-929 fibroblasts was evaluated by means of cell proliferation using a tetrazolium salt XTT (sodium 3´-[1-phenyl-aminocarbonyl-3,4-tetrazolium]bis(4-methoxy-6-nitrobenzenesulphonic acid assay. Differences in [MMA]r of eluates and cell proliferation values between polymerization cycles were statistically analyzed by Kruskal-Wallis, Friedman and Dunn's multiple comparison tests. The correlation between [MMA]r of eluates and cell proliferation was analyzed by Pearson's correlation test (p<0.05. RESULTS: [MMA]r was significantly (p<0.001 higher in eluates of specimens polymerized with cycle without terminal boiling after elution of 1 and 2 days. Cell proliferation values for all cycles were significantly (p<0.01 lower in eluates of 1 day than those of 2 days. The correlation between [MMA]r and cell proliferation values was negative after all elution periods, showing significance (p<0.05 for elution of 1 and 2 days. MMA continued to leach from acrylic resin throughout 7 days and leaching concentrations markedly reduced after elution of 1 and 2 days. CONCLUSION: Due to reduction of leaching residual MMA concentrations, use of terminal boiling in

  16. Pressure-induced polymerization of phenoxyethyl acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, K; Wrzalik, R; Paluch, M; Ziolo, J [Institute of Physics, Silesian University, Uniwersytecka 4, 40-007 Katowice (Poland); Roland, C M [Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342 (United States)

    2008-06-18

    Polymerization of phenoxyethyl acrylate was induced without catalyst or initiators by the application of hydrostatic pressure at elevated temperature. Broadband dielectric and infrared spectroscopy were employed to follow the course of the reaction, which reached a degree of conversion of 60%. The structure of the obtained polymer was determined from density functional theory calculations.

  17. Ion induced polymerization in benzene frozen films

    Energy Technology Data Exchange (ETDEWEB)

    Calcagno, G [Catania Univ. (Italy). Ist. di Fisica; Strazzulla, G [Catania Univ. (Italy). Osservatorio Astrofisico; Fichera, M; Foti, G [Catania Univ. (Italy). Ist. di Radiologia

    1983-07-01

    The cross section of the polymerization process induced by energetic protons colliding with frozen benzene layers has been measured. The results have been described by a simple theory and they show that the process is a volume one occurring along the ion track and interesting all of the crossed layers.

  18. Photo-polymerization of photocurable resins containing polyhedral oligomeric silsesquioxane methacrylate

    International Nuclear Information System (INIS)

    Lin, Ho-May; Wu, Shi-Yin; Chang, Feng-Chih; Yen, Ying-Chieh

    2011-01-01

    Photocurable resins, bisphenol A propoxylate glycerolate diacrylate (BPA-PGDA, containing two hydroxyl) and bisphenol A propoxylate diacrylate (BPA-PDA), with fixed photoinitiator (Irgacure 907) concentration and various contents of methacrylisobutyl polyhedral oligomeric silsesquioxane (MI-POSS) were prepared and characterized by FTIR spectroscopy, scanning electron microscope and differential photocalorimetry. The MI-POSS molecules form crystals or aggregated particles in the cured resin matrix. The BPA-PGDA series photocurable resins show higher viscosity and lower photo-polymerization reactivity than the BPA-PDA series resins. The photo-polymerization rate and conversion of BPA-PGDA series are improved with increasing MI-POSS content. On the contrary, the photo-polymerization behavior of BPA-PDA series photocurable resins remains nearly unchanged by the addition of MI-POSS. Hydrogen-bonding interaction between the hydroxyl of BPA-PGDA and the siloxane of MI-POSS tends to attract and concentrate these acrylate double bonds around MI-POSS particles and thus enhances the photo-polymerization rate and conversion.

  19. TERMINATION PROCESS AND THE TERMINATION PARAMETER k_t OF METHYL METHACRYLATE BULK RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    沈家骢; 田元; 王国斌; 杨梅林

    1990-01-01

    In this work the exact k_t data during the whole process of MMA bulk radical polymerization have been determined under unsteady state by using the post effect technique and ESR method. The effect of the micro-environment of radicals on the termination is discussed.

  20. Alterations of energy metabolism and glutathione levels of HL-60 cells induced by methacrylates present in composite resins.

    Science.gov (United States)

    Nocca, G; De Palma, F; Minucci, A; De Sole, P; Martorana, G E; Callà, C; Morlacchi, C; Gozzo, M L; Gambarini, G; Chimenti, C; Giardina, B; Lupi, A

    2007-03-01

    Methacrylic compounds such as 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA) and bisphenol A glycerolate (1 glycerol/phenol) dimethacrylate (Bis-GMA) are largely present in auto- or photopolymerizable composite resins. Since the polymerization reaction is never complete, these molecules are released into the oral cavity tissues and biological fluids where they could cause local adverse effects. The aim of this work was to verify the hypothesis that the biological effects of HEMA, TEGDMA and Bis-GMA - at a non-cytotoxic concentration - depend on the interaction with mitochondria and exert consequent alterations of energy metabolism, GSH levels and the related pathways in human promyelocytic cell line (HL-60). The biological effects of methacrylic monomers were determined by analyzing the following parameters: GSH concentration, glucose-6-phosphate dehydrogenase (G6PDH) and glutathione reductase (GR) activity, oxygen and glucose consumption and lactate production along with cell differentiation and proliferation. All monomers induced both cellular differentiation and decrease in oxygen consumption. Cells treated with TEGDMA and Bis-GMA showed a significant enhancement of glucose consumption and lactate production. TEGDMA and HEMA induced GSH depletion stimulating G6PDH and GR activity. All the monomers under study affect the metabolism of HL-60 cells and show differentiating activity. Since alterations in cellular metabolism occurred at compound concentrations well below cytotoxic levels, the changes in energy metabolism and glutathione redox balance could be considered as potential mechanisms for inducing clinical and sub-clinical adverse effects and thus providing useful parameters when testing biocompatibility of dental materials.

  1. Surface-initiated polymerization of 2-hydroxyethyl methacrylate from heterotelechelic oligoperoxide-coated .gamma.-Fe2O3 nanoparticles and their engulfment by mammalian cells

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Shagotova, Tetiana; Mitina, N.; Trchová, Miroslava; Boiko, N.; Babič, Michal; Stoika, R.; Kovářová, Jana; Hevus, O.; Beneš, Milan J.; Klyuchivska, O.; Holler, Petr; Zaichenko, A.

    2011-01-01

    Roč. 23, č. 10 (2011), s. 2637-2649 ISSN 0897-4756 R&D Projects: GA ČR GA203/09/1242; GA ČR GAP503/10/0664; GA AV ČR(CZ) KAN401220801 Institutional research plan: CEZ:AV0Z40500505 Keywords : 2-hydroxyethyl methacrylate * oligoperoxide * surface-initiated polymerization Subject RIV: CD - Macromolecular Chemistry Impact factor: 7.286, year: 2011

  2. Synthesis,Characterization and Application of Benzyl-substituted Cyclopentadienyl lanthanide Complexes as Catalyst Precursors for the Syndiotactic Polymerization of Methyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    QIAN,Yan-Long(钱延龙); BALA,Muhammad D.; XIE,Xiao-Min(谢小敏); HUANG,Ji-Ling(黄吉玲)

    2004-01-01

    Benzyl-substituted cyclopentadienyl lanthanide complexes were synthesized and characterized by elemental analysis, MS and IR spectroscopy. The analytical data point out the formation of monomeric, unsolvated complexes.In conjunction with Al(Et)3 as co-catalyst, the title complexes are efficient catalysts for the syndiotactic polymerization of methyl methacrylate. For the complex (C6H5CH2C5H4)2YCI, under the optimum polymerization conditions (60 ℃, n(MMA):n(catalyst):n(co-catalyst)= 1000:1:10), a predominantly syndiotactic (rr=66%) polymer of high molecular weight (Mη = 105000) was obtained.

  3. Ultrasound-induced radical polymerization

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; Kemmere, M.F.; Keurentjes, J.T.F.

    2004-01-01

    Sonochemistry comprises all chemical effects that are induced by ultrasound. Most of these effects are caused by cavitations, ie, the collapse of microscopic bubbles in a liquid. The chemical effects of ultrasound include the formation of radicals and the enhancement of reaction rates at ambient

  4. Preparation of Mesoporous Carbons from Acrylonitrile-methyl Methacrylate Copolymer/Silica Nanocomposites Synthesized by in-situ Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    BAO Yongzhong; ZHAO Wenting; HUANG Zhiming

    2013-01-01

    Acrylonitrile-methyl methacrylate (AN-MMA) copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2′-azobis(2-amidinopropane) dihydrochloride absorbed onto colloidal silica particles,and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites,followed by HF etching.Thermogravimetric analysis of AN-MMA copolymer/silica nanocomposites showed that the carbon yield of copolymer was slightly decreased as silica particle incorporated.N2 adsorption-desorption,scan electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and morphology of the mesoporous carbon materials.Both SEM and TEM results showed that disordered mesopores were formed in the obtained carbon material mainly through templating effect of silica nanoparticles.The diameter of mesopores was mainly distributed in the range from 5 nm to 15 nm.The mean pore diameter and total pore volume of the material increased as the mass fraction of silica in the nanocomposites increased from 0 to 24.93%.The significant increase of the mean pore diameter and the decrease of surface area for the carbon material prepared from the nanocomposite with 24.93% silica were caused by partial aggregation of silica nanoparticles in the polymer matrix.

  5. Time-dependent conversion of a methacrylate-based sealer polymerized with different light-curing units.

    Science.gov (United States)

    Beriat, Nilufer C; Ertan, Atilla; Cehreli, Zafer C; Gulsahi, Kamran

    2009-01-01

    The purpose of this study was to investigate the degree of conversion of a methacrylate-based sealer (Epiphany; Pentron Clinical Technologies, Wallingford, CT) with regard to the method of photoactivation, distance from the light-curing unit (LCU), and post-curing time. Freshly mixed Epiphany sealer was dispensed into half-pipe-shaped silicone moulds (n = 48), after which the specimens were photoactivated with one of the following LCUs from the coronal aspect: (1) quartz tungsten halogen/40 seconds and (2) light-emitting diode/20 seconds. In each specimen, the degree of conversion was measured at three different locations (coronal, middle, and apical) using Fourier transform infrared spectroscopy before and after photoactivation. The amount of conversion was approximately 50% after photoactivation and improved by approximately 10% after 15 days. Conversion of Epiphany was not affected by the type of LCU (p > 0.001) or the distance from the LCU (p > 0.001) but showed a significant increase within time (p < 0.001). These results indicate incomplete polymerization of Epiphany, despite a post-curing time of as long as 2 weeks in vitro.

  6. Synthesis of Photocrosslinkable and Amine Containing Multifunctional Nanoparticles via Polymerization-Induced Self-Assembly.

    Science.gov (United States)

    Huang, Jianbing; Li, Decai; Liang, Hui; Lu, Jiang

    2017-08-01

    Photo-crosslinkable and amine-containing block copolymer nanoparticles are synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization-induced self-assembly of a multifunctional core-forming monomer, 2-((3-(4-(diethylamino)phenyl)acryloyl)oxy)ethyl methacrylate (DEMA), using poly(2-hydroxypropyl methacrylate) macromolecular chain transfer agent as a steric stabilizer in methanol at 65 °C. By tuning the chain length of PDEMA, a range of nanoparticle morphologies (sphere, worm, and vesicle) can be obtained. Since cinnamate groups can easily undergo a [2 + 2] cycloaddition of the carbon-carbon double bonds upon UV irradiation, the as-prepared block copolymer nanoparticles are readily stabilized by photo-crosslinking to produce anisotropic nanoparticles. The crosslinked block copolymer nanoparticles can be used as templates for in situ formation polymer/gold hybrid nanoparticles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Gamma Radiation-Induced Template Polymerization Technique

    International Nuclear Information System (INIS)

    Siyam, T.

    2005-01-01

    Gamma radiation induced copolymerization of acrylamide sodiumacrylate (AM-AANa) in the presence and absence of the polymer additive was studied at low monomer concentration(1.4M/l). The results showed that the exponents of the dose rate for the polymerization rate was found to be 1.3 and 1.4 in the absence and in the presence of the polymer additive respectively. The molecular weight of the formed polymer increased by addition of the polymer to the system. In the presence of the polymer the comonomers polymerize on the added polymer. In the absence of the added polymer the comonomers polymerize according to the copolymerization process at the initial stage of the copolymerization. While at high conversion the residual comonomers polymerize on the formed macromolecular chains of the produced polymer. These studies showed that the copolymerization in the presence of added polymer is completely template copolymerization while in the absence of the polymer the copolymerization process is only template process with a high conversion

  8. Hydroxyapatite induces spontaneous polymerization of model self-etch dental adhesives.

    Science.gov (United States)

    Zhang, Ying; Wu, Ningjing; Bai, Xinyan; Xu, Changqi; Liu, Yi; Wang, Yong

    2013-10-01

    The objective of this study is to report for the first time the spontaneous polymerization phenomenon of self-etch dental adhesives induced by hydroxylapatite (HAp). Model self-etch adhesives were prepared by using a monomer mixture of bis[2-(methacryloyloxy)ethyl] phosphate (2MP) with 2-hydroxyethyl methacrylate (HEMA). The initiator system consisted of camphorquinone (CQ, 0.022 mmol/g) and ethyl 4-dimethylaminobenzoate (4E, 0.022-0.088 mmol/g). HAp (2-8 wt.%) was added to the neat model adhesive. In a dark environment, the polymerization was monitored in-situ using ATR/FT-IR, and the mechanical properties of the polymerized adhesives were evaluated using nanoindentation technique. Results indicated that spontaneous polymerization was not observed in the absence of HAp. However, as different amounts of HAp were incorporated into the adhesives, spontaneous polymerization was induced. Higher HAp content led to higher degree of conversion (DC), higher rate of polymerization (RP) and shorter induction period (IP). In addition, higher 4E content also elevated DC and RP and reduced IP of the adhesives. Nanoindentation result suggested that the Young's modulus of the polymerized adhesives showed similar dependence on HAp and 4E contents. In summary, interaction with HAp could induce spontaneous polymerization of the model self-etch adhesives. This result provides important information for understanding the initiation mechanism of the self-etch adhesives, and may be of clinical significance to strengthen the adhesive/dentin interface based on the finding. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Anionic polymerization of acrylates. XII. Polymerization of methyl methacrylate and tert-butyl acrylate initiated with alkyllithiums or methyl 2-lithioisobutyrate in the presence of lithium tert-butoxide

    Czech Academy of Sciences Publication Activity Database

    Vlček, Petr; Otoupalová, Jaroslava; Janata, Miroslav; Látalová, Petra; Masař, Bohumil; Toman, Luděk

    2002-01-01

    Roč. 43, č. 25 (2002), s. 7179-7184 ISSN 0032-3861 R&D Projects: GA ČR GA203/01/0513; GA MŠk OC P1.10 Institutional research plan: CEZ:AV0Z4050913 Keywords : ligated anionic polymerization * (meth)acrylates * lithium tert-butoxide Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.838, year: 2002

  10. Studies on radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Omichi, Hideki

    1978-09-01

    Radiation-induced graft polymerization is used extensively to improve physical properties of polymers, but few processes are now commercialized. The reason for this is partly inadequate basic research on the reaction and partly the difficulty in developing the grafting process with large radiation source. Firstly, new techniques are proposed of studying kinetics of the graft polymerization in heterogeneous system. Based on the grafting yield, the molecular weight of graft chains, and the amount of radicals given by ESR and activation analysis, kinetic parameters are obtained and the reaction mechanism of grafting process is discussed. Secondly, the development of grafting process of poly (vinyl chloride)-butadiene is described. By study of the reaction, process design, construction and operation of the pilot plant, and economic analysis of the process, this process with 60 Co gamma ray sources is shown to be industrially promising. (author)

  11. Radiation-induced emulsion polymerization of tetrafluoroethylene

    International Nuclear Information System (INIS)

    Suwa, Takeshi

    1979-10-01

    The radiation-induced emulsifier-free emulsion polymerization of tetrafluoroethylene (TFE) has been studied at initial pressure 2 - 25 kg/cm 2 and temperature 30 0 - 110 0 C for dose rate 0.57 x 10 4 - 3.0 x 10 4 rad/hr. Polytetrafluoroethylene (PTFE), a hydrophobic polymer, forms as a stable latex in the absence of an emulsifier. Stability of the latex is governed by the dose rate/TFE pressure ratio; it increases with sufficient TFE monomer. PTFE particles produced in this polymerization system are stable due to the carboxyl end groups and adsorption of OH - and HF on the particles. PTFE latex of molecular weight higher than 2 x 10 7 is obtained by addition of a radical scavenger such as hydroquinone. The molecular weight of PTFE can be measured from the heat of crystallization conveniently with high reliability, which was found in the course of study on the melting and crystallization behavior. (author)

  12. New cobalt-mediated radical polymerization (CMRP of methyl methacrylate initiated by two single-component dinuclear β-diketone cobalt (II catalysts.

    Directory of Open Access Journals (Sweden)

    Feng Bao

    Full Text Available Two dinuclear cobalt complexes based on bis-diketonate ligands (ligand 1: 3,3'-(1,3-phenylenebis(1-phenylpropane-1,3-dione; ligand 2: 3,3'-(1,4-phenylenebis(1-phenylpropane-1,3-dione were successfully synthesized. The two neutral catalysts all showed satisfactory activities in the cobalt-mediated radical polymerization (CMRP of methyl methacrylate (MMA with the common initiator of azodiisobutyronitrile (AIBN. The resulting polymerizations have all of the characteristics of a living polymerization and displayed linear semilogarithmic kinetic plots, a linear correlation between the number-average molecular weight and the monomer conversion, and low polydispersities. Mono- or dicomponent low polydispersity polymers could be obtained by using the two dinuclear catalysts under proper reaction conditions. All these improvements facilitate the implementation of the acrylate CMRP and open the door to the scale-up of the syntheses and applications of the multicomponent low polydispersity polymers.

  13. 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)

  14. Photonic devices based on patterning by two photon induced polymerization techniques

    Science.gov (United States)

    Fortunati, I.; Dainese, T.; Signorini, R.; Bozio, R.; Tagliazucca, V.; Dirè, S.; Lemercier, G.; Mulatier, J.-C.; Andraud, C.; Schiavuta, P.; Rinaldi, A.; Licoccia, S.; Bottazzo, J.; Franco Perez, A.; Guglielmi, M.; Brusatin, G.

    2008-04-01

    Two and three dimensional structures with micron and submicron resolution have been achieved in commercial resists, polymeric materials and sol-gel materials by several lithographic techniques. In this context, silicon-based sol-gel materials are particularly interesting because of their versatility, chemical and thermal stability, amount of embeddable active compounds. Compared with other micro- and nano-fabrication schemes, the Two Photon Induced Polymerization is unique in its 3D processing capability. The photopolymerization is performed with laser beam in the near-IR region, where samples show less absorption and less scattering, giving rise to a deeper penetration of the light. The use of ultrashort laser pulses allows the starting of nonlinear processes like multiphoton absorption at relatively low average power without thermally damaging the samples. In this work we report results on the photopolymerization process in hybrid organic-inorganic films based photopolymerizable methacrylate-containing Si-nanobuilding blocks. Films, obtained through sol-gel synthesis, are doped with a photo-initiator allowing a radical polymerization of methacrylic groups. The photo-initiator is activated by femtosecond laser source, at different input energies. The development of the unexposed regions is performed with a suitable solvent and the photopolymerized structures are characterized by microscopy techniques.

  15. OH radical induced depolymerization of poly(methacrylic acid)

    Science.gov (United States)

    Ulanski, Piotr; Bothe, Eberhard; von Sonntag, Clemens

    1999-05-01

    Hydroxyl radicals (generated pulse radiolytically in dilute N 2O-saturated aqueous solutions) react with poly(methacrylic acid) producing two kinds of radicals. The primary radical is converted into a secondary one by H-abstraction ( k=3.5 × 10 2 s -1) as monitored by changes in the UV spectrum. Subsequently, the secondary radicals undergo chain scission ( k=1.8 s -1 at pH 7-9). This process has been followed both by spectrophotometry as well as by conductometry. In competition with the bimolecular decay of the radicals the ensuing end-chain radicals undergo efficient depolymerization resulting in the release of monomer. Since the lifetime of the radicals is much longer at high pH, where the polymer attains a rod-like conformation, depolymerization is most efficient in basic solution.

  16. Influence of Ethylene Glycol Methacrylate to the Hydration and Transition Behaviors of Thermo-Responsive Interpenetrating Polymeric Network Hydrogels

    Directory of Open Access Journals (Sweden)

    Bing Li

    2018-01-01

    Full Text Available The influence of ethylene glycol methacrylate (EGMA to the hydration and transition behaviors of thermo-responsive interpenetrating polymeric network (IPN hydrogels containing sodium alginate, N-isopropylacrylamide (NIPAAm, and EGMA were investigated. The molar ratios of NIPAAm and EGMA were varied from 20:0 to 19.5:0.5 and 18.5:1.5 in the thermo-responsive alginate-Ca2+/P(NIPAAm-co-EGMA IPN hydrogels. Due to the more hydrophilicity and high flexibility of EGMA, the IPN hydrogels exhibited higher lower critical solution temperature (LCST and lower glass transition temperature (Tg when the ratio of EGMA increases. The swelling/deswelling kinetics of the IPN hydrogels could be controlled by adjusting the NIPAAm/EGMA molar ratio. A faster water uptake rate and a slower water loss rate could be realized by increase the amount of EGMA in the IPN hydrogel (the shrinking rate constant was decreased from 0.01207 to 0.01195 and 0.01055 with the changing of NIPAAm/EGMA ratio from 20:0, 19.5:0.5 to 18.5:1.5. By using 2-Isopropylthioxanthone (ITX as a photo initiator, the obtained alginate-Ca2+/P(NIPAAm-co-EGMA360 IPN hydrogels were successfully immobilized on cotton fabrics. The surface and cross section of the hydrogel were probed by scanning electron microscopy (SEM. They all exhibited a porous structure, and the pore size was increased with the amount of EGMA. Moreover, the LCST values of the fabric-grafted hydrogels were close to those of the pure IPN hydrogels. Their thermal sensitivity remained unchanged. The cotton fabrics grafted with hydrogel turned out to be much softer with the continuous increase of EGMA amount. Therefore, compared with alginate-Ca2+/PNIPAAm hydrogel, alginate-Ca2+/P(NIPAAm-co-EGMA360 hydrogel is a more promising candidate for wound dressing in the field of biomedical textile.

  17. 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.

  18. Influence of degree of methyl methacrylate polymerization on spectroscopic properties of ethyl 5-(4-aminophenyl)- and 5-(4-dimethylaminophenyl)-3-amino-2,4-dicyanobenzoate

    International Nuclear Information System (INIS)

    Józefowicz, M.; Bajorek, A.; Pietrzak, M.; Jędrzejewska, B.; Heldt, J.R.; Heldt, J.

    2013-01-01

    The influence of degree of methyl methacrylate (MM) polymerization on the both emission modes (LE—locally excited and ICT—intramolecular charge transfer) of the fluorescence spectrum of ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate (EAADCy) and ethyl 5-(4-dimethylaminophenyl)-3-amino-2,4-dicyanobenzoate (EDMAADCy) has been studied using steady-state and time-resolved spectroscopic technique. The purpose of these studies was to find a relationship between the changes in the spectroscopic characteristics (fluorescence intensity, wavelength of maximum intensity, fluorescence full-width at half maximum, emission anisotropy, fluorescence decay time) of the tested compounds and degree of monomer conversion into polymer. On the basis of the experimental results, it was shown that the ICT fluorescence full-width at half maximum for EDMAADCy shows a linear dependence on the time of MM polymerization. Our findings predestine the molecule EDMAADCy to be used as fluorescence probe for monitoring the polymerization process of MM. - Highlights: ► The fluorescence excitation and emission spectra in MM possess a complex nature. ► Fluorescence decay kinetics for different degrees of polymerization of MM were investigated. ► The ICT fluorescence FWHM for EDMAADCy shows a linear dependence on the time of polymerization. ► EDMAADCy can be used as fluorescence probe for monitoring the polymerization process of MM

  19. Effect of Graphene Oxide on the Reaction Kinetics of Methyl Methacrylate In Situ Radical Polymerization via the Bulk or Solution Technique

    Directory of Open Access Journals (Sweden)

    Ioannis S. Tsagkalias

    2017-09-01

    Full Text Available The synthesis of nanocomposite materials based on poly(methyl methacrylate and graphene oxide (GO is presented using the in situ polymerization technique, starting from methyl methacrylate, graphite oxide, and an initiator, and carried out either with (solution or without (bulk in the presence of a suitable solvent. Reaction kinetics was followed gravimetrically and the appropriate characterization of the products took place using several experimental techniques. X-ray diffraction (XRD data showed that graphite oxide had been transformed to graphene oxide during polymerization, whereas FTIR spectra revealed no significant interactions between the polymer matrix and GO. It appears that during polymerization, the initiator efficiency was reduced by the presence of GO, resulting in a reduction of the reaction rate and a slight increase in the average molecular weight of the polymer formed, measured by gel permeation chromatography (GPC, along with an increase in the glass transition temperature obtained from differential scanning calorimetry (DSC. The presence of the solvent results in the suppression of the gel-effect in the reaction rate curves, the synthesis of polymers with lower average molecular weights and polydispersities of the Molecular Weight Distribution, and lower glass transition temperatures. Finally, from thermogravimetric analysis (TG, it was verified that the presence of GO slightly enhances the thermal stability of the nano-hybrids formed.

  20. Inducing β Phase Crystallinity in Block Copolymers of Vinylidene Fluoride with Methyl Methacrylate or Styrene

    Directory of Open Access Journals (Sweden)

    Nahal Golzari

    2017-07-01

    Full Text Available Block copolymers of poly(vinylidene fluoride (PVDF with either styrene or methyl methacrylate (MMA were synthesized and analyzed with respect to the type of the crystalline phase occurring. PVDF with iodine end groups (PVDF-I was prepared by iodine transfer polymerization either in solution with supercritical CO2 or in emulsion. To activate all iodine end groups Mn2(CO10 is employed. Upon UV irradiation Mn(CO5 radicals are obtained, which abstract iodine from PVDF-I generating PVDF radicals. Subsequent polymerization with styrene or methyl methacrylate (MMA yields block copolymers. Size exclusion chromatography and NMR results prove that the entire PVDF-I is converted. XRD, FT-IR, and differential scanning calorimetry (DSC analyses allow for the identification of crystal phase transformation. It is clearly shown that the original α crystalline phase of PVDF-I is changed to the β crystalline phase in case of the block copolymers. For ratios of the VDF block length to the MMA block length ranging from 1.4 to 5 only β phase material was detected.

  1. 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

  2. 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)

  3. 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...

  4. Stereocontrol during the radical polymerization of methyl methacrylates with combined Lewis acids:Aluminium trichloride(AlCl3) and iron dichloride tetrahydrate

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The radical polymerization of methyl methacrylate(MMA) was carried out in the presence of combined Lewis acids of the AlCl3-FeCl2 system.Compared with the polymerization produced in the presence of single Lewis acids,AlCl3 or FeCl2,the MMA polymerization in the presence of AlCl3-FeCl2 composite in CHCl3 or 1-butanol produced a polymer with a higher isotacticity and in toluene produced a polymer with a much higher isotacticity(mm=50%) .The molecular weight and polydispersity of PMMA in the presence of Lewis acids were similar with those in the absence of Lewis acids,although Lewis acids decelerate the polymerization of MMA.The effects of the Lewis acids were greater in a solvent with a lower polarity.A possible stereocontrol mechanism of the polymerization was proposed.The Lewis acid composite of AlCl3-FeCl2 readily formed a complex with growing species.These complexes possessed apparent bulkiness that changes the direction of monomer addition to the growing radical center.

  5. Research work of radiation induced graft polymerization for synthesis and modification of polymer materials in CRICI

    Energy Technology Data Exchange (ETDEWEB)

    Hu Fumin; Ma Xueming [Chenguan Research Institute of Chemical Industry, Chengdu (China)

    2000-03-01

    The direct and post radiation induced graft polymerization had been studied in CRICI (Chenguan Research Institute of Chemical Industry). The method consists of irradiation of various polymer substrates in the presence (or absence) of monomers in a liquid, saturated vapour or gaseous and non-saturated vapour. 1. Grafting of functional monomers. --- It is possible to divide the grafting into two main approaches for synthesis of functional polymer materials. The first is grafting of monomers attached required functional group such as unsaturated carboxylic acid (acrylic and methacrylic acid), unsaturated nitrogen containing (alkali) base (vinylpyridine), monomers with hydrophilic unionized and polar groups (acrylamide, N-vinylpyrrolidone glycidylmethacrylate) and so on. The second is grafting of monomers capable of continuing chemical modification after graft polymerization. This approach essentially expands synthetic possibility of RGP for preparing functional polymers. 2. The effect of some salts on aqueous solution graft polymerization. The grafting of AA or AAm onto PE by direct or post radiation method in the presence of Mohr's salt or cupric nitrate was studied in detail. 3. Radiation induced graft polymerization by gaseous phase of monomers. This method consists of irradiation or preirradiation of various polymer substrates in the presence (or absence for preirradiation) of monomer in a gaseous of nonsaturated vapour state. (J.P.N.)

  6. Research work of radiation induced graft polymerization for synthesis and modification of polymer materials in CRICI

    International Nuclear Information System (INIS)

    Hu Fumin; Ma Xueming

    2000-01-01

    The direct and post radiation induced graft polymerization had been studied in CRICI (Chenguan Research Institute of Chemical Industry). The method consists of irradiation of various polymer substrates in the presence (or absence) of monomers in a liquid, saturated vapour or gaseous and non-saturated vapour. 1. Grafting of functional monomers. --- It is possible to divide the grafting into two main approaches for synthesis of functional polymer materials. The first is grafting of monomers attached required functional group such as unsaturated carboxylic acid (acrylic and methacrylic acid), unsaturated nitrogen containing (alkali) base (vinylpyridine), monomers with hydrophilic unionized and polar groups (acrylamide, N-vinylpyrrolidone glycidylmethacrylate) and so on. The second is grafting of monomers capable of continuing chemical modification after graft polymerization. This approach essentially expands synthetic possibility of RGP for preparing functional polymers. 2. The effect of some salts on aqueous solution graft polymerization. The grafting of AA or AAm onto PE by direct or post radiation method in the presence of Mohr's salt or cupric nitrate was studied in detail. 3. Radiation induced graft polymerization by gaseous phase of monomers. This method consists of irradiation or preirradiation of various polymer substrates in the presence (or absence for preirradiation) of monomer in a gaseous of nonsaturated vapour state. (J.P.N.)

  7. Kinetics and Mechanism of the Polymerization of Methyl Methacrylate in a Y(acac)3/n-BuMgCl System

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the kinetics equation proposed by T. Kagiya, the kinetic study on the polymerization of methyl methacrylate(MMA) by Y(acac)3/n-BuMgCl was carried out with a dilatometer. It was found that the rate of propagation is the first order with respect to the concentration of both active center and monomer. Thus, the equation of propagation rate can be described as Rp=Kp[c*][M]. In addition, the instantaneous chain initiation and single molecular termination were concluded for the present system. The activation energy is close to 32 kJ/mol. In the polymerization, n-BuMgCl acts not only as the cocatalyst, but also as chain transfer agent with cI=3.6×10-4.

  8. 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

  9. Precipitation Polymerization of Methyl Methacrylate by AGET ATRP%MMA的电子活化再生原子转移自由基沉淀聚合

    Institute of Scientific and Technical Information of China (English)

    张守成; 陈永平

    2013-01-01

    Precipitation polymerization of methyl methacrylate (MMA) by AGET ATRP, with cuprous chloride (CuCl2 · 2H2O)/ascorbic acid/PMDETA(C9 H23 N3) as catalyst, and initiated by ethyl bromoacetate in ethanol solution, was carried out. Molecular weight and molecular weight distribution were characterized by GPC. The results show that MMA can be rapidly polymerized with high monomer conversioa PMMA with relative narrow molecular weight distribution can be synthesized. Precipitation polymerization of methyl methacrylate (MMA) by AGET ATRP possesses characteristics of controlled/" living" radical polymerization.%以乙醇为溶剂,氯化铜(CuCl2·2H2O)为催化剂,抗坏血酸为还原剂,溴乙酸乙酯为引发剂,PMDETA为配体,进行了甲基丙烯酸甲酯(MMA)的电子活化再生原子转移自由基(AGET ATRP)沉淀聚合,通过GPC和称重法对聚合物进行表征.结果表明,在这种催化体系中甲基丙烯酸甲酯的转化速率较快,甲基丙烯酸甲酯的AGETATRP沉淀聚合得到了较好的实现,获得了分子量分布较窄的聚合物,并且沉淀聚合实现了产物与催化剂的分离.

  10. 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

  11. Shock-induced electrical activity in polymeric solids. A mechanically induced bond scission model

    International Nuclear Information System (INIS)

    Graham, R.A.

    1979-01-01

    When polymeric solids are subjected to high-pressure shock loading, two anomalous electrical phenomena, shock-induced conduction and shock-induced polarization, are observed. The present paper proposes a model of mechanically induced bond scission within the shock front to account for the effects. An experimental study of shock-induced polarization in poly(pyromellitimide) (Vespel SP-1) is reported for shock compressions from 17 to 23% (pressures from 2.5 to 5.4 GPa). Poly(pyromellitimide) is found to be a strong generator of such polarization and the polarization is found to reflect an irreversible or highly hysteretic process. The present measurements are combined with prior measurements to establish a correlation between monomer structure and strength of shock-induced polarization; feeble signals are observed in the simpler monomer repeat units of poly(tetrafluoroethylene) and polyethylene while the strongest signals are observed in more complex monomers of poly(methyl methacrylate) and poly(pyromellitimide). It is also noted that there is an apparent correlation between shock-induced conduction and shock-induced polarization. Such shock-induced electrical activity is also found to be well correlated with the propensity for mechanical bond scission observed in experiments carried out in conventional mechanochemical studies. The bond scission model can account for characteristics observed for electrical activity in shock-loaded polymers and their correlation to monomer structure. Localization of elastic energy within the monomer repeat unit or along the main chain leads to the different propensities for bond scission and resulting shock-induced electrical activity

  12. 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)

  13. 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.

  14. 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

  15. POLYMERIZATION OF METHYL METHACRYLATE WITH ETHYLENE BRIDGED HETERODINUCLEAR METALLOCENE OF SAMARIUM AND TITANIUM-STUDY ON SYNERGISM AND KINETICS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Comparison of MMA polymerization results with samarocene chloride, titanocene chloride and the title heterodinuclear (Sm-Ti) catalyst, respectively, showed synergism in the Sm-Ligand-Ti system, which ob viously influenced the polymerization behaviors, for example, of yielding higher activity and higher molecular weight polymer. Kinetic studies on polymerization of MMA with ethylene bridged samarocene and titanocene chloride/M(i-Bu) 3 showed that the polymerization rate was first-order on the catalyst concentration, and 1.9- order on the monomer. The overall activation energy measured was 52.8 kJ/mol.

  16. 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.

  17. Pressure-induced polymerization in substituted acetylenes

    Energy Technology Data Exchange (ETDEWEB)

    Chellappa, Raja S.; Dattelbaum, Dana M.; Sheffield, Stephen; Robbins, David (LANL)

    2012-04-10

    A fundamental understanding of shock-induced chemical reactions in organics is still lacking and there are limited studies devoted to determining reaction mechanisms, evolution of bonding, and effect of functional group substitutions. The fast timescale of reactions occurring during shock compression create significant experimental challenges (diagnostics) to fully quantify the mechanisms involved. Static compression combined with temperature provides a complementary route to investigate the equilibrium phase space and metastable intermediates under extreme P-T conditions. In this study, we present our results from our ongoing high pressure in situ synchrotron x-ray diffraction experiments on substituted acetylenes: tert-butyl acetylene [TBA: (CH{sub 3}){sub 3}-C=CH] and ethynyl trimethylsilane [ETMS: (CH{sub 3}){sub 3}-SiC=CH]. We observed that the onset pressure of chemical reactions (at room temperature) in these compounds is higher under static compression (TBA: 12 GPa and ETMS: 17.6 GPa) when compared to shock input pressures (TBA: 6.1 GPa and ETMS: 6.6 GPa). At elevated temperatures, reactivity was observed to occur at pressures comparable to shock conditions. The products were polymeric in nature, recovered to ambient conditions with little degradation.

  18. 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.

  19. Synthesis of New Silicon-linked Lanthanocene Complexes and Their High Catalytic Activity for Methyl Methacrylate Polymerization with Nanometric Sodium Hydride as Co-catalyst

    Institute of Scientific and Technical Information of China (English)

    谢小敏; 黄吉玲

    2005-01-01

    The synthesis and characterization of four new silicon-linked lanthanocene complexes with pendant phenyl groups on cyclopentadiene were reported. Based on the data of elemental analyses, MS and IR, the complexes were presumed to be unsolvated and dimeric complexes [Me2Si(C5H3CMe2C6H5)2LnC1]2 [Ln=Er (1), Gd (2), Sm (3), Dy (4)]. In conjunction with AlEt3 or sodium hydride as the co-catalyst, these complexes could efficiently catalyze the polymerization of methyl methacrylate (MMA). When the nanometric sodium hydride was used as a co-catalyst, the complexes were highly effective for the polymerization of MMA. At low temperature and in short time, in [MeESi(C5H3CMe2C6H5)2LnC1]2/NaH (nanometric) system, the polymer was obtained in more than 80% yield and the molecular weight was greater than 105. The activity reached that of organolanthanide hydride as a single-component catalyst. In ]MeESi(C5H3CMe2C6H5)2ErC1]2/Nail (nanometric) system, the effects of the molar ratio of MMA/catalyst and catalyst/co-catalyst, and the temperature on polymerization were studied.

  20. Polymethyl methacrylate-co-methacrylic acid coatings with controllable concentration of surface carboxyl groups: A novel approach in fabrication of polymeric platforms for potential bio-diagnostic devices

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, Samira; Ibrahim, Fatimah [Center for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Djordjevic, Ivan, E-mail: ivan.djordjevic@um.edu.my [Center for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Koole, Leo H. [Center for Innovation in Medical Engineering, Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Biomedical Engineering, Faculty of Health. Medicine and Life Science, Maastricht University, PO Box 616, NL 6200 MD Maastricht (Netherlands)

    2014-05-01

    Highlights: • Synthesis and processing of PMMA-co-MAA spin-coatings on silicon wafers. • Surface chemistry and morphology as a function of tailored co-polymer structure. • Polymer coatings with controlled number of surface carboxyl groups. - Abstract: The generally accepted strategy in development of bio-diagnostic devices is to immobilize proteins on polymeric surfaces as a part of detection process for diseases and viruses through antibody/antigen coupling. In that perspective, polymer surface properties such as concentration of functional groups must be closely controlled in order to preserve the protein activity. In order to improve the surface characteristics of transparent polymethacrylate plastics that are used for diagnostic devices, we have developed an effective fabrication procedure of polymethylmetacrylate-co-metacrylic acid (PMMA-co-MAA) coatings with controlled number of surface carboxyl groups. The polymers were processed effectively with the spin-coating technique and the detailed control over surface properties is here by demonstrated through the variation of a single synthesis reaction parameter. The chemical structure of synthesized and processed co-polymers has been investigated with nuclear magnetic resonance spectroscopy (NMR) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-ToF-MS). The surface morphology of polymer coatings have been analyzed with atomic force microscopy (AFM) and scanning electron microscopy (SEM). We demonstrate that the surface morphology and the concentration of surface –COOH groups (determined with UV–vis surface titration) on the processed PMMA-co-MAA coatings can be precisely controlled by variation of initial molar ratio of reactants in the free-radical polymerization reaction. The wettability of developed polymer surfaces also varies with macromolecular structure.

  1. Polymethyl methacrylate-co-methacrylic acid coatings with controllable concentration of surface carboxyl groups: A novel approach in fabrication of polymeric platforms for potential bio-diagnostic devices

    International Nuclear Information System (INIS)

    Hosseini, Samira; Ibrahim, Fatimah; Djordjevic, Ivan; Koole, Leo H.

    2014-01-01

    Highlights: • Synthesis and processing of PMMA-co-MAA spin-coatings on silicon wafers. • Surface chemistry and morphology as a function of tailored co-polymer structure. • Polymer coatings with controlled number of surface carboxyl groups. - Abstract: The generally accepted strategy in development of bio-diagnostic devices is to immobilize proteins on polymeric surfaces as a part of detection process for diseases and viruses through antibody/antigen coupling. In that perspective, polymer surface properties such as concentration of functional groups must be closely controlled in order to preserve the protein activity. In order to improve the surface characteristics of transparent polymethacrylate plastics that are used for diagnostic devices, we have developed an effective fabrication procedure of polymethylmetacrylate-co-metacrylic acid (PMMA-co-MAA) coatings with controlled number of surface carboxyl groups. The polymers were processed effectively with the spin-coating technique and the detailed control over surface properties is here by demonstrated through the variation of a single synthesis reaction parameter. The chemical structure of synthesized and processed co-polymers has been investigated with nuclear magnetic resonance spectroscopy (NMR) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-ToF-MS). The surface morphology of polymer coatings have been analyzed with atomic force microscopy (AFM) and scanning electron microscopy (SEM). We demonstrate that the surface morphology and the concentration of surface –COOH groups (determined with UV–vis surface titration) on the processed PMMA-co-MAA coatings can be precisely controlled by variation of initial molar ratio of reactants in the free-radical polymerization reaction. The wettability of developed polymer surfaces also varies with macromolecular structure

  2. Swelling-induced optical anisotropy of thermoresponsive hydrogels based on poly(2-(2-methoxyethoxy)ethyl methacrylate): deswelling kinetics probed by quantitative Mueller matrix polarimetry.

    Science.gov (United States)

    Patil, Nagaraj; Soni, Jalpa; Ghosh, Nirmalya; De, Priyadarsi

    2012-11-29

    Thermodynamically favored polymer-water interactions below the lower critical solution temperature (LCST) caused swelling-induced optical anisotropy (linear retardance) of thermoresponsive hydrogels based on poly(2-(2-methoxyethoxy)ethyl methacrylate). This was exploited to study the macroscopic deswelling kinetics quantitatively by a generalized polarimetry analysis method, based on measurement of the Mueller matrix and its subsequent inverse analysis via the polar decomposition approach. The derived medium polarization parameters, namely, linear retardance (δ), diattenuation (d), and depolarization coefficient (Δ), of the hydrogels showed interesting differences between the gels prepared by conventional free radical polymerization (FRP) and reversible addition-fragmentation chain transfer polymerization (RAFT) and also between dry and swollen state. The effect of temperature, cross-linking density, and polymerization technique employed to synthesize hydrogel on deswelling kinetics was systematically studied via conventional gravimetry and corroborated further with the corresponding Mueller matrix derived quantitative polarimetry characteristics (δ, d, and Δ). The RAFT gels exhibited higher swelling ratio and swelling-induced optical anisotropy compared to FRP gels and also deswelled faster at 30 °C. On the contrary, at 45 °C, deswelling was significantly retarded for the RAFT gels due to formation of a skin layer, which was confirmed and quantified via the enhanced diattenuation and depolarization parameters.

  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(allyl methacrylate) functionalized hydroxyapatite nanocrystals via the combination of surface-initiated RAFT polymerization and thiol-ene protocol: a potential anticancer drug nanocarrier.

    Science.gov (United States)

    Bach, Long Giang; Islam, Md Rafiqul; Vo, Thanh-Sang; Kim, Se-Kwon; Lim, Kwon Taek

    2013-03-15

    Hydroxyapatite nanocrystals (HAP NCs) were encapsulated by poly(allyl methacrylate) (PolyAMA) employing controlled surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization of allyl methacrylate to afford HAP-PolyAMA nanohybrids. The subsequent thiol-ene coupling of nanohybrids with 2-mercaptosuccinic acid resulted HAP-Poly(AMA-COOH) possessing multicarboxyl group. The formation of the nanohybrids was confirmed by FT-IR and EDS analyses. The TGA and FE-SEM investigation were further suggested the grafting of PolyAMA onto HAP NCs. The utility of the HAP-PolyAMA nanohybrid as drug carrier was also explored. The pendant carboxyl groups on the external layers of nanohybrids were conjugated with anticancer drug cisplatin to afford HAP-Poly(AMA-COOH)/Pt complex. The formation of the complex was confirmed by FT-IR, XPS, and FE-SEM. In vitro evaluation of the synthesized complex as nanomedicine revealed its potential chemotherapeutic efficacy against cancer cell lines. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. 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.

  6. Photocatalytic polymerization induced by a transparent anatase titania aqueous sol and fabrication of polymer composites

    Directory of Open Access Journals (Sweden)

    2010-06-01

    Full Text Available The surface modification of the anatase titania nanoparticles prepared via a controlled nonhydrolytic sol-gel process is achieved by the formation of the bidentate coordination between titania and methacrylic acid (MAA molecules. The in situ photocatalytic polymerization of methyl methacrylate (MMA monomer is initiated by surface modified anatase titania nanoparticles under Xe lamp irradiation. A variety of techniques including differential scanning calorimetry (DSC, thermo-gravimetric analysis (TGA and scanning electron microscopy (SEM are employed to characterize the resulting materials. The glass transition temperatures and the thermal stabilities of polymethyl methacrylate (PMMA composite materials prepared via photocatalytic polymerization are enhanced compared with pure polymer. The partial aggregation of titania nanoparticles in PMMA composite films is derived from the surface polymerization of MMA, which makes the inorganic particles hydrophobic and drives them to the water/oil interfaces.

  7. Co-polymerization of methyl methacrylate and styrene via surfactant-free emulsion polymerization, as a potential material for photonic crystal application

    Science.gov (United States)

    Kassim, Syara; Zahari, Siti Balqis; Tahrin, Rabiatul Addawiyah Azwa; Harun, Noor Aniza

    2017-09-01

    Photonic crystals are being the great interest of researcher to studies due to a variety of potential application for the interaction of light including the solar cells, optical sensors and paints. In order to evaluate the fabrication of photonic crystals thin film, a free-emulsifier emulsion copolymerization of styrene and methyl methacrylate was carried out. By using the self -assembly approach, this method offers the opportunity to produce crystalline polymer sphere in more ease operation, low cost and environmental friendly. The influences of the mixing ratio of monomer and amount of initiators were studied. In advance, the presence of styrene as co-monomer had improved the thermal degradation of polymer methyl methacrylate. While in changing the mixing ratio of styrene and methyl methacrylate resulted in particle size of the sphere. The size of polymer particles slightly increased on increasing volume of styrene monomer ratio. This occurred because the properties of styrene in water where it sparingly soluble and lead to coagulation of particles. This simple, yet effective method for preparing functional complex 3D structures has the potential to be used generically to fabricate a variety of functional porous 3D structures that could find application not only in new or improved photonic crystal (PC) devices but also in areas such as catalysis, solar cell, separation, fuel cells technology, microelectronics and optoelectronics.

