Sample records for acryl sucrose monomers

  1. Synthesis of Hydrophilic and Amphiphilic Acryl Sucrose Monomers and Their Copolymerisation with Styrene, Methylmethacrylate and α- and β-Pinenes

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    Maria Teresa Barros


    Full Text Available Herein, we report the synthesis of monomethacryloyl sucrose esters, and their successful free radical homo- and co-polymerisation with styrene, methylmethacrylate, α- and β-pinene. The chemical, physical, structural and surface chemical properties of these polymers, containing a hydrophobic olefin backbone and hydrophilic sugar moieties as side chains, have been investigated. Biodegradation tests of the copolymer samples by a microbial fungal culture (Aspergillus niger method showed good biodegradability. The chemical structure and surface chemistry of the synthesized homo- and co-polymers demonstrate their potential technological relevance as amphiphilic and biodegradable polymers.


    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenfeng; HU Xingzhou; YAN Qing


    Photoinduced grafting of acrylic and allyl monomers on polyethylene surface was generally studied by using benzophenone (BP) as a photoinitiator. The grafting process was carried out either in vapor-phase or in solution of the monomers. In the vapor-phase reaction with a filter used to cut off the short wavelength UV light, allyl amine is the most reactive of the four monomers used and acrylic amide is comparatively more reactive than acrylic acid and allyl alcohol. Acetone, as a solvent and carrier for initiator and monomers, however, shows its reactivity to participate the reaction. The solution grafting with a filter is much faster than the corresponding vapor-phase reaction, and a fully covered surface by the grafted polymer can be achieved in this way.


    Institute of Scientific and Technical Information of China (English)

    Tai-jiang Gui; Hao Wei; Ying Zhao; Xiu-lin Wang; Du-jin Wang; Duan-fu Xu


    A series of copolymers comprising butylmethacrylate, styrene, butylacrylate, hydroxypropyl acrylate and perfluoroalkyl methacrylate were synthesized by the free radical polymerization using BPO as an initiator. The surface property of the copolymer films was subsequently characterized. The contact angle measurements and energy dispersive analysis of X-ray (EDAX) show that the length and content ofperfluoroalkyl side chains in the copolymers are crucial for the preparation of the film with low surface energy. At a given content of fluorinated monomers in the copolymers, the longer the perfluoroalkyl side chain, the larger the water contact angle of the copolymer films will be. On the other hand, the higher the content of fluorinated monomers, the lower the surface energy is. The water contact angle increases with the increase of the fluorinated monomer content and reaches a plateau at 3 wt% of fluorinated monomer content.

  4. Wet air oxidation of epoxy acrylate monomer industrial wastewater. (United States)

    Yang, Shaoxia; Liu, Zhengqian; Huang, Xiaohui; Zhang, Beiping


    Epoxy acrylate monomer industrial wastewater contained highly concentrated and toxic organic compounds. The wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) were used to eliminate pollutants in order to examine the feasibility of the WAO/CWAO as a pre-treatment method for the industrial wastewater. The results showed that in the WAO 63% chemical oxygen demand (COD) and 41% total organic carbon (TOC) removals were achieved and biological oxygen demand (BOD(5))/COD ratio increased from 0.13 to 0.72 after 3h reaction at 250 degrees C, 3.5MPa and the initial concentration of 100g(COD)/L. Among homogenous catalysts (Cu(2+), Fe(2+), Fe(3+) and Mn(2+) salts), Cu(2+) salt exhibited better performance. CuO catalyst was used in the CWAO of the wastewater, COD and TOC conversion were 77 and 54%, and good biodegradability was achieved. The results proved that the CWAO was an effective pre-treatment method for the epoxy acrylate monomer industrial wastewater.

  5. Effect of cationic monomer on properties of fluorinated acrylate latex

    Institute of Scientific and Technical Information of China (English)

    Li Jun Chen


    Cationic fluorinated acrylate latex was prepared via semi-continuous emulsion copolymerization of cationic monomer and other monomers.The resultant latex and its film were characterized with dynamic light scattering detector and contact angle meter.Influences of amount of DMDAAC on the properties of resultant latex and its film were investigated in detail.Results show that the particle size of the latex has the minimum value and the zeta potential of the latex is increased when the amount of DMDAAC is increased.In addition,the particle size of the latex is unimodal distribution when the amount of DMDAAC is not more than 2.5%.However,the particle size of the latex is bimodal distribution when the amount of DMDAAC is more than 2.5%.The contact angle is varied slightly with the increase of amount of DMDAAC when it is not more than 2.5%.Nevertheless,the contact angle is decreased with the increase of the amount of DMDAAC when it is more than 25%.

  6. Synthesis of acrylic and allylic bifunctional cross-linking monomers derived from PET waste (United States)

    Cruz-Aguilar, A.; Herrera-González, A. M.; Vázquez-García, R. A.; Navarro-Rodríguez, D.; Coreño, J.


    An acrylic and two novel allylic monomers synthesized from bis (hydroxyethyl) terephthalate, BHET, are reported. This was obtained by glycolysis of post-consumer PET with boiling ethylene glycol. The bifunctional monomer bis(2-(acryloyloxy)ethyl) terephthalate was obtained from acryloyl chloride, while the allylic monomers 2-(((allyloxi)carbonyl)oxy) ethyl (2-hydroxyethyl) terephthalate and bis(2-(((allyloxi)carbonyl)oxy)ethyl) terephthalate, from allyl chloroformate. Cross-linking was studied in bulk polymerization using two different thermal initiators. Monomers were analyzed by means of 1H NMR and the cross-linked polymers by infrared spectroscopy. Gel content higher than 90% was obtained for the acrylic monomer. In the case of the mixture of the allylic monomers, the cross-linked polymer was 80 % using BPO initiator, being this mixture 24 times less reactive than the acrylic monomer.

  7. Evaluation of the level of residual monomer in acrylic denture base materials having different polymerization properties. (United States)

    Kalipçilar, B; Karaağaçlioğlu, L; Hasanreisoğlu, U


    The aim of this study was to evaluate the level of residual monomer in acrylic denture base materials having different polymerization properties. The investigation included a conventional-type acrylic cured under heat and pressure, as well as a pour-type resin polymerized by an injection-moulding technique at room temperature and under pressure. It was found that the residual monomer content ranged from 0.22-0.54% in pour-type resin, and from 0.23-0.52% in routinely used resins when the specimens were analysed by high performance liquid chromatography. These findings revealed that there were no significant differences between the two types of acrylic in terms of their residual monomer content.

  8. Effects of acrylic resin monomers on porcine coronary artery reactivity. (United States)

    Abebe, Worku; West, Daniel; Rueggeberg, Frederick A; Pashley, David; Mozaffari, Mahmood S


    The purpose of the present investigation was to assess the reactivity of porcine coronary arteries under in vitro conditions following their exposure to methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA) monomers. Confirming previous studies using rat aortas, both MMA and HEMA induced acute/direct relaxation of coronary ring preparations, which was partly dependent on the endothelium. With prolonged tissue exposure, both monomers caused time- and concentration-dependent inhibition of receptor-mediated contraction of the vascular smooth muscle caused by prostaglandin F2∝ (PGF2∝), with HEMA causing more inhibition than MMA. Hydroxyethyl methacrylate, but not MMA, also produced impairment of non-receptor-mediated contraction of the coronary smooth muscle induced by KCl. On the other hand, neither HEMA nor MMA altered relaxation of the smooth muscle produced by the direct-acting pharmacological agent, sodium nitroprusside (SNP). While exposure to HEMA impaired endothelium-dependent vasorelaxation caused by bradykinin (BK), MMA markedly enhanced this endothelial-mediated response of the arteries. The enhanced endothelial response produced by MMA was linked to nitric oxide (NO) release. In conclusion, with prolonged tissue exposure, MMA causes less pronounced effects/adverse consequences on coronary smooth muscle function relative to the effect of HEMA, while enhancing vasorelaxation associated with release of NO from the endothelium. Accordingly, MMA-containing resin materials appear to be safer for human applications than materials containing HEMA.

  9. Residual monomer content determination in some acrylic denture base materials and possibilities of its reduction

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    Kostić Milena


    Full Text Available Background/Aim. Polymethyl methacrylate is used for producing a denture basis. It is a material made by the polymerization process of methyl methacrylate. Despite of the polymerization type, there is a certain amount of free methyl methacrylate (residual monomer incorporated in the denture, which can cause irritation of the oral mucosa. The aim of this study was to determine the amount of residual monomer in four different denture base acrylic resins by liquid chromatography and the possibility of its reduction. Methods. After the polymerization, a postpolymerization treatment was performed in three different ways: in boiling water for thirty minutes, with 500 W microwaves for three minutes and in steam bath at 22º C for one to thirty days. Results. The obtained results showed that the amount of residual monomer is significantly higher in cold polymerizing acrylates (9.1-11%. The amount of residual monomer after hot polymerization was in the tolerance range (0.59- 0.86%. Conclusion. The obtained results denote a low content of residual monomer in the samples which have undergone postpolymerization treatment. A lower percent of residual monomer is established in samples undergone a hot polymerization.