  8. Radiation-induced polymerization and radiation effect on polymers

    International Nuclear Information System (INIS)

    Seguchi, Tadao

    1977-12-01

    The processes of radiation-induced polymerization of monomers and also radiation effects on polymers have been studied by instrumental analyses of electron spin resonance (ESR), nuclear magnetic resonance (NMR) and electron microscopy. In radiation-induced polymerization, graft-copolymerization and absorbed state polymerization were taken up. For graft-copolymerization, monomers such as methylmethacrylate and butadiene were made to react with irradiated polyethylene, and behaviors of the initiating radicals and propagating radicals were followed under the reaction by ESR. For absorbed state polymerization, acrylonitrile/zeolite and methylmethacrylate/zeolite were chosen. Absorbed monomers were irradiated at 77 0 K and polymerized at room temperature. Active species and the concentrations were measured by ESR and the yields of polymer were observed by NMR. In radiation effect on polymers, polyvinylfluoride, polyvinylidenfluoride and polytetrafluoroethylene were taken up. Active species trapped in the polymer matrixes were identified and decay and reactivity of the species were also studied. On the basis of information from the electron microscopy and x-ray analysis, radiation effects on these polymers are described. In polytetrafluoroethylene produced by radiation polymerization, the relation between morphology and polymerization conditions and also the process of crystallization during polymerization were studied. (auth.)

  9. 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.

  10. 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.

  11. Immobilization of enzymes by radiation-induced polymerization of glass-forming monomers

    International Nuclear Information System (INIS)

    Yoshida, M.; Kumakura, M.; Kaetsu, I.

    1979-01-01

    The effect of cooling rate of a monomeric system on the porosity and activity of an immobilized enzyme prepared by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperatures has been studied. Slow cooling gave the same effect on porosity of the polymer as decreasing the monomer concentration. A glass-forming solvent such as diethylene glycol was added to water to study the effect of the supercooling tendency of the solvent. Addition of diethylene glycol decreased porosity and also enzymic activity. Water was replaced by the miscible solvent p-dioxane and the immiscible solvent n-decane in order to clarify the effect of solvent. p-Dioxane had a similar effect to water on the relation between the monomer concentration, porosity and activity. On the other hand, polymer prepared from the system containing n-decane showed different immobilization properties owing to the presence of independent pores in the matrix. (author)

  12. Radical-Scavenging Activity of Thiols, Thiobarbituric Acid Derivatives and Phenolic Antioxidants Determined Using the Induction Period Method for Radical Polymerization of Methyl Methacrylate

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2012-04-01

    Full Text Available The radical-scavenging activities of two thiols, eight (thiobarbituric acid derivatives and six chain-breaking phenolic antioxidants were investigated using the induction period method for polymerization of methyl methacrylate (MMA initiated by thermal decomposition of 2,2’-azobisisobutyronitrile (AIBN and monitored by differential scanning calorimetry (DSC. The induction period (IP for the thiols 2-mercaptoethanol (ME and 2-mercapto-1-methylimidazole (MMI was about half that for phenolic antioxidants. Except for the potent inhibitor 5,5-dimethyl-2-thiobarbituric acid (3, the IP for thiobarbituric acid derivatives was about one tenth of that for phenolic antioxidants. The IP for 1,3,5-trimethyl-2-thiobarbituric acid (1 and 5-allyl-1, 3-dimethyl-2-thiobarbituric acid (7 was less than that of the control, possibly due to inhibition by a small amount of atmospheric oxygen in the DSC container. The ratio of the chain inhibition to that of chain propagation (CI/CP for the thiols and thiobarbituric acid compounds except for 1, 3 and 7 was about 10 times greater or greater than that for phenolic compounds. A kinetic chain length (KCL about 10% greater than that of the control was observed for 1, suggesting that 1 had chain transfer reactivity in the polymerization of MMA. The average molecular weight of polymers formed from thiobarbituric acid derivatives is discussed.

  13. The synthesis of poly(vinylphosphonic acid-co-methacrylic acid) microbeads by suspension polymerization and the characterization of their indium adsorption properties

    International Nuclear Information System (INIS)

    Kwak, Noh-Seok; Baek, Youngmin; Hwang, Taek Sung

    2012-01-01

    Highlights: ► Microbeads were synthesized by suspension polymerization based on VPA, MAA and PEGDA. ► The best preparation condition was determined from the yield, water uptake and IEC. ► The adsorption isotherm of indium was fit to the Langmuir and Freundlich models. - Abstract: Poly(vinylphosphonic acid-co-methacrylic acid) microbeads were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The obtained microbeads were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The microbeads were wrinkled spheres, irrespective of the components, and their sizes ranged from 100 to 200 μm. The microbeads were thermally stable up to 260 °C. As the vinylphosphonic acid (VPA) content was increased, the synthetic yields and ion-exchange capacities decreased and the water uptakes increased. The optimum synthetic yield, ion-exchange capacity and water uptake were obtained at a 0.5 mol ratio of VPA. In addition, the maximum adsorption predicted by the Langmuir adsorption isotherm model was greatest at a 0.5 mol ratio of VPA.

  14. The synthesis of poly(vinylphosphonic acid-co-methacrylic acid) microbeads by suspension polymerization and the characterization of their indium adsorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Noh-Seok; Baek, Youngmin [Department of Applied Chemistry and Biological Engineering, Chungnam National University, 79 Daehangno, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Hwang, Taek Sung, E-mail: tshwang@cnu.ac.kr [Department of Applied Chemistry and Biological Engineering, Chungnam National University, 79 Daehangno, Yuseong-gu, Daejeon 305-764 (Korea, Republic of)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Microbeads were synthesized by suspension polymerization based on VPA, MAA and PEGDA. Black-Right-Pointing-Pointer The best preparation condition was determined from the yield, water uptake and IEC. Black-Right-Pointing-Pointer The adsorption isotherm of indium was fit to the Langmuir and Freundlich models. - Abstract: Poly(vinylphosphonic acid-co-methacrylic acid) microbeads were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The obtained microbeads were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The microbeads were wrinkled spheres, irrespective of the components, and their sizes ranged from 100 to 200 {mu}m. The microbeads were thermally stable up to 260 Degree-Sign C. As the vinylphosphonic acid (VPA) content was increased, the synthetic yields and ion-exchange capacities decreased and the water uptakes increased. The optimum synthetic yield, ion-exchange capacity and water uptake were obtained at a 0.5 mol ratio of VPA. In addition, the maximum adsorption predicted by the Langmuir adsorption isotherm model was greatest at a 0.5 mol ratio of VPA.

  15. Preparation of high-capacity, weak anion-exchange membranes by surface-initiated atom transfer radical polymerization of poly(glycidyl methacrylate) and subsequent derivatization with diethylamine

    International Nuclear Information System (INIS)

    Qian, Xiaolei; Fan, Hua; Wang, Chaozhan; Wei, Yinmao

    2013-01-01

    Ion-exchange membrane is of importance for the development of membrane chromatography. In this work, a high-capacity anion-exchange membrane was prepared by grafting of glycidyl methacrylate (GMA) onto the surface of regenerated cellulose (RC) membranes via surface-initiated atom transfer radical polymerization (SI-ATRP) and subsequent derivatization with diethylamine. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to characterize changes in the chemical functionality, surface topography and pore morphology of the modified membranes. The static capacity of the prepared anion-exchange membrane was evaluated with bovine serum albumin (BSA) as a model protein. The results indicated that the anion-exchange membrane which could reach a maximum capacity of 96 mg/mL for static adsorption possesses a higher adsorption capacity, and the adsorption capacity increases with the polymerization time. The effect of pH and salt concentration confirmed that the adsorption of BSA followed ion-exchange mechanism. The established method would have potential application in the preparation of anion-exchange membrane.

  16. 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.

  17. 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)

  18. Synthesis of defined polyhedral oligosilsesquioxane-containing diblock and triblock methacrylate copolymers by atom transfer radical polymerization

    Czech Academy of Sciences Publication Activity Database

    Janata, Miroslav; Sikora, Antonín; Látalová, Petra; Čadová, Eva; Raus, Vladimír; Matějka, Libor; Vlček, Petr

    2013-01-01

    Roč. 128, č. 6 (2013), s. 4294-4301 ISSN 0021-8995 R&D Projects: GA ČR GAP106/12/0844; GA ČR GAP108/12/1459 Institutional support: RVO:61389013 Keywords : copolymers * nanostructured polymers * radical polymerization Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.640, year: 2013

  19. Radiation-induced polymerization of hydrogen cyanide

    International Nuclear Information System (INIS)

    Mozhaev, P.S.; Kichigina, G.A.; Kiryukhin, D.P.

    1995-01-01

    The chain reaction of HCN polymerization in a γ-radiation field does not occur at 77 K. When irradiated HCN is warmed up to ambient temperature, a polymer is formed. The heat of polymerization of HCN is 44.0±6.0 kJ/mol and the polymer yield reaches 2.5% for a dose of 725 kGy. Amorphous polymer products (with yields increasing up to 33.5%) and needle crystals (presumably HCN tetramer) are formed upon storage of irradiated HCN at room temperature. The polymer is stable below 700 K, has a conductivity of 3x10 -5 Ω -1 cm -f1 , and displays an EPR spectrum typical of polyconjugated systems. A radical mechanism of the formation of conjugated chain -C=N-C=N- is suggested. The tetramer is produced by a combination of aminocyanocarbene biradicals

  20. Poly(methacrylic acid-ran-2-vinylpyridine Statistical Copolymer and Derived Dual pH-Temperature Responsive Block Copolymers by Nitroxide-Mediated Polymerization

    Directory of Open Access Journals (Sweden)

    Milan Marić

    2017-02-01

    Full Text Available Nitroxide-mediated polymerization using the succinimidyl ester functional unimolecular alkoxyamine initiator (NHS-BlocBuilder was used to first copolymerize tert-butyl methacrylate/2-vinylpyridine (tBMA/2VP with low dispersity (Đ = 1.30–1.41 and controlled growth (linear number average molecular Mn versus conversion, Mn = 3.8–10.4 kg·mol−1 across a wide composition of ranges (initial mol fraction 2VP, f2VP,0 = 0.10–0.90. The resulting statistical copolymers were first de-protected to give statistical polyampholytic copolymers comprised of methacrylic acid/2VP (MAA/2VP units. These copolymers exhibited tunable water-solubility due to the different pKas of the acidic MAA and basic 2VP units; being soluble at very low pH < 3 and high pH > 8. One of the tBMA/2VP copolymers was used as a macroinitiator for a 4-acryloylmorpholine/4-acryloylpiperidine (4AM/4AP mixture, to provide a second block with thermo-responsive behavior with tunable cloud point temperature (CPT, depending on the ratio of 4AM:4AP. Dynamic light scattering of the block copolymer at various pHs (3, 7 and 10 as a function of temperature indicated a rapid increase in particle size >2000 nm at 22–27 °C, corresponding to the 4AM/4AP segment’s thermos-responsiveness followed by a leveling in particle size to about 500 nm at higher temperatures.

  1. 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.

  2. 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

  3. Reverse atom transfer radical polymerization of methyl methacrylate initiated by AIBN/FeCl3/isophthalic acid system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The reverse ATRP of MMA using AIBN/FeCl3/ isophthalic acid as the initiating system was successfully performed. The new initiating system can be used to synthesize PMMA with high molecular weight and narrow polydis- persity index. The polymerization shows 'living'/controlled characteristics. Compared with other initiating system used in reverse ATRP, the easy availability and non-toxicity of isophthalic acid make it very attractive.

  4. Microfluidic Fabrication of Morphology-Controlled Polymeric Microspheres of Blends of Poly(4-butyltriphenylamine and Poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Saki Yoshida

    2018-04-01

    Full Text Available Multicomponent polymer particles with specific morphology are promising materials exhibiting novel functionality which cannot be obtained with single-component polymer particles. Particularly, the preparation of such kinds of polymer particles involving electrically or optically active conjugated polymers with uniform size is a challenging subject due to their intense demands. Here, microspheres of binary polymer blend consisting of poly(4-butyltriphenylamine (PBTPA/poly(methyl methacrylate (PMMA (1:1 in weight were produced via a microfluidic emulsification with a Y-shaped microreactor, and a subsequent solvent evaporation method. The flow rate of the dispersed phase (polymer solution was fixed to 7 µL/min, and 140 or 700 µL/min of the flow rate of the continuous phase (aqueous 0.6 wt % of poly(vinyl alcohol (PVA solution was utilized to produce the dispersion with different diameter. The concentration of dispersed phase was adjusted to 0.1 or 1.0 w/v%. Core-shell, Janus and dumbbell type microspheres were obtained dependent on the flow rate of continuous phase. Incomplete core-shell type microspheres were produced for the blend involving low molecular weight PMMA. Complex Janus and core-shell type microspheres were fabricated by the addition of sodium dodecyl sulfate (SDS to continuous phase. It is found that final morphologies are strongly dependent on the initial conditions of dispersion including the particle size suggesting that the morphologies are governed by the kinetical factors together with the conventionally accepted thermodynamic ones.

  5. 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.

  6. Surface-Initiated Atom Transfer Radical Polymerization of Magnetite Nanoparticles with Statistical Poly(tert-butyl acrylate-poly(poly(ethylene glycol methyl ether methacrylate Copolymers

    Directory of Open Access Journals (Sweden)

    Patcharin Kanhakeaw

    2015-01-01

    Full Text Available This work presented the surface modification of magnetite nanoparticle (MNP with poly[(t-butyl acrylate-stat-(poly(ethylene glycol methyl ether methacrylate] copolymers (P[(t-BA-stat-PEGMA] via a surface-initiated “grafting from” atom transfer radical polymerization (ATRP. Loading molar ratio of t-BA to PEGMA was systematically varied (100 : 0, 75 : 25, 50 : 50, and 25 : 75, resp. such that the degree of hydrophilicity of the copolymers, affecting the particle dispersibility in water, can be fine-tuned. The reaction progress in each step of the synthesis was monitored via Fourier transform infrared spectroscopy (FTIR. The studies in the reaction kinetics indicated that PEGMA had higher reactivity than that of t-BA in the copolymerizations. Gel permeation chromatography (GPC indicated that the molecular weights of the copolymers increased with the increase of the monomer conversion. Transmission electron microscopy (TEM revealed that the particles were spherical with averaged size of 8.1 nm in diameter. Dispersibility of the particles in water was apparently improved when the copolymers were coated as compared to P(t-BA homopolymer coating. The percentages of MNP and the copolymer in the composites were determined via thermogravimetric analysis (TGA and their magnetic properties were investigated via vibrating sample magnetometry (VSM.

  7. 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.

  8. Shear-induced transitions in a ternary polymeric system

    NARCIS (Netherlands)

    Zvelindovsky, AV; Sevink, GJA; Fraaije, JGEM

    The first three-dimensional simulation of shear-induced phase transitions in a polymeric system has been performed. The method is based on dynamic density-functional theory. The pathways between a bicontinuous phase with developing gyroid mesostructure and a lamellar/cylinder phase coexistence are

  9. Immobilization of yeast cells by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Fujimura, T.; Kaetsu, I.

    1982-01-01

    Radiation-induced polymerization method was applied to the immobilization of yeast cells. The effects of irradiation, cooling and monomer, which are neccessary for polymerization, were recovered completely by subsequent aerobical incubation of yeast cells. The ethanol productive in immobilized yeast cells increased with the increase of aerobical incubation period. The growth of yeast cells in immobilized yeast cells was indicated. The maximum ethanol productivity in immobilized yeast cell system was around three times as much as that in free yeast cell system. (orig.)

  10. Effect of homopolymer in polymerization-induced microphase separation process

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jongmin; Saba, Stacey A.; Hillmyer, Marc A.; Kang, Dong-Chang; Seo, Myungeun (IBS-Korea); (KAIST); (UMMN)

    2017-09-01

    We report on the phase separation behaviors of polymerization mixtures containing a polylactide macro-chain transfer agent (PLA-CTA), styrene, divinylbenzene, hydroxyl-terminated PLA (PLA-OH), and a molecular chain transfer agent which enable the ability to tune the pore size of a cross-linked polymer monolith in a facile manner. Cross-linked monoliths were produced from the mixtures via reversible addition-fragmentation chain transfer (RAFT) polymerization and converted into cross-linked porous polymers by selective removal of PLA while retaining the parent morphology. We demonstrate that pore sizes are tunable over a wide range of length scales from the meso- to macroporous regimes by adjusting the ratio of PLA-CTA to PLA-OH in the reaction mixture which causes the phase separation mechanism to change from polymerization-induced microphase separation to polymerization-induced phase separation. The possibility of increasing porosity and inducing simultaneous micro- and macrophase separation was also realized by adjustments in the molar mass of PLA which enabled the synthesis of hierarchically meso- and macroporous polymers.

  11. 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.

  12. Preparation and self-assembly behavior of polystyrene-block-poly (dimethylaminoethyl methacrylate amphiphilic block copolymer using atom transfer radical polymerization

    Directory of Open Access Journals (Sweden)

    2008-03-01

    Full Text Available Asymmetric and semi-symmetric amphiphilic diblock copolymers polystyrene-block-poly (dimethylaminoethyl methacrylate (PS-b-PDMAEMA with the same PS block length of 62 repeat units and quite short (3 repeat units or equivalent (47 repeat units length of PDMAEMA have been prepared simply by varying the ratio of the bromine-terminated macroinitiator polystyrene (PS-Br to DMAEMA using atom transfer radical polymerization (ATRP. The chemical structures and compositions of the PS-b-PDMAEMA block copolymers are studied by nuclear magnetic resonance (NMR spectroscopy, gel permeation chromatography (GPC, and elementary analysis (EA. The self-assembly behaviors of copolymers in N,N-dimethyl formamide (DMF with different pH and dioxane/water binary solvent mixture by direct dissolution method (DD, are studied by transmission electron microscopy (TEM, electron diffracting analysis (EDA, and energy-dispersive analysis of X-rays (EDAX techniques. Transmission electron microscopy results suggest that asymmetric block copolymer PS62-b-PDMAEMA3 (the numbers in the form of footnotes represent repeated units of each monomer in the copolymer can form spherical core-shell micelles, large compound reverse micelles (LCRMs, hexagonal/rhombic phases, reverse hexagonal/rhombic phases, vesicles, reverse vesicles and necklace-like reverse micelles, controlled by common or selective solvent and pH, while most of the aggregates of semi-symmetric PS62-b-PDMAEMA47 are simply spherical, such as spherical core-shell micelles and reverse spherical core-shell micelles, besides hexagonal/rhombic phases. All above structures are controlled by three components of the free energy of aggregation: core-chain stretching, interfacial energy and intercoronal chain interaction.

  13. 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.

  14. Cytotoxicity and cytokine expression induced by silorane and methacrylate-based composite resins.

    Science.gov (United States)

    Longo, Daniele Lucca; Paula-Silva, Francisco Wanderley Garcia; Faccioli, Lucia Helena; Gatón-Hernández, Patrícia Maria; Queiroz, Alexandra Mussolino de; Silva, Léa Assed Bezerra da

    2016-01-01

    The aim of this study was to evaluate cytotoxicity and cytokine production induced by light-cured or non-light-cured methacrylate-based and silorane composite resins in RAW 264.7 macrophages. Cells were stimulated with the extracts from light-cured or non-light-cured composite resins. After incubation for 24 h, cytotoxicity was assessed with the lactate dehydrogenase (LDH) and methyl thiazolyl tetrazolium (MTT) assays, and total protein was quantified using the Lowry method. TNF-α detection was examined with an enzyme-linked immunosorbent assay (ELISA) conducted with cell supernatants after cell stimulation for 6, 12, and 24 h. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's post hoc test (α=0.05). KaloreTM and FiltekTM Silorane were cytotoxic with or without light curing (p0.05). However, after 24 h FiltekTM Silorane inhibited the production of TNF-α (p<0.05). KaloreTM and FiltekTM Silorane were cytotoxic regardless of light curing. The extract obtained from KaloreTM after 15 days of incubation stimulated the production of TNF-α, unlike that obtained from FiltekTM Silorane.

  15. Immobilized glucose oxidase by radiation induced polymerization of HEMA at low temperature

    International Nuclear Information System (INIS)

    Cao Jin; Su Zongxian

    1988-01-01

    The immobilized glucose oxidase (GOD) by 60 Co-γ induced polymerization of hydroxyethyl methacrylate (HEMA) at -78 deg C was studied. From the experiment results, it was found that the irradation dose until 1 x 10 4 Gy had not a significant effect on the native GOD activity. When the carrier (HEMA) concentration was 50% and the entrapped amount was 1.0 ml GOD/10 ml phosphoric acid buffer solution, the immobilized GOD had not only elastic, but also had high remaining activity. The native GOD was less sensitive to pH value than the immobilized GOD, but both the proper pH values didn't change. The kinetic reaction results showed, Michaelis constant k'm=1.42 x 10 -2 mol (native GOD km=1.0 x 10 -2 mol). This value indicated that diffuse velocity of substitue was restricted. The activation energies of the immobilized GOD were found to be 13.7kJ/mol

  16. Ring-opening metathesis polymerization based pore-size-selective functionalization of glycidyl methacrylate based monolithic media: access to size-stable nanoparticles for ligand-free metal catalysis.

    Science.gov (United States)

    Bandari, Rajendar; Höche, Thomas; Prager, Andrea; Dirnberger, Klaus; Buchmeiser, Michael R

    2010-04-19

    Monolithic polymeric supports have been prepared by electron-beam-triggered free-radical polymerization using a mixture of glycidyl methacrylate and trimethylolpropane triacrylate in 2-propanol, 1-dodecanol, and toluene. Under appropriate conditions, phase separation occurred, which resulted in the formation of a porous monolithic matrix that was characterized by large (convective) pores in the 30 μm range as well as pores of 7 nm were hydrolyzed by using poly(styrenesulfonic acid) (Mw = 69,400 g mol(-1), PDI=2.4). The remaining epoxy groups inside pores of nanoparticles 2 nm in diameter were formed. The palladium-nanoparticle-loaded monoliths were used in both Heck- and Suzuki-type coupling reactions achieving turnover numbers of up to 167,000 and 63,000, respectively. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. 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.

  18. Production and installation of equipments for radiation-induced graft polymerization in liquid phase and dipping techniques

    International Nuclear Information System (INIS)

    Seko, Noriaki; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu

    2005-01-01

    Fibrous adsorbent which is synthesized by radiation induced graft polymerization on the trunk polymers such as polymer nonwoven fabrics and woven cloths exhibits an excellent selective adsorption against heavy metal ions and toxic gases at extremely low concentrations. Two equipments were installed to synthesize the metal-ion and gas adsorbents by means of the radiation-induced graft polymerization in the liquid phase and the dipping, respectively. In the reation chamber of the liquid phase reactor, the oxygen decreased to 100 ppm. The inside temperature was elevated at 80C. These characteristics satisfied the specification. The fabric transport can regulate the rate in the range from 1 to 10 m/min. The reactor for the dip grafting could reduce the inside oxygen to 100ppm and inside temperature could reach to 80C, also. The transport system is stable during the dip grafting reaction. The grafting of glycidyl methacrylate was carried out as a characteristic test. The degree of grafting was controlled in the range of 40-70%. The both equipments can graft the trunk polymer, 2000mm in maximum width and 1m in maximum diameter. This size is enough for confirmation practical scale synthesis. (author)

  19. 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.

  20. The effect of ethanol on the γ radiation induced polymerization of styrene

    International Nuclear Information System (INIS)

    Zhang Xujia; Ha Hongfei; Wu Jilan

    1990-01-01

    The γ radiation induced polymerization of styrene in the presence of ethanol was studied at dose rate of 5 x 10 17 eV/ml min. The result showed that the radiation induced polymerization of styrene was sensitized by ethanol. The experimental results were in agreement with the theoretical calculation of WAS equation. The mechanism of sensitization was proposed as proton transfer reaction

  1. 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)

  2. Controlled release of biofunctional substances by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Yoshida, M.; Kumakura, M.; Kaetsu, I.

    1978-01-01

    The controlled release of potassium chloride from flat circular matrices made by radiation-induced polymerization of a glass-forming monomer at low temperatures has been studied. The water-particle phase content formed in a poly(diethylene glycol dimethacrylate) matrix was controlled by the addition of polyethylene glycol 600. The dispersed water-particle phase content in the matrix was estimated directly and by scanning electron microscopic observations. The release of potassium chloride from the matrix increased linearly with the square root of time. The water content of the matrix had an important effect on the release rate which increases roughly in proportion to water content. This effect can be attributed to the apparent increase of the rate of drug diffusion. (author)

  3. Controlled release of biofunctional substances by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Yoshida, M.; Kumakura, M.; Kaetsu, I.

    1978-01-01

    The release behaviour of a drug from flat circular capsules obtained by radiation-induced polymerization at low temperatures and with different hydrophilic properties has been studied. The effect of various factors on release property was investigated. The release process could be divided into three parts, an initial quick release stage, stationary state release stage and a retarded release stage. Release behaviour in the stationary state was examined using Noyes-Whitney and Higuchi equations. It was shown that the hydrophilic property of polymer matrix expressed by water content was the most important effect on diffusion and release rate. Rigidity of the polymer may also affect diffusivity. The first quick release step could be attributed to rapid dissolution of drug in the matrix surface due to polymer swelling. (author)

  4. Functionalization of nanochannels by radio-induced grafting polymerization on PET track-etched membranes

    International Nuclear Information System (INIS)

    Soto Espinoza, S.L.; Arbeitman, C.R.; Clochard, M.C.; Grasselli, M.

    2014-01-01

    The application of swift-heavy ion bombardment to polymers is a well-established technique to manufacture micro- and nanopores onto polymeric films to obtain porous membranes. A few years ago, it was realized that, during ion bombardment, the high energy deposition along the ion path through the polymer reached cylindrical damage regions corresponding to the core trace and the penumbra. After the etching procedure, there are still enough active sites left in the penumbra that can be used to initiate a polymerization process selectively inside the membrane pores. In this study, we report the grafting polymerization of glycidyl methacrylate onto etched PET foils to obtain functionalized nanochannels. Grafted polymers were labeled with a fluorescent tag and analyzed by different fluorescence techniques such as direct fluorescence, fluorescence microscopy and confocal microscopy. These techniques allowed identifying and quantifying the grafted regions on the polymeric foils. - Highlights: • Irradiated PET foils with swift-heavy ions were etched and grafted in a step-by-step process. • Grafting polymerization was performed on the remaining active sites after etching. • Track-etched PET membranes were fluorescently labeled by chemical functionalization. • Functionalized track-etched PET membranes were analyzed by fluorescence and confocal microscopy

  5. Radioactive cesium removal from seawater using adsorptive fibers prepared by radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Goto, Shota; Kawai-Noma, Shigeko; Umeno, Daisuke; Saito, Kyoichi; Fujiwara, Kunio; Sugo, Takanobu; Kikuchi, Takahiro; Morimoto, Yasutomi

    2015-01-01

    The meltdown of three reactors of the TEPCO Fukushima Daiichi nuclear power station (NPS) caused by the Great East Japan Earthquake on March 11th 2011 resulted in the emission of radionuclides such as cesium-137 and strontium-90 to the environment. For example, radioactive cesium exceeding the legal discharge limit (90 Bq/L, 2×10 -13 M) was detected in the seawater of the seawater-intake area of the NPS at the end of September 2014. Adsorbents with a high selectivity for cesium ions over other alkali metal ions such as sodium and potassium ions are required for cesium removal from seawater because sodium and potassium ions dissolve respectively at much higher concentrations of 5×10 -1 and 1×10 -2 M than cesium ions (2×10 -9 M). In addition, the simple operations of the immersion in seawater and the recovery of the adsorbents from seawater are desirable at decontamination sites. We prepared a cobalt-ferrocyanide-impregnated fiber capable of specifically capturing cesium ions in seawater by radiation-induced graft polymerization and chemical modifications. First, a commercially available 6-nylon fiber was irradiated with γ-rays. Second, an epoxy-group-containing vinyl monomer, glycidyl methacrylate, was graft-polymerized onto the γ-ray-irradiated nylon fiber. Third, the epoxy ring of the grafted polymer chain was reacted with triethylenediamine to obtain an anion-exchange fiber. Fourth, ferrocyanide ions, [Fe(CN) 6 ] 4 - , were bound to the anion-exchange group of the polymer chains. Finally, the ferrocyanide-ion-bound-fiber was placed in contact with cobalt chloride to precipitate insoluble cobalt ferrocyanide onto the polymer chains. Insoluble cobalt ferrocyanide was immobilized at the periphery of the fiber. However, the impregnation structure remains unclear. Here, we clarified the structure of insoluble cobalt ferrocyanide impregnated onto the polymer chain grafted onto the fiber to ensure the chemical and physical stability of the adsorptive fiber in

  6. From classical polymerizations in solution towards radio-induced polymerizations controlled in confined space

    International Nuclear Information System (INIS)

    Dubois-Clochard, M.-C.

    2013-01-01

    The manuscript of Mrs Marie-Claude Dubois-Clochard reports on the main results obtained in synthesis and structuration of functional polymers at the nano-scale. If the synthesis of functional polymers is the basic of the presented studies, the chronological order of her research activities from 1995 to 2013 shows an evolution from classical polymerizations in solution towards radio-induced polymerizations in confined space controlled by RAFT mechanism. The innovation is about the development of new objects made of polymers and organic/inorganic composites designed at the nano-scale to bring original physical and physico-chemical properties. Three applied fields stand out: Energy-Environment (Engines, Fuel cells, Sensors for water quality), Health (Nano-vector for tumour therapies and imaging, Ion and molecules translocation through a single nano-pore in a polymer membrane) and Nano-technologies (Magnetoresistance of a single magnetic nano-wire). Noteworthy results are: - the setting up of bi-langmuirian adsorption isotherm equations at solid/hydrocarbon interface for macromolecules at low concentrations, and, at high concentration, particular behaviour of reorganisation of these identical macromolecules, not in alternative layers but in reverse hemi-micelles formation. - the synthesis of a novel pH-degradable polymer allowing an hydrolytic degradation from pH 7.4 (Sang) to pH 5.5 (Intracellular lysosome) to deliver drugs into tumor cells (Sante). - the radiation-induced grafting-through process in solid polymers showed by a cooperative effect of solvent/growing polymer chains into fluoropolymers. - the synthesis of bi-functional nano-porous polymer track-etched membranes having a functionality in the pores and another on the surface. This membrane, after changing in electrode by simple metallization, has been the subject of valorisation projects to a start-up creation and/or a technological transfer for the development of a sensor able to detect heavy metals ions

  7. 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)

  8. Radiation-induced molecular imprinting of D-glucose onto poly(2-hydroxyethyl methacrylate) matrices using various crosslinking agents

    International Nuclear Information System (INIS)

    Ates, Zeliha; Gueven, Olgun

    2010-01-01

    Radiation-induced molecular imprinting of D-glucose onto poly(2-hydroxyethyl methacrylate) matrix was achieved to create three-dimensional cavities to recognize and bind D-glucose. The optimization of imprinting capability of matrices was achieved by investigating the effects of various parameters such as the type and amount of crosslinking agent, type of solvent, template to monomer ratio and total absorbed dose. Crosslinking agents with increasing chain lengths and different flexibilities were used in an attempt to elucidate the impact of relevant imprint parameters on the effectiveness of imprinting technique. The absorbed dose varied from 1 to 15 kGy. Cavity sizes of MIPs were measured by positron annihilation lifetime (PAL) experiments. Control matrices were synthesized with exactly the same composition in the absence of D-glucose. Separation of D-glucose has been shown to be successfully achieved in HPLC columns filled with MIPs whereas no separation was observed for non-imprint matrices.

  9. Dewetting-Induced Photoluminescent Enhancement of Poly(lauryl methacrylate)/Quantum Dot Thin Films.

    Science.gov (United States)

    Geldmeier, Jeffrey; Rile, Lexy; Yoon, Young Jun; Jung, Jaehan; Lin, Zhiqun; Tsukruk, Vladimir V

    2017-12-19

    A new method for enhancing photoluminescence from quantum dot (QD)/polymer nanocomposite films is proposed. Poly(lauryl methacrylate) (PLMA) thin films containing embedded QDs are intentionally allowed to undergo dewetting on substrates by exposure to a nonsolvent vapor. After controlled dewetting, films exhibited typical dewetting morphologies with increased amounts of scattering that served to outcouple photoluminescence from the film and reduce internal light propagation within the film. Up to a 5-fold enhancement of the film emission was achieved depending on material factors such as the initial film thickness and QD concentration within the film. An increase in initial film thickness was shown to increase the dewetted maximum feature size and its characteristic length until a critical thickness was reached where dewetting became inhibited. A unique light exposure-based photopatterning method is also presented for the creation of high contrast emissive patterns as guided by spatially controlled dewetting.

  10. The use of radiation-induced graft polymerization for obtaining polymeric biomaterial on the basis of preparation 'Piyavit'

    International Nuclear Information System (INIS)

    Kudryavtsev, V.N.; Degtyareva, T.V.; Kabanov, V.Ya.

    1998-01-01

    The purpose of the present study is to obtain hemocompatible polymeric materials. The method of modification of polymer surface have been elaborated using the radiation-induced graft polymerization after which the surface is capable of coupling with the biologically active substances (BAS) produced from the medicinal leeches. At the Biological Department of Lomonosov Moscow State University was created a medicinal preparation 'Piyavit' isolated from the salivary glands secretion of the medicinal leeches (Hirudo medicinalis). It possess a wide spectrum of biological action on the human organism thanks to the presence of an unique complex natural of BAS (enzymes, inhibitors of proteolityc ensymes, prostanoids and et. al) guaranteed the anticoagulating, thrombolytic, antithrombotic, antiphlogistic, antiatherosclerotic, hypotentic effects and et al.. It has several advantages over anticoagulant heparin which is widely used for above mentioned purpose. 'Piyavit' is the multifunctional preparation, has not negative side-effects and is more cheap. The method of obtaining biocompatible polymers (basically polyethylene) with immobilized 'Piyavit' consist of three stages: 1. The modification of polymer surface by the radiation-induced graft polymerization of acrylic acid to obtain grafted chains polyacrylic acid (PAA) with controlled number and length. 2. The treatment of radiation grafted PAA by thionyl chloride that lead to conversion carboxyl groups of PAA in highly reactive acide chloride groups. 3. The covalent immobilization BAS of 'Piyavit' by acylation amino- and hydroxy-groups (functional groups in BAS) by acide chloride of PAA grafted on the polymere. (author)

  11. Radiation-induced in-source polymerization of acrylonitrile in urea canal complex

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Abe, Toshihiko; Kobayashi, Yasushi.

    1975-01-01

    Effect of reaction conditions on the radiation-induced in-source polymerization of acrylonitrile in urea canal complex and the properties of obtained polyacrylonitriles were investigated. The results were discussed in comparison with previously reported of the post-polymerization experiments. 1) Rate of polymerization and viscosity (eta sub(sp)/C) were the highest when the molar ratio of acrylonitrile to urea in canal complex was unity. Similar results were also obtained in the post-polymerization. However, eta sub(sp)/C exhibited different behavior on polymerization time in comparison with post-polymerization. 2) The initial rate (Rsub(p)) of polymerization is proportional to the dose rate (I) at low dose rate, but at high dose rates (above 2x10 5 r/hr) makes Rsub(p) proportional to Isup(0.5). 3) Molecular weight distribution become broader with increasing polymerization time and is broad as compared with those obtained by the post-polymerization. G-value of initiation of polymerization decreased with increasing polymerization time. These value was larger than the that obtained in the post-polymerization. 4) The stereoregularity of the polyacrylonitriles was independent of the molar ratio of acrylonitrile to urea in the canal complex and conversion. 5) The appearance of the polyacrylonitriles observed by the scanning electron microscope changed from curled string to extended one as the polymerization proceed. 6) Infrared spectrum revealed the ketenimine and cyclization structure in the polyacrylonitriles obtained below -100 0 C. The content of these abnormal structures increased with increasing conversion. (auth.)

  12. Simultaneous FT-NIR and ESR analysis to study of the kinetics of photo induced polymerization of vinyl radical polymers

    International Nuclear Information System (INIS)

    Le, T.T.; Hill, D.J.T.; Pomery, P.J.

    2000-01-01

    Full text:The rate parameters for free vinyl radical polymerizations are difficult to determine accurately over the whole range of conversion. For systems which polymerize rapidly and for networks, this is a particular problem, because small differences in polymerization conditions, e.g., temperature, initiator concentration, photon flux, etc., can cause a large change in the time evolution of the concentration of carbon double bonds and radicals if these are monitored in separate experiments. The IUPAC Working Party on the Modeling of kinetics and processes of polymerization has the role of recommending the 'best' values for the kinetic parameters, using pulsed-laser polymerization (PLP) in conjunction with molar mass distribution (MMD) to determine k p as a function of temperature (T deg C) for bulk free-radical polymerization of methyl methacrylate at low conversions and ambient temperature. The vinyl radical polymers used in this study were methyl methacrylate and ethylene glycol dimethacrylate. In the past kinetic studies of vinyl photo-polymerization required the time dependence of the monomer and radical concentrations to be monitored separately by using FT-NIR spectroscopy and ESR spectroscopy, respectively. For the systems which polymerize rapidly, small differences in the conditions for two measurements, e.g. temperature and light intensity, can introduce significant errors. Hyphenated experiments involving in-situ ESR and FT-NIR spectroscopies using fibre optic, can overcome these problems. In this paper, the radical and monomer concentrations were measured under the same experimental conditions using the above techniques. The results obtained were used to evaluate the kinetic parameters for free radical vinyl polymerizations

  13. 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.

  14. Self-catalyzed photo-initiated RAFT polymerization for fabrication of fluorescent polymeric nanoparticles with aggregation-induced emission feature.

    Science.gov (United States)

    Zeng, Guangjian; Liu, Meiying; Jiang, Ruming; Huang, Qiang; Huang, Long; Wan, Qing; Dai, Yanfeng; Wen, Yuanqing; Zhang, Xiaoyong; Wei, Yen

    2018-02-01

    In recent years, the fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) feature have been extensively exploited in various biomedical fields owing to their advantages, such as low toxicity, biodegradation, excellent biocompatibility, good designability and optical properties. Therefore, development of a facile, efficient and well designable strategy should be of great importance for the biomedical applications of these AIE-active FPNs. In this work, a novel method for the fabrication of AIE-active FPNs has been developed through the self-catalyzed photo-initiated reversible addition fragmentation chain transfer (RAFT) polymerization using an AIE dye containing chain transfer agent (CTA), which could initiate the RAFT polymerization under light irradiation. The results suggested that the final AIE-active FPNs (named as TPE-poly(St-PEGMA)) showed great potential for biomedical applications owing to their optical and biological properties. More importantly, the method described in the work is rather simple and effective and can be further extended to prepare many other different AIE-active FPNs owing to the good monomer adoptability of RAFT polymerization. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Complexation-Induced Phase Separation: Preparation of Metal-Rich Polymeric Membranes

    KAUST Repository

    Villalobos, Luis Francisco

    2017-01-01

    The majority of state-of-the-art polymeric membranes for industrial or medical applications are fabricated by phase inversion. Complexation induced phase separation (CIPS)—a surprising variation of this well-known process—allows direct fabrication

  16. CuX2络合物催化甲基丙烯酸甲酯的氧化聚合%CuX2 COMPLEX-CATALYZED OXIDATIVE POLYMERIZATIONS OF METHYL METHACRYLATE

    Institute of Scientific and Technical Information of China (English)

    孙燕; 孙晋; 宋瑾; 黄文艳; 蒋必彪; 翟光群

    2011-01-01

    Oxidative polymerizations of methyl methacrylate ( MMA) catalyzed by complexes of transition metal halides in high oxidation states were investigated. First, CuBr2/2, 2'-bipyridine ( bPy)-catalyzed oxidative polymerizations of MMA in the presence of poly (2-( N, iV-dimethylamino) ethyl methacrylate) were performed in different solvents. When cyclohexanone was used as a solvent, only poly ( methyl methacrylate) ( PMMA) was obtained, suggesting redox initiation between CuBr2/bPy and tertiary amines in cyclohexanone is negligible. Second, oxidative polymerizations of MMA catalyzed by different complexes were carried out. Complexes of CuCl2 ,CuBr2 or FeCl3 with bPy,N,N,/V',N",/V"-pentamethyldiethylenetriamine or N,N,N',N'-tetramethylethylenediamine can catalyze oxidative polymerizations of MMA, and polymerization rates increased with the increase of the catalyst concentration. Molecular weight of PMMA increases with monomer conversions initially and maintains constant later. Last,atom transfer radical polymerization ( ATRP) chain extension using PMMA from the oxidative polymerizations at different conversions was performed. The results show the C-X functionality of PMMA chains at low conversion was also 100% ,and it decreased sharply with conversions. Two different mechanisms were conceived to contribute to the oxidative polymerization of MMA: (1) the complexes form ATRP initiators and catalysts with MMA via monomer addition, and then ATRP proceeds to give rise to PMMA chains with C-X terminal groups; (2) the complexes catalyze/initiate conventional free radical polymerizations of MMA.%研究了高氧化态过渡金属卤化物络合物催化甲基丙烯酸甲酯(MMA)的氧化聚合.首先在叔胺类聚合物存在条件下以CuBr2/2,2′-联吡啶(bPy)络合物催化MMA在不同溶剂中的氧化聚合,结果在环己酮中得到PMMA均聚物,CuBr2/bPy同叔胺的氧化还原引发可以忽略.随后在环己酮中分别以不同络合物催化MMA的

  17. Polimerizacija, toplinska stabilnost i mehanizam razgradnje kopolimera (metakril-dicikloheksiluree i (metakril-diizopropiluree sa stirenom i α-metilstirenom (Polymerization, Thermal Stability and Degradation Mechanism of (Methacryl-Dicyclohexylurea and (Methacryl-Diisopropylurea Copolymers with Styrene and α-Methylstyrene

    Directory of Open Access Journals (Sweden)

    Vuković, R.

    2006-05-01

    Full Text Available This paper describes the polymerization of N-acryl-N,N'-dicyclohexylurea (A-DCU, N-methacryl- N,N'-dicyclohexylurea (MA-DCU and N-methacryl-N,N'-diisopropylurea (MA-DiPrU monomers with styrene (St and α-methylstyrene (α-MeSt, thermal stability and degradation mechanism of prepared copolymers. Free-radical initiated polymerization was performed to low conversion by using dibenzoyl peroxyde (Bz2O2 in butanone at 70 °C under nitrogen stream. It was found that the pendant group in (methacrylic monomers have high influence to the polymerization as well as to the copolymer properties. A-DCU readily homopolymerized and copolymerized with St and r1,A-DCU = 0.72 and r2,α-MeSt= 0.07, while MA-DCU does not homopolymerized or copolymerized with α-MeSt under the same conditions, but copolymerized with St to randomly composed copolymers after a long heating of comonomers. Copolymers A-DCU with α-MeSt prepared under different monomer-to monomer-ratios in the feed have random composition with an azeotropic point at ratio of 0.75 (A-DCU to 0.25 (St. The initial rate of copolymerization indicates that the rate increases almost linearly with the increase of ratio of A-DCU in the comonomer feed. Reactivity ratios determined by the Kelen-Tüdös method are: r1,A-DCU = 0.72 and r2,α-MeSt = 0.07. Molar mass of copolymers increased from 8.5 to 30 (kg mol-1 when mole ratio of A-DCU to α-MeStin the feed increased from 0.1 to 0.9. Poly(A-DCU and copolymers with α-MeSt decomposed by two-step mechanism. Under TGA (nitrogen,10 °C min-1 conditions in the first step between 180 °C and 250 °C a quantitative yield of cyclohexylisocyanate (C6H11NCO separated by a decomposition of dicyclohexylurea (DCU. The thermally stable residue represented poly(acryl-cyclohexylamide, poly(A-CHA, and copolymer with α-MeSt, poly(A-CHA-co-α-MeSt. Glass transition temperature (Tg of poly(A-DCU was at 184 °C and Tg of residue, poly(A-CHA, was at 161 °C. Tg's of the copolymers are

  18. Anionic polymerization of acrylates. Synthesis of (meth)acrylate di- and triblock copolymers using the Li ester-enolate/tert-alkoxide initiating system

    Czech Academy of Sciences Publication Activity Database

    Vlček, Petr; Otoupalová, Jaroslava; Janata, Miroslav; Látalová, Petra; Kurková, Dana; Toman, Luděk; Masař, Bohumil

    2004-01-01

    Roč. 37, č. 2 (2004), s. 344-351 ISSN 0024-9297 R&D Projects: GA ČR GA203/01/0513; GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : ligated anionic polymerization * block copolymers Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.898, year: 2004

  19. Radiation-Induced Graft Polymerization of Vinyl Monomers with Anion Groups onto MWNT Supports and Their Application as Electrogenerated Chemiluminescence (ECL Biosensors

    Directory of Open Access Journals (Sweden)

    Ji-Hye Park

    2014-01-01

    Full Text Available Vinyl polymer-grafted multiwalled carbon nanotube (MWNT supports with anion groups were prepared for use as biosensor supports by radiation-induced graft polymerization (RIGP of the vinyl monomers acryloyl diphosphoric acid (ADPA, acrylic acid (AA, sodium styrenesulfonate (NaSS, and methacrylic acid (MA onto the surface of MWNTs. The electrogenerated chemiluminescence sensors based on a glass carbon electrode (ECL-GCE and a screen printed electrode (ECL-SPE were fabricated by immobilization of Ru(bpy3 2+ complex after coating of vinyl polymer-grafted MWNT inks on the surface of the GCE and SPE without any polymer binders in order to obtain high electrogenerated chemiluminescence intensity. For detection of alcohol concentration, alcohol dehydrogenase (ADH was immobilized onto an ECL-GCE sensor prepared by poly(NaSS-g-MWNT supports. The prepared biosensor based on ADH is suitable for the detection of ethanol concentration in commercial drinks.

  20. UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices

    Directory of Open Access Journals (Sweden)

    Claudio Gerbaldi

    2012-06-01

    Full Text Available In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature. The electrochemical stability window is wide (anodic breakdown voltages > 4.5 V vs. Li in all the cases along with good cyclability in lithium cells at ambient temperature. The galvanostatic cycling tests are conducted by constructing laboratory-scale lithium cells using LiFePO4 as cathode and lithium metal as anode with the selected polymer electrolyte membrane as the electrolyte separator. The results obtained demonstrate that UV induced radical photo-polymerization is a well suited method for an easy and rapid preparation of easy tunable quasi-solid polymer electrolyte membranes for energy storage devices.