  10. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units

    Energy Technology Data Exchange (ETDEWEB)

    Melinte, Violeta [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Buruiana, Tinca, E-mail: [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Aldea, Horia [Gr. T. Popa University of Medicine and Pharmacy, Faculty of Dentistry, Iasi (Romania); Matiut, Simona [Praxis Medical Investigations, 33 Independence, 700102 Iasi (Romania); Silion, Mihaela; Buruiana, Emil C. [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania)


    photopolymerizable phosphate acrylate monomers is reported. • Antimicrobial non-leaching triclosan urethane monomer was obtained and characterized. • Photopolymerization of monomers or reactive mixtures was evaluated by photo-DSC. • Inhibition of bacterial growth at contact of composite films with bacteria was evidenced.

  11. Dipentaerythritol penta-acrylate phosphate - an alternative phosphate ester monomer for bonding of methacrylates to zirconia (United States)

    Chen, Ying; Tay, Franklin R.; Lu, Zhicen; Chen, Chen; Qian, Mengke; Zhang, Huaiqin; Tian, Fucong; Xie, Haifeng


    The present work examined the effects of dipentaerythritol penta-acrylate phosphate (PENTA) as an alternative phosphate ester monomer for bonding of methacrylate-based resins to yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and further investigated the potential bonding mechanism involved. Shear bond strength testing was performed to evaluate the efficacy of experimental PENTA-containing primers (5, 10, 15, 20 or 30 wt% PENTA in acetone) in improving resin-Y-TZP bond strength. Bonding without the use of a PENTA-containing served as the negative control, and a Methacryloyloxidecyl dihydrogenphosphate(MDP)-containing primer was used as the positive control. Inductively coupled plasma-mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) were used to investigate the potential existence of chemical affinity between PENTA and Y-TZP. Shear bond strengths were significant higher in the 15 and 20 wt% PENTA groups. The ICP-MS, XPS and FTIR data indicated that the P content on the Y-TZP surface increased as the concentration of PENTA increased in the experimental primers, via the formation of Zr–O–P bond. Taken together, the results attest that PENTA improves resin bonding of Y-TZP through chemical reaction with Y-TZP. Increasing the concentration of PENTA augments its binding affinity but not its bonding efficacy with zirconia.


    DEFF Research Database (Denmark)

    Clemmensen, S.


    The cross-reaction patterns of selected acrylate and methacrylate esters were investigated using the guinea pig maximization test. Methacrylates were less potent sensitizers than acrylates. Cross-sensitization was found between (meth)acrylates with closely related core structures, most extensively...

  13. Copolymers of N-cyclohexylacrylamide and n-butyl acrylate: synthesis, characterization, monomer reactivity ratios and mean sequence length

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    Full Text Available Copolymerization of N-cyclohexylacrylamide (NCHA and n-butyl acrylate (BA was carried out in dimethylformamide at 55±1°C using azobisisobutyronitrile as a free radical initiator. The copolymers were characterized by 1H-NMR spectroscopy and the copolymer compositions were determined by 1H-NMR analysis. The reactivity ratios of the monomers were determined by both linear and non-linear methods. The reactivity ratios of monomers determined using linear methods like Fineman-Ross (r1 = 0.37 and r2 = 1.77 , Kelen-Tudos (r1 = 0.38 and r2 = 1.77, ext. Kelen-Tudos (r1 = 0.37 and r2 = 1.75 Yezrieler-Brokhina-Roskin (r1 = 0.37 and r2 = 1.77 and non-linear methods like Tidwell-Mortimer (r1 = 0.37 and r2 = 1.76, ProCop (r1 = 0.36 and r2 = 1.82. The Q and e values for NCHA are 0.67 and 0.68 respectively. Mean sequence lengths of copolymers are estimated from r1 and r2 values. It shows that the BA units increases in a linear fashion in the polymer chain as the concentration of BA increases in the monomer feed.

  14. Photopolymerizable phosphate acrylates as comonomers in dental adhesives with or without triclosan monomer units. (United States)

    Melinte, Violeta; Buruiana, Tinca; Aldea, Horia; Matiut, Simona; Silion, Mihaela; Buruiana, Emil C


    Phosphate diacrylates (CO-DAP, TMP-DAP) based on castor oil or trimethylolpropane were synthesized and evaluated in dental adhesive formulations in comparison with 3-acryloyloxy-2-hydroxypropyl methacrylate phosphate (AMP-P). In an attempt to promote antibacterial activity, another photopolymerizable monomer (TCS-UMA) containing 5-chloro-2-(2,4-dichlorophenoxy)phenol moiety (triclosan) was prepared and incorporated in adhesive resins. Each of these monomers had a molecular structure confirmed by spectral methods. The photopolymerization rates for monomers (0.063-0.088s(-1)) were lower than those determined in the monomer combinations (0.116-0.158s(-1)) incorporating phosphate diacrylate (11wt.%), BisGMA (33wt.%), TEGDMA (10wt.%), UDMA (10wt.%) and HEMA (15wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65-57.02μg/mm(3)) and water solubility (3.51-13.38μg/mm(3)), and the contact angle was dependent on the presence of CO-DAP (θF1: 66.67°), TMP-DAP (θF2: 55.05°) or AMP-P (θF3: 52.90°) in the photocrosslinked specimens compared to the sample without phosphate monomer (θF4: 82.14°). The scanning electron microscopy image of the dentin-resin composite interface after applying our F1 formulation (pH: 4.1) and its light-curing for 20s supports the evidence of the formation of the hybrid layer with the tooth structure created by self-etching approach, with no gaps or cracks in the adhesive. A comparative analysis of the adhesion achieved with commercial adhesive systems (Single Bond Universal, C-Bond) rather indicates similarities than differences between them. The addition of triclosan methacrylate (1wt.%) into the formulation inhibited the bacterial growth of the Streptococcus mutans and Escherichia coli in the direct contact area due to the covalently linked antibacterial monomer.

  15. Permeability of different types of medical protective gloves to acrylic monomers. (United States)

    Lönnroth, Emma-Christin; Wellendorf, Hanne; Ruyter, Eystein


    Dental personnel and orthopedic surgeons are at risk when manually handling products containing methyl methacrylate (MMA). Dental products may also contain cross-linking agents such as ethylene glycol dimethacrylate (EGDMA) or 1,4-butanediol dimethacrylate (1,4-BDMA). Skin contact with monomers can cause hand eczema, and the protection given by gloves manufactured from different types of material is not well known. The aim of this study was to determine the breakthrough time (BTT, min) as a measure of protection (according to the EU standard EN-374-3) for a mixture consisting of MMA, EGDMA and 1,4-BDMA. Fifteen different gloves representing natural rubber latex material, synthetic rubber material (e.g. nitrile rubbers), and synthetic polymer material were tested. The smallest monomer MMA permeated within 3 min through all glove materials. A polyethylene examination glove provided the longest protection period to EGDMA and 1, 4-BDMA (> 120 min and 25.0 min), followed by the surgical glove Tactylon (6.0 min and 8.7 min) and the nitrile glove Nitra Touch (5.0 min and 8.7 min). This study showed that the breakthrough time (based on permeation rate) cannot be regarded as a 'safe limit'. When the permeation rate is low, monomers may have permeated before BTT can be determined. Using double gloves with a synthetic rubber inner glove and a natural rubber outer glove provided longer protection when the inner glove was rinsed in water before placing the outer glove on top.

  16. Influence of acrylamide monomer addition to the acrylic denture-base resins on mechanical and physical properties. (United States)

    Aydogan Ayaz, Elif; Durkan, Rukiye


    The aim of the study was to evaluate the effect of adding acrylamide monomer (AAm) on the characterization, flexural strength, flexural modulus and thermal degradation temperature of poly(methyl methacrylate) (PMMA) denture-base resins. Specimens (n=10) were fabricated from a conventional heat-activated QC-20 (Qc-) and a microwave heat-activated Acron MC (Ac-) PMMA resins. Powder/liquid ratio followed the manufacturer's instructions for the control groups (Qc-c and Ac-c) and for the copolymer groups, the resins were prepared with 5% (-5), 10% (-10), 15% (-15) and 20% (-20) acrylamide contents, according to the molecular weight ratio, respectively. The flexural strength and flexural modulus were measured by a three-point bending test. The data obtained were statistically analyzed by Kruskal-Wallis test (α=0.05) to determine significant differences between the groups. The chemical structures of the resins were characterized by the nuclear magnetic resonance spectroscopy. Thermal stabilities were determined by thermogravimetric analysis (TGA) with a heating rate of 10 °C⋅min(-1) from 35 °C to 600 °C. Control groups from both acrylic resins showed the lowest flexural strength values. Qc-15 showed significant increase in the flexural strength when compared to Qc-c (PPMMA is increased by the insertion of AAm.