  1. UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices

    Directory of Open Access Journals (Sweden)

    Claudio Gerbaldi

    2012-10-01

    Full Text Available In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature. The electrochemical stability window is wide (anodic breakdown voltages > 4.5 V vs. Li in all the cases along with good cyclability in lithium cells at ambient temperature. The galvanostatic cycling tests are conducted by constructing laboratory-scale lithium cells using LiFePO4 as cathode and lithium metal as anode with the selected polymer electrolyte membrane as the electrolyte separator. The results obtained demonstrate that UV induced radical photo-polymerization is a well suited method for an easy and rapid preparation of easy tunable quasi-solid polymer electrolyte membranes for energy storage devices.

  2. Comparison of silorane and methacrylate-based composites on the polymerization heat generated with different light-curing units and dentin thicknesses.

    Science.gov (United States)

    Guiraldo, Ricardo Danil; Consani, Simonides; Consani, Rafael Leonardo Xediek; Berger, Sandrine Bittencourt; Correr, Américo Bortolazzo; Sinhoreti, Mário Alexandre Coelho; Correr-Sobrinho, Lourenço

    2013-01-01

    This study evaluated the temperature variation in the pulp chamber during photoactivation of two restorative composite resins (Filtek P90 silorane-based composite and Heliomolar methacrylate-based composite) with either a quartz-tungsten-halogen (QTH) or light-emitting diodes (LED) light-curing unit (LCU) and using dentin thicknesses (0.5 and 1.0 mm). Standardized cavities (2x2x2 mm) were prepared in 80 bovine incisors, which were randomly assigned to 8 groups according to the photoactivation method and dentin thickness. Filtek P90 and Heliomolar (both in shade A3) were used with their respective adhesive systems (P90 self-etch primer / P90 adhesive bond and Excite adhesive). All experiments were carried out in a controlled environment (37°C). The temperature variations (°C) were recorded using a digital thermometer attached to a K-type thermocouple. The results were analyzed statistically by ANOVA and Tukey's test (α=0.05). For composite/dentin thickness interaction, temperature increase was significantly higher in 0.5 mm dentin thickness (40.07°C) compared with 1.0 mm dentin thickness (39.61°C) for Filtek P90. For composite/LCU interaction, the temperature increase was significantly higher for Filtek P90 (39.21°C - QTH and 40.47°C - LED) compared with Heliomolar (38.40°C - QTH and 39.30°C - LED). The silorane-based composite promoted higher temperature increase in the pulp chamber than the methacrylate-based composite.

  3. In situ and real-time small-angle neutron scattering studies of living anionic polymerization process and polymerization-induced self-assembly of block copolymers

    International Nuclear Information System (INIS)

    Tanaka, H.; Yamauchi, K.; Hasegawa, H.; Miyamoto, N.; Koizumi, S.; Hashimoto, T.

    2006-01-01

    We have studied a simultaneous living anionic polymerization process of isoprene and deuterated styrene in deuterated benzene with sec-buthyl lithium as an initiator into polyisoprene-block-poly(styrene-d 8 ) and the polymerization-induced self-assembling process. This polymerization-induced self-assembling process was directly observed by an in situ and real-time small-angle neutron scattering (SANS) experiment. The time-resolved SANS studies enabled us to explore a time evolution of hierarchical structures induced by a time evolution of the primary structure (linear sequential connection of two monomers)

  4. Comparative study of pressure-induced polymerization in C60 nanorods and single crystals

    International Nuclear Information System (INIS)

    Hou Yuanyuan; Liu Bingbing; Wang Lin; Yu Shidan; Yao Mingguang; Chen Ao; Liu Dedi; Zou Yonggang; Li Zepeng; Zou Bo; Cui Tian; Zou Guangtian; Iwasiewicz-Wabnig, Agnieszka; Sundqvist, Bertil

    2007-01-01

    In this paper, we report a comparative study of pressure-induced polymerization in C 60 nanorods and bulk single crystals, treated simultaneously under various pressures and temperatures in the same experiment. For both materials, orthorhombic, tetragonal and rhombohedral phases have been produced under high pressure and high temperature. The structures have been identified and compared between the two sample types by Raman and photoluminescence spectroscopy. There are differences between the Raman and photoluminescence spectra from the two types of materials for all polymeric phases, but especially for the tetragonal phase. From the comparison between nanorods and bulk samples, we tentatively assign photoluminescence peaks for various polymeric phases

  5. 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

  6. Pressure induced graft-co-polymerization of acrylonitrile onto ...

    Indian Academy of Sciences (India)

    WINTEC

    The natural fibre (S. cilliare) (0⋅5 g) was masticated to create active sites onto the polymeric backbone and was then immersed in a known amount of distilled water for. 24 h. A known amount of initiator (FAS–KPS) and monomer (AN) were then added to the flask containing fibre at suitable pH and the reaction was carried ...

  7. Radiation-Induced Polymerization Monitored with Fluorogenic Molecular Probes

    NARCIS (Netherlands)

    Frahn, M.S.

    2003-01-01

    Each year over one billion pounds of acrylic-based polymeric products are produced world wide. Such products include windows in aircraft, lenses in eyeglasses and CD players, coatings on parquet flooring and various architectural structures such as skylights and domes. Often these products are made

  8. Functional polymeric materials : Complexing amphiphiles as structure-inducing elements

    NARCIS (Netherlands)

    ten Brinke, G.; Ikkala, O.

    2003-01-01

    Self-assembly of polymeric comb-shaped supramolecules is a powerful tool to prepare functional materials. Enhanced conductivity due to hexagonal self-organization of conducting polyaniline and polarized photoluminance in solid-state films of rodlike poly(2,5-pyridinediyl) obtained by removing

  9. Application of radiation-induced graft polymerization to preparation of functional materials

    International Nuclear Information System (INIS)

    Sugo, Takanobu

    2010-01-01

    Radiation-induced graft polymerization is a powerful method for appending various functionalities onto existing fabrics, nonwoven fabrics, fibers, membranes, and beads while maintaining the shape and mechanical strength. By using this method, the author has developed and commercialized functional polymeric materials over 45 years. The materials produced by the fruits of radiation chemistry contributed to the improvement of our lives and environments and the collection of rare metal resources. (author)

  10. Anionic polymerization of acrylates. XI. Effect of composition and ageing of the Li ester enolate/tert-butoxide initiating complex on the anionic polymerization of methyl methacrylate and 2-ethylhexyl acrylate

    Czech Academy of Sciences Publication Activity Database

    Vlček, Petr; Otoupalová, Jaroslava; Kříž, Jaroslav; Schmidt, Pavel

    2000-01-01

    Roč. 161, - (2000), s. 127-134 ISSN 1022-1360. [Microsymposium: Advances in Polymerization Methods: Controlled Synthesis of Functionalized Polymers /39./. Praha, 12.07.1999-15.07.1999] R&D Projects: GA MŠk OC P1.10; GA AV ČR KSK2050602 Grant - others:CZ-US(XC) 95009 Institutional research plan: CEZ:AV0Z4050913 Keywords : anionic polymerization * acrylates * initiating system Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.406, year: 2000

  11. Radiation-induced polymerization of water-saturated styrene in a wide range of dose rate

    International Nuclear Information System (INIS)

    Takezaki, J.; Okada, T.; Sakurada, I.

    1978-01-01

    Radiation-induced polymerization of water-saturated styrene (water content 3.5 x 10 -2 mole/liter) was carried out in a wide range of dose rate between 1.2 x 10 3 and 1.8 x 10 7 rad/sec, and compared with the polymerization of the moderately dried styrene (water content 3.2 x 10 -3 mole/liter). Molecular weight distribution curves of the polymerization products showed that they were generally consisted of four parts, namely, oligomers, radical, cationic, and super polymers. Contributions of the four constituents to the polymerization and the number average degrees of polymerization (DP) of the four kinds of polymers were calculated by the graphical analysis of the curves. The rate of radical polymerization and DP of radical polymers are independent of the water content; the dose rate dependences of the polymerization rate and DP agree with the well known square root and inverse square root laws, respectively, of the radical polymerization of styrene. The rate of ionic polymerization is directly proportional to the dose rate, but it decreases, at a given dose rate, inversely proportional to the water content of styrene. DP of ionic polymer is independent of the dose rate but decreases with increasing water content. The super polymer of DP about 10 4 is not formed in the case of the moderately dried styrene. G values for the initiating radical and ion formation are calculated to be independently of the dose rate and water content, 0.66 and 0.027, respectively. It was suggested that oligomer was formed in the early stage by the interaction of cation with anion and only those cations which had survived underwent polymerization. 10 figures, 4 tables

  12. 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.

  13. Preparation of a poly(3'-azido-3'-deoxythymidine-co-propargyl methacrylate-co-pentaerythritol triacrylate) monolithic column by in situ polymerization and a click reaction for capillary liquid chromatography of small molecules and proteins.

    Science.gov (United States)

    Lin, Zian; Yu, Ruifang; Hu, Wenli; Zheng, Jiangnan; Tong, Ping; Zhao, Hongzhi; Cai, Zongwei

    2015-07-07

    Combining free radical polymerization with click chemistry via a copper-mediated azide/alkyne cycloaddition (CuAAC) reaction in a "one-pot" process, a facile approach was developed for the preparation of a poly(3'-azido-3'-deoxythymidine-co-propargyl methacrylate-co-pentaerythritol triacrylate) (AZT-co-PMA-co-PETA) monolithic column. The resulting poly(AZT-co-PMA-co-PETA) monolith showed a relatively homogeneous monolithic structure, good permeability and mechanical stability. Different ratios of monomers and porogens were used for optimizing the properties of a monolithic column. A series of alkylbenzenes, amides, anilines, and benzoic acids were used to evaluate the chromatographic properties of the polymer monolith in terms of hydrophobic, hydrophilic and cation-exchange interactions, and the results showed that the poly(AZT-co-PMA-co-PETA) monolith exhibited more flexible adjustment in chromatographic selectivity than that of the parent poly(PMA-co-PETA) and AZT-modified poly(PMA-co-PETA) monoliths. Column efficiencies for toluene, DMF, and formamide with 35,000-48,000 theoretical plates per m could be obtained at a linear velocity of 0.17 mm s(-1). The run-to-run, column-to-column, and batch-to-batch repeatabilities of the retention factors were less than 4.2%. In addition, the proposed monolith was also applied to efficient separation of sulfonamides, nucleobases and nucleosides, anesthetics and proteins for demonstrating its potential.

  14. Pressure-induced polymerization of P(CN){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Gou, Huiyang, E-mail: hgou@ciw.edu, E-mail: tstrobel@ciw.edu; Kim, Duck Young; Strobel, Timothy A., E-mail: hgou@ciw.edu, E-mail: tstrobel@ciw.edu [Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington, DC 20015 (United States); Yonke, Brendan L. [NRC Postdoctoral Associate, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States); Epshteyn, Albert [Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 (United States); Smith, Jesse S. [High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439 (United States)

    2015-05-21

    Motivated to explore the formation of novel extended carbon-nitrogen solids via well-defined molecular precursor pathways, we studied the chemical reactivity of highly pure phosphorous tricyanide, P(CN){sub 3}, under conditions of high pressure at room temperature. Raman and infrared (IR) spectroscopic measurements reveal a series of phase transformations below 10 GPa, and several low-frequency vibrational modes are reported for the first time. Synchrotron powder X-ray diffraction measurements taken during compression show that molecular P(CN){sub 3} is highly compressible, with a bulk modulus of 10.0 ± 0.3 GPa, and polymerizes into an amorphous solid above ∼10.0 GPa. Raman and IR spectra, together with first-principles molecular-dynamics simulations, show that the amorphization transition is associated with polymerization of the cyanide groups into CN bonds with predominantly sp{sup 2} character, similar to known carbon nitrides, resulting in a novel phosphorous carbon nitride (PCN) polymeric phase, which is recoverable to ambient pressure.

  15. Polymerization of Methyl Methacrylate Catalyzed by Co(II), Cu(II), and Zn(II) Complexes Bearing N-Methyl-N-((pyridin-2-yl)methyl) cyclohexanamine

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Seoung Hyun; Lee, Hyosun [Kyungpook National University, Daegu (Korea, Republic of); Shin, Jongwon [POSTECH, Pohang (Korea, Republic of); Nayab, Saira [Shaheed Benazir Bhutto University, Sheringal (Pakistan)

    2016-05-15

    We demonstrated the synthesis and characterization of Co(II), Cu(II), and Zn(II) complexes ligated to N-methyl-N-((pyridin-2-yl)methyl)cyclohexanamine. The complex [Co(nmpc)Cl{sub 2}] in the presence of MMAO showed the highest catalytic activity for MMA polymerization at 60 °C compared with its Zn(II) and Cu(II) analogs. The metal center showed an obvious influence on the catalytic activity, although this appeared to have no effect on the stereo-regularity of the resultant PMMA. X-ray diffraction analysis revealed that [Co(nmpc)Cl{sub 2}] and [Zn(nmpc)Cl{sub 2}] crystallized in the monoclinic system with space group P2{sub 1}/c and existed as monomeric and solvent-free complexes.

  16. Effect of silver ion-induced disorder on morphological, chemical and optical properties of poly (methyl methacrylate)

    Energy Technology Data Exchange (ETDEWEB)

    Arif, Shafaq, E-mail: sarif2005@gmail.com [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Saleemi, Farhat [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Rafique, M. Shahid [Department of Physics, University of Engineering & Technology, Lahore 54000 (Pakistan); Naab, Fabian; Toader, Ovidiu [Department of Nuclear Engineering and Radiological Sciences, Michigan Ion Beam Laboratory, University of Michigan, MI 48109-2104 (United States); Mahmood, Arshad; Aziz, Uzma [National Institute of Lasers & Optronics (NILOP), P.O. Nilore, Islamabad (Pakistan)

    2016-11-15

    Ion implantation is a versatile technique to tailor the surface properties of polymers in a controlled manner. In the present study, samples of poly (methyl methacrylate) (PMMA) have been implanted with 400 keV silver (Ag{sup +}) ion beam to various ion fluences ranging from 5 × 10{sup 13} to 5 × 10{sup 15} ions/cm{sup 2}. The effect of Ag{sup +} ion-induced disorder on morphological, chemical and optical properties of PMMA is analyzed using Atomic Force Microscope (AFM), Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–Vis) spectroscopy. Furthermore, the electrical conductivity of pristine and implanted PMMA is measured using four probe apparatus. The AFM images revealed the growth of nano-sized grainy structures and hillocks above the surface of implanted PMMA. The FTIR spectra confirmed the modifications in chemical structure of PMMA along with the formation of −C=C− carbon contents. The refractive index, extinction coefficient and photoconductivity of implanted PMMA have been found to increase as a function of ion fluence. Simultaneously, indirect optical band gap is reduced from 3.13 to 0.81 eV at a relatively high fluence (5 × 10{sup 15} ions/cm{sup 2}). A linear correlation has been established between the band gap and Urbach energies. Moreover, the electrical conductivity of Ag{sup +} implanted PMMA has increased from 2.14 × 10{sup −10} (pristine) to 9.6 × 10{sup −6} S/cm.

  17. Modification of silica surface by gamma ray induced Ad micellar Polymerization

    International Nuclear Information System (INIS)

    Buathong, Salukjit; Pongprayoon, Thirawudh; Suwanmala, Phiriyatorn

    2005-10-01

    Precipitated silica is often added to natural rubber compounds in order to improve performance in commercial application. A problem with using silica as filler is the poor compatibility between silica and natural rubber. In this research, polyisoprene was coated on silica surface by gamma ray induced ad micellar polymerization in order to achieve the better compatibility between silica and natural rubber. The modified silica was characterized by FT-IR, and SEM. The results show that polyisoprene was successfully coated on silica surface via gamma ray induced ad micellar polymerization

  18. Carbon nanotubes polymerization induced by self-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Cassio Stein [Faculdade de Fisica, Pontificia Univ. Catolica do Rio Grande do Sul (PUCRS), Porto Alegre (Brazil)

    2008-07-01

    Full text: We discuss our recent results on the formation of cross-links between neighboring carbon nanotubes within a bundle. Classical molecular dynamics was used to follow the evolution of the system when it is bombarded by low-energy carbon atoms. We show that it is possible to polymerize carbon nanotubes through irradiation and discuss the most common types of defects produced. Cross-links are created mainly in the direction perpendicular to the surface, and for higher energies, defects are created deeper in the rope. The final defects geometries may provide a realistic input to electronic density first principle calculations. (author)

  19. Carbon nanotubes polymerization induced by self-irradiation

    International Nuclear Information System (INIS)

    Moura, Cassio Stein

    2008-01-01

    Full text: We discuss our recent results on the formation of cross-links between neighboring carbon nanotubes within a bundle. Classical molecular dynamics was used to follow the evolution of the system when it is bombarded by low-energy carbon atoms. We show that it is possible to polymerize carbon nanotubes through irradiation and discuss the most common types of defects produced. Cross-links are created mainly in the direction perpendicular to the surface, and for higher energies, defects are created deeper in the rope. The final defects geometries may provide a realistic input to electronic density first principle calculations. (author)

  20. Real time in situ spectroscopic characterization of radiation induced cationic polymerization of glycidyl ethers

    International Nuclear Information System (INIS)

    Mascioni, Matteo; Sands, James M.; Palmese, Giuseppe R.

    2003-01-01

    Radiation curable polymeric materials suffer from relatively poor mechanical properties. Moreover, the curing behavior of such systems (i.e. the exact relationship between chemical kinetics and key processing variables) is not fully understood. In order to design improved epoxy based electron beam (EB) curable systems, and in order to develop appropriate process models, a detailed knowledge of the kinetics of epoxy cationic polymerization induced by ultraviolet (UV) or EB irradiation is required. In this work, we present our development of a technique based on real time near infrared (RTIR) spectroscopy for performing in situ kinetic analysis of radiation induced cationic polymerization of epoxy systems. To our knowledge this is the first time such data have been collected and presented for high-energy EB (10 MeV) induced polymerization. A demonstration of the technique for deterministic evaluation of degree of cure is shown using model glycidyl ether (phenyl glycidyl ether and diglycidyl ether of bisphenol A) resins and isothermal curing conditions. The impact of initiation rate on polymerizations with UV and EB for the cationic initiator is directly evident by comparative analysis. The sensitivity of the RTIR method and ability to produce quantitative data evidence of reaction mechanisms is demonstrated. The type of data presented in this work forms the basis for cure models being developed

  1. Immobilization of yeast cells on hydrogel carriers obtained by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Luzhao Xin; Carenza, M.; Kaetsu, Isao; Kumakura, Minoru; Yoshida, Masaru; Fujimura, Takashi

    1992-01-01

    Polymer hydrogels were obtained by radiation-induced copolymerization at -78 o C of aqueous solutions of acrylic and methacrylic esters. The matrices were characterized by equilibrium water content measurements, by optical microscopy observations and by scanning electron microscopy analysis. Yeast cells were immobilized on these hydrogels and the ethanol productivity by batch fermentation was determined. Matrix hydrophilicity and porosity were found to deeply influence the adhesion of yeast cells and, hence, the ethanol productivity. The latter as well as other physico-chemical properties were also affected by the presence of a crosslinking agent added in small amounts to the polymerizating mixture. (author)

  2. 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.

  3. Radiation-Induced Polymerization of Butyl Acrylate for Recovery of Organic Solvents

    International Nuclear Information System (INIS)

    Kattan, M.; Al-Kassiri, H.

    2011-01-01

    Radiation-induced polymerization of butyl acrylate using 60 Co gamma rays has been investigated under different conditions, such as irradiation dose (0-130 kGy), dose rate (10 kGy/h), and temperature (25-70 degree C). A linear relationship between conversion and temperature of irradiation was found. The activation energy (E) of 9.37 kJ/mol was obtained from kinetic analysis of the result from the polymerization at 10 kGy/h. Thermal properties were examined using differential scanning calorimetry and thermal gravimetric analysis. Efficient extraction of organic solvents including chloroform, chlorobenzene, carbon tetrachloride, benzene, styrene was revealed by the swelling and releasing measurements. These results indicate the feasibility of applying this polymer, which was prepared by radiation-induced polymerization, to management of organic wastes in the field of environment. (author)

  4. Radiation-Induced Polymerization of Butyl Acrylate for Recovery of Organic Solvents

    International Nuclear Information System (INIS)

    Kattan, M.; Al-kassiri, H.

    2010-01-01

    Radiation-induced polymerization of butyl acrylate (BAc) using 60 Co gamma rays has been investigated under different conditions such as irradiation dose (0-130 kGy), dose rate (10 kGy/h) and temperature (25-70 C). A linear relationship between conversion and temperature of irradiation was found. The activation energy (E) of 9.37 kJ/mol was obtained from kinetic analysis of the result from the polymerization at 10 kGy/h. Thermal properties. were examined using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Efficient extraction of organic solvents including chloroform, chlorobenzene, carbon tetrachloride, benzene, styrene was revealed by the swelling and releasing measurements. These results indicate the feasibility of applying this polymer, which was prepared by radiation-induced polymerization, to management of organic wastes in the field of environment. (author)

  5. Development of water-borne thermosetting paint by radiation-induced emulsion polymerization

    International Nuclear Information System (INIS)

    Makuuchi, K.; Katakai, A.; Nakayama, H.

    1981-01-01

    In previous papers the features of γ-ray induced emulsion polymerization were studied to use the emulsion as vehicles for water-borne paint. In this paper, the physical properties of thermosetting paints made with emulsions containing N-(n-butoxymethyl)acrylamide (NBM) and hydroxyl and carboxyl functionality were investigated. Since NBM moieties can react with amide, hydroxyl, and carboxyl groups, NBM copolymer emulsions prepared in this study have the self-crosslinking capability. As far as it was investigated, it was difficult to prepare a stable emulsion containing 10% of NBM by the conventional emulsion polymerization by using a water soluble radical initiator such as persulfate. In addition to 1-liter reactor, a pilot-scale plant of 70 liters reactor was used for γ-ray induced emulsion polymerization. Experimental details are given, and results are discussed. (author)

  6. High-energy radiation monitoring based on radio-fluorogenic co-polymerization. I : Small volume in situ probe

    NARCIS (Netherlands)

    Warman, J.M.; De Haas, M.P.; Luthjens, L.

    2009-01-01

    A method of radiation dosimetry is described which is based on the radiation-induced initiation of polymerization of a bulk monomer (e.g. methyl methacrylate) containing a small concentration (about 100 ppm) of a compound which is non-fluorescent but which becomes highly fluorescent when it is

  7. 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.

  8. Color stability and flexural strength of poly (methyl methacrylate and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to beverages and food dye: An in vitro study

    Directory of Open Access Journals (Sweden)

    Anil K Gujjari

    2013-01-01

    Full Text Available Aim: To evaluate the color stability and flexural strength of poly (methyl methacrylate (PMMA and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to tea, coffee, cola, and food dye. Materials and Methods: Two provisional crown and bridge resins, one DPI self-cure tooth molding powder (PMMA (Group A, and one Protemp 4 Temporization Material (bis-acrylic composite (Group B were used. Disk-shaped specimens for color stability testing (n = 30 for each material and bar-shaped specimens for flexural strength testing (n = 30 for each material were fabricated using a metal mold. The specimens were immersed in artificial saliva, artificial saliva + tea, artificial saliva + coffee, artificial saliva + cola, and artificial saliva + food dye solutions and stored in an incubator at 37°C. Color measurements were taken before immersion, and then after 3 and 7 days of immersion. Flexural strength was evaluated after 7 days of immersion. Results: Group A showed significantly higher color stability as compared to Group B, and artificial saliva + coffee solution had the most staining capacity for the resins. Test solutions had no effect on the flexural strength of Group A, but Group B specimens immersed in artificial saliva + cola showed significantly lower flexural strength values as compared to the control group. Conclusion: The findings of the study showed that for materials used in the study, PMMA was more color stable than bis-acrylic composite based resin. Also, material based on PMMA was more resistant to damage from dietary beverages as compared to bis-acrylic composite based provisional crown and bridge resin.

  9. Color stability and flexural strength of poly (methyl methacrylate) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to beverages and food dye: an in vitro study.

    Science.gov (United States)

    Gujjari, Anil K; Bhatnagar, Vishrut M; Basavaraju, Ravi M

    2013-01-01

    To evaluate the color stability and flexural strength of poly (methyl methacrylate) (PMMA) and bis-acrylic composite based provisional crown and bridge auto-polymerizing resins exposed to tea, coffee, cola, and food dye. Two provisional crown and bridge resins, one DPI self-cure tooth molding powder (PMMA) (Group A), and one Protemp 4 Temporization Material (bis-acrylic composite) (Group B) were used. Disk-shaped specimens for color stability testing (n = 30 for each material) and bar-shaped specimens for flexural strength testing (n = 30 for each material) were fabricated using a metal mold. The specimens were immersed in artificial saliva, artificial saliva + tea, artificial saliva + coffee, artificial saliva + cola, and artificial saliva + food dye solutions and stored in an incubator at 37°C. Color measurements were taken before immersion, and then after 3 and 7 days of immersion. Flexural strength was evaluated after 7 days of immersion. Group A showed significantly higher color stability as compared to Group B, and artificial saliva + coffee solution had the most staining capacity for the resins. Test solutions had no effect on the flexural strength of Group A, but Group B specimens immersed in artificial saliva + cola showed significantly lower flexural strength values as compared to the control group. The findings of the study showed that for materials used in the study, PMMA was more color stable than bis-acrylic composite based resin. Also, material based on PMMA was more resistant to damage from dietary beverages as compared to bis-acrylic composite based provisional crown and bridge resin.

  10. Visible lights induced polymerization reactions: interactions between rose bengal and iron aren complex

    International Nuclear Information System (INIS)

    Burget, D.; Grotzinger, C.; Jacques, P.; Fouassier, J.P.

    1999-01-01

    The present paper is devoted to an investigation of the interactions between Rose Bengal (RB) and an Iron aren (Irg(+)) complex that are usable in visible light induced polymerization reactions. Steady state and flash photolysis experiments were performed in order to elucidate the nature of the intermediates formed after light excitation. A complete scheme of evolution of the excited states is discussed

  11. Surface grafting via photo-induced copper-mediated radical polymerization at extremely low catalyst concentrations

    Czech Academy of Sciences Publication Activity Database

    Laun, J.; Vorobii, Mariia; de los Santos Pereira, Andres; Pop-Georgievski, Ognen; Trouillet, V.; Welle, A.; Barner-Kowollik, C.; Rodriguez-Emmenegger, Cesar; Junkers, T.

    2015-01-01

    Roč. 36, č. 18 (2015), s. 1681-1686 ISSN 1022-1336 R&D Projects: GA ČR(CZ) GJ15-09368Y; GA MŠk(CZ) ED1.1.00/02.0109 Grant - others:OPPK(XE) CZ.2.16/3.1.00/21545 Program:OPPK Institutional support: RVO:61389013 Keywords : copper-mediated polymerization * photo-induced polymerization * polymer brushes Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.638, year: 2015

  12. Radiation-induced change of optical property of hydroxypropyl cellulose hydrogel containing methacrylate compounds: As a basis for development of a new type of radiation dosimeter

    International Nuclear Information System (INIS)

    Yamashita, Shinichi; Hiroki, Akihiro; Taguchi, Mitsumasa

    2014-01-01

    Hydrogels with matrix of a cellulose derivative, hydrogel of hydroxpropyl cellulose (HPC), containing two of methacrylate compounds (2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) dimethacrylate (9G)) were irradiated with 60 Co γ-rays. The gels become white with irradiation, and thus, could be candidates of a new type of radiation dosimeter utilized in radiation therapy because the gels become white with irradiation and can be confirmed directly by human eyes even at low doses of 1–2 Gy. Radiation-induced change of optical properties, haze value and UV–vis absorption spectrum, of the irradiated gels was measured. Dose response of the white turbidity appearance was different for different compositions of the methacrylate compounds as well as for different dose rates. The degree of the radiation-induced white turbidity was quantified by measuring haze value, showing linear dose response in low dose region (<2 Gy). We also analyzed the gels with a UV–vis spectrometer and HEMA- and 9G-rich gels gave different spectral shapes, indicating that there are at least two mechanisms leading to the white turbidity. In addition, dose rate dependence was smaller for 9G-rich gels than HEMA-rich gels in the range of 0.015–1.5 Gy/min. - Highlights: • White turbidity appeared even at 1 or 2 Gy of 60 Co γ-ray irradiation. • Haze could be used as an index of the degree of white turbidity. • UV–vis spectroscopy indicated multiple mechanisms leading to white turbidity

  13. Facile graft polystyrene onto multi-walled carbon nanotubes via in situ thermo-induced radical polymerization

    International Nuclear Information System (INIS)

    Liu Peng

    2009-01-01

    A facile procedure was developed for the grafting of polystyrene onto the surfaces of multi-walled carbon nanotubes (MWNTs) via the in situ thermo-induced bulk radical polymerization of styrene at the different polymerizing temperatures, in the presence of MWNTs without any initiator added. The grafting products were validated by the dispersibility, TEM, TGA, FT-IR, and Raman analysis. The TGA results also showed the lower polymerizing temperature was propitious to the free radical addition reactions.

  14. LL-37 induces polymerization and bundling of actin and affects actin structure.

    Directory of Open Access Journals (Sweden)

    Asaf Sol

    Full Text Available Actin exists as a monomer (G-actin which can be polymerized to filaments F-actin that under the influence of actin-binding proteins and polycations bundle and contribute to the formation of the cytoskeleton. Bundled actin from lysed cells increases the viscosity of sputum in lungs of cystic fibrosis patients. The human host defense peptide LL-37 was previously shown to induce actin bundling and was thus hypothesized to contribute to the pathogenicity of this disease. In this work, interactions between actin and the cationic LL-37 were studied by optical, proteolytic and surface plasmon resonance methods and compared to those obtained with scrambled LL-37 and with the cationic protein lysozyme. We show that LL-37 binds strongly to CaATP-G-actin while scrambled LL-37 does not. While LL-37, at superstoichiometric LL-37/actin concentrations polymerizes MgATP-G-actin, at lower non-polymerizing concentrations LL-37 inhibits actin polymerization by MgCl(2 or NaCl. LL-37 bundles Mg-F-actin filaments both at low and physiological ionic strength when in equimolar or higher concentrations than those of actin. The LL-37 induced bundles are significantly less sensitive to increase in ionic strength than those induced by scrambled LL-37 and lysozyme. LL-37 in concentrations lower than those needed for actin polymerization or bundling, accelerates cleavage of both monomer and polymer actin by subtilisin. Our results indicate that the LL-37-actin interaction is partially electrostatic and partially hydrophobic and that a specific actin binding sequence in the peptide is responsible for the hydrophobic interaction. LL-37-induced bundles, which may contribute to the accumulation of sputum in cystic fibrosis, are dissociated very efficiently by DNase-1 and also by cofilin.

  15. 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

  16. Membrane formation : diffusion induced demixing processes in ternary polymeric systems

    NARCIS (Netherlands)

    Reuvers, Albertus Johannes

    1987-01-01

    In this thesis the mechanism of membrane formation by means of immersion precipitation is studied. Immersion of a concentrated polymer solution film into a nonsolvent bath induces an exchange of solvent and nonsolvent in the film by means of diffusion. This process results in an asymmetric polymer

  17. Light-induced phenomena in polymeric thin films

    Czech Academy of Sciences Publication Activity Database

    Nešpůrek, Stanislav; Pospíšil, Jan

    2005-01-01

    Roč. 7, č. 3 (2005), s. 1157-1168 ISSN 1454-4164 R&D Projects: GA MŠk ME 700 Institutional research plan: CEZ:AV0Z40500505 Keywords : Light-induced phenomena * photodegradation * photochromism Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.138, year: 2005

  18. Multifunctional poly(alkyl methacrylate) films for dental care

    International Nuclear Information System (INIS)

    Nielsen, Birthe V; Nevell, Thomas G; Barbu, Eugen; Smith, James R; Tsibouklis, John; Rees, Gareth D

    2011-01-01

    Towards the evaluation of non-permanent dental coatings for their capacity to impart dental-care benefits, thin films of a homologous series of comb-like poly(alkyl methacrylate)s (ethyl to octadecyl) have been deposited, from aqueous latex formulations, onto dentally relevant substrates. AFM studies have shown that the thickness (40-300 nm) and surface roughness (8-12 nm) of coherent polymer films are influenced by the degree of polymerization and by the length of the pendant chain. Of the polymers under consideration, poly(butyl methacrylate) formed a close-packed film that conferred to dental substrates a high degree of inhibition to acid-mediated erosion (about 27%), as evaluated by released-phosphate determinations. The potential utility of the coatings to act as anti-sensitivity barriers has been evaluated by determining the hydraulic conductance of coated bovine-dentine substrates; single treatments of dentine discs with poly(butyl methacrylate) or with poly(ethyl methacrylate) effected mean respective reductions in fluid flow of about 23% with respect to water-treated controls; repeated applications of the poly(butyl methacrylate) latex led to mean reductions in fluid flow of about 80%. Chromometric measurements have shown that pellicle-coated hydroxyapatite discs treated with poly(butyl methacrylate), poly(hexyl methacrylate) or poly(lauryl methacrylate) exhibit significant resistance to staining by food chromogens.

  19. Multifunctional poly(alkyl methacrylate) films for dental care

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Birthe V; Nevell, Thomas G; Barbu, Eugen; Smith, James R; Tsibouklis, John [School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, Hampshire, PO1 2DT (United Kingdom); Rees, Gareth D [GlaxoSmithKline R and D, St George' s Avenue, Weybridge, Surrey, KT13 0DE (United Kingdom)

    2011-02-15

    Towards the evaluation of non-permanent dental coatings for their capacity to impart dental-care benefits, thin films of a homologous series of comb-like poly(alkyl methacrylate)s (ethyl to octadecyl) have been deposited, from aqueous latex formulations, onto dentally relevant substrates. AFM studies have shown that the thickness (40-300 nm) and surface roughness (8-12 nm) of coherent polymer films are influenced by the degree of polymerization and by the length of the pendant chain. Of the polymers under consideration, poly(butyl methacrylate) formed a close-packed film that conferred to dental substrates a high degree of inhibition to acid-mediated erosion (about 27%), as evaluated by released-phosphate determinations. The potential utility of the coatings to act as anti-sensitivity barriers has been evaluated by determining the hydraulic conductance of coated bovine-dentine substrates; single treatments of dentine discs with poly(butyl methacrylate) or with poly(ethyl methacrylate) effected mean respective reductions in fluid flow of about 23% with respect to water-treated controls; repeated applications of the poly(butyl methacrylate) latex led to mean reductions in fluid flow of about 80%. Chromometric measurements have shown that pellicle-coated hydroxyapatite discs treated with poly(butyl methacrylate), poly(hexyl methacrylate) or poly(lauryl methacrylate) exhibit significant resistance to staining by food chromogens.

  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. Final report of the safety assessment of methacrylate ester monomers used in nail enhancement products.

    Science.gov (United States)

    2005-01-01

    Methacrylate ester monomers are used in as artificial nail builders in nail enhancement products. They undergo rapid polymerization to form a hard material on the nail that is then shaped. While Ethyl Methacrylate is the primary monomer used in nail enhancement products, other methacrylate esters are also used. This safety assessment addresses 22 other methacrylate esters reported by industry to be present in small percentages as artificial nail builders in cosmetic products. They function to speed up polymerization and/or form cross-links. Only Tetrahydrofurfuryl Methacrylate was reported to the FDA to be in current use. The polymerization rates of these methacrylate esters are within the same range as Ethyl Methacrylate. While data are not available on all of these methacrylate esters, the available data demonstrated little acute oral, dermal, or i.p. toxicity. In a 28-day inhalation study on rats, Butyl Methacrylate caused upper airway irritation; the NOAEL was 1801 mg/m3. In a 28-day oral toxicity study on rats, t-Butyl Methacrylate had a NOAEL of 20 mg/kg/day. Beagle dogs dosed with 0.2 to 2.0 g/kg/day of C12 to C18 methacrylate monomers for 13 weeks exhibited effects only in the highest dose group: weight loss, emesis, diarrhea, mucoid feces, or salivation were observed. Butyl Methacrylate (0.1 M) and Isobutyl Methacrylate (0.1 M) are mildly irritating to the rabbit eye. HEMA is corrosive when instilled in the rabbit eye, while PEG-4 Dimethacrylate and Trimethylolpropane Trimethacrylate are minimally irritating to the eye. Dermal irritation caused by methacrylates is documented in guinea pigs and rabbits. In guinea pigs, HEMA, Isopropylidenediphenyl Bisglycidyl Methacrylate, Lauryl Methacrylate, and Trimethylolpropane Trimethacrylate are strong sensitizers; Butyl Methacrylate, Cyclohexyl Methacrylate, Hexyl Methacrylate, and Urethane Methacrylate are moderate sensitizers; Hydroxypropyl Methacrylate is a weak sensitizer; and PEG-4 Dimethacrylate and

  2. Macromolecular Architectures Designed by Living Radical Polymerization with Organic Catalysts

    Directory of Open Access Journals (Sweden)

    Miho Tanishima

    2014-01-01

    Full Text Available Well-defined diblock and triblock copolymers, star polymers, and concentrated polymer brushes on solid surfaces were prepared using living radical polymerization with organic catalysts. Polymerizations of methyl methacrylate, butyl acrylate, and selected functional methacrylates were performed with a monofunctional initiator, a difunctional initiator, a trifunctional initiator, and a surface-immobilized initiator.

  3. Radiation-induced polymerization of unsaturated phospholipid mixtures for the synthesis of artificial red cells

    Science.gov (United States)

    Hosoi, F.; Omichi, H.; Akama, K.; Awai, K.; Endo, S.; Nakano, Y.

    1997-08-01

    Radiation induced polymerization of phospholipid containing unsaturated acyl chains was applied to the synthesis of artificial red cells. Vesicles of 1,2-bis-(2,4-octadecadienoyl)-phosphatidylcholine (DODPC) and 1-stearoyl-2-(2,4-octadecadienoyl)-phosphatidylcholine (AODPC) were irradiated by 60Co γ-rays to obtain polymerized bilayer structure of these monomers. It was found that the polymerization of unsaturated groups located at 2-acyl chain of DODPC polymerized faster than those of AODPC. The difference was explained by the packed state of these monomers in the bilayer vesicles. The artificial red cell was obtained by irradiating the mixture of DODPC or AODPC with hemoglobin, cholesterol and palmitic acid sodium salt. The integrity of the irradiated hemoglobin in the vesicle was maintained by keeping the suspended solution at low temperature. On the other hand, oxidation of heme part became remarkable when the vesicle was kept at 37°C. The presence of extra hemoglobin outside the vesicle was found useful to prevent this oxidation.

  4. Stereosequence distributions of poly(t-butyl methacrylate)s prepared with butyllithium

    International Nuclear Information System (INIS)

    Suzuki, Toshimitsu; Yamada, Osamu; Watanabe, Yoshihisa; Takegami, Yoshinobu

    1982-01-01

    13 C NMR spectra of poly(t-butyl methacrylate)s (PBMA) prepared with butyl-lithium (n-BuLi) were studied. Methylene carbon resonances appeared as five overlapped peaks, which were interpreted as a combination of hexad stereosequence distributions. The stereosequence distribution of PBMA prepared with n-BuLi at -78 0 C obeyed the first order Markov chain model even polymerized in tetrahydrofuran (THF). Syndiotactic PBMA was obtained with azobisisobutyronitrile (AIBN) as the initiator, and the stereosequence distribution of this polymer agreed well with Bernoullian statistics. (author)

  5. Radiation-induced crosslinking of polymeric micelles as nanoparticle for immobilization of bioactive compound

    International Nuclear Information System (INIS)

    Rida Tajau; Khairul Zaman Mohd Dahlan; Mohd Hilmi Mahmood; Wan Md Zin Wan Yunus; Kamaruddin Hashim; Nor Azowa Ibrahim; Maznah Ismail; Mek Zah Salleh

    2012-01-01

    The purpose of this study was to develop the bioactive-loaded polymeric nanoparticle by radiation-induced crosslinking technique. The polymeric micelles consist of acrylated palm oil (APO), anionic surfactant and aqueous solution was prepared for immobilization of bioactive compound for example the Thymoquinone (TQ). The TQ-loaded APO micelle was subjected to ionizing radiation to induce crosslinked polymeric structure of the TQ-loaded APO nanoparticle. The formation of TQ-loaded APO micro micelle and nano particle were evaluated by the Dynamic Light Scattering (DLS), the Fourier Transform Infrared (FTIR) Spectroscopy and the Transmission Electron Microscopy (TEM) for characterization the size, the shape, the chemical structure and the irradiation effect of the micelle and the nano particle. The results indicate that the size of APO micro and nano particles varies from 120 to 270 nanometer (nm) upon gamma irradiation at doses ranging from 1 to 25 kilo gray (kGy). In addition, size of the particle was found decreasing upon irradiation due to the crosslinking interaction. The study demonstrated that the APO micro-and nanoparticle can retained and controlled the release rate of the thymoquinone at up to 24 hours as determined using ultraviolet-visible (UV-Vis) spectrophotometer. These findings suggested that the ionizing radiation method can be utilized to prepare nano-size APO particles, with the presence of TQ. (author)

  6. Electron beam induced cationic polymerization of epoxy resins. Dependence of Tg on conversion

    International Nuclear Information System (INIS)

    Degrand, H.; Cazaux, F.; Coqueret, X.

    2002-01-01

    Complete text of publication follows. The high-energy radiation curing of monomer blends polymerizing by a free radical or by a cationic mechanism receives increasing attention in the perspective of high performance composite materials. In the present work, we have focused our attention on epoxy formulations as models of the matrices polymerizing by a cationic mechanism that could be used in fiber-reinforced composites for aerospace applications. We have examined the progress of the electron beam (EB) induced polymerization of diglycidylether of bisphenol A (DGEBA) in the presence of a diaryliodonium salt (DAIS) by FTIR spectroscopy and by dynamic mechanical thermal analysis (DMA). The obtained results allow to draw the gradual increase of the temperature for the network thermomechanical transition (T a , associated with the glass transition temperature T g ) over a broad range of conversion (p) and reveal a peculiar behavior at high conversion. In this domain (p > 0.90), the material's T g is shown to decrease when conversion approaches unity. Moreover, the post-irradiation thermal treatment of the materials, that generally yields effective 'dark curing', appears to induce a decrease of T g , with an amplitude correlated with the amount of DAIS in the formulation. Owing to the particular nature of the propagating centers in cationic polymerisation, the thermal relaxation of ionic clusters trapped in the glassy matrix can be reasonably invoked as a possible cause for this behavior

  7. Changes induced by gamma radiation in nanocomposites based on copper II and antimony sulfides in commercial poly(methyl methacrylate) matrix

    International Nuclear Information System (INIS)

    Albuquerque, M.C.C. de; Garcia, O.P.; Aquino, K.A.S.; Araujo, E.S.

    2010-01-01

    Poly (methyl methacrylate) (PMMA) is a polymer with wide application in the manufacture of medical devices that is exposed to gamma irradiation. Currently the use of composite materials has been disseminated and PMMA is an excellent polymer matrix to package various materials. This study aimed to analyze the changes induced by gamma irradiation (25 kGy) on the properties of PMMA nanocomposites with nanoparticles of copper II sulfide (250nm-900nm) and antimony sulfite (300-500 nm). The nanoparticles were added to the polymer in different concentrations and synthesized by ultrasonic irradiation from the corresponding chlorides with thioacetamide. Viscometric results showed a good radioprotective effect of nanoparticles of copper and antimony. It was found a good protection of nanoparticles on PMMA matrix in the concentration of 0.3% wt. The protections of 75% and 50% were calculated for nanoparticles of antimony and copper II, respectively. (author)

  8. Pressure-Induced Polymerization of Acetylene: Structure-Directed Stereoselectivity and a Possible Route to Graphane.

    Science.gov (United States)

    Sun, Jiangman; Dong, Xiao; Wang, Yajie; Li, Kuo; Zheng, Haiyan; Wang, Lijuan; Cody, George D; Tulk, Christopher A; Molaison, Jamie J; Lin, Xiaohuan; Meng, Yufei; Jin, Changqing; Mao, Ho-Kwang

    2017-06-01

    Geometric isomerism in polyacetylene is a basic concept in chemistry textbooks. Polymerization to cis-isomer is kinetically preferred at low temperature, not only in the classic catalytic reaction in solution but also, unexpectedly, in the crystalline phase when it is driven by external pressure without a catalyst. Until now, no perfect reaction route has been proposed for this pressure-induced polymerization. Using in situ neutron diffraction and meta-dynamic simulation, we discovered that under high pressure, acetylene molecules react along a specific crystallographic direction that is perpendicular to those previously proposed. Following this route produces a pure cis-isomer and more surprisingly, predicts that graphane is the final product. Experimentally, polycyclic polymers with a layered structure were identified in the recovered product by solid-state nuclear magnetic resonance and neutron pair distribution functions, which indicates the possibility of synthesizing graphane under high pressure. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Gamma Radiation -Induced Preparation of Polymeric Composite Resins and their Structure Assignments

    International Nuclear Information System (INIS)

    El-Zahhar, A.A.; Abdel-Aziz, H.M.; Siyam, T.

    2005-01-01

    Poly(acrylamide-acrylic acid). ethylenediamine tetra acetic acid disodium salt P(AM-AA). EDTANa2, Poly(acrylamide-acrylic acid)montmorillonite P(AM-AA). montmorillonite, and Poly(acrylamide acrylic acid)-potassium nickel hexacyanoferrate P(AM-AA)-KNiHCF were prepared by gamma radiation- induced template polymerization of (AA) on P(AM) as a template polymer in the presence of EDTANa2, Clay(montmorillonite), KNiHCF and KZnHCF, respectively. The capacity of the prepared P (AM-AA)-EDTANa2 and P (AM-AA)-montmorillonite composites increases with increasing of EDTANa2 and montmorillonite concentration then decreases. While the capacity of P(AM- AA). KNiHCF composites increases with increasing of KNiHCF content. The characteristic properties of prepared polymeric composites resins were studied by using FTIR spectroscopy

  10. Study on non-ionic membrane prepared by radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Hegazy, E.-S.A.; Mokhtar, S.M.; Osman, M.B.S.; Mostafa, A.E.-K.B.