  17. Influence of acrylamide monomer addition to the acrylic denture-base resins on mechanical and physical properties

    Institute of Scientific and Technical Information of China (English)

    Elif Aydogan Ayaz; Rukiye Durkan


    The aim of the study was to evaluate the effect of adding acrylamide monomer (AAm) on the characterization, flexural strength, flexural modulus and thermal degradation temperature of poly(methyl methacrylate) (PMMA) denture-base resins. Specimens (n510) were fabricated from a conventional heat-activated QC-20 (Qc-) and a microwave heat-activated Acron MC (Ac-) PMMA resins. Powder/liquid ratio followed the manufacturer’s instructions for the control groups (Qc-c and Ac-c) and for the copolymer groups, the resins were prepared with 5%(25), 10%(210), 15%(215) and 20%(220) acrylamide contents, according to the molecular weight ratio, respectively. The flexural strength and flexural modulus were measured by a three-point bending test. The data obtained were statistically analyzed by Kruskal-Wallis test (a50.05) to determine significant differences between the groups. The chemical structures of the resins were characterized by the nuclear magnetic resonance spectroscopy. Thermal stabilities were determined by thermogravimetric analysis (TGA) with a heating rate of 10 6C?min21 from 35 6C to 600 6C. Control groups from both acrylic resins showed the lowest flexural strength values. Qc-15 showed significant increase in the flexural strength when compared to Qc-c (P,0.01). Ac-10 and Ac-15 showed significance when compared to Ac-c (P,0.01). Acrylamide incorporation increased the elastic modulus in Qc-10, Qc-15 and Qc-20 when compared to Qc-c (P,0.01). Also significant increase was observed in Ac-10, Ac-15 and Ac-20 copolymer groups when compared to Ac-c (P,0.01). According to the 1H-nuclear magnetic resonance (NMR) results, acrylamide copolymerization was confirmed in the experimental groups. TGA results showed that the thermal stability of PMMA is increased by the insertion of AAm.

  18. Computational study of cyclohexanone-monomer co-initiation mechanism in thermal homo-polymerization of methyl acrylate and methyl methacrylate. (United States)

    Liu, Shi; Srinivasan, Sriraj; Grady, Michael C; Soroush, Masoud; Rappe, Andrew M


    This paper presents a systematic computational study of the mechanism of cyclohexanone-monomer co-initiation in high-temperature homopolymerization of methyl acrylate (MA) and methyl methacrylate (MMA). Previous experimental studies of spontaneous thermal homopolymerization of MA and MMA showed higher monomer conversion in the presence of cyclohexanone than xylene. However, these studies did not reveal the initiation mechanism(s) or the initiating species. To identify the initiation mechanism and the initiating species, we explore four different mechanisms, (1) Kaim, (2) Flory, (3) α-position hydrogen transfer, and (4) Mayo, using first-principles density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2) calculations. Transition-state geometries for each mechanism are determined using B3LYP/6-31G* and assessed with MP2/6-31G*. Activation energies and rate constants are calculated using transition-state theory. The harmonic oscillator approximation and tunneling corrections are applied to compute the reaction rate constants. This study indicates that α-position hydrogen transfer and Mayo mechanisms have comparable barriers and are capable of generating monoradicals for initiating polymerization of MA and MMA; these two mechanisms can cause cyclohexanone-monomer co-initiation in thermal polymerization of MA and MMA.

  19. Aspect of sucrose and its monomers from sugarcane juice submitted to different doses of cobalt-60 irradiation

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    Lima, Roberta B.; Rela, Paulo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Arthur, Valter, E-mail: [Centro de Energia Nuclear da Agricultura (CENA/USP), Piracicaba, SP (Brazil). Dept. de Radiobiologia e Ambiente; Souza, Juliana Ap.; Prezotto, Mariane P.; Baptista, Antonio S.; Aguiar, Claudio L., E-mail: [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP, (Brazil). Dept. de Agroindustria, Alimentos e Nutricao


    The sugarcane is an important source of sucrose, which has been for years an essential source of energy, even for consumption as food or to produce liquid fuels. During the manufacturing process of crystal sugar, one of the main concerns is to avoid the inversion of sucrose to glucose and fructose, which could decrease the efficiency of crystal's production. The increase of sugar production and the growing interest of foreign market have encouraged the development of numerous investigative studying, searching for alternative technologies and a better efficiency of process of current clarifying, sulphitation, producing a whiter sugar in a process named 'sulfur free' with effectiveness production of crystal sucrose. In acid conditions or extended exposure to high temperatures, inversion reaction can occur, resulting in the formation of reducing sugars - i.e. mainly glucose and fructose - which affect the sucrose crystallization process. This study aimed to evaluate the impact of gamma irradiation (Co-60) on the rate of reducing sugars and also totals reducing sugars (i.e., sucrose, glucose and fructose) into sugarcane juice before and after treatment with different doses: 5, 10 and 20 kGy. Some parameters were evaluated, such as: Brix, pH, reducing sugar and total reducing sugar, and from the results it was observed that parameters such as Brix and pH did not have a significant variation between the control and irradiated samples, varying from 13.2 Brix (Control) to 13.0 Brix (20 kGy) and 5.26 (10KGy) to 5.36 (20 kGy), respectively. For the analysis of reducing sugar, the contents varying from 29 {+-}0.87 to 43{+-}1.43 mg.mL{sup -1} with the largest rise occurred in the sample irradiated at 20 kGy. For analysis of total reducing sugar, the results ranged from 12.02{+-}0.46% in control sample to 11.93{+-}0.21% in the sample which received the highest radiation dose, 20 kGy. Against these results, we could conclude that the impact of gamma radiation

  20. Curing behavior of a UV-curable coating based on urethane acrylate oligomer: the influence of reactive monomers

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    Dapawan Kunwong


    Full Text Available A hybrid organic-organic urethane acrylate oligomer was synthesized by the reaction of polypropyleneglycol (PPG,2,4-toluene diisocyanate (TDI and 2-hydroxyethyl methacrylate (HEMA using dibutyltin dilaurate (DBTDL as a catalyst.The urethane acrylate oligomer’s structure was characterized by nuclear magnetic resonance (NMR and Fourier transforminfrared spectroscopy (FT-IR. Two UV-curable coatings were prepared by blending the urethane acrylate oligomer, a reactivemonomer (1,6- hexanediol diacrylate (HDDA or trimethylol propane triacrylate (TMPTA and a photoinitiator (2,2-dimethoxy-2-phenyl acetophenone. The UV curing process of such coatings was monitored by FT-IR and determination of thegel fraction. It was found that as the UV dose increased, the specific peaks at 1635 cm-1 and 810 cm-1, related to the carboncarbondouble (C=C bond, decreased. Gel fraction of the cured coating film was found to increase with increasing radiationtime. Thermal properties of the cured coating were also investigated using differential scanning calorimetry (DSC andthermal gravimetric analysis (TGA.

  1. Organocatalytic conjugate-addition polymerization of linear and cyclic acrylic monomers by N-heterocyclic carbenes: Mechanisms of chain initiation, propagation, and termination

    KAUST Repository

    Zhang, Yuetao


    This contribution presents a full account of experimental and theoretical/computational investigations into the mechanisms of chain initiation, propagation, and termination of the recently discovered N-heterocyclic carbene (NHC)-mediated organocatalytic conjugate-addition polymerization of acrylic monomers. The current study specifically focuses on three commonly used NHCs of vastly different nucleophilicity, 1,3-di-tert-butylimidazolin-2-ylidene (ItBu), 1,3- dimesitylimidazolin-2-ylidene (IMes), and 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4- triazol-5-ylidene (TPT), and two representative acrylic monomers, the linear methyl methacrylate (MMA) and its cyclic analog, biomass-derived renewable γ-methyl-α-methylene-γ-butyrolactone (MMBL). For MMA, there exhibits an exquisite selectivity of the NHC structure for the three types of reactions it promotes: enamine formation (single-monomer addition) by IMes, dimerization (tail-to-tail) by TPT, and polymerization by ItBu. For MMBL, all three NHCs promote no dimerization but polymerization, with the polymerization activity being highly sensitive to the NHC structure and the solvent polarity. Thus, ItBu is the most active catalyst of the series and converts quantitatively 1000-3000 equiv of MMBL in 1 min or 10 000 equiv in 5 min at room temperature to MMBL-based bioplastics with a narrow range of molecular weights of Mn = 70-85 kg/mol, regardless of the [MMBL]/[ItBu] ratio employed. The ItBu-catalyzed MMBL polymerization reaches an exceptionally high turnover frequency up to 122 s -1 and a high initiator efficiency value up to 1600%. Unique chain-termination mechanisms have been revealed, accounting for the production of relative high-molecular-weight linear polymers and the catalytic nature of this NHC-mediated conjugate-addition polymerization. Computational studies have provided mechanistic insights into reactivity and selectivity between two competing pathways for each NHC-monomer zwitterionic adduct, namely enamine