    1990-01-01

    The preparation of good hydrogel supported on polymeric material was carried out by means of direct radiation-induced graft polymerization of N-vinyl-2-pyrrolidone (NVP) onto low density polyethylene films (LDPE). The optimum conditions were determined, at which the grafting process occurred and suitable degrees of grafting were obtained with a homogeneous distribution of the graft chains throughout the polymer. The effect of different inhibitors, addition of ZnCl 2 and monomer concentration on the grafting yield was also studied. Some investigations and characterization on the prepared graft copolymer were investigated and the possibility of its practical use was discussed. Mechanical properties, thermal and chemical stability and hydrophilic properties of such prepared grafted films showed a great promise in some practical applications. (author)

  11. Obtention of cationic polymeric membranes by radiation-induced grafting method

    International Nuclear Information System (INIS)

    Marin H E, H.

    1994-01-01

    Radiation-induced grafting of LDPE with the monomers, acrylic acid and methacrylic acid, has been studied. The grafting was made with several presentations of LDPE (foil, powder and pellets) by direct method using a Co 60 gamma rays. The irradiation was carried out in vacuum at room temperature at different doses (0.02 kGy - 0.2 kGy) with a rate dose of 0.8632 kGy/h. The graft yield was measured by the relation of initial and final weights. The variations of the LDPE structure was followed by infrared absorption spectroscopy and the results showed that there was important variations in LDPE structure when the dose increases. The tensile strong properties of the copolymers were investigated and it was found that the structure of LDPE was modified by the presence of chains of poly (acrylic) and poly (methacrylic) acid and this was reflected in the tensile properties of the polymer. A trial has been made in order to use the powder presentation of the copolymer like ion exchange resin first we measured volumetrically the quantity of milliequivalents per gram of carboxylic groups by titration 5 ml. of a solution 0.1 N of NaOH, which was 48 h. in contact with the copolymer, with a solution 0.1 N of HCl and we found that the quantity of milliequivalents enhance according with the irradiation dose. Finally, we made ion exchange experiments by passing a solution containing Ca +2 ions through ion exchange columns packed with the copolymer the results showed that these copolymers has good properties in retaining Ca +2 ions. We conclude that these copolymers can be used for ion exchange process however final conditions must be improved. (Author)

  12. Preparation of Rhodamine B Fluorescent Poly(methacrylic acid) Coated Gelatin Nanoparticles

    OpenAIRE

    Gan, Zhenhai; Ju, Jianhui; Zhang, Ting; Wu, Daocheng

    2011-01-01

    Poly(methacrylic acid) (PMAA)-coated gelatin nanoparticles encapsulated with fluorescent dye rhodamine B were prepared by the coacervation method with the aim to retard the release of rhodamine B from the gelatin matrix. With sodium sulfate as coacervation reagent for gelatin, a kind of biopolymer with excellent biocompatibility, the formed gelatin nanoparticles were cross-linked by formaldehyde followed by the polymerization of methacrylic acid coating. The fluorescent poly(methacrylic acid)...

  13. In Situ Monitoring of RAFT Polymerization by Tetraphenylethylene-Containing Agents with Aggregation-Induced Emission Characteristics.

    Science.gov (United States)

    Liu, Shunjie; Cheng, Yanhua; Zhang, Haoke; Qiu, Zijie; Kwok, Ryan T K; Lam, Jacky W Y; Tang, Ben Zhong

    2018-05-22

    A facile and efficient approach is demonstrated to visualize the polymerization in situ. A group of tetraphenylethylene (TPE)-containing dithiocarbamates were synthesized and screened as agents for reversible addition fragmentation chain transfer (RAFT) polymerizations. The spatial-temporal control characteristics of photochemistry enabled the RAFT polymerizations to be ON and OFF on demand under alternating visible light irradiation. The emission of TPE is sensitive to the local viscosity change owing to its aggregation-induced emission characteristic. Quantitative information could be easily acquired by the naked eye without destroying the reaction system. Furthermore, the versatility of such a technique was well demonstrated by 12 different polymerization systems. The present approach thus demonstrated a powerful platform for understanding the controlled living radical polymerization process. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. 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

  15. Synthesis, Characterization and Gold Loading of Polystyrene-Poly(pyridyl methacrylate) Core-Shell Latex Systems

    NARCIS (Netherlands)

    Oláh, A.; Hempenius, Mark A.; Vancso, Gyula J.

    2004-01-01

    In this research, novel 3-(2-pyridyl)propyl methacrylate and 3-(3-pyridyloxy)propyl methacrylate monomers were synthesized and emulsion polymerized on colloidal polystyrene seeds, resulting in core–shell latex systems. The cores and the core–shell particles were characterized by static light

  16. Structure and properties of hybrid poly(2-hydroxyethyl methacrylate)/SiO2 monoliths

    DEFF Research Database (Denmark)

    Ji, Xiangling; Jiang, Shichun; Qiu, Xuepeng

    2003-01-01

    Abstract: Hybrid poly(2-hydroxyethyl methacrylate) (PHEMA)/SiO2 monoliths were synthesized via a sol-gel process of the precursor tetraethyl orthosilicate (TEOS) and the in situ free-radical polymerization of 2-hydroxyethyl methacrylate (HEMA). The weight ratio of the starting chemicals, TEOS...

  17. Monodisperse macroporous poly(glycidyl methacrylate) microspheres coated with silica: Design, preparation and characterization

    Czech Academy of Sciences Publication Activity Database

    Grama, Silvia; Plichta, Zdeněk; Trchová, Miroslava; Kovářová, Jana; Beneš, Milan J.; Horák, Daniel

    2014-01-01

    Roč. 77, April (2014), s. 11-17 ISSN 1381-5148 R&D Projects: GA MŠk EE2.3.30.0029 Institutional support: RVO:61389013 Keywords : multistep swelling polymerization * poly(glycidyl methacrylate) * poly(2,3-dihydroxypropyl methacrylate) Subject RIV: CE - Biochemistry Impact factor: 2.515, year: 2014

  18. Radiation-induced controlled polymerization of acrylic acid by RAFT and RAFT-MADIX methods in protic solvents

    Science.gov (United States)

    Sütekin, S. Duygu; Güven, Olgun

    2018-01-01

    The kinetic investigation of one-pot synthesis of poly(acrylic acid) (PAA) prepared via gamma radiation induced controlled polymerization was reported. PAA homopolymers were prepared by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization in the presence of trithiocarbonate-based chain transfer agent (CTA) 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) and also by Reversible Addition-Fragmentation/Macromolecular Design by Inter-change of Xanthates (RAFT/MADIX) polymerization in the presence of a xanthate based CTA O-ethyl-S-(1-methoxycarbonyl) ethyl dithiocarbonate (RA1). The polymerizations were performed at room temperature by the virtue of ionizing radiation. Protic solvents were used for the RAFT polymerization of AA considering environmental profits. The linear first-order kinetic plot, close control of molecular weight by the monomer/CTA molar ratio supported that the polymerization proceeds in a living fashion. The linear increase in molecular weight with conversion monitored by Size Exclusion Chromatography (SEC) is another proof of controlling of polymerization. [Monomer]/[RAFT] ratio and conversion was controlled to obtain PAA in the molecular weight range of 6900-35,800 with narrow molecular weight distributions. Reaction kinetics and effect of the amount of RAFT agent were investigated in detail. Between two different types of CTA, trithiocarbonate based DDMAT was found to be more efficient in terms of low dispersity (Đ) and linear first-order kinetic behavior for the radiation induced controlled synthesis of PAA homopolymers.

  19. 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)

  20. Desalination by electrodialysis with the ion-exchange membrane prepared by radiation-induced graft polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seong-Ho; Han Jeong, Young; Jeong Ryoo, Jae; Lee, Kwang-Pill E-mail: kplee@kyungpook.ac.kr

    2001-07-01

    Ion-exchange membranes modified with the triethylamine [-N(CH{sub 2}CH{sub 3}){sub 3}] and phosphoric acid (-PO{sub 3} H) groups were prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto the polyolefin nonwavon fabric (PNF) and subsequent chemical modification of poly(GMA) graft chains. The physical and chemical properties of the GMA-grafted PNF and the PNF modified with ion-exchange groups were investigated by SEM, XPS, TGA, and DSC. Furthermore, electrochemical properties such as specific electric resistance, transport number of K{sup +}, and desalination were examined. The grafting yield increased with increasing reaction time and reaction temperature. The maximum grafting yield was obtained with 40% (vol.%) monomer concentration in dioxane at 60 deg. C. The content of the cation- and anion-exchange group increased with increasing grafting yield. Electrical resistance of the PNF modified with TEA and -PO{sub 3} H group decreased, while the water uptake (%) increased with increasing ion-exchange group capacities. Transport number of the PNF modified with ion-exchange group were the range of ca. 0.82-0.92. The graft-type ion-exchange membranes prepared by radiation-induced graft copolymerization were successfully applied as separators for electrodialysis. (author)

  1. Porous Polymer Drug-Eluting Coating Prepared by Radiation Induced Polymerization

    International Nuclear Information System (INIS)

    Veres, M.; Tóth, S.; Koós, M.; Beiler, B.

    2009-01-01

    Drug-eluting stents have several advantages over bare metal implants. They eliminate restenosis, the main drawback of bare metal stents. In addition the locally delivered drug is more effective and causes less side-effects. However in some cases dangerous stent thrombosis, inflammatory and allergy reactions were observed after their implantation, which first of all related to the drug-eluting coating. This project is aimed to develop a novel biocompatible nanoporous polymer layer by radiation induced polymerization that is capable of holding and eluting drugs and promotes endothelization after the release of the drug. (author)

  2. Hydrolysis of fish protein by Bacillus megaterium cells immobilized in radiation induced polymerized wood

    International Nuclear Information System (INIS)

    Ghosh, S.; Alur, M.D.; Nerkar, D.P.

    1992-01-01

    The immobilization of Bacillus megaterium cells in radiation-induced polymerized wood was studied for hydrolysis of trash fish protein. The optimum conditions and reaction kinetics for hydrolysis of protein by free and immobilized cells were found to be similar. Maximum hydrolysis occurred at 50 o C and at pH 7.5 with 15-20% (w/v) of immobilized matrix. The soluble content of the resultant hydrolysate about 2.4% (w/v). (author). 10 refs., 4 figs

  3. Porous Polymer Drug-Eluting Coating Prepared by Radiation Induced Polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Veres, M.; Tóth, S.; Koós, M. [Research Institute for Solid State Physics and Optics, Budapest (Hungary); Beiler, B. [Institute of Isotopes, HAS, Budapest (Hungary)

    2009-07-01

    Drug-eluting stents have several advantages over bare metal implants. They eliminate restenosis, the main drawback of bare metal stents. In addition the locally delivered drug is more effective and causes less side-effects. However in some cases dangerous stent thrombosis, inflammatory and allergy reactions were observed after their implantation, which first of all related to the drug-eluting coating. This project is aimed to develop a novel biocompatible nanoporous polymer layer by radiation induced polymerization that is capable of holding and eluting drugs and promotes endothelization after the release of the drug. (author)

  4. Production of plastified wood with stronger static bending strength means of polymerization induced by gamma radiation

    International Nuclear Information System (INIS)

    Silva Filho, Elias

    1999-01-01

    The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

  5. A Critical Appraisal of RAFT-Mediated Polymerization-Induced Self-Assembly

    Science.gov (United States)

    2016-01-01

    Recently, polymerization-induced self-assembly (PISA) has become widely recognized as a robust and efficient route to produce block copolymer nanoparticles of controlled size, morphology, and surface chemistry. Several reviews of this field have been published since 2012, but a substantial number of new papers have been published in the last three years. In this Perspective, we provide a critical appraisal of the various advantages offered by this approach, while also pointing out some of its current drawbacks. Promising future research directions as well as remaining technical challenges and unresolved problems are briefly highlighted. PMID:27019522

  6. 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.

  7. Comparison of a polymeric pseudostationary phase in EKC with ODS stationary phase in RP-HPLC.

    Science.gov (United States)

    Ni, Xinjiong; Zhang, Min; Xing, Xiaoping; Cao, Yuhua; Cao, Guangqun

    2018-01-01

    Poly(stearyl methacrylate-co-methacrylic acid) (P(SMA-co-MAA)) was induced as pseudostationary phase (PSP) in electrokinetic chromatography (EKC). The n-octadecyl groups in SMA were the same as that in octadecylsilane (ODS) C18 column. Thus, the present work focused on the comparison of selectivity between polymeric PSP and ODS stationary phase (SP), and the effect of organic modifiers on the selectivity of polymeric PSP and ODS SP. 1-butanol could directly interacted with PSP as a Class I modifier, and improved both of the methylene selectivity and polar group selectivity. When the analysis times were similar, the polymeric PSP exhibited better methylene selectivity and polar group selectivity. Although the hydrophobic groups were similar, the substituted benzenes elution order was different between polymeric PSP and ODS SP. Linear solvation energy relationships (LSER) model analysis found that polymeric PSP and ODS SP exhibited two same key factors in selectivity: hydrophobic interaction and hydrogen bonding acidity. But polymeric PSP exhibited relatively strong n- and π-electrons interaction to the analytes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Primary processes of the radiation-induced cationic polymerization of aromatic olefins studied by pulse radiolysis

    International Nuclear Information System (INIS)

    Brede, O.; Boes, J.; Helmstreit, W.; Mehnert, R.

    1982-01-01

    By pulse radiolysis of solutions of aromatic olefins (styrene, 1-methylstyrene, 1,1-diphenylethylene) in non-polar solvents (cyclohexane, carbon tetrachloride, n-butylchloride) the mechanism and kinetics of primary processes of radiation-induced cationic polymerization were investigated. In cyclohexane, radical cations of the olefins are generated by charge transfer from solvent cations. These cations dimerize in a diffusion-controlled reaction. The next step of chain-growth is slower by 3 to 4 orders of magnitude. In carbon tetrachloride and in n-butyl chloride growing olefin cations are produced by a reaction of radical cations with solvent as well as by addition of solvent carbonium ions to the monomer. In strongly acidic aqueous solution of olefins radical cations produced indirectly from hydroxycyclohexadienyl radicals dimerize and react in a subsequent step by deprotonation forming non-saturated dimer radicals. The reaction mechanism established shows that in the case of radiation-induced cationic polymerization it is not possible to define a uniform first step of the chain reaction. (author)

  9. Primary processes of the radiation-induced cationic polymerization of aromatic olefins studied by pulse radiolysis

    International Nuclear Information System (INIS)

    Brede, O.; Boes, J.; Helmstreit, W.; Mehnert, R.

    1981-01-01

    By pulse radiolysis of solutions of aromatic olefins (styrene, 1-methylstyrene, 1,1-diphenylethylene) in nonpolar solvents (cyclohexane, carbon tetrachloride, n-butyl chloride) the mechanism and kinetics of primary processes of radiation-induced cationic polymerization were investigated. In cyclohexane, radical cations of the olefins are generated by charge transfer from solvent cations (k about 10 11 l mol -1 s -1 ). These cations dimerize in a diffusion-controlled reaction (k approximately 10 10 l mol -1 s -1 ). The next step of chain-growth is slower by 3 to 4 orders of magnitude. Furthermore, in carbon tetrachloride and in n-butyl chloride growing olefin cations are produced by a reaction of the radical cations with the solvent as well as by addition of solvent carbonium ions to the monomer. In strongly acidic aqueous solution of olefins radical cations produced indirectly from hydroxycyclohexadienyl radicals dimerize and react in a subsequent step by deprotonation forming non-saturated dimer radicals. The established reaction mechanism shows that in the case of radiation-induced cationic polymerization it is not possible to define a uniform first step of the chain reaction. (author)

  10. Fabrication and Evaluation of 2-Hydroxyethyl Methacrylate-co ...

    African Journals Online (AJOL)

    Purpose: To fabricate and evaluate oral 2-hydroxyethyl methacrylate co-acrylic acid hydrogels as a drug delivery system for sustained release of nicorandil. Methods: HEMA-co-AA hydrogels using different monomer concentrations were prepared by free radical polymerization. N, N-methylene bis acrylamide (MBA) was ...

  11. Desalination by electrodialysis with ion-exchange membrane prepared by radiation-induced graft polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seong-Ho; Jeong, Young Han; Ryoo, Jae Jeong; Lee, Kwang-Pill [Department of Chemistry Graduate School, Kyungpook National University, Taegu (Korea)

    2000-07-01

    Ion-exchange membranes modified with triethylamine [-N(CH{sub 2}CH{sub 3}){sub 3}] and phosphoric acid (-PO{sub 3}H) groups were prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto polyolefin nonwavon fabric (PNF) and subsequent chemical modification of poly (GMA) graft chains. The physical and chemical properties of the GMA-grafted PNF and the PNF modified with ion-exchange groups were investigated by SEM and XPS. The ion-exchange capacities of the cation- and anion-exchange membrane were 0.20 and 1.24mmol/g, respectively. The content of cation- and anion exchange group increased with increasing grafting yield (d.g.=100%). Electrical resistance of PNF modified with TEA and -PO{sub 3}H group decreased with increasing ion-exchange group capacities. Application of the graft-type ion-exchange membranes as separators for electrodialysis enabled use to reduce the time required to achieve 85.5% desalination of the 0.5M NaCl solution. (author)

  12. Magnetic poly(glycidyl methacrylate)-based microspheres prepared by suspension polymerization in the presence of modified La0.75Sr0.25MnO3 nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Pollert, Emil; Trchová, Miroslava; Kovářová, Jana

    2009-01-01

    Roč. 45, č. 4 (2009), s. 1009-1016 ISSN 0014-3057 R&D Projects: GA AV ČR 1QS100100553; GA AV ČR KAN200200651 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z10100521; CEZ:AV0Z1010921 Keywords : glycidyl methacrylate * perovskite * magnetic Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.310, year: 2009

  13. Gamma-ray-induced polymerization of mixed liposomes consisting of 2,4-octadecadienoyl groups of phospholipids and unpolymerizable components

    Energy Technology Data Exchange (ETDEWEB)

    Akama, Kazuhiro; Awai, Kouji; Yano, Yoshihiro; Tokuyama, Satoru; Nakano, Yoshio [Tsukuba Research Laboratory, NOF Corporation, Tsukuba, Ibaraki (Japan); Hosoi, Fumio; Omichi, Hideki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-06-01

    We studied the {gamma}-ray-induced polymerization of two mixed-liposome systems containing 1,2-bis-[(2E,4E)-octadecadienoyl]-sn-glycero-3-phosphocholine (DODPC) to clarify its mechanism; (a) containing DODPC and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), or DODPC/DPPC liposome, and (b) containing DODPC, DPPC, Cholesterol (Chol), and stearic acid (SA), or DODPC/DPPC/Chol/SA liposomes was carried out. For each system, various molar ratios of DODPC/DPPC were studied. For DODPC/DPPC/Chol/SA liposomes, the molar ratio of phospholipid/Chol/SA was 7/7/2. Liposomes were prepared by extrusion through a 0.2-{mu}m-pore polycarbonate filter and polymerized by {gamma}-irradiation at a dose rate of 3.3 kGy/h at 4degC. Polymerization rate increased when DODPC/DPPC was 5/5 in DODPC/DPPC liposomes and when it was 9/1, 8/2, 7/3, and 5/5 in DODPC/DPPC/Chol/SA liposomes. The degree of polymerization at molar ratio 5/5 for each mixed-liposome system significantly increased compared with that of DODPC liposomes containing no DPPC. For polymerized mixed liposomes stability, mean diameter after one freeze-thaw cycle remained unchanged for molar ratios from 10/0 to 8/2 of either DODPC/DPPC or DODPC/DPPC/Chol/SA liposomes. {gamma}-Ray-induced polymerization of each mixed-liposome system was analyzed using kinetic treatment of polymerization. Although the rate of polymerization for either systems differed from that of DODPC liposomes, the polymerization mechanism was the same. Immiscibility between DODPC and unpolymerizable components was estimated based on the kinetic data of polymerization. Hydrophobic interactions of DPPC and/or Chol with DODPC significantly affected the conformation of DODPC, which rearranges into an easily polymerizable conformation. The rate and degree of polymerization thus increased. (author)

  14. Contact allergy to epoxy (meth)acrylates.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Jungewelter, Soile; Henriks-Eckerman, Maj-Len; Kuuliala, Outi; Jolanki, Riitta

    2009-07-01

    Contact allergy to epoxy (meth)acrylates, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA), 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (bis-GA), 2,2-bis[4-(methacryl-oxyethoxy)phenyl] propane (bis-EMA), 2,2-bis[4-(methacryloxy)phenyl]-propane (bis-MA), and glycidyl methacrylate (GMA) is often manifested together with contact allergy to diglycidyl ether of bisphenol A (DGEBA) epoxy resin. To analyse patterns of concomitant allergic reactions to the five epoxy (meth)acrylates in relation to exposure. We reviewed the 1994-2008 patch test files at the Finnish Institute of Occupational Health (FIOH) for reactions to the five epoxy (meth)acrylates, and examined the patients' medical records for exposure. Twenty-four patients had an allergic reaction to at least one of the studied epoxy (meth)acrylates, but specific exposure was found only in five patients: two bis-GMA allergies from dental products, two bis-GA allergies from UV-curable printing inks, and one bis-GA allergy from an anaerobic glue. Only 25% of the patients were negative to DGEBA epoxy resin. The great majority of allergic patch test reactions to bis-GMA, bis-GA, GMA and bis-EMA were not associated with specific exposure, and cross-allergy to DGEBA epoxy resin remained a probable explanation. However, independent reactions to bis-GA indicated specific exposure. Anaerobic sealants may induce sensitization not only to aliphatic (meth)acrylates but also to aromatic bis-GA.

  15. Atrazine Molecular Imprinted Polymers: Comparative Analysis by Far-Infrared and Ultraviolet Induced Polymerization

    Directory of Open Access Journals (Sweden)

    Jun Chen

    2014-01-01

    Full Text Available Atrazine molecular imprinted polymers (MIPs were comparatively synthesized using identical polymer formulation by far-infrared (FIR radiation and ultraviolet (UV-induced polymerization, respectively. Equilibrium binding experiments were carried out with the prepared MIPs; the results showed that MIPuv possessed specific binding to atrazine compared with their MIPFIR radiation counterparts. Scatchard plot’s of both MIPs indicated that the affinities of the binding sites in MIPs are heterogeneous and can be approximated by two dissociation-constants corresponding to the high- and low-affinity binding sites. Moreover, several common pesticides including atrazine, cyromazine, metamitron, simazine, ametryn, terbutryn were tested to determine their specificity, similar imprinting factor (IF and different selectivity index (SI for both MIPs. Physical characterization of the polymers revealed that the different polymerization methods led to slight differences in polymer structures and performance by scanning electron microscope (SEM, Fourier transform infrared absorption (FT-IR, and mercury analyzer (MA. Finally, both MIPs were used as selective sorbents for solid phase extraction (SPE of atrazine from lake water, followed by high performance liquid chromatography (HPLC analysis. Compared with commercial C18 SPE sorbent (86.4%–94.8%, higher recoveries of atrazine in spiked lake water were obtained in the range of 90.1%–97.1% and 94.4%–101.9%, for both MIPs, respectively.

  16. The use of radiation-induced graft polymerization for modification of polymer track membranes

    International Nuclear Information System (INIS)

    Shtanko, N.I.; Kabanov, V.Ya.; Apel, P.Yu.; Yoshida, M.

    1999-01-01

    Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called 'intelligent' materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 μm and pore density of 10 6 cm -2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl 2 ) and then exposed to the γ-rays from a 60 Co source. The transport properties of the

  17. The use of radiation-induced graft polymerization for modification of polymer track membranes

    Science.gov (United States)

    Shtanko, N. I.; Kabanov, V. Ya.; Apel, P. Yu.; Yoshida, M.

    1999-05-01

    Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called "intelligent" materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 μm and pore density of 10 6 cm -2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl 2) and then exposed to the γ-rays from a 60Co source. The transport properties of the grafted

  18. Radiation copolymerization of tributyltin methacrylate and methylmathacrylate

    International Nuclear Information System (INIS)

    Zhao Binxi; Zhu Xiaohong; Murat; Han Zhewen

    1987-01-01

    The copolymer of tributytin methacrylate and methylmethacrylate is a useful self-polishing antifouling paints materials. It was synthesized by radiation polymerization using 60 Co γ ray at room temperature. The copolymerization kinetics of the pair of monomers was studied. The relationship between the reaction rate and the dose rate was found to be R p = K p ·I -053 and the reactivity ratios were measured to be less than 1. The overall activition energy was 1.29 x 10 4 J/mol. It was supposed that the copolymerization was of radical machanism

  19. Radio-iodide uptake by modified poly (glycidyl methacrylate) as anion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Sameh H. [Atomic Energy Authority, Cairo (Egypt). Nuclear Research Center; Atomic Energy Authority, Cairo (Egypt). Second Research Reactor; Elbarbary, Ahmed M. [Atomic Energy Authority, Cairo (Egypt). Radiation Research of Polymer Chemistry Dept.; Rashad, Ghada; Fasih, T.W. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories Center

    2017-03-01

    Poly(glycidyl methacrylate) (PGMA) microspheres were prepared by radiation induced polymerization of glycidyl methacrylate (GMA) monomer. The factors affecting the degree of polymerization and yield (%) of PGMA such as type of solvent, monomer concentration, and irradiation dose were investigated. It was found that the PGMA yield (%) increases with increasing monomer concentration up to 50% and absorbed dose of 5 kGy. The resulting PGMA containing the epoxy group was chemically modified by hydroxyl amine to act as anion-exchange resin for uptake of {sup 131}I{sup -} ions. The modified PGMA (MPGMA) was characterized by Fourier transform infrared (FT-IR) spectrophotometer, thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). I-131 is produced from the fission of U-235 with low-enrichment uranium (LEU) targets in the Egyptian Second Research Reactor (ETRR-2). Separation of iodide from the radioactive solution by batchwise and column techniques was employed to determine the adsorption capacity of the MPGMA. Quality control of {sup 131}I product solution and radiochemical purity was examined by using the ascending paper chromatography method. The uptake behavior of MPGMA towards {sup 131}I{sup -} ions were studied at different experimental conditions and achieved by X-ray fluorescence (XRF). The synthesized MPGMA showed good results as anion-exchange and an effective adsorbent for uptaking {sup 131}I{sup -} ions.

  20. Production of polytetrafluoroethylene by means of polymerization induced by gamma radiation

    International Nuclear Information System (INIS)

    Sugao, A.B.

    1986-01-01

    The process of polytetrafluoroethylene (PTFE) production, is studied. The TFE monomer was prepared by pyrolisis of clorodifluoromethane (R-22) and purified by low temperature fractional distillation. The bulk polymerization of tetrafluoroethylene (TFE) induced by gamma rays from a 185 TBq (5000 Ci) Co-60 source was studied at several temperatures (0 0 C, -23 0 C e -78 0 C). The purified monomer was introduced into stainless steel cylindres of 15 and 60 ml under vacuum. Glass cylindres of 10,50 and 700 ml were also used for irradiation at -78 0 C. The polymer was obtained as white agglomerated particles. The I.R. spectra of polymer samples were consistent with those of commercial PTFE. The melting points of samples were between 327 and 331 0 C. (Author) [pt

  1. Evaluation of the compatibility induced by ionizing radiation on polymeric blends

    Energy Technology Data Exchange (ETDEWEB)

    Pino, Eddy S.; Machado, Luci D.B., E-mail: lmachado@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Feitosa, Marcos A.F. [Centro Paula Souza, Faculdade de Tecnologia da Zona Leste, Sao Paulo, SP (Brazil); Giovedi, Claudia, E-mail: claudia.giovedi@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil). Dept. de Tecnologia de Reatores Nucleares

    2011-07-01

    To produce new polymers is a costly and time consuming task. Therefore, the utilization of existing polymers in form of blends enables to obtain new polymeric materials at a competitive cost. In this sense, polymer blending has become a growing scientific and commercial development activity. In most of the cases, polymeric blends have immiscible components and this represents an unbecoming situation on blend design. For such immiscible blends, it is required the use of compatibilizers to gain properties advantage. Compatibilization process can be achieved by chemical handling using additives and heat. On the other hand, ionizing radiation induces compatibilization by free radicals, which improve the dispersion and adhesion of the blend phases, without use of chemical additives and at room temperature. In this work, a polyamide 6.6/low-density polyethylene 75/25% wt/wt composition blend was electron beam irradiated up to 250 kGy, and thereafter mechanical tests were carried out. Tensile measurements have shown that the strength at break increases, the elongation at break decreases, the resistance to impact decreases and hardness increases when the radiation dose increases. Since this mechanical behavior is due to cross-linking and to the radiation induced blend compatibilization, this compatibility was evaluated by the approach of the glass transition temperatures for both components using DMA measurements. The results have shown that the glass transition temperatures of the blend components got closer in 8 deg C in the irradiated sample, when compared to the glass transition temperature values obtained for non-irradiated blend. (author)

  2. Porous Polymer Drug-Eluting Coating Prepared by Radiation Induced Polymerization

    International Nuclear Information System (INIS)

    Veres, M.; Beiler, B.; Himics, L.; Tóth, S.; Koós, M.

    2010-01-01

    Many areas of modern medicine are almost unimaginable without the use of different kinds of implants. They used as replacements, supports, auxiliary devices etc. for various parts or functions of the body. Their use has many advantages, however there could be some drawbacks too, like the possibility of rejection, inflammation and other side-effects. Many of these drawbacks are directly related to the materials used for the implant fabrication. Coatings are widely used to eliminate the unwanted effects appearing after the implantation. In addition to the protection and separation of tissues from the implant material they could also enhance the functionality and the acceptance of the artificial device and also promote the regeneration of the tissues after the intervention. Drug-eluting coatings are a good example for the latter. By delivery and controlled elution of drugs they could actively suppress inflammatory reactions, allergy and rejection of the implant, and their activity is localized to the place where these effects could mainly occur – to the region of the implant. This project is aimed to develop a drug-eluting porous polymer coating by radiation induced polymerization that can be used in different medical implants. The primary objects for this research are coronary stents however these porous layers could have perspective in other types of medical devices too. The main objectives are to develop a method for coating the surface of medical grade metallic alloy wires, plates and tubes with a porous polymer nanocomposite layer prepared by radiation induced polymerization and to characterize the obtained coatings

  3. Evaluation of the compatibility induced by ionizing radiation on polymeric blends

    International Nuclear Information System (INIS)

    Pino, Eddy S.; Machado, Luci D.B.; Feitosa, Marcos A.F.; Giovedi, Claudia

    2011-01-01

    To produce new polymers is a costly and time consuming task. Therefore, the utilization of existing polymers in form of blends enables to obtain new polymeric materials at a competitive cost. In this sense, polymer blending has become a growing scientific and commercial development activity. In most of the cases, polymeric blends have immiscible components and this represents an unbecoming situation on blend design. For such immiscible blends, it is required the use of compatibilizers to gain properties advantage. Compatibilization process can be achieved by chemical handling using additives and heat. On the other hand, ionizing radiation induces compatibilization by free radicals, which improve the dispersion and adhesion of the blend phases, without use of chemical additives and at room temperature. In this work, a polyamide 6.6/low-density polyethylene 75/25% wt/wt composition blend was electron beam irradiated up to 250 kGy, and thereafter mechanical tests were carried out. Tensile measurements have shown that the strength at break increases, the elongation at break decreases, the resistance to impact decreases and hardness increases when the radiation dose increases. Since this mechanical behavior is due to cross-linking and to the radiation induced blend compatibilization, this compatibility was evaluated by the approach of the glass transition temperatures for both components using DMA measurements. The results have shown that the glass transition temperatures of the blend components got closer in 8 deg C in the irradiated sample, when compared to the glass transition temperature values obtained for non-irradiated blend. (author)

  4. Porous Polymer Drug-Eluting Coating Prepared by Radiation Induced Polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Veres, M.; Beiler, B.; Himics, L.; Tóth, S.; Koós, M., E-mail: vm@szfki.hu [Hungarian Academy of Sciences, Research Institute for Solid State Physics and Optics, Department of Laser Applications, Konkoly Thege Miklós ut 29-33, 1121 Budapest, P.O. Box 49, 1525 Budapest (Hungary)

    2010-07-01

    Many areas of modern medicine are almost unimaginable without the use of different kinds of implants. They used as replacements, supports, auxiliary devices etc. for various parts or functions of the body. Their use has many advantages, however there could be some drawbacks too, like the possibility of rejection, inflammation and other side-effects. Many of these drawbacks are directly related to the materials used for the implant fabrication. Coatings are widely used to eliminate the unwanted effects appearing after the implantation. In addition to the protection and separation of tissues from the implant material they could also enhance the functionality and the acceptance of the artificial device and also promote the regeneration of the tissues after the intervention. Drug-eluting coatings are a good example for the latter. By delivery and controlled elution of drugs they could actively suppress inflammatory reactions, allergy and rejection of the implant, and their activity is localized to the place where these effects could mainly occur – to the region of the implant. This project is aimed to develop a drug-eluting porous polymer coating by radiation induced polymerization that can be used in different medical implants. The primary objects for this research are coronary stents however these porous layers could have perspective in other types of medical devices too. The main objectives are to develop a method for coating the surface of medical grade metallic alloy wires, plates and tubes with a porous polymer nanocomposite layer prepared by radiation induced polymerization and to characterize the obtained coatings.

  5. Morphology and film formation of poly(butyl methacrylate)-polypyrrole core-shell latex particles

    NARCIS (Netherlands)

    Huijs, F; Lang, J

    Core-shell latex particles made of a poly(butyl methacrylate) (PBMA) core and a thin polypyrrole (PPy) shell were synthesized by two-stage polymerization. In the first stage, PBMA latex particles were synthesized in a semicontinuous process by free-radical polymerization. PBMA latex particles were

  6. Continuous ARGET ATPR of methyl methacrylate and butyl acrylate in a stirred tank reactor

    NARCIS (Netherlands)

    Chan, N.; Meuldijk, J.; Cunningham, M.F.; Hutchinson, R.A.

    2013-01-01

    ARGET ATRP (activator regenerated by electron transfer atom transfer radical polymerization) of butyl acrylate (BA) and methyl methacrylate (MMA) was successfully adapted from a batch process to a continuous stirred tank reactor (CSTR) with 50 ppm copper. A series of batch polymerizations were first

  7. Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst.

    Science.gov (United States)

    Yeow, Jonathan; Xu, Jiangtao; Boyer, Cyrille

    2016-06-08

    Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (λ = 460 nm, 0.7 mW/cm(2)), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

  8. 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)

  9. Study of fracture and stress-induced morphological instabilities in polymeric materials

    Science.gov (United States)

    Sabouri-Ghomi, Mohsen

    We study the phenomena of fracture in polymers at the molecular and continuum level. At a molecular level, we study the failure of polymer/polymer interfaces. Our main focus is on a specific mode of failure known as chain pull-out fracture, which is common to weak adhesive junctions, and polymer blends and mixtures. In the case of the interface between incompatible polymers, reinforcement is achieved by adding a block copolymer to the interface. We introduce a microscopic model based on Brownian dynamics to investigate the effect of the polymerization index N, of the block connector chain, on fracture toughness of such reinforced polymeric junctions. We consider the mushroom regime, where connector chains are grafted with low surface density, for the case of large pulling velocity. We find that for short chains the interface fracture toughness depends linearly on the polymerization index N of the connector chains, while for longer chains the dependence becomes N 3/2. We propose a scaling argument, based on the geometry of the initial configuration, that accounts for both short and long chains and the crossover between them. At the continuum level, we study the pattern selection mechanism of finger-like crack growth phenomena in gradient driven growth problems in general, and the structure of stress-induced morphological instabilities in crazing of polymer glasses in particular. We simulate solidification in a narrow channel through the use of a phase-field model with an adaptive grid. By tuning a dimensionless parameter, the Peclet number, we show a continuous crossover from a free dendrite at high Peclet numbers to anisotropic viscous fingering at low Peclet numbers. At low Peclet numbers we find good agreement between our results, theoretical predictions, and experiment, providing the first quantitative test of solvability theory for anisotropic viscous fingers. For high undercoolings, we find new phenomena, a solid forger which satisfies stability and

  10. Study on the immobilization of alpha-amylase by radiation-induced polymerization at low-temperature, (3)

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Kumakura, Minoru; Kaetsu, Isao

    1975-07-01

    The immobilization of α-amylase in high concentration (50-200 mg) by radiation induced polymerization at low temperature, with HEMA has been studied. A feature of the high concentration α-amylase system is phase separation of the mixed solution prior to polymerization, markedly at HEMA concentrations above 50%. Useful immobilization is possible, however, by irradiation of the suspended composition at -196 0 C, which is obtained by shaking the phase-separated system. At temperatures below 0 0 C, the immobilization is possible, but not above this because of the phase separation. The polymerizability of HEMA changes abruptly at 0 0 C. The largest polymerization rate is obtained at -24 0 C, possibly due to phase change by crystallization of water of the buffer solution at 0 0 C. Activity of the immobilized high-concentration α-amylase is as high as 80-85% being somewhat higher than that in the low-concentration case. (auth.)

  11. Complexation-Induced Phase Separation: Preparation of Metal-Rich Polymeric Membranes

    KAUST Repository

    Villalobos Vazquez de la Parra, Luis Francisco

    2017-08-01

    The majority of state-of-the-art polymeric membranes for industrial or medical applications are fabricated by phase inversion. Complexation induced phase separation (CIPS)—a surprising variation of this well-known process—allows direct fabrication of hybrid membranes in existing facilities. In the CIPS process, a first step forms the thin metal-rich selective layer of the membrane, and a succeeding step the porous support. Precipitation of the selective layer takes place in the same solvent used to dissolve the polymer and is induced by a small concentration of metal ions. These ions form metal-coordination-based crosslinks leading to the formation of a solid skin floating on top of the liquid polymer film. A subsequent precipitation in a nonsolvent bath leads to the formation of the porous support structure. Forming the dense layer and porous support by different mechanisms while maintaining the simplicity of a phase inversion process, results in unprecedented control over the final structure of the membrane. The thickness and morphology of the dense layer as well as the porosity of the support can be controlled over a wide range by manipulating simple process parameters. CIPS facilitates control over (i) the thickness of the dense layer throughout several orders of magnitude—from less than 15 nm to more than 6 μm, (ii) the type and amount of metal ions loaded in the dense layer, (iii) the morphology of the membrane surface, and (iv) the porosity and structure of the support. The nature of the CIPS process facilitates a precise loading of a high concentration of metal ions that are located in only the top layer of the membrane. Moreover, these metal ions can be converted—during the membrane fabrication process—to nanoparticles or crystals. This simple method opens up fascinating possibilities for the fabrication of metal-rich polymeric membranes with a new set of properties. This dissertation describes the process in depth and explores promising

  12. Characterization of A Am/MBA hydrogels prepared by radiation induced polymerization

    International Nuclear Information System (INIS)

    Mahmudi, N.; Rendevski, S.

    2012-01-01

    In this research the network structure of polyacrylamide hydrogels prepared by gamma radiation-induced polymerization has been investigated. The average molecular weight between cross-link junctions ‾M c and effective cross-link density of hydrogels were calculated from swelling data as well as shear modulus data. The mechanical tests showed that by increasing the amount of the cross linker methylenebisacrylamide (MBA) into hydrogels, the value of shear modulus G and cross-link density ν e increased, but the average molecular weight between cross-link junctions ‾M c , decreased. The ‾M c and the effective cross-link density ν e obtained from the mechanical characterization were significantly different than the values obtained from swelling experiments. These differences were attributed to the uncertainty on the value of the χ parameter used in the Flory-Rehner equations. The results have shown that simple compression analyses can be used for the determination of ν e without any need of polymer-solvent interaction parameter for its calculations from the swelling analysis. (Author)

  13. Photo polymerization-induced vertical phase separation and homeotropic alignment in liquid crystal and polymer mixtures

    International Nuclear Information System (INIS)

    Kang, Hyo; Joo, Sangwoo; Kang, Daeseung

    2012-01-01

    We presented a novel method for the homeotropic alignment of LC by using the irradiation of UV light on the LC/NOA65 mixture cell, in which the photo-initiated-polymerization-induced phase separation lowers the surface energy. When the amount of polymer content is sufficiently small, the gravel and network patterns were formed at the substrates via the vertical phase separation. We found that surface roughness plays an important role in the formation of the homeotropic alignment of LC. We also observed the alignment transition of the cells by varying the mixing ratio of LC/NOA65 or the UV radiation time. Furthermore, the present proposed method has great potential for application in display devices. For decades, studies on the alignment of liquid crystal (LC) molecules have been of significant interest due to their immediate applications for display devices and the intriguing physiochemical properties they exhibit at the surface of mixtures. Usually, homeotropic (or vertical) alignment, in which the long axes of the LC molecules are oriented in a direction perpendicular to the surface, is achieved by using surfactants such as lecithin, silanes or polyimide. Recently homeotropic alignment of liquid crystal molecules was achieved by irradiating photosensitive polymers, by doping nanoparticles into LC, by utilizing nano/micro patterns, or by incorporating self-assembled monolayers (SAMs). However, a clear understanding about the alignment mechanism is still elusive. In this paper, we report a novel method for homeotropic alignment of LC by utilizing the phase separation of LC/polymer mixtures

  14. Preparation of Dimethylaminoethylmethacrylate Grafted Polymeric Adsorbent by Using Radiation-Induced Grafting Technique for Removal of Anions

    International Nuclear Information System (INIS)

    Kavakli, P. A.

    2006-01-01

    The development of efficient separation and purification techniques is very important from industrial, environmental and economic points of view. Polymeric materials having polyfunctional groups such as carboxylic, amide, nitrile, iminodiacetic acid, amidoxime, and ammonium groups, etc., not only possess good hydrophilic properties, but also have good ion exchange properties which make them suitable for metal recovery from aqueous solutions. Radiation induced grafting is a powerful technique capable of controlling the introduction of various functional groups to the polymeric materials, keeping the original properties and especially the mechanical strength of the base material, and thus, allowing the synthesis of more stable polymeric adsorbents. The main objective of this study was to develop special polymeric adsorbents to remove NOx and PO 4 anions from aqueous systems. For this purpose, a novel nonwoven fabric was prepared by radiation-induced graft polymerization of imethylaminoethylmethacrylate (DMAEMA) onto polypropylene coated polyethylene nonwoven fabric. The trunk polymer was irradiated by electron beam at a voltage of 2 MeV and a current of 3 mA in a nitrogen atmosphere at dry-ice temperature at different doses. The degree of grafting was determined as a function of the total dose, monomer concentration, temperature, and reaction time. It was found that the degree of grafting of grafted polymer was greatly affected by reaction conditions. Grafting conditions were optimized, and about 150 % degree of grafting samples was used for further experiments. DMAEMA grafted polymer was later protonated by using acid solution to prepare adsorbent for the removal of anions. Adsorption experiments were performed in column mode for removal of phosphate. Approximately 2000 bed volumes of phosphate-free water can be produced from 10 ppb phosphate solution at high space velocity

  15. 几个二价稀土金属配合物的催化甲基丙烯酸甲酯聚合反应活性研究%Catalytic Activities of Some Organolanthanide(Ⅱ) Complexes on Methyl Methacrylate (MMA) Polymerization

    Institute of Scientific and Technical Information of China (English)

    周双六; 钱慧民; 陈国栋; 凡家喜

    2008-01-01

    研究了二价稀土金属配合物(η5:η1-C9H6CH2CH2CH2NMe2)2YbⅡ(1),[{η5:η5:η1-(C9H5CH2SiMe2NC4H8)2}EuII2(μ-Cl)]2[μ-η3:η5:η1:η3:η5:η1-(C9H5CH2SiMe2NC4H8)2]·C7H8·(C6H6)0.5(2),and[η5:η1-C9H6CH2SiMe2NC4H8]2YbⅡ(3)催化甲基丙烯酸甲酯聚合活性.探索了催化剂与MMA单体摩尔比、溶剂的极性、温度对MMA聚合反应的影响.%The catalytic activities of the organolanthanide(Ⅱ) complexes(η5:η1-C9H6CH2CH2CH2NMe2)2YbII (1),[{η5:η5:η1-(C9H5CH2SiMe2NC4H8)2}EuII2(μ-Cl)]2[μ-η3:η5:η1:η3:η5:η1-(C9H5CH2SiMe2NC4H8)2]·C7H8·(C6H6)0.5 (2), and [η5:η1-C9H6CH2SiMe2NC4H8]2YbⅡ(3) on methyl methacrylate (MMA) polymerization have been studied. The catalyst/MMA monomer mole ratio, solvents, and temperature effects on MMA polymerization were also examined.

  16. 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

  17. Study on the immobilization of alpha-amylase by radiation-induced polymerization at low-temperature, (2)

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Kumakura, Minoru; Kaetsu, Isao

    1975-07-01

    The immobilization α-amylase in low concentration (50-250μg) by radiation induced polymerization at low temperature, with HEMA has been studied. The immobilization was performed in the temperature range of -196 0 C to +40 0 C. Activity of the immobilized enzyme decreases at temperatures above 0 0 C. The optimum temperatures for immobilization of α-amylase are -78 0 C - -24 0 C, where only the polymerization by irradiation is effective. HEMA is a suitable monomer as the immobilization carrier, because of its high polymerization rate of 100% in the temperature range. The suitable concentration of HEMA is less than 30%, and above this concentration the activity of enzyme decreases considerably. The optimum irradiation dose for immobilization is 1 x 10 6 R, and the activity of enzyme decreases at 5 x 10 6 R. The polymerization composition is porous gel structure, so the enzymatic reaction can be carried out merely by introducing a substrate to the composition. The activity attained in the immobilized enzyme is 75-80% that of the native α-amylase. The immobilized enzyme is more heat-resistant than the native one. (auth.)

  18. Ecological approach to graphene oxide reinforced poly (methyl methacrylate) nanocomposites.

    Science.gov (United States)

    Morimune, Seira; Nishino, Takashi; Goto, Takuya

    2012-07-25

    Graphene oxide (GO) possesses the desirable characteristic of aqueous solution processability attributed to the oxygen-containing functional groups on the basal planes and edges of graphene. To provide an alternative to conventional procedures for fabricating poly (methyl methacrylate) (PMMA)/GO nanocomposites, which use organic solutions and/or surfactants, we have developed an environmentally friendly technique in which PMMA is polymerized by soap-free emulsion polymerization and incorporated with GO using water as a processing medium. Experimental results showed that the fabricated PMMA/GO nanocomposites had excellent mechanical, thermal, and O2 barrier properties with the nanodispersion of GO.