  2. Effects of Hydrophilic Monomer Types and Level on Polystyrene-Acrylate/montmorillonite Nanocomposite Made by Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    F.A.Zhang; L.Chen; J.Q.Ma; X.Yang


    1 Results Nanocomposite has attracted more and more interest all over the world.Polystyrene (PS) is a commercialized and mass-productive polymer,continuous research efforts have been devoted to the development of polystyrene/montmorillonite (PS/MMT) nanocomposites[1-2].But the polarity of styrene (St) is too small to intercalate the space between the clay layers.The polarity of hydrophilic monomer is so strong that it can intercalate the MMT easily,the intercalated smectic clays maybe exfoliated by usin...

  3. Reactivity of Amine/E(C6F53 (E = B, Al Lewis Pairs toward Linear and Cyclic Acrylic Monomers: Hydrogenation vs. Polymerization

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    Jiawei Chen


    Full Text Available This work reveals the contrasting reactivity of amine/E(C6F53 (E = B, Al Lewis pairs toward linear and cyclic acrylic monomers, methyl methacrylate (MMA and biorenewable γ-methyl-α-methylene-γ-butyrolactone (γMMBL. While mixing of 2,2,6,6-tetramethylpiperidine (TMP and B(C6F53 leads to a frustrated Lewis pair (FLP, Et3N reacts with B(C6F53 to form disproportionation products, ammonium hydridoborate ionic pair and iminium zwitterion. On the other hand, the stoichiometric reaction of either TMP or Et3N with Al(C6F53 leads to clean formation of a classic Lewis adduct (CLA. Neither TMP nor Et3N, when paired with E(C6F53, polymerizes MMA, but the Et3N/2B(C6F53 pair promotes transfer hydrogenation of MMA to form methyl isobutyrate. In contrast, the amine/E(C6F53 pairs promote rapid polymerization of γMMBL carrying the more reactive exocyclic methylene moiety, achieving full conversion in less than 3 min even at a low catalyst loading of 0.0625 mol %. TMP is more effective than Et3N for the polymerization when paired with either the borane or the alane, while the alane exhibits higher polymerization activity than the borane when paired with Et3N. Overall, the TMP/Al(C6F53 system exhibits the highest polymerization activity, achieving a maximum turn-over frequency of 96,000 h−1 at 0.125 mol % of catalyst loading, producing high molecular weight PγMMBL with Mn = 1.29 × 105 g∙mol−1.

  4. Impact of Crosslinking Monomer on Property of Silicone-Acrylic Copolymer Emulsion for Printing Adhesive%交联单体对硅丙乳液印花粘合剂性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘宗旭; 赵振河


    A soap-free silicone acrylic emulsion was prepared with acrylic monomers , vinyl silicone oil , potassium persulfate , TM-200 or N-methylol acrylamide or CX -600 silicone-acrylic copolymer emulsion . The integrated emulsion was used as the printing binder for fabric pigment .The optimal emulsion preparation process was with 0.6% of emulsifier to monomer and 0.8% of initiator to monomer .When the crosslinking monomer was TM-200, N-methylol acrylamide, CX-600, respectively, the corresponding amount of vinyl silicone oil was 9%, 6%and 6%, respectively .%以丙烯酸类单体、乙烯基硅油为主要原料,过硫酸钾为引发剂,甲基丙烯酸类羰基化合物( TM-200)或N-羟甲基丙烯酰胺或甲基丙烯酸类化合物(CX-600)为交联单体,采用阴-非离子复合型可聚合乳化剂制备出无皂硅丙共聚乳液;并将此硅丙共聚乳液作为织物涂料印花粘合剂。综合乳液性能及印花效果,得到的最优乳液制备工艺为:乳化剂用量为单体质量的0.6%,引发剂用量为单体质量的0.8%,当交联单体分别为TM-200、 N-羟甲基丙烯酰胺、 CX-600时,乙烯基硅油用量分别为单体质量的9%、6%、6%。