  19. Influência das condições reacionais nas características de copolímeros de metacrilato de metila e divinilbenzeno obtidos por polimerização em suspensão Influence from the reaction conditions on the characteristics of methyl methacrylate-divinylbenzene copolymers obtained by suspension polymerization

    Directory of Open Access Journals (Sweden)

    Anelise M. Cardoso

    2004-09-01

    Full Text Available Foram sintetizados copolímeros esféricos e porosos à base de metacrilato de metila e divinilbenzeno através de polimerização em suspensão aquosa utilizando metil-etil-cetona (MEK e ciclo-hexano (CH como diluentes. Diferentes estruturas morfológicas foram obtidas através da modificação dos parâmetros reacionais tais como teor de divinilbenzeno e razão MEK/CH. Os copolímeros foram caracterizados por porosimetria de mercúrio, análise de área específica, densidade aparente e microscopia ótica. Foram obtidas estruturas macroporosas com os teores mais altos do DVB e do diluente não-solvatante (CH.Spherical and porous copolymers based on methyl methacrylate and divinylbenzene were synthesized by aqueous suspension polymerization using methyl-ethyl-ketone (MEK and cyclohexane (CH as diluents. Different morphological structures were obtained by modifying the reaction parameters, such as divinylbenzene content and MEK/CH ratio. The copolymers were characterized by several techniques: mercury porosimetry, specific superficial area analyzer, apparent density and optical microcopy. Macroporous structures were obtained when using high content of DVB and of nonsolvatant diluent (CH.

  20. Acetone-induced Polymerization of 3-Aminopropyltrimethoxysilane (APTMS) as Revealed by NMR Spectroscopy - Revisited.

    Czech Academy of Sciences Publication Activity Database

    Schraml, Jan; Korec, S.; Krump, M.; Čermák, Jan

    2015-01-01

    Roč. 53, č. 2 (2015), s. 154-159 ISSN 0749-1581 Institutional support: RVO:67985858 Keywords : NMR * polymerization * 3-aminopropyltrimethoxysilane Subject RIV: CC - Organic Chemistry Impact factor: 1.226, year: 2015

  1. Radiation-induced cationic polymerization of isobutylene-isopene systems: advantages and disadvantages compared to catalytic initiation

    International Nuclear Information System (INIS)

    Williams, F.; Shinkawa, A.; Kennedy, J.P.

    1976-01-01

    The cationic copolymerization of isobutylene (1) with isoprene (2) has been induced by γ-irradiation of dry comonomer systems in bulk. Although the polymer conversion per unit dose is reduced about a thousand-fold by the addition of 3 mole % isoprene to isobutylene, the molecular weight of the copolymer is comparable to that of the homopolymer of isobutylene prepared at the same polymerization temperature. The copolymer composition corresponds closely to that of the monomer feed up to 7.1 mole % isoprene. The results are consistently accounted for by postulating that the slow step in the kinetic chain is the cross-propagation reaction described by the rate constant k/sub p21/ with an estimated value of 3 x 10 8 M -1 sec -1 at 0 0 C, this constant being much less than k/sub p12/ similarly ordered k/sub p11/ = 1.5 x 10 8 M -1 sec -1 . The viscosity-average molecular weights of the radiation-induced copolymers are about a factor of ten higher than those produced by BF 3 , AlEtCl 2 , and AlCl 3 at the same polymerization temperature. This effect is similar to that observed previously for the homopolymers of isobutylene and is attributed to the free-ion character of the radiation-induced polymerization. Despite this advantage enjoyed by the γ-irradiation method, it is subject to various practical limitations, of which the foremost is the inability to tolerate suitable solvents such as methyl chloride without sacrificing a large reduction in polymerization rate

  2. Synthesis of polyphenylacetylene by radiation-induced polymerization in deoxycholic acid clathrate

    International Nuclear Information System (INIS)

    Cataldo, Franco; Strazzulla, Giovanni; Iglesias-Groth, Susana

    2009-01-01

    Phenylacetylene was polymerized as inclusion compound (clathrate) inside deoxycholic acid (DOCA) crystals. The polymerization was initiated by γ radiation and a total dose of 320 kGy was employed. The resulting polyphenylacetylene (PPA) was isolated by dissolution of deoxycholic acid in boiling ethanol. PPA high polymer was accompanied by a series of phenylacetylene oligomers, which were detected by liquid chromatographic analysis (HPLC). PPA was characterized by electronic absorption spectroscopy and by FT-IR spectroscopy in comparison to a reference PPA prepared by a stereospecific catalyst. The microstructure of PPA from inclusion polymerization was highly trans type, similar to that observed on PPA prepared by bulk radiolysis. No optical activity was detected by polarimetry on PPA prepared by inclusion polymerization. The host-guest complex PPA/DOCA was studied by differential thermal analysis (DTA) and by thermogravimetry (TGA). DTA provided evidences of the host-guest complex formation from the shift of the melting point of DOCA while the TGA confirmed the identity - in terms of thermal behaviour - of the PPA from inclusion polymerization with that from stereospecific polymerization

  3. Radiation-induced heterogeneous polymerization of acrylamide in acetone and acetone--water mixtures

    International Nuclear Information System (INIS)

    Wada, T.; Sekiya, H.; Machi, S.

    1975-01-01

    The effects of temperature, dose rate, and monomer concentration on the heterogeneous polymerization of acrylamide in acetone--water mixtures have been studied. Heterogeneous polymerization takes place in mixtures containing less than 60 vol-percent water. The polymerization is steady in acetone and nonsteady in mixtures containing 10 to 50 vol-percent water. The average rate of polymerization is highest in mixtures with about 20 vol-percent water. Polymer molecular weight increases with the increasing water content in the range 0 to 10 vol-percent and does not change in the range of 30 to 70 vol-percent water. For the polymerization in acetone and an acetone-water 60/40 mixture, the activation energies are 2.3 and -1.8 kcal/mole, the dose rate exponents of rate are 0.78 and 0.52, and the monomer concentration exponents of rate are 0.5 and 1.6, respectively. The polymer molecular weight increases with decreasing dose rate, decreasing temperature, and increasing monomer concentration. These results are discussed in connection with the mechanism of heterogeneous polymerization and the solvent effect

  4. Radiation-induced cationic polymerization of limonene oxide, α-pinene oxide, and β-pinene oxide

    International Nuclear Information System (INIS)

    Aikins, J.A.; Williams, F.

    1984-01-01

    After suitable drying, the subject monomers in the form of neat liquids undergo radiation-induced polymerization with no apparent side reactions and high conversions to precipitatable polymers of low molecular weight. A cationic mechanism is evidenced by the strongly retarding effect of tri-n-propylamine on the polymerization rate. At 25 0 C, limonene oxide gives the highest polymerization rates, an average conversion of 36% per Mrad being obtained in comparison with values of 5.7 and 7.3% per Mrad for the α-pinene and β-pinene oxides, respectively. Similarly, the average anti DP/sub n/ decreases from 11.8 for the limonene oxide polymer to 5.6 and 4.0 for the α-pinene oxide and β-pinene oxide polymers, respectively. A high frequency of chain transfer to monomer is indicated in each case by the fact that the kinetic chain lengths are estimated to be on the order of a hundred times larger than the anti DP/sub n/ values. Structural characterization of the limonene oxide polymer by 1 H and 13 C NMR spectroscopy provides conclusive evidence that the polymerization proceeds by the opening of the epoxide ring to yield a 1,2-trans polyether. Similar NMR studies on the polymers formed from the α-pinene and β-pinene oxides show that in the polymerization of these monomers, the opening of the epoxide ring is generally accompanied by the concomitant ring opening of the cyclobutane ring structure to yield a gem-dimethyl group in the main chain. The detection of isopropenyl end groups in the pinene oxide polymers is also consistent with this mode of propagation being followed by chain (proton) transfer to monomer

  5. Casting of organic glass by radiation-induced polymerization of glass-forming monomers at low temperature. II. Optical strain of remaining stress type

    International Nuclear Information System (INIS)

    Okubo, H.; Yoshii, F.; Kaetsu, I.; Honda, S.

    1978-01-01

    Previously it was found that casting could be carried out efficiently without strain formation by radiation-induced polymerization of glass-forming monomers. Two types of strain were observed in casting: thermal stream type, which was studied previously, and remained stress type. In this report, the effect of various factors on the formation of remaining stress-type strain in radiation-induced casting polymerization was studied. It was found that the molecular weight of prepolymer did not affect strain formation, while prepolymer concentration and viscosity of the system had a serious influence on strain formation. It could be deduced that this type of strain formed as a result of remaining inner stress due to poor relaxation of the shrinking stress. It was realized that less volume shrinkage of glass-forming monomers accompanying casting polymerization reduced the strain formation of this type in radiation-induced casting polymerization at low temperatures

  6. A gelatin-free model system for the study of the basic radiation-induced polymerization in PAG dosimeters

    International Nuclear Information System (INIS)

    Babic, S; Park, Y S; Schreiner, L J

    2004-01-01

    In this presentation we show results of investigations on gelatin-free dosimeters containing equal amounts of acrylamide and N,N'-methylene-bisacrylamide (named Aqueous Polyacrylamide, APA, dosimeters). The dosimeters were prepared with three different total monomer concentrations (2, 6, and 8% by weight). Nuclear magnetic resonance (NMR) spin-spin and spin-lattice proton relaxation measurements at 20 MHz, and gravimetric analyses performed on all three dosimeters, show a continuous degree of polymerization over the range of dose 0.5 - 25 Gy. The developed NMR model explains the relationship observed between the relaxation data and the amount of cross-linked polymer formed at each dose. This model may be extended with gelatin relaxation data to provide a fundamental understanding of radiation-induced polymerization in the conventional PAG dosimeters

  7. Radiation-induced cationic polymerization of limonene oxide, α-pinene oxide, and β-pinene oxide

    International Nuclear Information System (INIS)

    Aikins, J.A.; Williams, F.

    1985-01-01

    After suitable drying, the subject monomers in the form of neat liquids undergo radiation-induced polymerization with no apparent side reactions and high conversions to precipitatable polymers of low molecular weights. A high frequency of chain (proton) transfer to monomer is indicated by the fact that the kinetic chain lengths are estimated to be several hundred times larger than the range of DP/sub n/ values (12-4). Structural characterization of the limonene oxide polymer by 1 H and 13 C NMR spectroscopy provides conclusive evidence that the polymerization proceeds by the opening of the epoxide ring to yield a 1,2-trans polyether. Similar NMR studies on the polymers formed from the α-pinene and β-pinene oxides show that the opening of the epoxide ring for these monomers is generally accompanied by the concomitant ring opening of the cyclobutane ring structure to yield a gem-di-methyl group in the main chain

  8. Radiation induced polymerization of MMA in imidazolium ionic liquids and their mixed solutions with organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Qi Mingying [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai 201800 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu Guozhong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai 201800 (China)], E-mail: wuguozhong@sinap.ac.cn; Sha Maolin; Liu Yusheng [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai 201800 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China)

    2008-10-15

    Considerably higher molecular weight (M{sub w}) and multi-modal molecular weight distribution (MWD) of poly(methyl methacrylate) (PMMA) were observed in neat ionic liquids ([bmim][PF{sub 6}] and [bmim][BF{sub 4}]), as well as their mixed solutions with organic solvents, probably due to the high viscosity and inhomogeneity of ionic liquids. FTIR spectra for PMMA showed that a slight amount of ionic liquid remained in the resulting polymer, and DSC measurement indicated the increase of glass transition point of PMMA with increasing of ionic liquid fraction in mixed solutions.

  9. Graft copolymers of polyurethane with various vinyl monomers via radiation-induced miniemulsion polymerization: Influential factors to grafting efficiency and particle morphology

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

    Graft copolymers of polyurethane (PU) with various vinyl monomers were synthesized through a one-pot but two-step miniemulsion polymerization process. Firstly, the polycondensation of isophorone diisocyanate (IPDI) with hydroxyl-terminated polybutadiene (HTPB) had been performed in aqueous miniemulsion at 40 deg. C in order to obtain PU dispersions. Consecutively, an in-situ graft copolymerization of the vinyl monomers with the synthesized PU was initiated by {gamma}-ray radiation at room temperature. The grafting efficiency of PU with vinyl monomer (G{sub PU/monomer}) was calculated from {sup 1}H NMR spectra and the particle morphology of the final hybrid latex was observed by transmission electron microscopy (TEM). As there was no monomer transferring in miniemulsion system, homogenous hybrid particles would be synthesized provided that the monomer was miscible with PU, such as styrene. With the increase of the polarity of the monomer, the compatibility of PU with monomer decreased. G{sub PU/monomer} varied as G{sub PU/styrene}(37%)>G{sub PU/butyl} {sub acrylate} {sub (BA)}(21%)>G{sub PU/methyl} {sub methacrylate} {sub (MMA)}(12%). The proportion of homogeneous nucleation would increase as the hydrophilicity of the monomer increased. High temperature would destabilize the miniemulsion so as to result in a less grafting efficiency. Compared to the phase separation during the seeded emulsion polymerization, the miniemulsion polymerization method facilitated the preparation of homogeneous materials owing to its monomer droplet nucleation mechanism.

  10. Functionalized polymer film surfaces via surface-initiated atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Hu, Y.; Li, J.S.; Yang, W.T.; Xu, F.J.

    2013-01-01

    The ability to manipulate and control the surface properties of polymer films, without altering the substrate properties, is crucial to their wide-spread applications. In this work, a simple one-step method for the direct immobilization of benzyl chloride groups (as the effective atom transfer radical polymerization (ATRP) initiators) on the polymer films was developed via benzophenone-induced coupling of 4-vinylbenzyl chloride (VBC). Polyethylene (PE) and nylon films were selected as examples of polymer films to illustrate the functionalization of film surfaces via surface-initiated ATRP. Functional polymer brushes of (2-dimethylamino)ethyl methacrylate, sodium 4-styrenesulfonate, 2-hydroxyethyl methacrylate and glycidyl methacrylate, as well as their block copolymer brushes, have been prepared via surface-initiated ATRP from the VBC-coupled PE or nylon film surfaces. With the development of a simple approach to the covalent immobilization of ATRP initiators on polymer film surfaces and the inherent versatility of surface-initiated ATRP, the surface functionality of polymer films can be precisely tailored. - Highlights: ► Atom transfer radical polymerization initiators were simply immobilized. ► Different functional polymer brushes were readily prepared. ► Their block copolymer brushes were also readily prepared

  11. Polymerized-Type I Collagen Induces Upregulation of Foxp3-Expressing CD4 Regulatory T Cells and Downregulation of IL-17-Producing CD4+ T Cells (Th17 Cells in Collagen-Induced Arthritis

    Directory of Open Access Journals (Sweden)

    Janette Furuzawa-Carballeda

    2012-01-01

    Full Text Available Previous studies showed that polymerized-type I collagen (polymerized collagen exhibits potent immunoregulatory properties. This work evaluated the effect of intramuscular administration of polymerized collagen in early and established collagen-induced arthritis (CIA in mice and analyzed changes in Th subsets following therapy. Incidence of CIA was of 100% in mice challenged with type II collagen. Clinimorphometric analysis showed a downregulation of inflammation after administration of all treatments (P<0.05. Histological analysis showed that the CIA-mice group had extensive bone erosion, pannus and severe focal inflammatory infiltrates. In contrast, there was a remarkable reduction in the severity of arthritis in mice under polymerized collagen, methotrexate or methotrexate/polymerized collagen treatment. Polymerized Collagen but not methotrexate induced tissue joint regeneration. Polymerized Collagen and methotrexate/polymerized collagen but not methotrexate alone induces downregulation of CD4+/IL17A+ T cells and upregulation of Tregs and CD4+/IFN-γ+ T cells. Thus, Polymerized Collagen could be an effective therapeutic agent in early and established rheumatoid arthritis by exerting downregulation of autoimmune inflammation.

  12. Highly efficient and selective pressure-assisted photon-induced polymerization of styrene

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Jiwen [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada); Song, Yang, E-mail: yang.song@uwo.ca [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada); Department of Chemistry, University of Western Ontario, London, Ontario N6A 5B7 (Canada)

    2016-06-07

    The polymerization process of condensed styrene to produce polystyrene as an industrially important polymeric material was investigated using a novel approach by combining external compression with ultraviolet radiation. The reaction evolution was monitored as a function of time and the reaction products were characterized by in situ Fourier transform infrared spectroscopy. By optimizing the loading pressures, we observed highly efficient and selective production of polystyrene of different tacticities. Specifically, at relatively low loading pressures, infrared spectra suggest that styrene monomers transform to amorphous atactic polystyrene (APS) with minor crystalline isotactic polystyrene. In contrast, APS was found to be the sole product when polymerization occurs at relatively higher loading pressures. The time-dependent reaction profiles allow the examination of the polymerization kinetics by analyzing the rate constant and activation volume as a function of pressure. As a result, an optimized pressure condition, which allows a barrierless reaction to proceed, was identified and attributed to the very desirable reaction yield and kinetics. Finally, the photoinitiated reaction mechanism and the growth geometry of the polymer chains were investigated from the energy diagram of styrene and by the topology analysis of the crystal styrene. This study shows strong promise to produce functional polymeric materials in a highly efficient and controlled manner.

  13. Controlled release of potassium chloride from radiation-polymerized copolymer matrices

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Kumakura, Minoru; Kaetsu, Isao

    1979-01-01

    Release behavior of potassium chloride (KCl) from the flat circular copolymer composites, obtained by radiation-induced polymerization at low temperatures, was studied. The release rate agreed with the first-order kinetics based on the Noyes-Whitney equation in relation to the swelling of the composites. Release profiles of KCl from copolymer composites was affected by monomer composition between hydroxyethyl acrylate (HEA) and polyfunctional glass-forming monomers such as 2-hydroxyethyl methacrylate (HEMA), diethylene glycol dimethacrylate (DGDA), and trimethylolpropane trimethacrylate (TMPT) owing to change of swelling property of copolymers. The release rate decreased at HEA-poor composition in any system. In the case of hydrophobic comonomer system such as glycidyl methacrylate (GMA) and DGDA, release profile of KCl showed a minimum at 50% GMA-50% DGDA monomer composition. (author)

  14. Glass transition of poly (methyl methacrylate) filled with nanosilica and core-shell structured silica

    DEFF Research Database (Denmark)

    Song, Yihu; Bu, Jing; Zuo, Min

    2017-01-01

    transition and segmental dynamics of PMMA in the nanocomposites prepared via solution casting was compared. The remarkable depression (≥10 °C) of glass transition temperature (Tg) induced by the incorporation of SiO2 and CS was both observed at low loadings. Here, different mechanisms were responsible...... for the effect of SiO2 and CS on the segmental acceleration of PMMA matrix. The formation of rigid amorphous fraction (RAF) layer around SiO2 with the thickness of 16.4 nm led to the adjacent molecular packing frustration, while the “lubrication” effect of nonwetting interface between the grafted crosslinked......Core-shell (CS) nanocomposite particles with 53.4 wt% cross-linked poly (methyl methacrylate) (PMMA) shell of 11.6 nm in thickness were fabricated via miniemulsion polymerization of methyl methacrylate in the presence of modified nanosilica. The influence of nanosilica and CS nanoparticles on glass...

  15. Radiation induced solid-state polymerization of long-chain acrylates containing fluorocarbon chain

    International Nuclear Information System (INIS)

    Shibasaki, Y.; Zhu, Zhi-Qin

    1995-01-01

    γ-Ray irradiation post-polymerizations of long-chain acrylates containing fluorocarbon chain, H(CF 2 ) 10 CH 2 OCOCH=CH 2 and H(CF 2 ) 8 CH 2 OCOCH=CH 2 , were investigated and also the structures and thermal properties of comb-like polymers obtained were studied. It was found that these monomers exhibited very high polymerizability at wide temperature ranges around the melting points. Because the fluorocarbon chains are less flexible and thicker than the hydrocarbon chains, it can be expected that the aggregation force among the monomer molecules is strong and the conformational freedom of functional group for polymerization is large. According to the DSC and the X-ray diffraction measurements of the comb-like polymers obtained, the fluorocarbon chains are aggregated in a mode of hexagonal packing in the lamellar crystals. This situation can be considered as an optimum condition for the γ-ray irradiation post-polymerization. (author)

  16. In situ polymerization of vinyl monomers in polyester yarns

    International Nuclear Information System (INIS)

    Avny, Y.; Rebenfeld, L.; Weigmann, H.D.

    1978-01-01

    The effects of a pretreatment of polyester (PET) yarns with a strongly interacting solvent such as dimethylformamide (DMF) on vinyl monomer incorporation were investigated. When the DMF pretreatment is carried out at high temperatures (above 120 0 C), the swollen PET structure is stabilized by solvent-induced secondary crystallization. This substrate is highly suitable for the incorporation of vinyl monomers. In situ polymerization of vinyl monomers in DMF-treated PET was investigated using chemical and γ-irradiation polymerization techniques, both in the presence and in the absence of excess monomer outside the PET fibers. When polymerization was carried out in a system in which a constant supply of free radicals was available from the outside of the PET fibers, lower initiator concentrations and smaller γ-irradiation doses were necessary. These results are attributed to a low efficiency of the initiator inside the PET fiber due to mobility restrictions. Water uptake and moisture regain of PET yarns containing poly(hydroxyethyl methacrylate) and poly(acrylic acid) were also investigated. When most of the vinyl polymer was inside the PET fiber, water absorption was limited. The changes in mechanical properties of the PET yarns resulting from the DMF pretreatment were partially reversed by in situ polymerization of vinyl monomers

  17. Studies on entrapping of enzymes and drugs in matrices by radiation-induced polymerization at low temperatures and their capabilities

    International Nuclear Information System (INIS)

    Yoshida, Masaru

    1980-03-01

    The author has studied a immobilization method for enzymes and drugs by means of radiation-induced polymerization at low temperatures in a supercooled state using glass-forming monomers. The proposed technique using glass-forming monomer has features as follows. (1) Inactivation of the bio-component by heat and radiation is almost eliminated due to the low temperature treatment. (2) Moulding or shaping of the mixture of monomer and bio-component in difference forms and sizes of polymerized composite is easy due to high viscosity of the supercooled monomer. (3) The carrier matrix may be selected from a wide range of hydrophilic and hydrophobic vinyl monomers and polymers. (4) No impurities such as a polymerization catalyst are introduced in the system. (5) A bio-component can be easily distributed in high stability, either concentrated on surface of the monomer or homogeneously within the monomer, due to large viscosity of the monomer. Furthermore, the author attempted practical usage of the technique in such as enzyme fixation for long continuous or repeated application (PART I) and controlled slow release of medicine in efficient and durable without secondary reaction (PART II). (author)

  18. Band structure of cavity-type hypersonic phononic crystals fabricated by femtosecond laser-induced two-photon polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Rakhymzhanov, A. M.; Utegulov, Z. N., E-mail: zhutegulov@nu.edu.kz, E-mail: fytas@mpip-mainz.mpg.de [Department of Physics, School of Science and Technology, Nazarbayev University, Astana 010000 (Kazakhstan); Optics Laboratory, National Laboratory Astana, Nazarbayev University, Astana 10000 (Kazakhstan); Gueddida, A. [Institut d' Electronique, Microélectronique et Nanotechnologie, 59650 Villeneuve d' Ascq (France); LPMR, Département de Physique, Faculté des Sciences, Université Mohamed I, 60000 Oujda (Morocco); Alonso-Redondo, E. [Max Planck Institute of Polymer Research, Ackermannweg 10, 55128 Mainz (Germany); Perevoznik, D.; Kurselis, K. [Laser Zentrum Hannover e.V., 30419 Hannover (Germany); Chichkov, B. N. [Laser Zentrum Hannover e.V., 30419 Hannover (Germany); Institute of Laser and Information Technologies RAS, Moscow, 142092 Troitsk (Russian Federation); El Boudouti, E. H. [LPMR, Département de Physique, Faculté des Sciences, Université Mohamed I, 60000 Oujda (Morocco); Djafari-Rouhani, B. [Institut d' Electronique, Microélectronique et Nanotechnologie, 59650 Villeneuve d' Ascq (France); Fytas, G., E-mail: zhutegulov@nu.edu.kz, E-mail: fytas@mpip-mainz.mpg.de [Max Planck Institute of Polymer Research, Ackermannweg 10, 55128 Mainz (Germany); Department of Materials Science, University of Crete and FORTH, 71110 Heraklion (Greece)

    2016-05-16

    The phononic band diagram of a periodic square structure fabricated by femtosecond laser pulse-induced two photon polymerization is recorded by Brillouin light scattering (BLS) at hypersonic (GHz) frequencies and computed by finite element method. The theoretical calculations along the two main symmetry directions quantitatively capture the band diagrams of the air- and liquid-filled structure and moreover represent the BLS intensities. The theory helps identify the observed modes, reveals the origin of the observed bandgaps at the Brillouin zone boundaries, and unravels direction dependent effective medium behavior.

  19. A new lithography of functional plasma polymerized thin films

    International Nuclear Information System (INIS)

    Kim, Sung-O

    2001-01-01

    The preparation of the resist for the vacuum lithography was carried out by plasma polymerization. The resist manufactured by plasma polymerization is a monomer produced by MMA (Methyl methacrylate). The functional groups of MMA appeared in the PPMMA (Plasma Polymerized Methyl methacrylate) as well, and this was confirmed through an analysis using FT-IR. The polymerization rate increased as a function of the plasma power and decreased as a function of the system pressure. The sensitivity and contrast of the plasma polymerized thin films were 15 μC/cm2 and 4.3 respectively. The size of the pattern manufactured by Vacuum Lithography using the plasma polymerized thin films was 100 nm

  20. Radiation-induced grafting polymerization of MMA onto polybutadiene rubber latex

    International Nuclear Information System (INIS)

    Peng Jing; Wang Maolin; Qiao Jinliang; Wei Genshuan

    2005-01-01

    The grafting of methyl methacrylate (MMA) onto polybutadiene rubber latex by the direct radiation method was carried out. The effects of monomer concentration, absorbed dose and dose rate of gamma rays on the grafting yield were investigated. The graft copolymers were characterized by transmission electron microscopy (TEM), FTIR spectroscopy, and differential scanning calorimetry. TEM photographs revealed that the core-shell structures of latex particles are formed at low MMA content, and with the increasing of MMA content, the semi-IPN-like structure with core-shell could be developed due to the high gel fraction of polybutadiene (PBD) seed particles. In addition, infrared analysis confirmed that MMA could be grafted onto PBD molecular chains effectively under appropriate irradiation conditions. The interfacial adhesion between PBD rubber (core) and PMMA (shell) phases could be enhanced with the increase of MMA concentration

  1. Copolymerization of poly (ethylene oxide) and poly (methyl methacrylate) initiated by ceric ammonium nitrate

    International Nuclear Information System (INIS)

    Gomes, A.S.; Ferreira, A.A.; Coutinho, F.M.B.; Marinho, J.R.D.

    1984-01-01

    Cerium (IV) salts such as the ceric ammonium nitrate and ceric ammonium sulfate in aqueous acid solution with reducing agents such as alcohols, thiols, glycols, aldehydes and amines are well known initiators of vinyl polymerization. In this work, the polymerization of methyl methacrylate initiated by ceric ammonium nitrate/HNO 3 -poly(ethylene oxide) with hydroxyl end group system was studied in aqueous solution at 25 0 C to obtain block copolymers. (Author) [pt

  2. Synthesis, characterization and photoinduced curing of polysulfones with (methacrylate functionalities

    Directory of Open Access Journals (Sweden)

    Cemil Dizman

    2010-06-01

    Full Text Available The UV-curable telechelic polysulfones with (methacrylate functionalities were synthesized by condensation polymerization and subsequent esterification. The final polymers and intermediates at various stages were characterized by 1H NMR, FT-ATR, and GPC. The oligomeric films prepared from the appropriate solutions containing these telechelics and 2,2-dimethoxy-2-phenylacetophenone (DMPA as the photoinitiator undergo rapid polymerization upon irradiation forming insoluble networks. The photo-curing behavior was investigated by photo-DSC and the effects of the molecular weight of the polysulfone precursor and type of functionality on the rate of polymerization and conversion were evaluated. Thermal properties of the photochemically cured films were studied by differential scanning calorimeter (DSC and thermal gravimetric analysis (TGA.

  3. Injection profiles with radiation induced copolymers

    International Nuclear Information System (INIS)

    Knight, B.L.; Rhudy, J.S.; Gogarty, W.B.

    1976-01-01

    The injectivity profile of a heterogeneous formation and/or vertical conformance is improved by injecting an aqueous solution into the formation, the solution containing a polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in a 10 to 60 percent aqueous solution with gamma radiation; the aqueous monomer solution preferably contains 25 to 99 percent acrylamide and 1 to 75 percent sodium acrylate. Immiscible, miscible, or miscible-like displacing processes can be used in conjunction with this invention. 20 claims

  4. Multifunctional methacrylate-based coatings for glass and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pospiech, Doris, E-mail: pospiech@ipfdd.de [Leibniz-Institut für Polymerforschung Dresden e. V., Dresden (Germany); Jehnichen, Dieter [Leibniz-Institut für Polymerforschung Dresden e. V., Dresden (Germany); Starke, Sandra; Müller, Felix [Leibniz-Institut für Polymerforschung Dresden e. V., Dresden (Germany); Technische Universität Dresden, Organic Chemistry of Polymers, Dresden (Germany); Bünker, Tobias [Leibniz-Institut für Polymerforschung Dresden e. V., Dresden (Germany); Wollenberg, Anne [Leibniz-Institut für Polymerforschung Dresden e. V., Dresden (Germany); Technische Universität Dresden, Organic Chemistry of Polymers, Dresden (Germany); Häußler, Liane; Simon, Frank; Grundke, Karina; Oertel, Ulrich [Leibniz-Institut für Polymerforschung Dresden e. V., Dresden (Germany); Opitz, Michael; Kruspe, Rainer [IDUS Biologisch Analytisches Umweltlabor GmbH, Ottendorf-Okrilla (Germany)

    2017-03-31

    Highlights: • New methacrylate-based copolymers synthesized by free radical polymerization. • Comonomer AAMA was able to complex Cu (II) ions in solvent annealing procedure. • Coatings had efficient anti-biofouling efficacy. - Abstract: In order to prevent freshwater biofouling glass and metal surfaces were coated with novel transparent methacrylate-based copolymers. The multifunctionality of the copolymers, such as adhesion to the substrate, surface polarity, mechanical long-term stability in water, and ability to form metal complexes was inserted by the choice of suitable comonomers. The monomer 2-acetoacetoxy ethyl methacrylate (AAMA) was used as complexing unit to produce copper(II) complexes in the coating’s upper surface layer. The semifluorinated monomer 1H,1H,2H,2H-perfluorodecyl methacrylate was employed to adjust the surface polarity and wettability. Comprehensive surface characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and contact angle measurements showed that surface compositions and properties can be easily adjusted by varying the concentrations of the comonomers. The formation of copper(II) complexes along the copolymer chains and their stability against washing out with plenty of water was proven by XPS. Copolymers containing semifluorinated comonomers significantly inhibited the growth of Achnanthidium species. Copolymers with copper-loaded AAMA-sequences were able to reduce both the growth of Achnanthidium spec. and Staphylococcus aureus.

  5. Methacrylate-Based Copolymers for Polymer Optical Fibers

    Directory of Open Access Journals (Sweden)

    Daniel Zaremba

    2017-01-01

    Full Text Available Waveguides made of poly-methyl-methacrylate (PMMA play a major role in the homogeneous distribution of display backlights as a matrix for solid-state dye lasers and polymer optical fibers (POFs. PMMA is favored because of its transparency in the visible spectrum, low price, and well-controlled processability. Nevertheless, technical drawbacks, such as its limited temperature stability, call for new materials. In this work, the copolymerization technique is used to modify the properties of the corresponding homopolymers. The analytical investigation of fourteen copolymers made of methyl-methacrylate (MMA or ethyl-methacrylate (EMA as the basis monomer is summarized. Their polymerization behaviors are examined by NMR spectroscopy with subsequent copolymerization parameter evaluation according to Fineman-Ross and Kelen-Tüdös. Therefore, some r-parameter sets are shown to be capable of copolymerizations with very high conversions. The first applications as high-temperature resistant (HT materials for HT-POFs are presented. Copolymers containing isobornyl-methacrylate (IBMA as the comonomer are well-suited for this demanding application.

  6. Multifunctional methacrylate-based coatings for glass and metal surfaces

    International Nuclear Information System (INIS)

    Pospiech, Doris; Jehnichen, Dieter; Starke, Sandra; Müller, Felix; Bünker, Tobias; Wollenberg, Anne; Häußler, Liane; Simon, Frank; Grundke, Karina; Oertel, Ulrich; Opitz, Michael; Kruspe, Rainer

    2017-01-01

    Highlights: • New methacrylate-based copolymers synthesized by free radical polymerization. • Comonomer AAMA was able to complex Cu (II) ions in solvent annealing procedure. • Coatings had efficient anti-biofouling efficacy. - Abstract: In order to prevent freshwater biofouling glass and metal surfaces were coated with novel transparent methacrylate-based copolymers. The multifunctionality of the copolymers, such as adhesion to the substrate, surface polarity, mechanical long-term stability in water, and ability to form metal complexes was inserted by the choice of suitable comonomers. The monomer 2-acetoacetoxy ethyl methacrylate (AAMA) was used as complexing unit to produce copper(II) complexes in the coating’s upper surface layer. The semifluorinated monomer 1H,1H,2H,2H-perfluorodecyl methacrylate was employed to adjust the surface polarity and wettability. Comprehensive surface characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and contact angle measurements showed that surface compositions and properties can be easily adjusted by varying the concentrations of the comonomers. The formation of copper(II) complexes along the copolymer chains and their stability against washing out with plenty of water was proven by XPS. Copolymers containing semifluorinated comonomers significantly inhibited the growth of Achnanthidium species. Copolymers with copper-loaded AAMA-sequences were able to reduce both the growth of Achnanthidium spec. and Staphylococcus aureus.

  7. Carboxyl-Functionalized Polymeric Microspheres Prepared by One-Stage Photoinitiated RAFT Dispersion Polymerization

    Directory of Open Access Journals (Sweden)

    Jianbo Tan

    2017-12-01

    Full Text Available Herein, we report a photoinitiated reversible addition-fragmentation chain transfer (RAFT dispersion copolymerization of methyl methacrylate (MMA and methyl methacrylic (MAA for the preparation of highly monodisperse carboxyl-functionalized polymeric microspheres. High rates of polymerization were observed, with more than 90% particle yields being achieved within 3 h of UV irradiation. Effects of reaction parameters (e.g., MAA concentration, RAFT agent concentration, photoinitiator concentration, and solvent composition were studied in detail, and highly monodisperse polymeric microspheres were obtained in most cases. Finally, silver (Ag composite microspheres were prepared by in situ reduction of AgNO3 using the carboxyl-functionalized polymeric microspheres as the template. The obtained Ag composite microspheres were able to catalyze the reduction of methylene blue (MB with NaBH4 as a reductant.

  8. Preservation of archaeological artefacts by γ-ray induced polymerization technique

    International Nuclear Information System (INIS)

    Gueven, O.

    1983-01-01

    For the preservation and consolidation of archaeological artefacts irradiation of these objects with γ-rays seems to be a very promising method. In situ polymerization of monomers impregnated in the capillaries and cavities of the objects by γ-rays provides a simultaneous sterilization and consolidation effect. In the present work this method of preservation is applied to some XIIth century ceramic findings belonging to Seljuk period found in South-East Anatolia. Monomer impregnation is restricted to the surfaces of the objects. The colored figures and structures which are present but not perceptible on these objects became fully apparent upon polymerizing hydrophilic monomers on their surfaces. Crosslinking of the top polymer layer further provides a permanent protection of the substrate material. (author)

  9. 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.

  10. Model for UV induced formation of gold nanoparticles in solid polymeric matrices

    Science.gov (United States)

    Sapogova, N.; Bityurin, N.

    2009-09-01

    UV irradiation of polymeric PMMA films containing HAuCl 4 followed by annealing at 60-80 °C forms gold nanoparticles directly within the bulk material. The kinetics of nanoparticle formation was traced by extinction spectra of nanocomposite film changes vs annealing time. We propose that UV irradiation causes HAuCl 4 dissociation and thus provides a polymeric matrix with atomic gold. The presence of an oversaturated solid solution of atomic gold in the polymeric matrix leads to Au nanoparticle formation during annealing. This process can be understood as a phase transition of the first order. In this paper we apply several common kinetic models of the phase transition for describing Au nanoparticle formation inside the solid polymer matrix. We compare predictions of these models with the experimental data and show that these models cannot describe the process. We propose that the stabilization effect of the matrix on the growing gold nanoparticles is important. The simplest model introducing some probability for the transition from growing nanoparticle to the non-growing, stabilized form is suggested. It is shown that this model satisfactorily describes the experimentally observed evolution of the extinction spectrum of Au nanoparticles forming in a polymer matrix.

  11. Corona-induced graft polymerization for surface modification of porous polyethersulfone membranes

    International Nuclear Information System (INIS)

    Zhu Liping; Zhu Baoku; Xu Li; Feng Yongxiang; Liu Fu; Xu Youyi

    2007-01-01

    Graft polymerization of acrylic acid (AA) onto porous polyethersulfone (PES) membrane surfaces was developed using corona discharge in atmospheric ambience as an activation process followed by polymerization of AA in aqueous solution. The effects of the corona parameters and graft polymerization conditions on grafting yield (GY) of AA were investigated. The grafting of AA on the PES membranes was confirmed by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) analysis. Porosimetry measurements indicate the average pore diameters and porosities of the modified membranes decrease with the increase of the GY. The hydrophilicity and surface wetting properties of the original and modified membranes were evaluated by observing the dynamic changes of water contact angles. It is found that the grafting of AA occurs not only on the membrane surfaces, but also on the pore walls of the cells inside the membrane. The permeability experiments of protein solution reveal that the grafting of PAA endows the modified membranes with enhanced fluxes and anti-fouling properties. The optimized GY of AA is in the range of 150-200 μg/cm 2 . In addition, the tensile experiments show the corona discharge treatment with the power lower than 150 W yields little damage to the mechanical strength of the membranes

  12. Core/shell silicon/polyaniline particles via in-flight plasma-induced polymerization

    International Nuclear Information System (INIS)

    Yasar-Inceoglu, Ozgul; Mangolini, Lorenzo; Zhong, Lanlan

    2015-01-01

    Although silicon nanoparticles have potential applications in many relevant fields, there is often the need for post-processing steps to tune the property of the nanomaterial and to optimize it for targeted applications. In particular surface modification is generally necessary to both tune dispersibility of the particles in desired solvents to achieve optimal coating conditions, and to interface the particles with other materials to realize functional heterostructures. In this contribution we discuss the realization of core/shell silicon/polymer nanoparticles realized using a plasma-initiated in-flight polymerization process. Silicon particles are produced in a non-thermal plasma reactor using silane as a precursor. After synthesis they are aerodynamically injected into a second plasma reactor into which aniline vapor is introduced. The second plasma initiates the polymerization reactor leading to the formation of a 3–4 nm thick polymer shell surrounding the silicon core. The role of processing conditions on the properties of the polymeric shell is discussed. Preliminary results on the testing of this material as an anode for lithium ion batteries are presented. (paper)

  13. Core/shell silicon/polyaniline particles via in-flight plasma-induced polymerization

    Science.gov (United States)

    Yasar-Inceoglu, Ozgul; Zhong, Lanlan; Mangolini, Lorenzo

    2015-08-01

    Although silicon nanoparticles have potential applications in many relevant fields, there is often the need for post-processing steps to tune the property of the nanomaterial and to optimize it for targeted applications. In particular surface modification is generally necessary to both tune dispersibility of the particles in desired solvents to achieve optimal coating conditions, and to interface the particles with other materials to realize functional heterostructures. In this contribution we discuss the realization of core/shell silicon/polymer nanoparticles realized using a plasma-initiated in-flight polymerization process. Silicon particles are produced in a non-thermal plasma reactor using silane as a precursor. After synthesis they are aerodynamically injected into a second plasma reactor into which aniline vapor is introduced. The second plasma initiates the polymerization reactor leading to the formation of a 3-4 nm thick polymer shell surrounding the silicon core. The role of processing conditions on the properties of the polymeric shell is discussed. Preliminary results on the testing of this material as an anode for lithium ion batteries are presented.

  14. Synthesis and characterization of sugar-based methacrylates and their random copolymers by ATRP

    Directory of Open Access Journals (Sweden)

    G. Acik

    2017-10-01

    Full Text Available Various sugar-based methacrylate monomers have been prepared and randomly copolymerized with methyl methacrylate (MMA using classical atom transfer radical polymerization (ATRP. Firstly, four different sugar-based methacrylates are synthesized by two-step method: (i etherification of protected monosaccharides with epichlorohydrin and (ii following ring-opening reaction of obtained epoxides with methacrylic acid (MAA in the presence of triethylamine. Next, these monomers are copolymerized with MMA via ATRP at 90 °C to obtain corresponding random copolymers. The molecular weights of the copolymers are determined by both GPC (gel permeation chromatography and 1H-NMR (nuclear magnetic resonance spectroscopy analyses and found as 10600~16800 and 12200~18500 g/mol, respectively. Moreover, the copolymer compositions are also determined by 1H-NMR analysis using characteristic signals of the monomers and found as about 94.1~97.8%, which are good agreement with feeding ratio. In addition, the glass transition temperatures of copolymers are found as 101.2~102.9 °C by changing type and composition of sugar-based methacrylate monomers. Overall, a series of well-defined random copolymers comprising different sugar-based methacrylates and methyl methacrylates were successfully synthesized by classical ATRP method.

  15. Electron-beam-induced post-grafting polymerization of acrylic acid onto the surface of Kevlar fibers

    Science.gov (United States)

    Xu, Lu; Hu, Jiangtao; Ma, Hongjuan; Wu, Guozhong

    2018-04-01

    The surface of Kevlar fibers was successfully modified by electron beam (EB)-induced post-grafting of acrylic acid (AA). The generation of radicals in the fibers was confirmed by electron spin resonance (ESR) measurements, and the concentration of radicals was shown to increase as the absorbed dose increased, but decrease with increasing temperature. The influence of the synthesis conditions on the degree of grafting was also investigated. The surface microstructure and chemical composition of the modified Kevlar fibers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed that the surface of the grafted fibers was rougher than those of the pristine and irradiated fibers. XPS analysis confirmed an increase in C(O)OH groups on the surface of the Kevlar fibers, suggesting successful grafting of AA. These results indicate that EB-induced post-grafting polymerization is effective for modifying the surface properties of Kevlar fibers.

  16. 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.

  17. Copolymers containing phosphorescent iridium(III) complexes obtained by free and controlled radical polymerization techniques

    NARCIS (Netherlands)

    Ulbricht, C.; Becer, C.R.; Winter, A.; Veldman, D.; Schubert, U.S.

    2008-01-01

    A methacrylate-functionalized phosphorescent Ir(III)-complex has been synthesized, characterized, and applied as a monomer in radical copolymerizations. Together with methyl methacrylate, the complex has been copolymerized under free radical polymerization conditions. Aiming for host-guest-systems,

  18. 21 CFR 175.320 - Resinous and polymeric coatings for polyolefin films.

    Science.gov (United States)

    2010-04-01

    ... lauryl sulfate Sorbitan and sorbitol esters of fatty acids from vegetable or animal oils Spermaceti wax... only as a polymerization inhibitor in 2-sulfoethyl methacrylate, sodium salt. 2-Ethylhexyl acrylate... scale as measured in 50 percent mineral spirits solution 2-Sulfoethyl methacrylate, sodium salt Chemical...

  19. Energy dependency of mechanical properties on polymer impregnated concrete polymerized by radiation induced method

    International Nuclear Information System (INIS)

    Ono, Hironobu

    1978-01-01

    The purpose of this paper is to study the characteristics of polymerization on polymer impregnated concrete (PIC) polymerized by various radiation source which have the peculiar energy respectively as follows; Gamma-rays: 60 Co-1.25MeV, 137 Cs-0.66MeV, X-Ray: 0.88MeV and accelerated electron beam 4.0, 2.0 and 1.2MeV. This experimental program was carried out to investigate the effect of radiation energy, density of cementmortar, optimum irradiating conditions and other factors which have influence upon the polymerization and strength of PIC. The test results shows that the energy dependency on the accelerated electron was remarkable effect for relative absorption energy and strength of specimens (Fig. 5) and it can be estimate that the impregnation depth from the surface of specimens in ordinary mortar MMA-PIC were about 10 mm, 6 mm, and 3 mm as to 4.0, 2.0 and 1.2MeV respectively under curing 50 Mrads (Fig. 2). It is also show that the optimum total exposure dose on magnetic electro wave methods, estimate about 3 MR at 60 Co; 1 x 10 6 R/hr, 2 MR at 137 Cs; 4.5 x 10 4 R/hr and 2 MR at X-ray; 5 x 10 5 R/hr at curing temperature 20 0 C (Fig. 9, Fig. 10). We can see the fact that the energy dependency is noticiable only comparing same kinds of radiation source. (author)

  20. Preparation of antifouling ultrafiltration membranes via irradiation induced graft polymerization technique

    International Nuclear Information System (INIS)

    Deng Bo; Liu Zhognying; Lu Xiaofeng; Li Jingye; Yang Xuanxuan; Yu Ming; Zhang Bowu

    2010-01-01

    PVDF powders were irradiated in air at dose of 15 kGy by using gamma-rays. Macromolecular peroxides transformed from free radicals in the irradiated PVDF powders in air can be preserved for long-term at appropriate temperature stably. By mixing acrylic monomers with irradiated PVDF powders then the graft polymerization can be initiated by heating. Then a series of hydrophilic ultrafiltration (UF) membranes were fabricated by dissolving the PVDF-g-PAAc powders in the NMP under phase inversion method. The antifouling performances of UF membranes cast from virgin and grafted PVDF powders were compared. (authors)

  1. Growth of polymer nanoparticles in microemulsion polymerization initiated with γ ray

    International Nuclear Information System (INIS)

    Xu Xiangling; Ge Xuewu; Ye Qiang; Zhang Zhicheng; Zuo Ju; Niu Aizhen; Zhang Manwei

    1999-01-01

    In microemulsion polymerization of styrene, butyl acrylate and methyl methacrylate initiated with gamma ray, growth of polymer nanoparticles was observed with photon correlation spectroscopy, and the conversion curve was recorded with a dilatometer. There is some similarity in the growth of polymer particles. The size of polymer particles rapidly increases up to their maximum at the early stage. With the increase of conversion, the large particles supply their monomer to newly formed particles and become smaller. In all these three microemulsion polymerizations, the evidence of continuous nucleation was observed. When monomer is styrene or butyl acrylate, a plateau of polymerization rate emerges. When monomer is methyl methacrylate, no plateau of polymerization is observed

  2. Study on the immobilization of alpha-amylase by radiation-induced polymerization at low-temperature, (4)

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Kumakura, Minoru; Kaetsu, Isao

    1975-07-01

    The immobilization of α-amylase by radiation-induced polymerization at low-temperature in the presence of an adsorbent has been studied. In the previous method, part of the enzyme escapes from the immobilized composition of HEMA polymer with a few enzyme reactions. This is prevented, however, by the present method in which the adsorbent-HEMA-α-amylase mixtures is immobilized by the polymerization with HEMA. Anhydride of an inorganic salt such as calcium carbonate, sodium acetate, calcium acetate, or DRIERETE (composed mainly of calcium sulfate) is especially useful as the adsorbent. Use of an inorganic ion such as Ca ++ or Na + improves remarkably heat-stability of the immobilized composition. The most effective composition for immobilization is 200 μg of α-amylase, 1 ml of 30% HEMA solution (in 0.02M phosphate buffer solution, pH 6.9) and 0.3g of DRIERETE. Frozen and irradiated with γ-rays of Co-60 to a total dose 1 x 10 6 R at -24 0 C, the immobilized enzyme has the activity about 93% that of the native one. (auth.)

  3. Study on the immobilization of alpha-amylase by radiation-induced polymerization at low-temperature, (1)

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Kumakura, Minoru; Kaetsu, Isao

    1975-07-01

    The immobilization of enzymes by radiation-induced polymerization at low temperatures has been studied. It is important to know how the enzymes are affected by irradiation. The radiation effect of enzyme itself before immobilization must thus be investigated. In radiation effect on α-amylase from Bacillus subtilis, interesting results were obtained, as follows. The enzyme is very stable for irradiation in the total dose range of 1 x 10 4 to 1 x 10 7 R, and the activity is hardly affected. And further, the relative activity increases by irradiation, when the α-amylase is of high purity or contains some appropriate additive. A certain substance such as diatomaceous earth or CaCl 2 thus decreases the activity, while the addition of DRIERITE composed mainly of CaSO 4 increases the activity. α-Amylase is then more stable and higher in activity in the irradiation at lower temperatures. The activity is independent of presence or absence of the ambient air. In conclusion, α-amylase is very stable for irradiation at low temperatures; therefore, its immobilization by polymerization at low temperature is recommended. (auth.)

  4. Swelling and thermodynamic studies of temperature responsive 2-hydroxyethyl methacrylate/itaconic acid copolymeric hydrogels prepared via gamma radiation

    International Nuclear Information System (INIS)

    Tomic, Simonida L.J.; Micic, Maja M.; Filipovic, Jovanka M.; Suljovrujic, Edin H.

    2007-01-01

    The copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were synthesized by gamma radiation induced radical polymerization. Swelling and thermodynamic properties of PHEMA and copolymeric P(HEMA/IA) hydrogels with different IA contents (2, 3.5 and 5 mol%) were studied in a wide pH and temperature range. Initial studies of so-prepared hydrogels show interesting pH and temperature sensitivity in swelling and drug release behavior. Special attention was devoted to temperature investigations around physiological temperature (37 deg. C), where small changes in temperature significantly influence swelling and drug release of these hydrogels. Due to maximum swelling of hydrogels around 40 deg. C, the P(HEMA/IA) hydrogel containing 5 mol% of IA without and with drug-antibiotic (gentamicin) were investigated at pH 7.40 and in the temperature range 25-42 deg. C, in order to evaluate their potential for medical applications

  5. Preparation of Transparent Bulk TiO2/PMMA Hybrids with Improved Refractive Indices via an in Situ Polymerization Process Using TiO2 Nanoparticles Bearing PMMA Chains Grown by Surface-Initiated Atom Transfer Radical Polymerization.

    Science.gov (United States)

    Maeda, Satoshi; Fujita, Masato; Idota, Naokazu; Matsukawa, Kimihiro; Sugahara, Yoshiyuki

    2016-12-21

    Transparent TiO 2 /PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO 2 nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO 2 nanoparticles in the bulk hybrids was investigated. The surfaces of TiO 2 nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO 2 nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO 2 nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO 2 nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO 2 nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO 2 content and could be increased up to 1.566 for 6.3 vol % TiO 2 content (1.492 for pristine PMMA).

  6. Poly(methyl-methacrylate) nanocomposites with low silica addition.

    Science.gov (United States)

    Balos, Sebastian; Pilic, Branka; Markovic, Dubravka; Pavlicevic, Jelena; Luzanin, Ognjan

    2014-04-01

    Poly(methyl-methacrylate) (PMMA) represents the most popular current denture material. However, its major drawbacks are insufficient ductility and strength. The purpose of this study was to improve the mechanical properties of PMMA in denture base application by adding small quantities of nanosilica. Silica nanoparticles were added to the liquid component of the tested materials. The standard heat polymerizing procedure was followed to obtain 6 PMMA--silicon dioxide (/SiO2) concentrations (0.023%, 0.046%, 0.091%, 0.23%, 0.46%, and 0.91% by volume). Microhardness and fracture toughness of each set of specimens was compared with the unmodified specimens. Furthermore, differential scanning calorimetry and scanning electron microscopy analyses were conducted, and the results obtained were correlated with the results of mechanical properties. It was found that the maximum microhardness and fracture toughness values of the materials tested were obtained for the lowest nanosilica content. A nanosilica content of 0.023% resulted in an almost unchanged glass transition temperature (Tg), whereas the maximum amount of nanosilica induced a considerable increase in Tg. A higher Tg indicated the possible existence of a thicker interfacial layer caused by the chain immobility due to the presence of the particles. However, scanning electron microscopy results demonstrated extensive agglomeration at 0.91% nanosilica, which may have prevented the formation of a homogenous reinforced field. At a nanosilica content of 0.023%, no agglomeration was observed, which probably influenced a more homogenous distribution of nanoparticles as well as uniform reinforcing fields. Low nanoparticle content yields superior mechanical properties along with the lower cost of nanocomposite synthesis. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  7. 13C n.m.r. study of solvation mechanisms in the radiation-induced polymerization of vinyl ethers

    International Nuclear Information System (INIS)

    Deffieux, A.; Subira, F.; Stannett, V.T.

    1984-01-01

    A 13 C n.m.r. study of the microstructure of ethyl vinyl ether (EVE) and isopropyl vinyl ether (IPVE) polymers prepared under various experimental conditions and using chemical or γ-ray initiation has been made. Long stereo-sequence assignments were conducted for poly EVE allowing determination of the configurational statistics of propagation in the radiation-induced polymerization of EVE in low polar solvents. Stereo-sequence intensities are found in good agreement with the Markovian model. The results are considered as further support for the occurrence of a specific interaction between the growing active centres and the polymer chains. In the case of IPVE polymers much more important overlappings of the resonance patterns are observed thus preventing any similar detailed study. (author)

  8. Proton-transfer lasers based on solid copolymers of modified 2-(2'-hydroxyphenyl)benzimidazoles with methacrylate monomers

    Science.gov (United States)

    Costela, A.; García-Moreno, I.; Mallavia, Ricardo; Amat-Guerri, F.; Barroso, J.; Sastre, R.

    1998-06-01

    We report on the lasing action of two newly synthesized 2-(2'-hydroxyphenyl) benzimidazole derivatives copolymerized with methyl methacrylate. The laser samples were transversely pumped with a N 2 laser at 337 nm. The influence on the proton-transfer laser performance of the distance between the chromophore group and the polymeric main chain and of the rigidity of the polymeric host matrix, were studied. Significant increases in lasing efficiency and photostability are demonstrated for some of the new materials, as compared to those previously obtained with related proton-transfer dyes also covalently bound to methacrylic monomers.

  9. Improved biotribological properties of PEEK by photo-induced graft polymerization of acrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaoduo; Xiong, Dangsheng, E-mail: xiongds@163.com; Wang, Kun; Wang, Nan

    2017-06-01

    The keys of biomaterials application in artificial joints are good hydrophilicity and wear resistance. One kind of the potential bio-implant materials is polyetheretherketone (PEEK), which has some excellent properties such as non-toxic and good biocompatibility. However, its bioinert surface and inherent chemical inertness hinder its application. In this study, we reported an efficient method for improving the surface wettability and wear resistance for PEEK, a layer of acrylic acid (AA) polymer brushes on PEEK surface was prepared by UV-initiated graft polymerization. The effects of different grafting parameters (UV-irradiation time/AA monomer solution concentration) on surface characteristics were clearly investigated, and the AA-g-PEEK specimens were examined by ATR-FTIR, static water contact angle measurements and friction tests. Our results reveal that AA can be successfully grafted onto the PEEK surface after UV irradiation, the water wettability and tribological properties of AA-g-PEEK are much better than untreated PEEK because that AA is a hydrophilic monomer, the AA layer on PEEK surface can improve its bearing capacity and reduce abrasion. This detailed understanding of the grafting parameters allows us to accurately control the experimental products, and this method of surface modification broadens the use of PEEK in orthopedic implants. - Highlights: • Acrylic acid was successful grafted onto PEEK substrate by UV-initiated graft polymerization. • AA-g-PEEK owned better hydrophilicity than untreated PEEK. • Wear resistance of AA-g-PEEK were significantly improved due to AA brushes could bear high contact stress.

  10. Use of radiation-induced polymers in cement slurries

    International Nuclear Information System (INIS)

    Knight, B.L.; Rhudy, J.S.; Gogarty, W.B.

    1976-01-01

    Water loss from cement slurries is reduced by incorporating within a cement slurry a polymer obtained as a product of radiation-induced polymerization of acrylamide and/or methacrylamide and acrylic acid, methacrylic acid, and/or alkali metal salts thereof. The polymerization is preferably carried out in 10-60 percent aqueous monomer solution with gamma radiation. The aqueous monomer solution preferably contains 25-99 percent acrylamide and 75-1 percent sodium acrylate. The polymer can be present in concentration of about 0.001 to about 3.0 weight percent, based on the aqueous phase of the slurry

  11. The Morphology of Emulsion Polymerized Latex Particles

    Science.gov (United States)

    Wignall, G. D.; Ramakrishnan, V. R.; Linne, M. A.; Klein, A.; Sperling, L. H.; Wai, M. P.; Gelman, R. A.; Fatica, M. G.; Hoerl, R. H.; Fisher, L. W.

    1987-11-01

    Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structure as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10{sup 4} 10{sup 6} the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights.

  12. Investigation of Complexation of Linear Poly(N-vinyl-2-pyrrolidone with Poly(methacrylic acid-co-methyl methacrylate Gel

    Directory of Open Access Journals (Sweden)

    Guoqin Liu

    2011-01-01

    Full Text Available The contraction of poly(methacrylic acid-co-methyl methacrylate (P(MAA-co-MMA gel induced by complexation with linear poly(N-vinyl-2-pyrrolidone (PVP is quite different from that of poly(acrylic acid (PAA or poly(methacrylic acid (PMAA gel. It was found that the concentration of PVP has a strong effect on the complexation with P(MAA-co-MMA gel. When PVP was introduced into the P(MAA-co-MMA network, its dynamic mechanic properties vary greatly between complexed and uncomplexed networks. It had the following results: (1 the higher modulus ratio; (2 a slight contraction of gel.

  13. Investigation of Complexation of Linear Poly(N-vinyl-2-pyrrolidone) with Poly(methacrylic acid-co-methyl methacrylate) Gel

    OpenAIRE

    Liu, Guoqin; Yan, Guojin; Zou, Wenjun; Li, Zhengxin

    2011-01-01

    The contraction of poly(methacrylic acid-co-methyl methacrylate) (P(MAA-co-MMA)) gel induced by complexation with linear poly(N-vinyl-2-pyrrolidone) (PVP) is quite different from that of poly(acrylic acid) (PAA) or poly(methacrylic acid) (PMAA) gel. It was found that the concentration of PVP has a strong effect on the complexation with P(MAA-co-MMA) gel. When PVP was introduced into the P(MAA-co-MMA) network, its dynamic mechanic properties vary greatly between complexed and uncomplexed netwo...

  14. Process for production of an alkyl methacrylate

    NARCIS (Netherlands)

    Eastham, Graham Ronald; Johnson, David William; Fraaije, Marco; Winter, Remko

    2015-01-01

    A process for the production of an alkyl methacrylate, particularly methyl methacrylate, is provided, in which a Baeyer-Villiger Monooxygenase enzyme is used to convert an alkylisopropenylketone substrate to the relevant alkyl methacrylate by abnormal asymmetric oxygen insertion. The invention

  15. Radiation-induced synthesis and swelling properties of p(2-hydroxyethyl methacrylate-co-itaconic acid-co-oligo(ethylene glycol) acrylate) copolymeric hydrogels

    International Nuclear Information System (INIS)

    Micic, M.; Suljovrujic, E.

    2011-01-01

    Complete text of publication follows. Since it is presumed that by incorporation of pH-responsive (IA) and temperature-responsive (OEGA) co-monomers it is possible to prepare P(HEMA-co-IA-co-OEGA) hydrogels with duel (pH and thermo) responsiveness, the main purpose of this paper is to investigate the influence of different mole fractions of IA and especially OEGA on the diversity of the swelling properties of obtained hydrogels. For that reason, a series of copolymeric hydrogels with different mole ratios of 2-hydroxyethyl methacrylate (HEMA), itaconic acid (IA) and oligo(ethylene glycol) acrylates (OEGA) was synthesized by gamma radiation. The obtained hydrogels were characterized by swelling studies in the wide pH (2.2-9.0) and temperature range (25-70 deg C), confirming dual (pH and thermo) responsiveness and a large variation in swelling capability. It was observed that the equilibrium swelling of P(HEMA-co-IA-co-OEGA) hydrogels, for a constant amount of IA, increases progressively with increasing in OEGA share. On the other hand, the dissociation of carboxyl (-COOH) groups from IA occurs at pH > 4; therefore, small mole fractions of IA render good pH sensitivity and a large increase in the swelling capacity of these hydrogels at higher pH values. Additional characterization of structure and properties was conducted by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and mechanical measurements, confirming that the inherent properties of the P(HEMA-co-IA-co-OEGA) hydrogels can be significantly tuned by variation in their composition. According to all presented, it seems that the obtained copolymeric hydrogels can be a beneficial synergetic combination for controlled delivery of bioactive molecules such as drugs, nucleic acids, peptides, and proteins.

  16. (meth)acrylates on in situ visible light polymerization of ...

    Indian Academy of Sciences (India)

    60

    ... faster to be cured using a visible light source with a Tungsten-Halogen lamp ... ranging from 350 to 1100 nm, which even covers some UV and near IR region. .... incorporation of the acid-containing and/or acrylate-containing monomer led to.

  17. Reaction calorimetry for the development of ultrasound-induced polymerization processes in CO2-expanded fluids

    NARCIS (Netherlands)

    Kemmere, M.F.; Kuijpers, M.W.A.; Keurentjes, J.T.F.

    2007-01-01

    A strong viscosity increase upon polymn. hinders radical formation during an ultrasound-induced bulk polymn. Since CO2 acts as a strong anti-solvent for most polymers, it can be used to reduce the viscosity of the reaction mixt. In this work, a process for the ultrasound-induced polymn. in

  18. Shear-induced nano-macro structural transition in a polymeric bicontinuous microemulsion

    DEFF Research Database (Denmark)

    Krishnan, K.; Almdal, K.; Burghardt, W.R.

    2001-01-01

    structure. In situ neutron scattering shows flow-induced anisotropy in the nanometer-scale microemulsion structure at moderate shear rates, while higher rates induce bulk phase separation, with micron-size morphology, which is characterized with in situ light scattering and optical microscopy....

  19. Heparin molecularly imprinted polymer thin flm on gold electrode by plasma-induced graft polymerization for label-free biosensor.

    Science.gov (United States)

    Orihara, Kouhei; Hikichi, Atsushi; Arita, Tomohiko; Muguruma, Hitoshi; Yoshimi, Yasuo

    2018-03-20

    Heparin, a highly sulfated glycosaminoglycan, is an important biomaterial having biological and therapeutic functionalities such as anticoagulation, regeneration, and protein stabilization. This study addresses a label-free quartz crystal microbalance (QCM) biosensor for heparin detection based on a macromolecularly imprinted polymer (MIP) as an artificial recognition element. We demonstrate the novel strategy for MIP in the form of thin film on a gold (Au) electrode with the plasma-induced graft polymerization (PIP) technique. The procedure of PIP is as follows: (i) Hexamethyldisiloxane plasma-polymerized thin film (PPF) as a pre-coating scaffold of active species for PIP (post-polymerization) is deposited on an Au electrode. (ii) The PPF/Au electrode is soaked in an water solution containing heparin (template), (2-(methacryloxy)-ethyl)trimethylammonium chloride acrylamide (functional monomer), acrylamide, and N,N-methylenebisacrylamide (crosslinker). Double bonds of monomer and crosslinker attacked by residually active species in pre-coating PPF cause radical chain reaction. Consequently, a growing polymer network of 20 nm thickness of PIP-MIP thin film is formed and grafted on the PPF/Au surface. (iii) The PIP-MIP/PPF/Au is washed by sodium chloride solution so as to remove the template. Non-imprinted polymer (NIP) is carried out like the same procedure without a template. The AFM, XPS, and QCM measurements show that the PIP process facilitates macromolecularly surface imprinting of template heparin where the template is easily removed and is rapidly rebound to PIP-MIP without a diffusional barrier. The heparin-PIP-MIP specifically binds to heparin compared with heparin analog chondroitin sulfate C (selective factor: 4.0) and a detectable range of heparin in the presence of CS (0.1 wt%) was 0.001-0.1 wt%. The PIP-NIP does not show selectivity between them. The evaluated binding kinetics are association (k a  = 350 ± 100 M -1  s -1

  20. 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.

  1. Preparation of microspheres for slow release drug by radiation-induced suspension polymerization and their properties

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Asano, Masaharu; Kaetsu, Isao

    1982-01-01

    The polymer microspheres containing drugs as drug delivery system were made by means of suspension-polymerization by radiation at low temperature by using glass-forming monomers which have stable supercooling properties and large polymerizability at low temperature. The particle distribution depended on the kind of monomer. It was found that the entrapping yield of drug in polymer microspheres increased with increasing viscosity of monomer and that the maximum value on the particle size distribution curve was also shifted to large particle diameter side. In the case of trimethylolpropane trimethacrylate monomer (43 cps), TMPT, the entrapping yield of drug reached 74% and the maximum value in particle size distribution curve appeared in the neighborhood of 105 to 210 mu m ranges. On the other hand, those values in neopentyl glycol dimethacrylate monomer (4 cps) were 12% in former and 44 -- 105 mu m in the latter. The release phenomenon of drugs from polymer microspheres was investigated. for example, the cumulative amount of mitomycin C (water soluble drug) released from TMPT polymer microsphere was about 90% after 30-day dissolution, while in the case of water-insoluble drug such as testosterone the amount of release was about 49% after 40-day dissolution. In all cases, the release rate is constant during the experimental period. Therefore, it was concluded that the release of drugs from polymer microspheres obtained in this study is possible over the long periods. (author)

  2. Pressure-induced structural transformations and polymerization in ThC2

    Science.gov (United States)

    Guo, Yongliang; Yu, Cun; Lin, Jun; Wang, Changying; Ren, Cuilan; Sun, Baoxing; Huai, Ping; Xie, Ruobing; Ke, Xuezhi; Zhu, Zhiyuan; Xu, Hongjie

    2017-04-01

    Thorium-carbon systems have been thought as promising nuclear fuel for Generation IV reactors which require high-burnup and safe nuclear fuel. Existing knowledge on thorium carbides under extreme condition remains insufficient and some is controversial due to limited studies. Here we systematically predict all stable structures of thorium dicarbide (ThC2) under the pressure ranging from ambient to 300 GPa by merging ab initio total energy calculations and unbiased structure searching method, which are in sequence of C2/c, C2/m, Cmmm, Immm and P6/mmm phases. Among these phases, the C2/m is successfully observed for the first time via in situ synchrotron XRD measurements, which exhibits an excellent structural correspondence to our theoretical predictions. The transition sequence and the critical pressures are predicted. The calculated results also reveal the polymerization behaviors of the carbon atoms and the corresponding characteristic C-C bonding under various pressures. Our work provides key information on the fundamental material behavior and insights into the underlying mechanisms that lay the foundation for further exploration and application of ThC2.

  3. Improved biotribological properties of PEEK by photo-induced graft polymerization of acrylic acid.

    Science.gov (United States)

    Zhao, Xiaoduo; Xiong, Dangsheng; Wang, Kun; Wang, Nan

    2017-06-01

    The keys of biomaterials application in artificial joints are good hydrophilicity and wear resistance. One kind of the potential bio-implant materials is polyetheretherketone (PEEK), which has some excellent properties such as non-toxic and good biocompatibility. However, its bioinert surface and inherent chemical inertness hinder its application. In this study, we reported an efficient method for improving the surface wettability and wear resistance for PEEK, a layer of acrylic acid (AA) polymer brushes on PEEK surface was prepared by UV-initiated graft polymerization. The effects of different grafting parameters (UV-irradiation time/AA monomer solution concentration) on surface characteristics were clearly investigated, and the AA-g-PEEK specimens were examined by ATR-FTIR, static water contact angle measurements and friction tests. Our results reveal that AA can be successfully grafted onto the PEEK surface after UV irradiation, the water wettability and tribological properties of AA-g-PEEK are much better than untreated PEEK because that AA is a hydrophilic monomer, the AA layer on PEEK surface can improve its bearing capacity and reduce abrasion. This detailed understanding of the grafting parameters allows us to accurately control the experimental products, and this method of surface modification broadens the use of PEEK in orthopedic implants. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Hollow magnetic nano-CO3O4/polystyrene microspheres synthesized through radiation induced interfacial polymerization

    International Nuclear Information System (INIS)

    Zhang Wei; Wang Mozhen; Wang Shufeng; Zhang Zhicheng

    2010-01-01

    Co 3 O 4 nanoparticles (around 8 nm) were synthesized hydrothermally by dissolving Co 2+ in the mixture of ethanol and water, and then decorated with oleic acid to endow them with hydrophobic surface nature. After that, nano-particles were added into emulsion which consisted by sodium dodecyl sulfate, water, styrene and cetyl alcohol. Hollow magnetic composite spheres were prepared by irradiated the emulsion with γ-rays. The final products are thoroughly characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques, which showed the formation of hollow magnetic composite spheres. The influence of addition dosage of nano-particles, sodium dodecyl sulfate and the types of nano-particles on the average size and shape of hollow composites were studied. The effects of nano-particles to the polymerization of styrene were studied by kinetics. Nano-particles are capsulated by polystyrene to form hollow composites, which confirmed by XPS results. Finally, magnetic property of hollow composites is compared with pure nano-Co 3 O 4 . (authors)

  5. Methyl methacrylate released from autopolymerized denture base polymers at different polymerization temperature during processing-monitoring by time-of-flight mass spectrometer%飞行时间质谱仪监测不同聚合温度下义齿基托树脂中甲基丙烯酸甲酯释放量的研究

    Institute of Scientific and Technical Information of China (English)

    邸宏鸣; 马玉娟

    2013-01-01

    目的 探讨使用飞行时间质谱仪监测不同聚合温度下自凝树脂反应时释放的甲基丙烯酸甲酯(methylmethacrylate,MMA)的量,分析MMA释放量的变化趋势,研究聚合温度对MMA释放量的影响.方法 按生产厂家要求的比例把自凝仿生义齿基托树脂粉2 g和液1 g调拌40 s后,立即用飞行时间质谱仪连续监测MMA释放量,待释放量的变化稳定后停止监测.室温20℃和40℃、60℃水浴下各监测5个样本,每分钟记录1次监测结果,并加以比较.结果 不同聚合温度下自凝树脂反应时释放的MMA的量的变化趋势相像:在反应初期20℃、40℃和60℃时MMA释放量低,变化不明显,而分别在11 min、(46.2±3.5)mg/L;6 min、(6.4±0.5)mg/L;2 min、(7.2±1.2)mg/L时开始快速升高,之后分别在13 min、(225.4±23.1) mg/L;7 min、(57.7±5.4) mg/L;4 min、(38.1±4.9) mg/L时到达最高,然后由快速下降到缓慢下降并分别在23 min、(9.4±1.6) mg/L;12 min、(1.3 ±0.1) mg/L;6min、(1.3±0.2)mg/L时趋于稳定.40℃与20℃、60℃与20℃相比MMA释放量小,并且到达稳定期的时间短(P<0.05),40℃与60℃相比MMA的释放量无明显差异(P>0.05).结论 把聚合温度从室温20℃升高到40℃或60℃时可以降低自凝树脂反应过程中释放的MMA的量,但从40℃继续升高到60℃时MMA的释放量无显著变化.%Objective Time - of - flight mass spectrometer was investigated for monitoring methyl methacrylate (MMA) released from autopolymerized denture base polymer (self - curing resin) at different polymerization temperature during processing. The effect of the polymerization temperature on the amount of MMA was analyzed. Methods Self - curing resin was mixed in the container at room temperature (20℃) using a ratio of 2 g of powder to 1 g of liquid in accordance with the manufacturer' s instructions for 40s as a specimen. The amount of MMA released from the specimen was on line analyzed and simultaneously

  6. Organization in sol-gel polymerization of methacrylate co-oligomers containing trimethoxysilylpropyl methacrylate

    Czech Academy of Sciences Publication Activity Database

    Vraštil, J.; Matějka, Libor; Špaček, V.; Večeřa, M.; Prokůpek, L.

    2005-01-01

    Roč. 46, č. 25 (2005), s. 11232-11240 ISSN 0032-3861 Institutional research plan: CEZ:AV0Z40500505 Keywords : organic-inorganic hybrid * sol-gel process * oligomers Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.849, year: 2005

  7. 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

  8. Destruction-polymerization transformations as a source of radiation-induced extended defects in chalcogenide glassy semiconductors

    International Nuclear Information System (INIS)

    Shpotyuk, Oleh; Filipecki, Jacek; Shpotyuk, Mykhaylo

    2013-01-01

    Long-wave shift of the optical transmission spectrum in the region of fundamental optical absorption edge is registered for As 2 S 3 chalcogenide glassy semiconductors after γ-irradiation. This effect is explained in the frameworks of the destruction-polymerization transformations concept by accepting the switching of the heteropolar As-S covalent bonds into homopolar As-As ones. It is assumed that (As 4 + ; S 1 - ) defect pairs are created under such switching. Formula to calculate content of the induced defects in chalcogenide glassy semiconductors is proposed. It is assumed that defects concentration depends on energy of broken covalent bond, bond-switching energy balance, correlation energy, optical band-gap and energy of excitation light. It is shown that theoretically calculated maximally possible content of radiation-induced defects in As 2 S 3 is about 1.6% while concentration of native defects is negligible. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Radiation-induced synthesis and swelling properties of p(2-hydroxyethyl methacrylate/itaconic acid/oligo (ethylene glycol) acrylate) terpolymeric hydrogels

    International Nuclear Information System (INIS)

    Micic, M.; Stamenic, D.; Suljovrujic, E.

    2012-01-01

    Since it is presumed that by incorporation of pH-responsive (IA) and temperature-responsive (OEGA) co-monomers, it is possible to prepare P(HEMA/IA/OEGA) hydrogels with dual (pH and thermo) responsiveness, the main purpose of our study is to investigate the influence of different mole fractions of IA and especially OEGA on the diversity of the swelling properties of the obtained hydrogels. For that reason, a series of terpolymeric hydrogels with different mole ratios of 2-hydroxyethyl methacrylate (HEMA), itaconic acid (IA) and oligo(ethylene glycol) acrylates (OEGA) was synthesised by gamma radiation. The obtained hydrogels were characterised by swelling studies in the wide pH (2.2–9.0) and temperature range (20–70 °C), confirming dual (pH and thermo) responsiveness and a large variation in the swelling capability. It was observed that the equilibrium swelling of P(HEMA/IA/OEGA) hydrogels, for a constant amount of IA, increased progressively with an increase in OEGA share. On the other hand, the dissociation of carboxyl groups from IA occurs at pH>4; therefore, small mole fractions of IA render good pH sensitivity and a large increase in the swelling capacity of these hydrogels at higher pH values. Additional characterisation of structure and properties was conducted by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and mechanical measurements, confirming that the inherent properties of P(HEMA/IA/OEGA) hydrogels can be significantly tuned by variation in their composition. According to all presented, it seems that the obtained hydrogels can be a beneficial synergetic combination for controlled delivery of bioactive molecules such as drugs, peptides, proteins, etc. - Highlights: ► pH- and thermo-sensitive P(HEMA/IA/OEGA) hydrogels were synthesised by γ radiation. ► OEGA units have a large hydrophilic potential. ► Swelling capacity increases with the OEGA content. ► Variation in composition of hydrogels can give

  10. Structural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) copolymer by nuclear magnetic resonance and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Giordanengo, Remi [Universites Aix-Marseille I, II et III - CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrometries Appliquees a la Chimie Structurale, F-13397 Marseille (France); Viel, Stephane [Aix-Marseille Universite - CNRS, UMR 6263: Institut des Sciences Moleculaires de Marseille, Chimiometrie et Spectrometries, F-13397 Marseille (France); Hidalgo, Manuel; Allard-Breton, Beatrice [ARKEMA, Centre de Recherche Rhone Alpes, Rue Henri Moissan, F-69493 Pierre-Benite (France); Thevand, Andre [Universites Aix-Marseille I, II et III - CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrometries Appliquees a la Chimie Structurale, F-13397 Marseille (France); Charles, Laurence, E-mail: laurence.charles@univ-provence.fr [Universites Aix-Marseille I, II et III - CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrometries Appliquees a la Chimie Structurale, F-13397 Marseille (France)

    2009-11-03

    Mass spectrometry (MS) and nuclear magnetic resonance (NMR) have been combined to achieve the complete microstructural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) (PMAA-PMMA) copolymer synthesized by nitroxide-mediated polymerization. Various PMAA-PMMA species could be identified which mainly differ in terms of terminaisons. {sup 1}H and {sup 13}C NMR experiments revealed the structure of the end-groups as well as the proportion of each co-monomer in the copolymers. These end-group masses were further confirmed from m/z values of doubly charged copolymer anions detected in the single stage mass spectrum. In contrast, copolymer composition derived from MS data was not consistent with NMR results, obviously due to strong mass bias well known to occur during electrospray ionization of these polymeric species. Tandem mass spectrometry could reveal the random nature of the copolymer based on typical dissociation reactions, i.e., water elimination occurred from any two contiguous MAA units while MAA-MMA pairs gave rise to the loss of a methanol molecule. Polymer backbone cleavages were also observed to occur and gave low abundance fragment ions which allowed the structure of the initiating end-group to be confirmed.

  11. On Surface-Initiated Atom Transfer Radical Polymerization Using Diazonium Chemistry To Introduce the Initiator Layer

    DEFF Research Database (Denmark)

    Iruthayaraj, Joseph; Chernyy, Sergey; Lillethorup, Mie

    2011-01-01

    This work features the controllability of surface-initiated atom transfer radical polymerization (SI-ATRP) of methyl methacrylate, initiated by a multilayered 2-bromoisobutyryl moiety formed via diazonium chemistry. The thickness as a function of polymerization time has been studied by varying di...

  12. Functionalized ormosil scaffolds processed by direct laser polymerization for application in tissue engineering

    DEFF Research Database (Denmark)

    Matei, A.; Schou, Jørgen; Canulescu, Stela

    2013-01-01

    Synthesized N,N′-(methacryloyloxyethyl triehtoxy silyl propyl carbamoyl-oxyhexyl)-urea hybrid methacrylate was polymerized by direct laser polymerization using femtosecond laser pulses with the aim of using it for subsequent applications in tissue engineering. The as-obtained scaffolds were...

  13. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G2/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    International Nuclear Information System (INIS)

    Magalhães, Hemerson I.F.; Wilke, Diego V.; Bezerra, Daniel P.; Cavalcanti, Bruno C.; Rotta, Rodrigo; Lima, Dênis P. de; Beatriz, Adilson; Moraes, Manoel O.; Diniz-Filho, Jairo; Pessoa, Claudia

    2013-01-01

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC 50 values in the nanomolar range. Cell cycle arrest in G 2 /M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G 2 /M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G 2 /M phase of the cell cycle. • PHT induces caspase-dependent apoptosis

  14. (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone inhibits tubulin polymerization, induces G{sub 2}/M arrest, and triggers apoptosis in human leukemia HL-60 cells

    Energy Technology Data Exchange (ETDEWEB)

    Magalhães, Hemerson I.F. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Centro de Ciências da Saúde, Departamento de Ciências Farmacêuticas, Universidade Federal da Paraíba, João Pessoa, Paraíba (Brazil); Wilke, Diego V. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Bezerra, Daniel P., E-mail: danielpbezerra@gmail.com [Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia (Brazil); Cavalcanti, Bruno C. [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Rotta, Rodrigo; Lima, Dênis P. de; Beatriz, Adilson [Centro de Ciências Exatas e Tecnológicas (Laboratório LP4), Universidade Federal do Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul (Brazil); Moraes, Manoel O.; Diniz-Filho, Jairo [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil); Pessoa, Claudia, E-mail: c_pessoa@yahoo.com [Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará (Brazil)

    2013-10-01

    (4-Methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone (PHT) is a known cytotoxic compound belonging to the phenstatin family. However, the exact mechanism of action of PHT-induced cell death remains to be determined. The aim of this study was to investigate the mechanisms underlying PHT-induced cytotoxicity. We found that PHT displayed potent cytotoxicity in different tumor cell lines, showing IC{sub 50} values in the nanomolar range. Cell cycle arrest in G{sub 2}/M phase along with the augmented metaphase cells was found. Cells treated with PHT also showed typical hallmarks of apoptosis such as cell shrinkage, chromatin condensation, phosphatidylserine exposure, increase of the caspase 3/7 and 8 activation, loss of mitochondrial membrane potential, and internucleosomal DNA fragmentation without affecting membrane integrity. Studies conducted with isolated tubulin and docking models confirmed that PHT binds to the colchicine site and interferes in the polymerization of microtubules. These results demonstrated that PHT inhibits tubulin polymerization, arrests cancer cells in G{sub 2}/M phase of the cell cycle, and induces their apoptosis, exhibiting promising anticancer therapeutic potential. - Highlights: • PHT inhibits tubulin polymerization. • PHT arrests cancer cells in G{sub 2}/M phase of the cell cycle. • PHT induces caspase-dependent apoptosis.

  15. 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)

  16. Immobilization of microbial cells on cellulose-polymer surfaces by radiation polymerization

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1983-01-01

    Streptomyces phaeochromogens cells were immobilized on cellulose-polymer surfaces by radiation polymerization using hydrophilic monomers and paper. The enzyme activity of immobilized cell sheets was higher than that of immobilized cell composites obtained by the usual radiation polymerization technique. The enzyme activity of the sheets was affected by monomer concentration, the thickness of paper, and the degree of polymerization of paper. The copolymerization of hydroxyethyl methacrylate and methoxytetraethyleneglycol methacrylate in the sheets led to a further increase of the enzyme activity due to the increase of the hydrophilicity of the polymer matrix. The Michaelis constant of the sheets from low monomer concentration was close to that of intact cells

  17. PREPARATION AND PROPERTY OF POLYMERIC PENDANT Ru(bpy)32+ COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    HOU Xiaohuai; Masao Kaneko; Akira Yamada

    1984-01-01

    Polymeric pendant Ru(bpy)32+ complexes were prepared from homopolymer and copolymers of 4-methyl-4'-vinyl-2,2'-bipyridine (Vbpy). Vbpy was prepared from 4-methylpyridine. The comonomers were styrene (St), acrylic acid (AA), N-vinylpyrrolidone (Pyr), 4-vinylpyridine (Vpy), methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), acrylonitrile (AN) and N-ethyl-4-vinylpyridium bromide (EQ-Vpy). The fraction of the pendant Ru(bpy)32+ repeating unit in the polymeric complex was 0.022 to 0.052. Absorption maximum, molar extinction coefficient, emission maximum and relative emission intensity of the polymeric complexes were studied.

  18. 4-(ALPHA, ALPHA-DIMETHYLBENZYL)PHENYL METHACRYLATE .3. SYNTHESIS, TACTICITY AND GLASS-TRANSITION TEMPERATURES OF ITS POLYMERS

    NARCIS (Netherlands)

    VANEKENSTEIN, GORA; TAN, YY

    Depending on the kind of initiator, anionic Polymerization of 4-(alpha,alpha-dimethylbenzyl)phenyl methacrylate in toluene at -78-degrees-C led either to highly isotactic or predominantly syndiotactic polymers as determined by C-13 NMR spectro copy. The glass transition temperature difference

  19. Poly (acrylonitrile-co-methyl methacrylate nanoparticles: I. Preparation and characterization

    Directory of Open Access Journals (Sweden)

    M.S. Mohy Eldin

    2017-12-01

    Full Text Available This work concerns the preparation and characterization of poly (acrylonitrile-co-methyl methacrylate Copolymer, P(AN-co-MMA, nano-particles using precipitation polymerization technique. Potassium per-sulfate redox initiation system was used to perform polymerization process in an alcoholic aqueous system. The impact of different polymerization conditions such as comonomer concentration and ratio, polymerization time, polymerization temperatures, initiator concentration and co-solvent composition on the polymerization yield and particle size was studied. Maximum polymerization yield, 70%, was obtained with MMA:AN (90%:10% comonomer composition. Particle sizes ranging from 16 nm to 1483 nm were obtained and controlled by variation of polymerization conditions. The co-polymerization process was approved by FT-IR and TGA analysis. The copolymer composition was investigated by nitrogen content analysis. Copolymers with a progressive percentage of PAN show thermal stabilities close to PAN Homopolymer. SEM photographs prove spherical structure of the produced copolymers. The investigated system shows promising future in the preparation of nanoparticles from comonomers without using emulsifiers or dispersive agents.

  20. Oral Delivery of Curcumin Polymeric Nanoparticles Ameliorates CCl4-Induced Subacute Hepatotoxicity in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Gregory Marslin

    2018-05-01

    Full Text Available Curcumin is the major bioactive compound of Curcuma longa, an important medicinal plant used in traditional herbal formulations since ancient times. In the present study, we report that curcumin nanoparticles (ηCur protects Wistar rats against carbon tetrachloride (CCl4-induced subacute hepatotoxicity. Nanoparticles of sizes less than 220 nm with spherical shape were prepared using PLGA and PVA respectively as polymer and stabilizer. Test animals were injected via intraperitoneal route with 1 mL/kg CCl4 (8% in olive oil twice a week over a period of 8 weeks to induce hepatotoxicity. On the days following the CCl4 injection, test animals were orally administered with either curcumin or its equivalent dose of ηCur. Behavioural observation, biochemical analysis of serum and histopathological examination of liver of the experimental animals indicated that ηCur offer significantly higher hepatoprotection compared to curcumin.

  1. Radiation-Induced Polymerization of Aldehydes and Ketones; Polymerisation radiochimique des aldehydes et des cetones; Radiatsionnaya polimerizatsiya al'degidov i ketonov; Polimerizacion radioinducida de aldehidos y cetonas

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, K.; Yamaoka, H.; Fujiwara, K.; Sakamoto, M.; Mori, S.; Natori, T.; Yoshida, H.; Okamura, S. [Japanese Association for Radiation Research on Polymers, Neyagawa Osaka (Japan); Kyoto University, Kyoto (Japan)

    1963-11-15

    Several kinds of aldehydes and ketones are polymerized by irradiation. Formaldehyde can be polymerized into high molecular weight polyoxymethylene by radiation-induced polymerization in the liquid phase at low temperatures. The polymerization mechanism is considered to be a cationic chain reaction both in the case of bulk and of solution in methylenechloride and toluene, but to be anionic in ethylether. Acetaldehyde and propionaldehyde are recognized as being hardly polymerized in the pure liquid phase, but easily polymerized in the presence of {gamma}-alumina. In the solid state polymerization, crystalline polymers are obtained as the stable- for- heat-treatment form under suitableconditions. Glyoxal can be polymerized into a three-dimensional network polymer. With formaldehyde it can be copolymerized into some cross-linked polyoxymethylene. Acetones such as chloroor bromoacetone and methylethylketone or diacetyl can be polymerized in the solid state into polymers which are unstable. Ketene can be polymerized into a polyester-type polymer with liquid phase polymerization; polyketone is obtained additionally when polymerization is carried out in the solid state. The copolymer with formaldehyde is slightly more stable. Dimethylketene can be easily polymerized both in the liquid and solid states into polyacetal. All these polymerizations are special examples of radiation-induced reactions and the reaction kinetics are interesting. Some details of this are discussed here. (author) [French] Plusieurs sortes d'aldehydes et de cetones se polymerisent sous l'effet des rayons gamma. L'aldehyde formique peut se transformer en polyoxymethylene de poids moleculaire eleve par polymerisation radiochimique en phase liquide a basses temperatures. On pense que la polymerisation est une reaction cationique en chaine lorsqu'il s'agit de masses ou de solutions dans du chlorure de methylene et du toluene, mais une reaction anionique en chaule dans une solution d'ether ethylique. L

  2. Self-organization of porphyrin units induced by magnetic field during sol-gel polymerization.

    Science.gov (United States)

    Lerouge, Frédéric; Cerveau, Geneviève; Corriu, Robert J P; Stern, Christine; Guilard, Roger

    2007-04-21

    The use of a magnetic field as a controlling factor during the hydrolysis-polycondensation of porphyrin precursors substituted by Si(OR)(3) groups, induces a self-organization of porphyrin moieties due to the stacking of these units in the hybrid material and this study also confirms the effect of the magnetic field in the nano- and micrometric organization during the kinetically controlled polycondensation process.

  3. Preparation and application of conducting polymer/Ag/clay composite nanoparticles formed by in situ UV-induced dispersion polymerization

    Science.gov (United States)

    Zang, Limin; Qiu, Jianhui; Yang, Chao; Sakai, Eiichi

    2016-02-01

    In this work, composite nanoparticles containing polypyrrole, silver and attapulgite (PPy/Ag/ATP) were prepared via UV-induced dispersion polymerization of pyrrole using ATP clay as a templet and silver nitrate as photoinitiator. The effects of ATP concentration on morphology, structure and electrical conductivity were studied. The obtained composite nanoparticles with an interesting beads-on-a-string morphology can be obtained in a short time (10 min), which indicates the preparation method is facile and feasible. To explore the potential applications of the prepared PPy/Ag/ATP composite nanoparticles, they were served as multifunctional filler and blended with poly(butylene succinate) (PBS) matrix to prepare biodegradable composite material. The distribution of fillers in polymer matrix and the interfacial interaction between fillers and PBS were confirmed by scanning electron microscope, elemental mapping and dynamic mechanical analysis. The well dispersed fillers in PBS matrix impart outstanding antibacterial property to the biodegradable composite material as well as enhanced storage modulus due to Ag nanoparticles and ATP clay. The biodegradable composite material also possesses modest surface resistivity (106 ~ 109 Ω/◻).

  4. Self-Supporting, Hydrophobic, Ionic Liquid-Based Reference Electrodes Prepared by Polymerization-Induced Microphase Separation.

    Science.gov (United States)

    Chopade, Sujay A; Anderson, Evan L; Schmidt, Peter W; Lodge, Timothy P; Hillmyer, Marc A; Bühlmann, Philippe

    2017-10-27

    Interfaces of ionic liquids and aqueous solutions exhibit stable electrical potentials over a wide range of aqueous electrolyte concentrations. This makes ionic liquids suitable as bridge materials that separate in electroanalytical measurements the reference electrode from samples with low and/or unknown ionic strengths. However, methods for the preparation of ionic liquid-based reference electrodes have not been explored widely. We have designed a convenient and reliable synthesis of ionic liquid-based reference electrodes by polymerization-induced microphase separation. This technique allows for a facile, single-pot synthesis of ready-to-use reference electrodes that incorporate ion conducting nanochannels filled with either 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-dodecyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide as ionic liquid, supported by a mechanically robust cross-linked polystyrene phase. This synthesis procedure allows for the straightforward design of various reference electrode geometries. These reference electrodes exhibit a low resistance as well as good reference potential stability and reproducibility when immersed into aqueous solutions varying from deionized, purified water to 100 mM KCl, while requiring no correction for liquid junction potentials.

  5. Adsorption of crude oil from aqueous solution by hydrogel of chitosan based polyacrylamide prepared by radiation induced graft polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Sokker, H.H., E-mail: hesham_sokkre@yahoo.com [Jazan University, Faculty of Science (Saudi Arabia); National Center for Radiation Research and Technology, Polymer Chemistry Department, P.O. Box 29, Cairo (Egypt); El-Sawy, Naeem M. [National Center for Radiation Research and Technology, Polymer Chemistry Department, P.O. Box 29, Cairo (Egypt); Hassan, M.A. [Scib Company of Paints, Cairo (Egypt); El-Anadouli, Bahgat E. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

    2011-06-15

    The adsorption of crude oil (initial concentration 0.5-30 g/L) from aqueous solution using hydrogel of chitosan based polyacrylamide (PAM) prepared by radiation induced graft polymerization has been investigated. The prepared hydrogel was characterized by FTIR and SEM micrographs. The experiments were carried out as a function of different initial concentrations of oil residue, acrylamide concentration, contact time and pH to determine the optimum condition for the adsorption of residue oil from aqueous solution and sea water. The results obtained showed that the hydrogel prepared at concentration of 40% acrylamide (AAm) and at a radiation dose of 5 kGy has high removal efficiency of crude oil 2.3 g/g at pH 3. Equilibrium studies have been carried out to determine the capacity of the hydrogel for adsorption of crude oil, Langmuir and Freundlich adsorption models were applied to describe the experimental isotherms and isotherms constants. Equilibrium data were found to fit very well with both Freundlich and Langmuir models. Also the adsorption of oil onto the hydrogel behaves as a pseudo-second-order kinetic models rather than the pseudo-first-order kinetic model.

  6. The synthesis of a new type adsorbent for the removal of toxic gas by radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Okamoto, Jiro; Sugo, Takanobu

    1990-01-01

    A new type of adsorbent containing sulfuric acid group for the removal of ammonia gas was synthesized by radiation-induced graft polymerization of styrene onto fibrous and nonwoven type polypropylene followed by sulufonation with chlorosulfonic acid. The rate of the adsorption of ammonia gas by H-type adsorbent is independent of the ion-exchange capacity. The amount of ammonia gas adsorbed by the chemical adsorption was dependent on the ion-exchange capacity of H-type fibrous adsorbent and was kept constant value in spite of the equilibrium pressure of ammonia gas. Cu(II)- and Ni(II)-types fibrous adsorbent were prepared by the ion exchange reaction of Na-type fibrous adsorbent with metal nitrate solutions. Although, the rate of adsorption of ammonia gas by metal-type fibrous adsorbent is lower than that of H-type adsorbent, the amount of ammonia gas adsorbed increases compared to H-type adsorbent with the same ion exchange capacity. It was related to the highest coordination number of metal ion. The ratio of the number of ammonia molecules adsorbed chemically and the number of metal ion adsorbed in fibrous adsorbent was 4 for Cu-type and 6 for Ni-type fibrous adsorbent, respectively. (author)

  7. Simultaneously and separately immobilizing incompatible dual-enzymes on polymer substrate via visible light induced graft polymerization

    Science.gov (United States)

    Zhu, Xing; He, Bin; Zhao, Changwen; Ma, Yuhong; Yang, Wantai

    2018-04-01

    Developing facile and mild strategy to construct multi-enzymes immobilization system has attracted considerable attentions in recent years. Here a simple immobilization strategy called visible light induced graft polymerization that can simultaneously and separately encapsulate two kinds of enzymes on one polymer film was proposed. Two incompatible enzymes, trypsin and transglutaminase (TGase) were selected as model dual-enzymes system and simultaneously immobilized on two sides of low-density polyethylene (LDPE) film. After immobilization, it was found that more than 90% of the enzymes can be embedded into dual-enzymes loaded film without leakage. And the activities of both separately immobilized enzymes were higher than the activities of mixed co-immobilized enzymes or the sequential immobilized ones. This dual-enzymes loaded film (DEL film) showed excellent recyclability and can retain >87% activities of both enzymes after 4 cycles of utilization. As an example, this DEL film was used to conjugate a prodrug of cytarabine with a target peptide. The successful preparation of expected product demonstrated that the separately immobilized two enzymes can worked well together to catalyze a two-step reaction.

  8. Radiation induced emulsion graft polymerization of 4-vinylpyridine onto PE/PP nonwoven fabric for As(V) adsorption

    Science.gov (United States)

    Akkaş Kavaklı, Pınar; Kavaklı, Cengiz; Seko, Noriaki; Tamada, Masao; Güven, Olgun

    2016-10-01

    A novel nonwoven fabric adsorbent having 4-vinylpyridine functional groups was prepared by using radiation-induced emulsion graft polymerization method and grafting 4-vinylpyridine monomer onto a polyethylene-coated polypropylene nonwoven fabric (NWF) in aqueous emulsion solution. The grafting conditions of the 4-vinylpyridine monomer onto the NWF were optimised and 150% Dg VP-g-NWF was prepared using 30 kGy pre-irradiation dose, 5% VP monomer concentration and 0.5% (w/w) Tween 20 in aqueous emulsion. Grafted 4-vinylpyridine chains on the NWF were then quaternized for the preparation of QVP-g-NWF adsorbent. All fabric structures were characterized by using Fourier-transform infrared spectrometer, x-ray photoelectron spectrometer and scanning electron microscope. QVP-g-NWF adsorbent was used in batch adsorption experiments for As(V) ions by studying the pH, contact time, and initial As(V) ion concentration parameters. Results showed that QVP-g-NWF adsorbent has significant As(V) adsorption and experimental As(V) adsorption capacity was 98.04 mg As(V)/g polymer from 500 mg/L initial As(V) concentration at pH 7.00.

  9. Preparation and application of conducting polymer/Ag/clay composite nanoparticles formed by in situ UV-induced dispersion polymerization.

    Science.gov (United States)

    Zang, Limin; Qiu, Jianhui; Yang, Chao; Sakai, Eiichi

    2016-02-03

    In this work, composite nanoparticles containing polypyrrole, silver and attapulgite (PPy/Ag/ATP) were prepared via UV-induced dispersion polymerization of pyrrole using ATP clay as a templet and silver nitrate as photoinitiator. The effects of ATP concentration on morphology, structure and electrical conductivity were studied. The obtained composite nanoparticles with an interesting beads-on-a-string morphology can be obtained in a short time (10 min), which indicates the preparation method is facile and feasible. To explore the potential applications of the prepared PPy/Ag/ATP composite nanoparticles, they were served as multifunctional filler and blended with poly(butylene succinate) (PBS) matrix to prepare biodegradable composite material. The distribution of fillers in polymer matrix and the interfacial interaction between fillers and PBS were confirmed by scanning electron microscope, elemental mapping and dynamic mechanical analysis. The well dispersed fillers in PBS matrix impart outstanding antibacterial property to the biodegradable composite material as well as enhanced storage modulus due to Ag nanoparticles and ATP clay. The biodegradable composite material also possesses modest surface resistivity (10(6)~ 10(9) Ω/◻).

  10. Investigations to increase the efficiency of fluorine and boron removal from groundwater using radiation-induced graft polymerization adsorbent

    International Nuclear Information System (INIS)

    Iyatomi, Yosuke; Shimada, Akiomi; Ogata, Nobuhisa; Sugihara, Kozo; Hoshina, Hiroyuki; Seko, Noriaki; Kasai, Noboru; Ueki, Yuji; Tamada, Masao

    2010-01-01

    The Japan Atomic Energy Agency is performing a research project in the Mizunami Underground Research Laboratory (MIU) to build a firm scientific and technological basis for the studies of the deep underground environment in crystalline rock. In the project, it is necessary to reduce the fluorine and boron concentrations in groundwater pumped from the MIU shafts to levels below the environmental standards. This is done at the MIU water treatment facility using coagulation and ion exchange treatment for fluorine and boron, respectively. In addition, in 2006, research started on the efficient treatment of groundwater for removal of fluorine and boron using a radiation-induced graft polymerization adsorbent. The adsorbent removed boron at a flow rate (space velocity (SV)=120 h -1 ) higher than that of a general ion exchange resin (SV=10 h -1 ) and the adsorbent could be used repeatedly. It was also apparent that the pH of groundwater had an influence on adsorption performance. With respect to fluorine removal, more than 90% of fluorine was removed. However, the adsorbent for fluorine showed a lower adsorption capacity than that for boron. The reason for this difference is considered to be related to the initial concentration difference between fluorine and boron in the groundwater. Therefore, it is necessary to define the initial concentrations of dissolved materials, which can be used as better indicators of the performance of the adsorbent. (author)

  11. Synthesis of 2-aryl-1,2,4-oxadiazolo-benzimidazoles: Tubulin polymerization inhibitors and apoptosis inducing agents.

    Science.gov (United States)

    Kamal, Ahmed; Reddy, T Srinivasa; Vishnuvardhan, M V P S; Nimbarte, Vijaykumar D; Subba Rao, A V; Srinivasulu, Vunnam; Shankaraiah, Nagula

    2015-08-01

    A new series of 2-aryl 1,2,4-oxadiazolo-benzimidazole conjugates have been synthesized and evaluated for their antiproliferative activity in the sixty cancer cell line panel of the National Cancer Institute (NCI). Compounds 5l (NSC: 761109/1) and 5x (NSC: 761814/1) exhibited remarkable cytotoxic activity against most of the cancer cell lines in the one dose assay and were further screened at five dose concentrations (0.01, 0.1, 1, 10 and 100 μM) which showed GI50 values in the range of 0.79-28.2 μM. Flow cytometric data of these compounds showed increased cells in G2/M phase, which is suggestive of G2/M cell cycle arrest. Further, compounds 5l and 5x showed inhibition of tubulin polymerization and disruption of the formation of microtubules. These compounds induce apoptosis by DNA fragmentation and chromatin condensation as well as by mitochondrial membrane depolarization. In addition, structure activity relationship studies within the series are also discussed. Molecular docking studies of compounds 5l and 5x into the colchicine-binding site of the tubulin, revealed the possible mode of interaction by these compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. UV-induced graft polymerization of acrylic acid in the sub-micronchannels of oxidized PET track-etched membrane

    Science.gov (United States)

    Korolkov, Ilya V.; Mashentseva, Anastassiya A.; Güven, Olgun; Taltenov, Abzal A.

    2015-12-01

    In this article, we report on functionalization of track-etched membrane based on poly(ethylene terephthalate) (PET TeMs) oxidized by advanced oxidation systems and by grafting of acrylic acid using photochemical initiation technique for the purpose of increasing functionality thus expanding its practical application. Among advanced oxidation processes (H2O2/UV) system had been chosen to introduce maximum concentration of carboxylic acid groups. Benzophenone (BP) photo-initiator was first immobilized on the surfaces of cylindrical pores which were later filled with aq. acrylic acid solution. UV-irradiation from both sides of PET TeMs has led to the formation of grafted poly(acrylic acid) (PAA) chains inside the membrane sub-micronchannels. Effect of oxygen-rich surface of PET TeMs on BP adsorption and subsequent process of photo-induced graft polymerization of acrylic acid (AA) were studied by ESR. The surface of oxidized and AA grafted PET TeMs was characterized by UV-vis, ATR-FTIR, XPS spectroscopies and by SEM.

  13. Analytical calculations and properties of gamma-rays polymerization of novel acrylates copolymer system

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed, S.M., E-mail: smelsayed@hotmail.co [National Center for Radiation Research and Technology, Nasr City, Cairo (Egypt); Madani, M.; El-Bayoumi, A.S. [National Center for Radiation Research and Technology, Nasr City, Cairo (Egypt)

    2009-11-15

    A detailed study of some physical properties of pure PMMA (polymethyl methacrylate) film and MMA/Ani (methyl methacrylate/aniline) films is presented. Films of thicknesses ranged from 0.04 to 0.72 mm for MMA/Ani were prepared while it is 0.68 mm for PMMA. The structure of the sample is analyzed by X-ray diffraction technique and is found to be amorphous (PMMA) and partially crystalline (MMA/Ani). Ultra violet-visible electronic absorption spectra measurements were analyzed to obtain some important parameters such as molar extrication coefficient, oscillator strength, dipole strength and having good thermal stability (T{sub d} >300 deg. C) was also reported. TGA studies revealed that the thermal stability of polymethyl methacrylate, prepared by radiation polymerization of methyl methacrylate, improved after copolymerization with aniline. Also, optical behavior of film samples was analyzed by obtaining transmission spectra, in the wavelength range of 200-1100 nm. It was found that all studied samples lead to the appearance of a second edge at lower photon energy due to the formation of the induced energy states. From the intensity of absorption interband transitions (B and Q) which are assigned as type pi-pi* for both PMMA and MMA/Ani films, the energy gaps E{sub g1} and E{sub g2} were calculated respectively. The optical conductivity (sigma) was determined and it was found that with the increase of thicknesses optical energy gap decreases monotonically and the refractive index increases.

  14. Monomode microwave-assisted atom transfer radical polymerization

    NARCIS (Netherlands)

    Zhang, H.; Schubert, U.S.

    2004-01-01

    The first monomode microwave-assisted atom transfer radical polymerization (ATRP) is reported. The ATRP of methyl methacrylate was successfully performed with microwave heating, which was well controlled and provided almost the same results as experiments with conventional heating, demonstrating the

  15. Alkyne End Group Production in Polymeric Materials Induced by Swift Heavy Ion Irradiations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Swift heavy ions in matter lose energy mainly through electronic processes.Since the energy deposition is centered in a very small region with a very high energy density,new effects such as production of alkyne end group can be induced.In this work,PET,PS,PC and PI films are irradiated with Ar,Kr,Xe and U ions and the relationship of the alkyne end group production with electronic energy loss is studied by Fourier transformed infrared infrared(FTLR)spectra measurements.

  16. Direct laser writing of polymeric nanostructures via optically induced local thermal effect

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Quang Cong [Laboratoire de Photonique Quantique et Moléculaire, UMR 8537, École Normale Supérieure de Cachan, CentraleSupélec, CNRS, Université Paris-Saclay, 61 avenue du Président Wilson, 94235 Cachan (France); Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, 10000 Hanoi (Viet Nam); Nguyen, Dam Thuy Trang; Do, Minh Thanh; Luong, Mai Hoang; Journet, Bernard; Ledoux-Rak, Isabelle; Lai, Ngoc Diep, E-mail: nlai@lpqm.ens-cachan.fr [Laboratoire de Photonique Quantique et Moléculaire, UMR 8537, École Normale Supérieure de Cachan, CentraleSupélec, CNRS, Université Paris-Saclay, 61 avenue du Président Wilson, 94235 Cachan (France)

    2016-05-02

    We demonstrate the fabrication of desired structures with feature size below the diffraction limit by use of a positive photoresist. The direct laser writing technique employing a continuous-wave laser was used to optically induce a local thermal effect in a positive photoresist, which then allowed the formation of solid nanostructures. This technique enabled us to realize multi-dimensional sub-microstructures by use of a positive photoresist, with a feature size down to 57 nm. This mechanism acting on positive photoresists opens a simple and low-cost way for nanofabrication.

  17. Preparation and Characterization of InP/Poly(methyl methacrylate) Nanocomposite Films.

    Science.gov (United States)

    Kwon, Younghoon; Kim, Jongsung

    2017-04-01

    Quantum dots (QDs) are nanocrystalline semiconductors with many unusual optical properties. They exhibit very high fluorescence intensities and possess exceptional stability against photo-bleaching. In this study, we report the preparation of InP QDs-poly(methyl methacrylate) (PMMA) hybrids by fabricating QDs via a thermal decomposition reaction, followed by radical polymerization. The InP QDs were synthesized using indium(III) chloride and tris(dimethylamino)phosphine. Flexible composite films were obtained by radical polymerization using methyl methacrylate (MMA) as the monomer and 2,2′-azobis(2-methylpropionitrile) (AIBN) as a radical initiator. The PL intensity of the QDs was lowered upon composite formation with PMMA. However, the composites exhibited higher thermal stability than pure PMMA.

  18. Radiation induced emulsion graft polymerization of 4-vinylpyridine onto PE/PP nonwoven fabric for As(V) adsorption

    International Nuclear Information System (INIS)

    Akkaş Kavaklı, Pınar; Kavaklı, Cengiz; Seko, Noriaki; Tamada, Masao; Güven, Olgun

    2016-01-01

    A novel nonwoven fabric adsorbent having 4-vinylpyridine functional groups was prepared by using radiation-induced emulsion graft polymerization method and grafting 4-vinylpyridine monomer onto a polyethylene-coated polypropylene nonwoven fabric (NWF) in aqueous emulsion solution. The grafting conditions of the 4-vinylpyridine monomer onto the NWF were optimised and 150% D g VP-g-NWF was prepared using 30 kGy pre-irradiation dose, 5% VP monomer concentration and 0.5% (w/w) Tween 20 in aqueous emulsion. Grafted 4-vinylpyridine chains on the NWF were then quaternized for the preparation of QVP-g-NWF adsorbent. All fabric structures were characterized by using Fourier-transform infrared spectrometer, x-ray photoelectron spectrometer and scanning electron microscope. QVP-g-NWF adsorbent was used in batch adsorption experiments for As(V) ions by studying the pH, contact time, and initial As(V) ion concentration parameters. Results showed that QVP-g-NWF adsorbent has significant As(V) adsorption and experimental As(V) adsorption capacity was 98.04 mg As(V)/g polymer from 500 mg/L initial As(V) concentration at pH 7.00. - Highlights: • Radiation induced grafting of 4-vinylpyridine onto PE/PP nonwoven fabric in emulsion. • 4-vinylpyridine grafting was characterized by FTIR, SEM and XPS. • As(V) adsorption was studied by QVP-g- NWF. • As(V) adsorption capacity was found to be 98.04 mg As(V)/g polymer.

  19. Pressure induced polymerization of acetylide anions in CaC 2 and 10 7 fold enhancement of electrical conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Haiyan; Wang, Lijuan; Li, Kuo; Yang, Youyou; Wang, Yajie; Wu, Jiajia; Dong, Xiao; Wang, Chun-Hai; Tulk, Christopher A.; Molaison, Jamie J.; Ivanov, Ilia N.; Feygenson, Mikhail; Yang, Wenge; Guthrie, Malcolm; Zhao, Yusheng; Mao, Ho-Kwang; Jin, Changqing (ORNL); (CIW); (CHPSTAR- China); (Agilent); (SUSTC); (Chinese Aca. Sci.); (COFCO); (Durham)

    2016-08-17

    Transformation between different types of carbon–carbon bonding in carbides often results in a dramatic change of physical and chemical properties. Under external pressure, unsaturated carbon atoms form new covalent bonds regardless of the electrostatic repulsion. It was predicted that calcium acetylide (also known as calcium carbide, CaC2) polymerizes to form calcium polyacetylide, calcium polyacenide and calcium graphenide under high pressure. In this work, the phase transitions of CaC2 under external pressure were systematically investigated, and the amorphous phase was studied in detail for the first time. Polycarbide anions like C66- are identified with gas chromatography-mass spectrometry and several other techniques, which evidences the pressure induced polymerization of the acetylide anions and suggests the existence of the polyacenide fragment. Additionally, the process of polymerization is accompanied with a 107 fold enhancement of the electrical conductivity. The polymerization of acetylide anions demonstrates that high pressure compression is a viable route to synthesize novel metal polycarbides and materials with extended carbon networks, while shedding light on the synthesis of more complicated metal organics.

  20. Radiation-induced graft polymerization of acrylic acid onto fluorinated polymers: Pt. 2

    International Nuclear Information System (INIS)

    Abdel-Ghaffar, M.; Hegazy, E.A.; Dessouki, A.M.; El-Sawy, N.M.; El-Assy, N.B.

    1991-01-01

    Radiation induced grafting of acrylic acid onto poly (tetrafluoroethylene-perfluorovinyl ether) (PFA) films was investigated. The grafted films rapidly absorbed Fe 3+ , Co 2+ , Ni 2+ , and Cu 2+ ions in high efficiency. The polyacrylic acid grafted onto PFA acted as a chelating site for the previously selected transition metal ions. Such prepared copolymer-metal complexes were confirmed spectrophotometrically via IR, UV-spectrometry, X-ray fluorescence, X-ray diffraction, and colour index measurements. Electrical conductivity and mechanical properties of PFA grafted copolymer-metal complexes were investigated. The applications of such prepared copolymer-metal complexes in the field of semiconductors besides its performance as a cation-exchange membrane may be of great interest. (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. Thermo-responsive polymeric nanoparticles for enhancing neuronal differentiation of human induced pluripotent stem cells.

    Science.gov (United States)

    Seo, Hye In; Cho, Ann-Na; Jang, Jiho; Kim, Dong-Wook; Cho, Seung-Woo; Chung, Bong Geun

    2015-10-01

    We report thermo-responsive retinoic acid (RA)-loaded poly(N-isopropylacrylamide)-co-acrylamide (PNIPAM-co-Am) nanoparticles for directing human induced pluripotent stem cell (hiPSC) fate. Fourier transform infrared spectroscopy and (1)H nuclear magnetic resonance analysis confirmed that RA was efficiently incorporated into PNIAPM-co-Am nanoparticles (PCANs). The size of PCANs dropped with increasing temperatures (300-400 nm at room temperature, 80-90 nm at 37°C) due to its phase transition from hydrophilic to hydrophobic. Due to particle shrinkage caused by this thermo-responsive property of PCANs, RA could be released from nanoparticles in the cells upon cellular uptake. Immunocytochemistry and quantitative real-time polymerase chain reaction analysis demonstrated that neuronal differentiation of hiPSC-derived neuronal precursors was enhanced after treatment with 1-2 μg/ml RA-loaded PCANs. Therefore, we propose that this PCAN could be a potentially powerful carrier for effective RA delivery to direct hiPSC fate to neuronal lineage. The use of induced pluripotent stem cells (iPSCs) has been at the forefront of research in the field of regenerative medicine, as these cells have the potential to differentiate into various terminal cell types. In this article, the authors utilized a thermo-responsive polymer, Poly(N-isopropylacrylamide) (PNIPAM), as a delivery platform for retinoic acid. It was shown that neuronal differentiation could be enhanced in hiPSC-derived neuronal precursor cells. This method may pave a way for future treatment of neuronal diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Investigation of magnetic nanoparticles in acrylonitrile-methyl methacrylate-divinylbenzene mesoporous template

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo, D. E-mail: denilson@quimica.ufg.br; Lima, E.C.D.; Barbosa, D.P.; Silva, V.J.; Silva, O.; Azevedo, R.B.; Silva, L.P.; Lemos, A.P.C.; Morais, P.C

    2002-11-01

    Preparation and characterization of nanosized magnetic particles using alkaline oxidation of ferrous ion retained in acrylonitrile-methyl methacrylate-divinylbenzene (AN-MMA-DVB) spherical micron-sized polymer template is described. Atomic absorption, transmission electron microscopy and magnetic resonance were used to investigate chemically cycled nanoparticle-based composites. The resonance field shifts towards higher values as the nanoparticle concentration reduces in the polymeric template, following two very distinct regimes.

  6. Peculiarities of the photoinitiator-free photopolymerization of pentabrominated and pentafluorinated aromatic acrylates and methacrylates.

    Science.gov (United States)

    Daikos, Olesya; Naumov, Sergej; Knolle, Wolfgang; Heymann, Katja; Scherzer, Tom

    2016-11-30

    Pentabrominated and fluorinated aromatic (meth)acrylates as well as their non-halogenated counterparts have been studied with the aim to avoid conventional photoinitiators and to overcome some negative consequences related to their use. Therefore, RTIR spectroscopy, laser flash photolysis and GC/MS were utilized. Even low concentrations (1 to 5 wt%) of brominated (meth)acrylates in the model varnish lead to initiation of a photopolymerization reaction under exposure to UV light with λ > 300 nm. This is due to the fact that excitation of the aryl moiety leads to the homolysis of bromine-phenyl bonds with a high quantum yield of ∼0.15-0.3. Both, bromine radicals released from either ortho, meta or para position as well as the corresponding tetrabromoaryl radicals, may initiate the polymerization of brominated aromatic (meth)acrylates. In contrast, fluorinated aromatic (meth)acrylates undergo α-cleavage of the carboxyl group (as in the case of non-halogenated aromatic (meth)acrylates), if excitation of the acrylic double bonds is done with UV-C light (λ fluorinated) and 0.16-0.36 (non-halogenated compounds), despite the different pathway of fragmentation. Thus, in all cases the efficiency of initiation is comparable to conventional photoinitiators. Quantum chemical calculations of orbitals involved and of the Gibbs free energy of transients and products support the suggested reaction pathway.

  7. Preparation and evaluation of poly(alkyl methacrylate-co-methacrylic acid-co-ethylene dimethacrylate) monolithic columns for separating polar small molecules by capillary liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shu-Ling; Wu, Yu-Ru; Lin, Tzuen-Yeuan; Fuh, Ming-Ren, E-mail: msfuh@scu.edu.tw

    2015-04-29

    Highlights: • Methacrylic acid (MAA) was used to increase hydrophilicity of polymeric monoliths. • Fast separation of phenol derivatives was achieved in 5 min using MAA-incorporated column. • Separations of aflatoxins and phenicol antibiotics were achieved using MAA-incorporated column. - Abstract: In this study, methacrylic acid (MAA) was incorporated with alkyl methacrylates to increase the hydrophilicity of the synthesized ethylene dimethacrylate-based (EDMA-based) monoliths for separating polar small molecules by capillary LC analysis. Different alkyl methacrylate–MAA ratios were investigated to prepare a series of 30% alkyl methacrylate–MAA–EDMA monoliths in fused-silica capillaries (250-μm i.d.). The porosity, permeability, and column efficiency of the synthesized MAA-incorporated monolithic columns were characterized. A mixture of phenol derivatives is employed to evaluate the applicability of using the prepared monolithic columns for separating small molecules. Fast separation of six phenol derivatives was achieved in 5 min with gradient elution using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. In addition, the effect of acetonitrile content in mobile phase on retention factor and plate height as well as the plate height-flow velocity curves were also investigated to further examine the performance of the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. Moreover, the applicability of prepared polymer-based monolithic column for potential food safety applications was also demonstrated by analyzing five aflatoxins and three phenicol antibiotics using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column.

  8. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Science.gov (United States)

    2010-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new uses...

  9. Effect of cerium (IV) ions on the anticorrosion properties of siloxane-poly(methyl methacrylate) based film applied on tin coated steel

    International Nuclear Information System (INIS)

    Suegama, P.H.; Sarmento, V.H.V.; Montemor, M.F.; Benedetti, A.V.; de Melo, H.G.; Aoki, I.V.; Santilli, C.V.

    2010-01-01

    This work investigates the influence of the addition of cerium (IV) ions on the anticorrosion properties of organic-inorganic hybrid coatings applied to passivated tin coated steel. In order to evaluate the specific effect of cerium (IV) addition on nanostructural features of the organic and inorganic phases of the hybrid coating, the hydrolytic polycondensation of silicon alkoxide and the radical polymerization of the methyl methacrylate (MMA) function were induced separately. The corrosion resistance of the coatings was evaluated by means of linear polarization, Tafel type curves and electrochemical impedance measurements. The impedance results obtained for the hybrid coatings were discussed based on an electrical equivalent circuit used to fit the experimental data. The electrochemical results clearly showed the improvement of the protective properties of the organic-inorganic hybrid coating mainly when the cerium (IV) was added to the organic phase solution precursor, which seemed to be due to the formation of a more uniform and densely reticulated siloxane-PMMA film.

  10. Effect of cerium (IV) ions on the anticorrosion properties of siloxane-poly(methyl methacrylate) based film applied on tin coated steel

    Energy Technology Data Exchange (ETDEWEB)

    Suegama, P.H. [Departamento de Engenharia Quimica, Escola Politecnica, Universidade de Sao Paulo, CP 61548, 05424-970 Sao Paulo, SP (Brazil); Sarmento, V.H.V. [Departamento Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil); Montemor, M.F. [ICEMS, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Benedetti, A.V. [Departamento Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil); de Melo, H.G.; Aoki, I.V. [Departamento de Engenharia Quimica, Escola Politecnica, Universidade de Sao Paulo, CP 61548, 05424-970 Sao Paulo, SP (Brazil); Santilli, C.V., E-mail: santilli@iq.unesp.b [Departamento Fisico-Quimica, Instituto de Quimica, Universidade Estadual Paulista, UNESP, CP 355, 14801-970 Araraquara, SP (Brazil)

    2010-07-15

    This work investigates the influence of the addition of cerium (IV) ions on the anticorrosion properties of organic-inorganic hybrid coatings applied to passivated tin coated steel. In order to evaluate the specific effect of cerium (IV) addition on nanostructural features of the organic and inorganic phases of the hybrid coating, the hydrolytic polycondensation of silicon alkoxide and the radical polymerization of the methyl methacrylate (MMA) function were induced separately. The corrosion resistance of the coatings was evaluated by means of linear polarization, Tafel type curves and electrochemical impedance measurements. The impedance results obtained for the hybrid coatings were discussed based on an electrical equivalent circuit used to fit the experimental data. The electrochemical results clearly showed the improvement of the protective properties of the organic-inorganic hybrid coating mainly when the cerium (IV) was added to the organic phase solution precursor, which seemed to be due to the formation of a more uniform and densely reticulated siloxane-PMMA film.

  11. Elektroaktive polymerer

    DEFF Research Database (Denmark)

    West, K.

    Traditionelt tænker vi på polymerer (plastik) som elektrisk isolerende materialer - det som er udenpå ledningerne. I dag kender vi imidlertid også polymerer med intrinsisk elektrisk ledningsevne, og plast er på vej ind i anvendelser, der tidligereudelukkende var baseret på metaller og uorganiske...... halvledere. Hertil kommer, at en del af de ledende polymerer kan stimuleres til at skifte mellem en ledende og en halvledende tilstand, hvorved de ændret både form og farve. I foredraget gives der enrække eksempler på anvendelse af polymerer som elektriske komponenter - rækkende fra polymer elektronik over...

  12. Studies on atom transfer radical polymerization of acrylates and styrenes with controlled polymeric block structures

    OpenAIRE

    Ibrahim, Khalid

    2006-01-01

    Atom transfer radical polymerization (ATRP) was applied to homo and block copolymerization of vinyl monomers methacrylates, acrylates, and styrene with iron (FeCl2.4H2O) as the transition metal in most cases. As complexing ligand either a commercially available ligand (triphenyl phosphine) (PPh3) or synthetic aliphatic amines were used. As initiators, methyl 2-bromopropionate, ethyl 2-bromoisobutyrate, α,α-dichloroacetophenone, and poly(ethylene oxide) macroinitiator were employed. Block ...

  13. SYNTHESIS OF BLOCK COPOLYMER BY INTEGRATED LIVING ANIONIC POLYMERIZATION-ATOM TRANSFER RADICAL POLYMERIZATION (ATRP)

    Institute of Scientific and Technical Information of China (English)

    Bing Liu; Feng Liu; Ning Luo; Sheng-kang Ying; Qing Liu

    2000-01-01

    Alpha-trichloroacetoxy terminated polystyrene oligomer (PS-CH2CH2OCOCCl3) and poly-(styrene-b-butadiene)oligomer [P(S-b-B)-CH2CH2OCOCCl3)] were synthesized by living anionic polymeri-zation using n-butyllithium as initiator.Then the PS-CH2CH2OCOCCl3 (PS-Cl3) or P(S-b-B)-CH2CH2O-COCCl3 (PSB-Cl3) was used as the macroinitiator in the polymerization of (meth)acrylates in the presence of CuX/bpy. AB diblock and ABC triblock copolymers were prepared by the integrated living anionic polymerization (LAP)-atom transfer radical polymerization (ATRP). The structures of the PSB-Cl3 and the P(S-b-MMA) were identified by FTIR and 1H-NMR spectrum, respectively. A new way to design block copolymers (the combination of LAP and ATRP) was developed.

  14. Radiation-induced polymerization of 1, 3-butadiene in urea canal complex as studied by broad line NMR

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Hayakawa, Naohiro; Abe, Toshihiko

    1975-01-01

    Dependence of the NMR spectrum on the molar ratio of 1,3-butadiene to urea, temperature dependence of the spectrum and changes of the spectrum during polymerization were observed. The results were discussed in comparison with previously reported results for the canal polymerization of acrylonitrile and vinyl chloride. 1,3-butadiene formes a canal complex with the molar ratio of 1 to 4 for 1,3-butadiene to urea. The urea canal complex is decomposed at -15 0 C. The spectrum of 1,3-butadiene in urea canal complex shows existence of a remarkably mobile component which was not observed on the spectra of acrylonitrile - urea of vinyl chloride - urea canal complex. The line width of 1,3-butadiene in the urea canal complex except the very narrow component was broader than that for vinyl chloride in the urea canal complex over an observed temperature range. The line width of urea formed the canal decreases at lower temperature than those of urea in vinyl chloride - urea canal complex. The post-polymerization of 1,3-butadiene in the urea canal complex started clearly from -78 0 C and completes when the temperature was raised to 20 0 C. The polymerization will be proceeded by the such way that monomer molecules move to the active center in the canal, as considered in the case of the polymerization of acrylonitrile and vinyl chloride in the canal complex. The crystal structure of the urea canal was maintained during polymerization and than the polybutadiene - urea canal complex was necessarily formed after the polymerization. The formation of the polymer - urea canal complex has distinct difference between 1,3-butadiene and acrylonitrile or vinyl chloride. For acrylonitrile and vinyl chloride the canals around the polymer formed are destroyed. The structure of polybutadiene - urea canal complex was hexagonal having a=8.21, c=10.50 A. (auth.)

  15. Process for the production of methyl methacrylate

    NARCIS (Netherlands)

    Eastham, G.R.; Johnson, D.W.; Straathof, A.J.J.; Fraaije, Marco; Winter, Remko

    2015-01-01

    A process of producing methyl methacrylate or derivatives thereof is described. The process includes the steps of; (i) converting 2-butanone to methyl propionate using a Baeyer-Villiger monooxygenase, and (ii) treating the methyl propionate produced to obtain methyl methacrylate or derivatives

  16. Metathesis Polymerization Reactions Induced by the Bimetallic Complex (Ph4P2[W2(μ-Br3Br6

    Directory of Open Access Journals (Sweden)

    Despoina Chriti

    2015-12-01

    Full Text Available The reactivity of the bimetallic complex (Ph4P2[W2(μ-Br3Br6] ({W 2.5 W}7+, a′2e3 towards ring opening metathesis polymerization (ROMP of norbornene (NBE and some of its derivatives, as well as the mechanistically related metathesis polymerization of phenylacetylene (PA, is presented. Our results show that addition of a silver salt (AgBF4 is necessary for the activation of the ditungsten complex. Polymerization of PA proceeds smoothly in tetrahydrofuran (THF producing polyphenylacetylene (PPA in high yields. On the other hand, the ROMP of NBE and its derivatives is more efficient in CH2Cl2, providing high yields of polymers. 13C Cross Polarization Magic Angle Spinning (CPMAS spectra of insoluble polynorbornadiene (PNBD and polydicyclopentadiene (PDCPD revealed the operation of two mechanisms (metathetic and radical for cross-linking, with the metathesis pathway prevailing.

  17. 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)

  18. Thiol-ene/methacrylate systems for mechanical damping

    Science.gov (United States)

    McNair, Olivia; Senyurt, Askim; Wei, Huanyu; Gould, Trent; Piland, Scott; Hoyle, Charles; Savin, Daniel

    2010-03-01

    Ternary thiol-ene-methacrylate (TEMA) networks as materials for mechanical energy damping are unique to the sports world. Using a photoinitiation process, TEMA systems are formed via an initial thiol-ene step-growth mechanism along with traditional radical polymerization of acrylate and ene monomers. Final networks have two-part morphologies: acrylate homopolymer sectors imbedded in a multi-component mesh. Several (TEMA) systems have been synthesized and analyzed via thermal and mechanical probing. Initial studies on these ternary systems have shown excellent properties compared to traditional ethylene vinyl alcohol (EVA) copolymers. For example, PEMA networks exhibit glass transition temperatures 33 K higher than EVA, resulting in improved damping at room temperature. This research will help develop relationships between tan delta, glass transition and their effects on mechanical energy damping for ternary (TEMA) systems.

  19. Synthesis and characterization of poly(styrene-co-methyl methacrylate)

    International Nuclear Information System (INIS)

    Augustinho, Tiago R.; Abarca, Silvia A.C.; Machado, Ricardo A.F.

    2011-01-01

    Polystyrene (PS) is nowadays commonly used due its advantages over competitors. PS presents a lower cost when compared with Acrylonitrile Butadiene Styrene (ABS) and with Polyethylene Tere-phthalate (PET), and can be easier processed than polypropylene (PP). At expandable form (EPS), can be used as projective equipment, thermal insulation, floating boards, refrigerators, isothermal, and low cost applications such as packaging and disposable material. Searching for more resistant materials and with a low cost, researches with copolymers materials are being developed. In this study, copolymerization reactions were carried out by suspension polymerization using monomers styrene and methyl methacrylate (MMA) with styrene. Styrene was in the highest percentage in relation to the MMA. The MMA was selected because is a monomer that presents a higher resistance than PS. The copolymerization was confirmed by performing infrared spectroscopy (IR), nuclear magnetic resonance of hydrogen (RMN 1 H), differential scanning calorimetry (DSC) and thermogravimetry (TGA). (author)

  20. Investigation of nanocomposites made with poly(methacrylic acid-co-methyl methacrylate)/poly(N-vinyl-2-pyrrolidone)/multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Guoqin, Liu; Wei, Miao [College of Material Science and Engineering, Henan University of Technology (China); Lin-Jian, Shangguan, E-mail: mikepolymer@126.com [School of Mechanical Engineering, North China University of Water Conservancy and Electric Power (China)

    2014-06-01

    Poly(methacrylic acid-co-methyl methacrylate) (P(MAA-co-MMA)) was prepared in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) and multi-walled carbon nanotubes (MWNTs) via ultrasonic assisted solution free radical polymerization, i.e., P(MAA-co-MMA)/PVP/MWNTs nanocomposites. The morphology, glassy-state storage modulus, thermal behavior and swelling characteristics of P(MAA-co-MMA)/PVP/MWNTs nanocomposites were investigated. Scanning electron micrographs (SEM) revealed that MWNTs at low concentration could be uniformly dispersed into P(MAA-co-MMA)/PVP blends. With increasing MWNTs weight fraction, the average glassy-state modulus, glass transition temperatures and decomposition temperature of the nanocomposites increased, but their swelling characteristics decreased. (author)

  1. Investigation of nanocomposites made with poly(methacrylic acid-co-methyl methacrylate/poly(N-vinyl-2-pyrrolidone/multi-walled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Liu Guoqin

    2014-01-01

    Full Text Available Poly(methacrylic acid-co-methyl methacrylate (P(MAA-co-MMA was prepared in the presence of poly(N-vinyl-2-pyrrolidone (PVP and multiwalled carbon nanotubes (MWNTs via ultrasonic assisted solution free radical polymerization, i.e., P(MAA-co-MMA/PVP/MWNTs nanocomposites. The morphology, glassy-state storage modulus, thermal behavior and swelling characteristics of P(MAA-co-MMA/PVP/MWNTs nanocomposites were investigated. Scanning electron micrographs (SEM revealed that MWNTs at low concentration could be uniformly dispersed into P(MAA-co-MMA/PVP blends. With increasing MWNTs weight fraction, the average glassy-state modulus, glass transition temperatures and decomposition temperature of the nanocomposites increased, but their swelling characteristics decreased.

  2. HYDROXYETHYL METHACRYLATE BASED NANOCOMPOSITE HYDROGELS WITH TUNABLE PORE ARCHITECTURE

    Directory of Open Access Journals (Sweden)

    Erhan Bat

    2016-10-01

    Full Text Available Hydroxyethyl methacrylate (HEMA based hydrogels have found increasing number of applications in areas such as chromatographic separations, controlled drug release, biosensing, and membrane separations. In all these applications, the pore size and pore interconnectivity are crucial for successful application of these materials as they determine the rate of diffusion through the matrix. 2-Hydroxyethyl methacrylate is a water soluble monomer but its polymer, polyHEMA, is not soluble in water. Therefore, during polymerization of HEMA in aqueous media, a porous structure is obtained as a result of phase separation. Pore size and interconnectivity in these hydrogels is a function of several variables such as monomer concentration, cross-linker concentration, temperature etc. In this study, we investigated the effect of monomer concentration, graphene oxide addition or clay addition on hydrogel pore size, pore interconnectivity, water uptake, and thermal properties. PolyHEMA hydrogels have been prepared by redox initiated free radical polymerization of the monomer using ethylene glycol dimethacrylate as a cross-linker. As a nanofiller, a synthetic hectorite Laponite® XLG and graphene oxide were used. Graphene oxide was prepared by the Tour Method. Pore morphology of the pristine HEMA based hydrogels and nanocomposite hydrogels were studied by scanning electron microscopy. The formed hydrogels were found to be highly elastic and flexible. A dramatic change in the pore structure and size was observed in the range between 22 to 24 wt/vol monomer at 0.5 % of cross-linker. In this range, the hydrogel morphology changes from typical cauliflower architecture to continuous hydrogel with dispersed water droplets forming the pores where the pores are submicron in size and show an interconnected structure. Such controlled pore structure is highly important when these hydrogels are used for solute diffusion or when there’s flow through monolithic hydrogels

  3. Fabrication of Reductive-Responsive Prodrug Nanoparticles with Superior Structural Stability by Polymerization-Induced Self-Assembly and Functional Nanoscopic Platform for Drug Delivery.

    Science.gov (United States)

    Zhang, Wen-Jian; Hong, Chun-Yan; Pan, Cai-Yuan

    2016-09-12

    A highly efficient strategy, polymerization-induced self-assembly (PISA) for fabrication of the polymeric drug delivery systems in cancer chemotherapy is reported. Diblock prodrug copolymer, PEG-b-P(MEO2MA-co-CPTM) was used as the macro-RAFT agent to fabricate prodrug nanoparticles through PISA. The advantages of fabricating intelligent drug delivery system via this approach are as following: (1) Simultaneous fulfillment of polymerization, self-assembly, and drug encapsulation in one-pot at relatively high concentration (100 mg/mL); (2) Almost complete monomer conversion allows direct application of the resultant prodrug nanoparticles without further purification; (3) Robust structures of the resultant prodrug nanoparticles, because the cross-linker was used as the comonomer, resulted in core-cross-linking simultaneously with the formation of the prodrug nanoparticles; (4) The drug content in the resultant prodrug nanoparticles can be accurately modulated just via adjusting the feed molar ratio of MEO2MA/CPTM in the synthesis of PEG-b-P(MEO2MA-co-CPTM). The prodrug nanoparticles with similar diameters but various drug contents were obtained using different prodrug macro-CTA. In consideration of the long-term biological toxicity, the prodrug nanoparticles with higher drug content exhibit more excellent anticancer efficiency due to that lower dosage of them are enough for effectively killing HeLa cells.

  4. Preparation of nano composite latex of poly(butyl acrylate-co-methyl methacrylate) P (BA-co-MMA) and layered double hydroxide (LDH) by mini emulsion polymerization; Preparacao de latex nanocomposito de poli(acrilato de butila-co-metacrilato de metila) P (BA-co-MMA) e hidroxido duplo lamelar (HDL) por meio da tecnica de polimerizacao em miniemulsao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rodrigo D; Lona, Liliane M.F., E-mail: liliane@feq.unicamp.br [Universidade Estadual de Campinas - Unicamp, Faculdade de Engenharia Quimica, SP (Brazil); Dube, Marc A [Universidade de Ottawa. Departamento de Engenharia Quimica e Biologica, Ottawa, ON (Canada)

    2011-07-01

    In the present work, the synthesis of polymeric nonconsumption (PNCs) of P(BA-coMMA) and layered LDH through mini emulsion polymerization (MEP) was studied. The commercial organically modified LDH Perkalite F100S was used as filler and octadecyl acrylate (ODA) as costabilizer of the mini emulsions. Two types of surfactant, a cationic and nonionic one, were investigated and the cationic one could not stabilize the system when the LDH was present. The polymerization kinetics was not significantly affected by the presence of LDH which kept the pH of the system constant during the reaction. The dispersion of the inorganic material in the polymeric matrix was evaluated by X-ray diffraction which suggested exfoliation of the LDH. (author)

  5. Role of radiolytically generated species in radiation induced polymerization of sodium p-styrene sulphonate (SSS) in aqueous solution: Steady state and pulse radiolysis study

    International Nuclear Information System (INIS)

    Bhardwaj, Y.K.; Mohan, H.; Sabharwal, S.; Majali, A.B.

    2000-01-01

    Radiation induced polymerization of sodium p-styrene sulphonate (SSS) in aqueous solution has been investigated by steady state and pulse radiolysis techniques. Effect of dose, dose rate, monomer concentration, pH and ambient conditions on polymerization was investigated. The reactions of primary radicals of water radiolysis such as OH radical, e - aq , H atom, O· - and some oxidizing radicals like N· 3 , Cl· - 2 ,Br· - 2 , and reducing specie like CO· - 2 with SSS have also been investigated. SSS reacts with OH radical with a rate constant of 5.9x10 9 dm 3 mol -1 s -1 at pH 6.3. The results indicate that ∼83% of OH radicals undergo electron transfer reaction resulting in a cation radical species while remaining ∼17% react via addition reaction. The hydrated electron reacts with SSS with a rate constant 1.3x10 10 dm 3 mol -1 s -1 to form an anion that undergoes fast protonation to form H-adduct at pH 6.3. At high pH (>10) the anion is able to transfer electron to methyl vilogen and p-nitro aceto phenone (p-NAP) where as H-adduct is unable to transfer electron. At pH ∼1 H atom reaction with SSS is diffusion controlled with a rate constant of 5x10 9 dm 3 mol -1 s -1 and results in formation of H adduct. It was seen that anion reacts with solute an order faster than cation generated radiolytically indicating anionic initiation of polymerization of SSS. Molecular weight of the polymer formed by radiation polymerization, determined by viscosity measurement, are of the order of 10 7 and higher molecular weight polymers are obtained at lower dose rates. In presence of a crosslinking agent gelation of polymer is much faster than the monomer and a polymer concentration ∼20% is most efficiently crosslinked. (author)

  6. 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.

  7. Initiation of MMA polymerization by iniferters based on dithiocarbamates

    Directory of Open Access Journals (Sweden)

    Jovanović Slobodan M.

    2005-01-01

    Full Text Available Twelve modified dithiocarbamates and a thiuramdisulfide used for the initiation of methyl methacrylate (MMA polymerization were synthesized in this study. The polymerization of MMA was followed by determine the yield and molar mass of the obtained PMMA as a function of polymerization time. Four of the synthesized dithiocarbamates S-benzyl-N,N-dibenzyldithiocarbamate, S-allyl-N,N-dibenzyldithiocarbamate S-benzyl-N,N-diisobutyldithiocarbamate and S-benzoyl-N,N-diisobutyldithiocarbamate, as well as N,N,N',N'-tetrabenzylthiuramdisulfide acted as iniferters. They were active as the initiators of the photo and/or thermally initiated radical polymerization of MMA in bulk and inert solvents (benzene and toluene. S Benzyl - N,N - dibenzyldithiocarbamate can be successfully used for the initiation of MMA polymerization in a polar solvent such as dimethylacetamide.

  8. Fluoropolymer materials and architectures prepared by controlled radical polymerizations

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Jankova Atanasova, Katja; Hvilsted, Søren

    2007-01-01

    This review initially summarizes the mechanisms, merits and limitations of the three controlled radical polymerizations: nitroxide mediated polymerization (NMP), atom transfer radical polymerization (ATRP) or metal catalyzed living radical polymerization, and reversible addition–fragmentation chain...... transfer (RAFT) polymerization. This is followed by two parts, one dealing with homo- and copolymerizations of fluorinated methacrylates and acrylates, and a second where fluorinated styrenes, alone or in combination with other monomers, are the main issues. In these parts, initiators (including...... properties and functionalities that can be obtained from these novel fluorinated materials and architectures are especially emphasized. Thus, various amphiphilic, biocompatible or low energy materials, fluorinated nanoparticles and nanoporous films/membranes as well as materials for submicron and nanolevel...

  9. Synthesis and characterization of functionalized methacrylates for coatings and biomedical applications

    Science.gov (United States)

    Shemper, Bianca Sadicoff

    The research presented in this dissertation involves the design of polymers for biomaterials and for coatings applications. The development of non-wettable, hard UV-curing, or reactive coatings is discussed. The biomaterials section involves the syntheses of linear and star-like polymers of the functionalized monomer poly(propylene glycol) monomethacrylate (PPGM) via atom transfer radical polymerization (ATRP) (Chapter II). Its copolymerization with a perfluoroalkyl ethyl methacrylate monomer (1H,1H,2H,2H-heptadecafluorodecyl methacrylate) and the syntheses of linear and star-like amphiphilic copolymers containing the fluorinated monomer and poly(ethyleneglycol) methyl ether methacrylate (MPEGMA) are discussed in Chapter III. The four-arm amphiphilic block copolymer obtained showed unique associative properties leading to micellization in selective solvents. Chapter IV includes research involving the design of films with low surface energy by incorporating fluorine into the polymer. The synthesis, characterization and polymerization of a perfluoroalkylether-substituted methacrylic acid (C8F7) are discussed, and the properties of coatings obtained after its photopolymerization on different substrates are evaluated to confirm formation of low-surface energy polymeric coatings. Subsequently, hard coatings based on methyl (alpha-hydroxymethyl)acrylate (MHMA) were prepared via photopolymerization using UV-light. Firstly, mechanistic investigations into the photopolymerization behavior of (alpha-hydroxymethyl)acrylates (RHMA's) are reported (Chapter V). RHMA derivatives were photopolymerized with various multifunctional acrylates and methacrylates and the effect of crosslinker type and degree of functionality on photopolymerization rates and conversions was investigated. Then, in Chapter VI the synthesis of a series of new crosslinkers is described and their photopolymerization kinetics was investigated in bulk. The effect of these novel crosslinkers on the

  10. Functionalization and Chemical Modification of 2-Hydroxyethyl Methacrylate with Carboxylic Acid

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Nasirtabrizi

    2012-01-01

    Full Text Available Free radical polymerization of the resulting monomers methyl methacrylate (MMA, ethyl methacrylate (EMA, methylacrylate (MA and ethylacrylate (EA with 2-hydroxyethyl methacrylate (HEMA (in 1:1 mole ratio were carried out using azobis(isoboutyronitrile (AIBN as initiator at the temperature ranges 60-70°C. The modification of polymers were carried out by 9-anthracenecarboxylic acid (9-ACA via the esterification reaction between —OH of poly(HEMA and —COOH of 9-ACA, in presence of N,N′-dicyclohexyl-carbodiimide (DCC, 4-(dimethylamino pyridine (DMAP and N,N-dimethyl formamid (DMF. It was found that the molar ratio acid/alcohol/catalysts= 0.02: 0.02: 0.02 and 0.002, optimal for preparation of the ester. As demonstrated by FT-IR, 1H-NMR and dynamic mechanical thermal analysis (DMTA. The Tg value of methacrylate and acrylate copolymers containing 9-ACA groups was found to increase with incorporation of 9-ACA groups in polymer structures. The presence of 9-ACA groups in the polymer side chains created new polymers with novel modified properties that find some applications in polymer industry. These anthracenic factors could take part in cyclo addition reaction with other factors such as anhydrides and kinons.

  11. Versatility of Alkyne-Modified Poly(Glycidyl Methacrylate) Layers for Click Reactions

    International Nuclear Information System (INIS)

    Soto-Cantu, Erick; Lokitz, Bradley S.; Hinestrosa Salazar, Juan Pablo; Deodhar, Chaitra; Messman, Jamie M.; Ankner, John Francis; Kilbey, S. Michael II

    2011-01-01

    Functional soft interfaces are of interest for a variety of technologies. We describe three methods for preparing substrates with alkyne groups, which show versatility for 'click' chemistry reactions. Two of the methods have the same root: formation of thin, covalently attached, reactive interfacial layers of poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by reactive modification with either propargylamine or 5-hexynoic acid. The amine or the carboxylic acid moieties react with the epoxy groups of PGMA, creating interfacial polymer layers decorated with alkyne groups. The third method consists of using copolymers comprising glycidyl methacrylate and propargyl methacrylate (pGP). The pGP copolymers are spin coated and covalently attached on silicon wafers. For each method, we investigate the factors that control film thickness and content of alkyne groups using ellipsometry, and study the nanophase structure of the films using neutron reflectometry. Azide-terminated polymers of methacrylic acid and 2-vinyl-4,4-dimethylazlactone synthesized via reversible addition-fragmentation chain transfer polymerization were attached to the alkyne-modified substrates using 'click' chemistry, and grafting densities in the range of 0.007-0.95 chains nm -2 were attained. The maximum density of alkyne groups attained by functionalization of PGMA with propargylamine or 5-hexynoic acid was approximately 2 alkynes nm -3 . The alkyne content obtained by the three decorating approaches was sufficiently high that it was not the limiting factor for the click reaction of azide-capped polymers.

  12. Radiation synthesis of nanosilver nanohydrogels of poly(methacrylic acid)

    International Nuclear Information System (INIS)

    Gupta, Bhuvanesh; Gautam, Deepti; Anjum, Sadiya; Saxena, Shalini; Kapil, Arti

    2013-01-01

    Nanosilver nanohydrogels (nSnH) of poly(methacrylic acid) were synthesized and stabilized using gamma irradiation. The main objective of this study was to develop silver nanoparticles and to evaluate the antimicrobial activity. Radiation helps in the polymerization, crosslinking and reduction of silver nitrate as well. Highly stable and uniformly distributed silver nanoparticles have been obtained within hydrogel network by water in oil nanoemulsion polymerization and were evaluated by dynamic light scattering (DLS) and transmission electron microscopy (TEM) respectively. TEM showed almost spherical and uniform distribution of silver nanoparticles through the hydrogel network. The mean size of silver nanoparticles ranging is 10–50 nm. The nanohydrogels showed good swelling in water. Antibacterial studies of nSnH suggest that it can be a good candidate as coating material in biomedical applications. - Highlights: • Nanosilver nanohydrogels of PMAA were synthesized and stabilized using Υ-irradiation. • The mean size of silver nanoparticles ranging is 10–50 nm. • Antibacterial studies of nSnH suggest it to be a good candidate for biomedical applications

  13. New photoresponsive (meth)acrylate (co)polymers containing azobenzene pendant sidegroups with carboxylic and dimethylamino substituents .2. Synthesis and characterization of polymers and copolymers

    NARCIS (Netherlands)

    Haitjema, HJ; Buruma, R; VanEkenstein, GORA; Tan, YY; Challa, G

    1996-01-01

    The title (co)polymers, used for our investigations on their photoresponsive behaviour were obtained by free radical (co)polymerization. The monomer was either an acrylate or a methacrylate to which an azobenzene group, modified with a para-placed dimethylamino or a carboxylic pendant group, was

  14. Preparation of epoxy-functionalized methyl methacrylate-butadiene-styrene core-shell particles and investigation of their dispersion in polyamide-6

    NARCIS (Netherlands)

    Aerdts, A.M.; Groeninckx, G.; Zirkzee, H.F.; Aert, van H.A.M.; Geurts, J.M.

    1997-01-01

    Functional core—shell impact modifiers of glycidyl methacrylate (GMA) functionalized methyl methacrylate—butadiene—styrene (MBS) have been prepared via a seeded semi-continuous emulsion polymerization. These functional MBS—GMA particles were blended with polyamide-6. Investigations by transmission

  15. Polymeric black tea polyphenols inhibit 1,2-dimethylhydrazine induced colorectal carcinogenesis by inhibiting cell proliferation via Wnt/β-catenin pathway

    International Nuclear Information System (INIS)

    Patel, Rachana; Ingle, Arvind; Maru, Girish B.

    2008-01-01

    Tea polyphenols like epigallocatechin gallate and theaflavins are established chemopreventive agents for colorectal carcinogenesis. However, studies on evaluating similar chemopreventive properties of thearubigins or polymeric black tea polyphenols (PBPs), the most abundant polyphenols in black tea, are limited. Hence, in the present study we aim to investigate chemopreventive effects along with probable mechanisms of action of PBP extract employing 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis in Sprague-Dawley rats as experimental model. The present study suggests that PBPs, like other tea polyphenols, also inhibit DMH-induced colorectal tumorigenesis by decreasing tumor volume and multiplicity. This study also shows that although the pretreatment with PBP extract could induce detoxifying enzymes in hepatic and colorectal tissue, it did not show any additional chemopreventive effects when compared to treatments with PBP extract after initiation with DMH. Mechanistically, PBP extract may inhibit colorectal carcinogenesis by decreasing DMH-induced cell proliferation via Wnt/β-catenin pathway. Treatments with PBP extract showed decreased levels of COX-2, c-MYC and cyclin D1 proteins which aid cell proliferation probably by regulating β-catenin by maintaining expression of APC and decreasing inactivation of GSK3β. DMH-induced activation of MAP kinases such as ERK and JNK was also found to be inhibited by treatments with PBP extract. In conclusion, the protective effects of PBP extract could be attributed to inhibition of DMH-induced cellular proliferation probably through β-catenin regulation

  16. Antibacterial inorganic-organic hybrid coatings on stainless steel via consecutive surface-initiated atom transfer radical polymerization for biocorrosion prevention.

    Science.gov (United States)

    Yuan, S J; Pehkonen, S O; Ting, Y P; Neoh, K G; Kang, E T

    2010-05-04

    To enhance the corrosion resistance of stainless steel (SS) and to impart its surface with antibacterial functionality for inhibiting biofilm formation and biocorrosion, well-defined inorganic-organic hybrid coatings, consisting of a polysilsesquioxane inner layer and quaternized poly(2-(dimethyamino)ethyl methacrylate) (P(DMAEMA)) outer blocks, were prepared via successive surface-initiated atom transfer radical polymerization (ATRP) of 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). The cross-linked P(TMASPMA), or polysilsesquioxane, inner layer provided a durable and resistant coating to electrolytes. The pendant tertiary amino groups of the P(DMAEMA) outer block were quaternized with alkyl halide to produce a high concentration of quaternary ammonium groups with biocidal functionality. The so-synthesized inorganic-organic hybrid coatings on the SS substrates exhibited good anticorrosion and antibacterial effects and inhibited biocorrosion induced by sulfate-reducing bacteria (SRB) in seawater media, as revealed by antibacterial assay and electrochemical analyses, and they are potentially useful to steel-based equipment under harsh industrial and marine environments.

  17. Ketamine alleviates bradykinin-induced disruption of the mouse cerebrovascular endothelial cell-constructed tight junction barrier via a calcium-mediated redistribution of occludin polymerization

    International Nuclear Information System (INIS)

    Chen, Jui-Tai; Lin, Yi-Ling; Chen, Ta-Liang; Tai, Yu-Ting; Chen, Cheng-Yu; Chen, Ruei-Ming

    2016-01-01

    Highlights: • Ketamine could suppress bradykinin-induced intracellular calcium mobilization. • Ketamine induced B1R protein and mRNA expressions but did not change B2R protein levels. • Ketamine attenuated bradykinin-induced redistribution of occludin tight junctions. • Ketamine prevented bradykinin-induced breakage of the MCEC-constructed tight junction barrier. - Abstract: Following brain injury, a sequence of mechanisms leads to disruption of the blood-brain barrier (BBB) and subsequent cerebral edema, which is thought to begin with activation of bradykinin. Our previous studies showed that ketamine, a widely used intravenous anesthetic agent, can suppress bradykinin-induced cell dysfunction. This study further aimed to evaluate the protective effects of ketamine against bradykinin-induced disruption of the mouse cerebrovascular endothelial cell (MCEC)-constructed tight junction barrier and the possible mechanisms. Exposure of MCECs to bradykinin increased intracellular calcium (Ca 2+ ) concentrations in a time-dependent manner. However, pretreatment of MCECs with ketamine time- and concentration-dependently lowered the bradykinin-induced calcium influx. As to the mechanisms, although exposure of MCECs to ketamine induced bradykinin R1 receptor protein and mRNA expression, this anesthetic did not change levels of the bradykinin R2 receptor, a major receptor that responds to bradykinin stimulation. Bradykinin increased amounts of soluble occludin in MCECs, but pretreatment with ketamine alleviated this disturbance in occludin polymerization. Consequently, exposure to bradykinin decreased the transendothelial electronic resistance in the MCEC-constructed tight junction barrier. However, pretreatment with ketamine attenuated the bradykinin-induced disruption of the tight junction barrier. Taken together, this study shows that ketamine at a therapeutic concentration can protect against bradykinin-induced breakage of the BBB via suppressing calcium

  18. 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.

  19. Preparation and performances of porous polyacrylonitrile-methyl methacrylate membrane for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-01

    A copolymer, polyacrylonitrile-methyl methacrylate P(AN-MMA), was synthesized by suspension polymerization with acrylonitrile (AN) and methyl methacrylate (MMA) as monomers. With this copolymer, polymer membrane was prepared by phase inversion. The performances of the polymer were characterized by FTIR, SEM, DSC/TG, EIS and LSV. The copolymer contains CH{sub 2}, CN and CO bonds, and shows its thermal stability up to 300 C. The polymer membrane has a porous structure with an average pore diameter of 0.5 {mu}m. The conductivity of the polymer electrolyte is 1.25 mS cm{sup -1} at room temperature, and it is electrochemically stable up to 5 V (vs. Li). Using the polymer electrolyte as the gel polymer electrolyte (GPE), the cell Li/GPE/LiCoO{sub 2} shows its cyclic stability as good as the cell with liquid electrolyte. (author)

  20. 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.

  1. 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

  2. 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.

  3. Properties of immobilized papain by radiation polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao

    1984-01-01

    Papain was immobilized by the radiation polymerization of various monomers at low temperatures and the effects of the polymer matrix on the enzyme activity and thermal stability of the immobilized enzymes were studied. The activity of the immobilized enzymes prepared from monofunctional (acrylate and methacrylate) monomers was higher than that from bifunctional (bismethacrylate) monomers and that from polyoxyethylene dimethacrylate monomers increased with an increase in the number of oxyethylene units. The thermal stability of the immobilized enzymes prepared from hydrophilic monomers was higher than that from hydrophobic monomers and increased markedly with increasing monomer concentration. (author)

  4. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate and...

  5. Development of novel ion-exchange membranes for electrodialysis of seawater by electron-beam-induced graft polymerization (4). Polymeric structures of cation-exchange membranes based on nylon-6 film

    International Nuclear Information System (INIS)

    Miyazawa, Tadashi; Asari, Yuki; Miyoshi, Kazuyoshi; Umeno, Daisuke; Saito, Kyoichi; Nagatani, Takeshi; Yoshikawa, Naohito; Motokawa, Ryuhei; Koizumi, Satoshi

    2010-01-01

    Cation-exchange membranes containing a sulfonic acid group were prepared by electron-beam-induced graft polymerization of sodium styrene sulfonate (SSS) onto a nylon-6 film with a thickness of 25 μm. The lamella sizes and lamella-to-lamella intervals of the resultant cation-exchange membranes (SSS membranes) were evaluated by X-ray diffraction (XRD) analysis and small-angle neutron scattering (SANS), respectively. With increasing degrees of grafting, the lamella size decreased, whereas the lamella-to-lamella interval increased. This can be explained by that the poly-SSS chain grafted to the periphery of the lamella of nylon 6 partially destroys the lamella and invades the amorphous domain among the lamella. The SSS membrane with a degree of grafting of 150% exhibited a similar performance in the electrodialysis of 0.5 M sodium chloride as a current cation-exchange membrane and possessed the lamella sizes and lamella-to-lamella intervals of 7.6 and 13 nm, respectively. (author)

  6. Preparation of porous adsorbers and supports most favorable for separation by using radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Saito, Kyoichi

    2014-01-01

    Various functional groups such as chelate-forming and ion-exchange groups were introduced into the poly-glycidyl methacrylate chain grafted onto a commercially available porous hollow-fiber membrane with a thickness of approximately 1 mm, an average pore size of 0.4 µm, and a porosity of 70%. Permeation of a target metal-ion or protein solution driven by a transmembrane pressure enables us to minimize the diffusional mass-transfer resistance of metal ions or proteins to the functional groups. Considerable degree of GMA grafting and molar conversion of the epoxy group into the functional group provide a higher functional group density of the porous hollow-fiber membrane than for conventional adsorbents. First, metal ions and proteins were transported to the chelating and ion-exchange groups, respectively, of the graft chain. The higher the permeation rate of the target solution is, the higher the overall adsorption rate of the target ions or proteins onto the modified porous hollow-fiber membrane becomes. In addition, proteins were bound to the ion-exchange polymer brush in multilayers because the polymer brush extends from the pore surface towards the pore interior due to its mutual electrostatic repulsion. Second, replacement adsorption was observed in a binary system of metal ions or proteins during the permeation of the solution through the membrane with a membrane thickness of approximately 1 mm. Third, chiral resolution of DL-tryptophan was demonstrated using albumin-multilayered porous hollow-fiber membranes. (author)

  7. 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)

  8. Bioinspired Hydroxyapatite/Poly(methyl methacrylate) Composite with a Nacre-Mimetic Architecture by a Bidirectional Freezing Method.

    Science.gov (United States)

    Bai, Hao; Walsh, Flynn; Gludovatz, Bernd; Delattre, Benjamin; Huang, Caili; Chen, Yuan; Tomsia, Antoni P; Ritchie, Robert O

    2016-01-06

    Using a bidirectional freezing technique, combined with uniaxial pressing and in situ polymerization, "nacre-mimetic" hydroxyapatite/poly(methyl methacrylate) (PMMA) composites are developed by processing large-scale aligned lamellar ceramic scaffolds. Structural and mechanical characterization shows "brick-and-mortar" structures, akin to nacre, with interesting combinations of strength, stiffness, and work of fracture, which provide a pathway to making strong and tough lightweight materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Syntheses of crosslinked latex nanoparticles using differential microemulsion polymerization

    Science.gov (United States)

    Hassmoro, N. F.; Rusop, M.; Abdullah, S.

    2013-06-01

    The differential microemulsion polymerization was used to synthesize latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinker respectively 1-5 weight% of monomer total. Butyl acrylate (BA), butyl methacrylate (BMA), and methacrylic acid (MAA) was used as the monomer. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinker added in the polymerization was optimized and we found that the particle sizes fall in the range of 30-60 nm. The structural morphology of the uncrosslinked latex represented the most homogeneous image compared to the crosslinked latex. The effect of the amount of crosslinker on the particle sizes investigated by the Zeta-sizer Nano series while Atomic Force microscopy (AFM) was used to study the structural properties of latex nanoparticles.

  10. Syntheses of crosslinked latex nanoparticles using differential microemulsion polymerization

    International Nuclear Information System (INIS)

    Hassmoro, N F; Abdullah, S; Rusop, M

    2013-01-01

    The differential microemulsion polymerization was used to synthesize latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinker respectively 1–5 weight% of monomer total. Butyl acrylate (BA), butyl methacrylate (BMA), and methacrylic acid (MAA) was used as the monomer. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinker added in the polymerization was optimized and we found that the particle sizes fall in the range of 30–60 nm. The structural morphology of the uncrosslinked latex represented the most homogeneous image compared to the crosslinked latex. The effect of the amount of crosslinker on the particle sizes investigated by the Zeta-sizer Nano series while Atomic Force microscopy (AFM) was used to study the structural properties of latex nanoparticles.

  11. Preparation of Color Filter Photo Resists for Generating Color Pixels in Liquid Crystal Displays by Synthesis and Applications of Polymeric Binders

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Chun [Sejong University, Seoul (Korea, Republic of); Choi, Jae Hong [Kyungpook National University, Daegu (Korea, Republic of)

    2010-09-15

    This study was carried out based on several purposes. First, introductions of new binders have been requested due to the recent trend of red pigments; that is, a dieketo-pyrrolo-pyrrole with a smaller particle size and less polarity for a high contrast ratio is desired. The pigments for a high contrast ratio usually have a particle size in the range of 40 - 60 nm, while conventional pigments of anthraquinone have a particle size of approximately 90 nm. For this reason, less polar styrene was introduced to increase affinity by replacing or reducing benzyl methacrylate. Traditionally, a binder prepared from benzyl methacrylate and methacrylic acid has been widely used. Second, introductions of less expensive materials, such as styrene and methyl methacrylate, have been requested to contribute to the extreme competitiveness of the LCD industry. For this study, styrene, methacrylic acid, methyl methacrylate and benzyl methacylate were employed to synthesize the random copolymer into polymeric binders.

  12. Polymeric micelles for drug targeting.

    Science.gov (United States)

    Mahmud, Abdullah; Xiong, Xiao-Bing; Aliabadi, Hamidreza Montazeri; Lavasanifar, Afsaneh

    2007-11-01

    Polymeric micelles are nano-delivery systems formed through self-assembly of amphiphilic block copolymers in an aqueous environment. The nanoscopic dimension, stealth properties induced by the hydrophilic polymeric brush on the micellar surface, capacity for stabilized encapsulation of hydrophobic drugs offered by the hydrophobic and rigid micellar core, and finally a possibility for the chemical manipulation of the core/shell structure have made polymeric micelles one of the most promising carriers for drug targeting. To date, three generations of polymeric micellar delivery systems, i.e. polymeric micelles for passive, active and multifunctional drug targeting, have arisen from research efforts, with each subsequent generation displaying greater specificity for the diseased tissue and/or targeting efficiency. The present manuscript aims to review the research efforts made for the development of each generation and provide an assessment on the overall success of polymeric micellar delivery system in drug targeting. The emphasis is placed on the design and development of ligand modified, stimuli responsive and multifunctional polymeric micelles for drug targeting.

  13. Mechanisms of Action of (Methacrylates in Hemolytic Activity, in Vivo Toxicity and Dipalmitoylphosphatidylcholine (DPPC Liposomes Determined Using NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2012-01-01

    Full Text Available We investigated the quantitative structure-activity relationships between hemolytic activity (log 1/H50 or in vivo mouse intraperitoneal (ip LD50 using reported data for α,β-unsaturated carbonyl compounds such as (methacrylate monomers and their 13C-NMR β-carbon chemical shift (δ. The log 1/H50 value for methacrylates was linearly correlated with the δCβ value. That for (methacrylates was linearly correlated with log P, an index of lipophilicity. The ipLD50 for (methacrylates was linearly correlated with δCβ but not with log P. For (methacrylates, the δCβ value, which is dependent on the π-electron density on the β-carbon, was linearly correlated with PM3-based theoretical parameters (chemical hardness, η; electronegativity, χ; electrophilicity, ω, whereas log P was linearly correlated with heat of formation (HF. Also, the interaction between (methacrylates and DPPC liposomes in cell membrane molecular models was investigated using 1H-NMR spectroscopy and differential scanning calorimetry (DSC. The log 1/H50 value was related to the difference in chemical shift (ΔδHa (Ha: H (trans attached to the β-carbon between the free monomer and the DPPC liposome-bound monomer. Monomer-induced DSC phase transition properties were related to HF for monomers. NMR chemical shifts may represent a valuable parameter for investigating the biological mechanisms of action of (methacrylates.

  14. 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...

  15. Synthesis and evaluation of novel siloxane-methacrylate monomers used as dentin adhesives.

    Science.gov (United States)

    Ge, Xueping; Ye, Qiang; Song, Linyong; Misra, Anil; Spencer, Paulette

    2014-09-01

    The objectives of this study were to synthesize two new siloxane-methacrylate (SM) monomers for application in dentin adhesives and to investigate the influence of different functionality of the siloxane-containing monomers on the adhesive photopolymerization, water sorption, and mechanical properties. Two siloxane-methacrylate monomers (SM1 and SM2) with four and eight methacrylate groups were synthesized. Dentin adhesives containing BisGMA, HEMA and the siloxane-methacrylate monomers were photo-polymerized. The experimental adhesives were compared with the control adhesive (HEMA/BisGMA, 45/55, w/w) and characterized with regard to degree of conversion (DC), water miscibility of the liquid resin, water sorption and dynamic mechanical analysis (DMA). The experimental adhesives exhibited improved water miscibility as compared to the control. When cured in the presence of 12 wt% water to simulate the wet environment of the mouth, the SM-containing adhesives showed DC comparable to the control. The experimental adhesives showed higher rubbery modulus than the control under dry conditions. Under wet conditions, the mechanical properties of the formulations containing SM monomer with increased functionality were comparable with the control, even with more water sorption. The concentration and functionality of the newly synthesized siloxane-methacrylate monomers affected the water miscibility, water sorption and mechanical properties of the adhesives. The experimental adhesives show improved water compatibility compared with the control. The mechanical properties were enhanced with an increase of the functionality of the siloxane-containing monomers. The results provide critical structure/property relationships and important information for future development of durable, versatile siloxane-containing dentin adhesives. Published by Elsevier Ltd.

  16. Towards bilirubin imprinted poly(methacrylic acid-co-ethylene glycol dimethylacrylate) for the specific binding of α-bilirubin

    International Nuclear Information System (INIS)

    Syu, M.-J.; Deng, J.-H.; Nian, Y.-M.

    2004-01-01

    With α-bilirubin as a molecular template, polymerization of methacrylic acid (MAA) was carried out with the aid of the initiator 2,2-azobisisobutyronitrile (AIBN) and the cross-linking agent ethylene glycol dimethylacrylate (EGDMA). Bulk polymerization was successfully carried out so that poly(methacrylic acid-co-ethylene glycol dimethylacrylate) (poly(MAA-EGDMA)) imprinted with α-bilirubin was first developed. UV irradiation polymerization and heated polymerization methods were compared. Effect of different ratios of monomer to EGDMA during the polymerization was also discussed. Proper solvent for better desorption of α-bilirubin from the imprinted poly(MAA-EGDMA) was investigated. In addition, SEM photos were provided for observing the differences between the surfaces of the imprinted poly(MAA-EGDMA) before and after extraction. The corresponding binding results of α-bilirubin imprinted poly(MAA-EGDMA) and non-imprinted poly(MAA-EGDMA) both after extraction were compared. How the pH values during extraction stage affected the binding capacities of the imprinted polymer as well as non-imprinted polymer were also discussed. Similar study and comparison were made for different binding pH values. Different compounds of similar molecular weight were used to show the specific binding of the imprinted polymer for bilirubin. The results further confirmed the successful binding as well as specificity of the imprinted poly(MAA-EGDMA) for α-bilirubin

  17. A Near-Infrared Photothermal Effect-Responsive Drug Delivery System Based on Indocyanine Green and Doxorubicin-Loaded Polymeric Micelles Mediated by Reversible Diels-Alder Reaction.

    Science.gov (United States)

    Li, Hui; Li, Junjie; Ke, Wendong; Ge, Zhishen

    2015-10-01

    Near-infrared light (NIR) possesses great advantages for light-responsive controllable drug release, such as deep tissue penetration and low damage to healthy tissues. Herein, a NIR-responsive drug delivery system is developed based on a NIR dye, indocyanine green (ICG), and anticancer drug, doxorubicin (DOX)-loaded thermoresponsive block copolymer micelles, in which the drug release can be controlled via NIR irradiation. First, block copolymers, poly(oligo(ethylene glycol) methacrylate)-block-poly(furfuryl methacrylate) (POEGMA-b-PFMA), are synthesized by sequential reversible addition-fragmentation chain-transfer (RAFT) polymerization, followed by modification with N-octyl maleimide through Diels-Alder (DA) reaction to produce POEGMA-b-POMFMA. The self-assembly of POEGMA-b-POMFMA by nano-precipitation in aqueous solution affords the polymeric micelles which are used to simultaneously encapsulate ICG and DOX. Upon irradiation by NIR light (805 nm), the loaded DOX is released rapidly from the micelles due to partial retro DA reaction and local temperature increase-induced faster drug diffusion by the photothermal effect. Cytotoxicity evaluation and intracellular distribution observation demonstrate significant synergistic effects of NIR-triggered drug release, photothermal, and chemotherapy toward cancer cells under NIR irradiation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A Versatile Approach to Unimolecular Water-Soluble Carriers: ATRP of PEGMA with Hydrophobic Star-Shaped Polymeric Core Molecules as an Alternative for PEGylation

    NARCIS (Netherlands)

    Schramm, O.G.; Pavlov, G.M.; Erp, van H.H.P; Meier, M.A.R.; Hoogenboom, R.; Schubert, U.S.

    2009-01-01

    New amphiphilic star-shaped architectures with dense hydrophilic shells were synthesized by a combination of ring-opening polymerization (ROP) of e-caprolactone (CL) and atom transfer radical polymerization (ATRP) of different poly(ethylene glycol) methacrylates (PEGMAs). The PCL hydrophobic cores

  19. Methacrylate and acrylate allergy in dental personnel.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Alanko, Kristiina; Kuuliala, Outi; Jolanki, Riitta

    2007-11-01

    Methacrylates are important allergens in dentistry. The study aimed to analyse patch test reactivity to 36 acrylic monomers in dental personnel in relation to exposure. We reviewed the test files at the Finnish Institute of Occupational Health from 1994 to 2006 for allergic reactions to acrylic monomers in dental personnel and analysed the clinical records of the sensitized patients. 32 patients had allergic reactions to acrylic monomers: 15 dental nurses, 9 dentists, and 8 dental technicians. The dentists and dental nurses were most commonly exposed to 2-hydroxyethyl methacrylate (2-HEMA), triethyleneglycol dimethacrylate (TREGDMA), and 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA). 8 dentists and 12 dental nurses were allergic to 2-HEMA. The remaining dentist was positive to bis-GMA and other epoxy acrylates. The remaining 3 dental nurses reacted to diethyleneglycol diacrylate (DEGDA) or triethyleneglycol diacrylate (TREGDA), but not to monofunctional and multifunctional methacrylates. Our dental technicians were mainly exposed and sensitized to methyl methacrylate (MMA) and ethyleneglycol dimethacrylate (EGDMA). 1 technician reacted only to 2-HEMA, and another to ethyl methacrylate (EMA) and ethyl acrylate (EA). 2-HEMA was the most important allergen in dentists and dental nurses, and MMA and EGDMA in dental technicians. Reactions to bis-GMA, DEGDA, TREGDA, EMA and EA were relevant in some patients.

  20. Polyglycidyl methacrylate based immunoaffinity cryogels for insulin adsorption

    International Nuclear Information System (INIS)

    Memmedova, Türkan; Armutcu, Canan; Uzun, Lokman; Denizli, Adil

    2015-01-01

    Immunoaffinity chromatography (IAC) is a kind of bioaffinity chromatography which used antibodies or antibody-related molecules as the stationary phase. IAC is used by many applications for analytical, clinical and diagnostic purposes, particularly preferring in analytical purposes on one-step separation and purification of target compounds. Moreover, immunoaffinity chromatography is used in antibody enrichment and separation of cells. IAC columns are usually applied in the antibody experiments due to powerful and selective binding of antibodies and/or their target antigens. Antigen or antibody molecules could be immobilized to the solid support. Therefore, target antibody or cell is purified. Specific bioligands can be immobilized directly on glycidyl based polymeric material with simple acid–base catalyst. In this study, polyglycidyl methacrylate based therefore cryogels were prepared and anti-insulin antibodies were immobilized on porous surface of cryogels. Swelling test, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM) were conducted to characterize cryogels developed. To optimize separation conditions, effects of pH, initial insulin concentration, flow rate, salt concentration, contact time and temperature on insulin adsorption capacity were examined. The results indicated that the immunoaffinity cryogel developed here could be classified as good alternative with prominent properties such as high reusability and cost-friendly adsorbent and would be one of the primary reports for immunoaffinity purification of insulin molecules in not only lab-scale but also for industrial purposes. - Highlights: • Polyglycidyl methacrylate based cryogels developed as stationary phase • Immunoaffinity cryogels for reusable and cost-friendly insulin adsorption • Increase in worldwide prevalence of diabetes, type 1 or 2 • An exponential increase in the demand on insulin market • Guiding researchers for not

  1. Polyglycidyl methacrylate based immunoaffinity cryogels for insulin adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Memmedova, Türkan; Armutcu, Canan; Uzun, Lokman, E-mail: lokman@hacettepe.edu.tr; Denizli, Adil

    2015-07-01

    Immunoaffinity chromatography (IAC) is a kind of bioaffinity chromatography which used antibodies or antibody-related molecules as the stationary phase. IAC is used by many applications for analytical, clinical and diagnostic purposes, particularly preferring in analytical purposes on one-step separation and purification of target compounds. Moreover, immunoaffinity chromatography is used in antibody enrichment and separation of cells. IAC columns are usually applied in the antibody experiments due to powerful and selective binding of antibodies and/or their target antigens. Antigen or antibody molecules could be immobilized to the solid support. Therefore, target antibody or cell is purified. Specific bioligands can be immobilized directly on glycidyl based polymeric material with simple acid–base catalyst. In this study, polyglycidyl methacrylate based therefore cryogels were prepared and anti-insulin antibodies were immobilized on porous surface of cryogels. Swelling test, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM) were conducted to characterize cryogels developed. To optimize separation conditions, effects of pH, initial insulin concentration, flow rate, salt concentration, contact time and temperature on insulin adsorption capacity were examined. The results indicated that the immunoaffinity cryogel developed here could be classified as good alternative with prominent properties such as high reusability and cost-friendly adsorbent and would be one of the primary reports for immunoaffinity purification of insulin molecules in not only lab-scale but also for industrial purposes. - Highlights: • Polyglycidyl methacrylate based cryogels developed as stationary phase • Immunoaffinity cryogels for reusable and cost-friendly insulin adsorption • Increase in worldwide prevalence of diabetes, type 1 or 2 • An exponential increase in the demand on insulin market • Guiding researchers for not

  2. 78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

    Science.gov (United States)

    2013-09-11

    ..., 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium, ammonium..., hydroxypropyl acrylate, hydroxyethyl methacrylate, and/or hydroxyethyl acrylate; and its sodium, potassium...

  3. Preparation and Characterization of Mesoporous Zirconia Made by Using a Poly (methyl methacrylate Template

    Directory of Open Access Journals (Sweden)

    Zhang Chunxiang

    2008-01-01

    Full Text Available AbstractSuperfine powders of poly (methyl methacrylate (PMMA have been prepared by means of an emulsion polymerization method. These have been used as templates in the synthesis of tetragonal phase mesoporous zirconia by the sol–gel method, using zirconium oxychloride and oxalic acid as raw materials. The products have been characterized by infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, N2adsorption-desorption isotherms, and pore size distribution. The results indicate that the average pore size was found to be 3.7 nm.

  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. Eosin blue dye based poly(methacrylate) films for data storage

    Science.gov (United States)

    Sankar, Deepa; Palanisamy, P. K.; Manickasundaram, S.; Kannan, P.

    2006-06-01

    Eosin dye based poly(methacrylates) with variation in the number of methylene spacers have been prepared by free radical polymerization process. The utility of the polymers for high-density optical data storage using holography has been studied by grating formation with the 514.5 nm line of the Argon ion laser as source. The influence of various parameters on the diffraction efficiency of the polymers has been studied. The effect of increase in the number of methylene spacers, hooked to the eosin blue dye, on the diffraction efficiency of the grating formed has also been discussed. Optical microscopic observations showing grating formation in the polymers have also been presented.

  6. 3'-Hydroxy-3,4'-dimethoxyflavone blocks tubulin polymerization and is a potent apoptotic inducer in human SK-MEL-1 melanoma cells.

    Science.gov (United States)

    Estévez-Sarmiento, Francisco; Said, Mercedes; Brouard, Ignacio; León, Francisco; García, Celina; Quintana, José; Estévez, Francisco

    2017-11-01

    Flavonoids are naturally occurring polyphenolic compounds and are among the most promising anticancer agents. A series of flavonols and their 3-methyl ether derivatives were synthesized and assessed for cytotoxicity. It was found that 3'-hydroxy-3,4'-dimethoxyflavone (flavonoid 7a) displayed strong cytotoxicity against human SK-MEL-1 melanoma cells and blocked tubulin polymerization, but had no significant cytotoxic effects against quiescent or proliferating human peripheral blood mononuclear cells. Our analyses showed that flavonoid 7a induces G 2 -M cell cycle arrest and apoptosis in melanoma cells which is associated with cytochrome c release and activation of both extrinsic and intrinsic apoptotic pathways of cell death. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 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.)

  8. 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.

  9. Porous polymer monoliths functionalized through copolymerization of a C60 fullerene-containing methacrylate monomer for highly efficient separations of small molecules

    KAUST Repository

    Chambers, Stuart D.

    2011-12-15

    Monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) and poly(butyl methacrylate-co-ethylene dimethacrylate) capillary columns, which incorporate the new monomer [6,6]-phenyl-C 61-butyric acid 2-hydroxyethyl methacrylate ester, have been prepared and their chromatographic performance have been tested for the separation of small molecules in the reversed phase. While addition of the C60-fullerene monomer to the glycidyl methacrylate-based monolith enhanced column efficiency 18-fold, to 85 000 plates/m at a linear velocity of 0.46 mm/s and a retention factor of 2.6, when compared to the parent monolith, the use of butyl methacrylate together with the carbon nanostructured monomer afforded monolithic columns with an efficiency for benzene exceeding 110 000 plates/m at a linear velocity of 0.32 mm/s and a retention factor of 4.2. This high efficiency is unprecedented for separations using porous polymer monoliths operating in an isocratic mode. Optimization of the chromatographic parameters affords near baseline separation of 6 alkylbenzenes in 3 min with an efficiency of 64 000 plates/m. The presence of 1 wt % or more of water in the polymerization mixture has a large effect on both the formation and reproducibility of the monoliths. Other factors such as nitrogen exposure, polymerization conditions, capillary filling method, and sonication parameters were all found to be important in producing highly efficient and reproducible monoliths. © 2011 American Chemical Society.

  10. 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.

  11. In vivo degradation characteristics of poly (β-propiolactone) prepared by radiation-induced polymerization at low temperature

    International Nuclear Information System (INIS)

    Asano, Masaharu; Yoshida, Masaru; Kaetsu, Isao

    1987-01-01

    The polymerization rate of β-propiolactone (PL) by irradiation at -78deg C in vacuo inceased markedly with the irradiation dose of up to 50 kGy and then gradually increased at an irradiation dose of up to 200 kGy. The yields of poly(PL) obtained at irradiation doses of 50 and 200 kGy were 22 and 25%, respectively. The polymer was shaped into a cylindrical form with high rigidity and density by pressing at 200 kg/cm 2 in a range of 50deg C to 75deg C. The in vivo degradation of cylindrical specimens was checked by implanting subcutaneously in the back of male Wistar rats. The degrees of in vivo degradation of poly(PL) obtained at 5, 10, 50, 100, 160, and 200 kGy irradiations were 5, 9, 25, 34, 37, and 40%, respectively. The viscosity (η sp /c value) of these polymers showed a decrease tendency with an increase in the irradiation dose. From the relationship between the η sp /c value and the in vivo degradation, it was found that the degree of in vivo degradation had a inflection point at a η sp /c value of 0.4 dl/g (30 kGy irradiation). That is, the in vivo degradation of poly(PL) with η sp /c values below 0.4 dl/g (above 30 kGy irradiation) was markedly accelerated by a slight decrease of viscosity, but such an acceleration was not remarkable at η sp /c values aboves 0.4 dl/g (below 30 kGy irradiation). This may be primarily attributed to the scssion of polymer chains during the irradiation polymerization. The data of X-ray diffraction patterns and DSC curves also showed that the in vivo degradation is influenced by a change in the crystallinity or by a decrease in the melting point of poly(PL). (author)

  12. Azo polymers with electronical push and pull structures prepared via RAFT polymerization and its photoinduced birefringence behavior

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Two methacrylate monomers containing azo and electronical push and pull structure, e.g. 2-Methyl-acrylic-acid-2-{[4-(4-cyano-phenylazo-3-methyl-phenyl]-ethyl-amino-ethyl ester (MACP with cyano substituted and 2-Methylacrylic-acid-2-{ethyl-[4-(4-methoxy-phenylazo-3-methyl-phenyl]-amino}-ethyl ester (MAMP with methoxy substituted, were synthesized and polymerized using 2-cyanoprop-2-yl dithiobenzoate (CPDB as chain transfer agent and 2,2'-azobisisobutyronitrile (AIBN as initiator. The results showed that the polymerization displayed characteristics of ‘living’/controlled free radical polymerization. Thus, the obtained polymers, polyMACP (pMACP and polyMAMP (pMAMP, had controlled molecular weights and narrow molecular weights distribution. The chain extension experiments of pMACP and pMAMP using styrene as the second monomer were successfully carried out. The photo-induced trans-cis-trans isomerization kinetic of pMACP and pMAMP in chloroform solution were described. Marked differences in rate for the trans-cis and cis-trans isomerization of pMACP and pMAMP were observed in chloroform solution due to the different electronic effects in these two polymers. Photoinduced birefringence and surface relief grating (SRG of the pMACP and pMAMP were investigated in thin film state.

  13. 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

  14. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor; Villalobos Vazquez de la Parra, Luis Francisco; Hilke, Roland

    2015-01-01

    microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  15. Radiation polymerization of tetrafluoroethylene

    International Nuclear Information System (INIS)

    Kadoi, H.; Lugao, A.B.; Oikawa, H.

    1984-01-01

    Tetrafluoroethylene (TFE) monomer was obtained by means of the pyrolysis of chlorodifluoromethane (R-22). The experiments were carried out in quartz tube with temperature between 700 0 and 800 0 C. The principal reaction of the pyrolysis is considered to be: 2CHClF2 ----> C 2 F 4 +2HCl. However, by-products such as HF, C 3 F 6 , C 2 HClF 4 , C 4 F 8 etc are also produced in the pyrolysis process. The conversions of R-22 varied from 30 to 50%, depending upon the temperature, pressure and flow rate of R-22 in the furnace. Finally the TFE monomer of purity higher than 99.98% was obtained by fractional distillation in low temperatures ranging from -10 0 to -30 0 C. The bulk polymerization of this monomer induced by γ-rays from 3000Ci cobalt-60 source was studied at various temperatures (room temperature, 0 0 , -23 0 and -78 0 C). The monomers were introduced into stainless steel vessels of 15 and 60 ml volume under vacuum. The control of polymerization reaction was rather hard at temperatures higher than -23 0 C due to the difficulty of removing the heat of reaction. However, the polymerization at -78 0 C was very easy to control. The white polymer particles were obtained in agglomerated state. The IR spectra of the polymers were consistent with those of commercial products. The melting points of samples were between 326 0 and 331 0 C. (Author) [pt

  16. A nonaqueous potentiometric titration study of the dissociation of t-butyl methacrylate-methacrylic acid copolymers.

    Science.gov (United States)

    Nakatani, Kiyoharu; Yamashita, Jun; Sekine, Tomomi; Toriumi, Minoru; Itani, Toshiro

    2003-05-01

    The dissociation of t-butyl methacrylate-methacrylic acid copolymers in dimethyl sulfoxide was analyzed by a nonaqueous potentiometric titration technique. The negative logarithm of the dissociation constant of the monomer unit of a methacrylic acid (MAA) monotonously increased with the increasing degree of dissociation corresponding to the titrant/MAA amount ratio, and was highly influenced by the copolymerization ratio. The results are discussed in terms of the suppression of the dissociation of MAA by a neighboring charged methacrylate anion unit.

  17. Magnetic Levitation To Characterize the Kinetics of Free-Radical Polymerization.

    Science.gov (United States)

    Ge, Shencheng; Semenov, Sergey N; Nagarkar, Amit A; Milette, Jonathan; Christodouleas, Dionysios C; Yuan, Li; Whitesides, George M

    2017-12-27

    This work describes the development of magnetic levitation (MagLev) to characterize the kinetics of free-radical polymerization of water-insoluble, low-molecular-weight monomers that show a large change in density upon polymerization. Maglev measures density, and certain classes of monomers show a large change in density when monomers covalently join in polymer chains. MagLev characterized both the thermal polymerization of methacrylate-based monomers and the photopolymerization of methyl methacrylate and made it possible to determine the orders of reaction and the Arrhenius activation energy of polymerization. MagLev also made it possible to monitor polymerization in the presence of solids (aramid fibers, and carbon fibers, and glass fibers). MagLev offers a new analytical technique to materials and polymer scientists that complements other methods (even those based on density, such as dilatometry), and will be useful in investigating polymerizations, evaluating inhibition of polymerizations, and studying polymerization in the presence of included solid materials (e.g., for composite materials).

  18. Changes induced by gamma radiation in nanocomposites based on copper II and antimony sulfides in commercial poly(methyl methacrylate) matrix; Alteracoes induzidas pela radiacao gama em nanocompositos a base dos sulfetos de cobre II e de antimonio na matriz de poli(metacrilato de metila) comercial

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, M.C.C. de; Garcia, O.P.; Aquino, K.A.S.; Araujo, E.S., E-mail: esa@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2010-07-01

    Poly (methyl methacrylate) (PMMA) is a polymer with wide application in the manufacture of medical devices that is exposed to gamma irradiation. Currently the use of composite materials has been disseminated and PMMA is an excellent polymer matrix to package various materials. This study aimed to analyze the changes induced by gamma irradiation (25 kGy) on the properties of PMMA nanocomposites with nanoparticles of copper II sulfide (250nm-900nm) and antimony sulfite (300-500 nm). The nanoparticles were added to the polymer in different concentrations and synthesized by ultrasonic irradiation from the corresponding chlorides with thioacetamide. Viscometric results showed a good radioprotective effect of nanoparticles of copper and antimony. It was found a good protection of nanoparticles on PMMA matrix in the concentration of 0.3% wt. The protections of 75% and 50% were calculated for nanoparticles of antimony and copper II, respectively. (author)

  19. Release of Water Soluble Drugs from Dynamically Swelling POLY(2-HYDROXYETHYL Methacrylate - CO - Methacrylic Acid) Hydrogels.

    Science.gov (United States)

    Kou, Jim Hwai-Cher

    In this study, ionizable copolymers of HEMA and methacrylic acid (MA) are investigated for their potential use in developing pH dependent oral delivery systems. Because of the MA units, these gels swell extensively at high pH. Since solute diffusion in the hydrophilic polymers depends highly on the water content of the matrix, it is anticipated that the release rate will be modulated by this pH induced swelling. From a practical point of view, the advantage of the present system is that one can minimize drug loss in the stomach and achieve a programmed release in intestine. This approach is expected to improve delivery of acid labile drugs or drugs that cause severe gastrointestinal side effects. This work mainly focuses on the basic understanding of the mechanism involved in drug release from the poly(HEMA -co- MA) gels, especially under dynamic swelling conditions. Equilibrium swelling is first characterized since water content is the major determinant of transport properties in these gels. Phenylpropanolamine (PPA) is chosen as the model drug for the release study and its diffusion characteristics in the gel matrix determined. The data obtained show that the PPA diffusivity follows the free volume theory of Yasuda, which explains the accelerating effect of swelling on drug release. A mathematical model based on a diffusion mechanism has been developed to describe PPA release from the swelling gels. Based on this model, several significant conclusions can be drawn. First, the release rate can be modulated by the aspect ratio of the cylindrical geometry, and this has a practical implication in dosage form design. Second, the release rate can be lowered quite considerably if the dimensional increase due to swelling is significant. Consequently, it is the balance between the drug diffusivity increase and the gel dimensional growth that determines the release rate from the swelling matrix. Third, quasi-steady release kinetics, which are characteristic of swelling

  20. Methacrylate hydrogels reinforced with bacterial cellulose

    Czech Academy of Sciences Publication Activity Database

    Hobzová, Radka; Dušková-Smrčková, Miroslava; Michálek, Jiří; Karpushkin, Evgeny; Gatenholm, P.

    2012-01-01

    Roč. 61, č. 7 (2012), s. 1193-1201 ISSN 0959-8103 R&D Projects: GA AV ČR KJB400500902 Institutional research plan: CEZ:AV0Z40500505 Keywords : bacterial cellulose * methacrylate hydrogel * composite Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.125, year: 2012