  5. Synthesis of Monomer Hydrogenated Rosin-Acrylic Glycerin Ester%氢化松香-丙烯酸丙三醇酯单体的合成

    Institute of Scientific and Technical Information of China (English)

    李浩; 王春平; 李鹏飞; 雷福厚; 段文贵


    Hydrogenated rosin-acrylic glycerin ester is synthesized from hydrogenated rosin modified by thionyl chloride obtained by reaction of hydrogenated rosin and thionyl chloride, glycerin and acryloyl chloride.Hydrogenated rosin acyl chloride is characterized by FTIR spectrum. Hydrogenated rosin glycerin ester obtained by reaction of hydrogenated rosin acyl chloride and glycerin is characterized by FTIR spectrum and determination of acid value, and its optimal synthetic reaction conditions are obtained as follows: molar ratio of hydrogenated rosinacyl chloride to glycerin is 1: 2. 5, pyridine as solvent, reaction time is 3 h, reaction temperature is ll0℃. The acid value of hydrogenated rosin glycerin ester is 21 mg·g-1 under above conditions. The structure of hydrogenated rosin-acrylic glycerin ester is confirmed by FTIR and UV-Vis. The monomer can polymerize in the presence of initiator. For the prepared polymer, its degree of cross linking is 75.1%, its solubility in aviation kerosene, carbinol, methylbenzene or cyclohexane is very small, and its softening point is 235℃.%以氢化松香、二氯亚砜、丙三醇、丙烯酰氯为主要原料,合成了可以均聚的氢化松香-丙烯酸丙三醇酯单体.氢化松香先与二氯亚砜反应制得氢化松香酰氯,通过FTIR对反应过程进行跟踪监测;氢化松香酰氯再与丙三醇经酯化反应合成氢化松香丙三醇酯,优化的反应条件为:吡啶作溶剂、n(氢化松香酰氯):n(丙三醇)=1:2.5、反应温度110℃、反应时间3 h,制得的氢化松香丙三醇酯酸值为21 mg·g-1;最后,氢化松香丙三醇酯与丙烯酰氯经酯化反应制得了氢化松香-丙烯酸丙三醇酯单体,通过FTIR和UV-Vis对其结构进行了表征.单体可以发生均聚反应,生成的颗粒状聚合物交联度为75.1%,在航空煤油、甲醇、甲苯、环己烷中的溶解度均很小,软化点为235℃.

  6. The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

    Directory of Open Access Journals (Sweden)

    K. A. Shaffei


    Full Text Available Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of polybutyl acrylate were achieved by using bis (2-ethylhexyl maleate (BEHM. The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

  7. Study on preparation of soap-free styrene-acrylate emulsion by water-soluble monomer copolymerization%水溶性单体共聚法制备无皂苯丙乳液的研究

    Institute of Scientific and Technical Information of China (English)

    唐宏科; 李婧


    以苯乙烯(St)、丙烯酸(AA)、甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为共聚单体,制备了无皂苯丙乳液;然后以AA含量、中和度、引发剂含量和软/硬单体配比等为试验因素,以乳液稳定性和粒径为考核指标,采用单因素试验法优选出制备无皂苯丙乳液的最佳工艺条件.结果表明:当ω(引发剂)=1.2%和ω(AA)=4.5%(均相对于单体总质量而言)、中和度为0.8、m(BA)∶m(St+MMA)=4∶6和反应温度为78℃时,可制得粒径为纳米级的高固含量稳定乳液.%With styrene(St),acrylic acid(AA),methyl methacrylate(MMA) and butyl acrylate(BA) as comonomers,a soap-free St-acrylate emulsion was prepared. Then,with AA contents,neutralisation degree,initiator contents and soft monomer/hard monomer ratios as experimental factors,emulsion stability and particle size as evaluation indices, the optimal process conditions of preparing soap-free St-acrylate emulsion were preferred by single-factor experiment.The results showed that the stable emulsion with nano-level size and high solid content was prepared when mass fractions of initiator and AA were 1.2% and 4.5% in total monomers respectively, neutralisation degree was 0.8,mass ratio of m(BA):m(St+MMA) was 4:6 and reaction temperature was 78 ℃.

  8. Characterization of the activity of penicillin G acylase immobilized onto nylon membranes grafted with different acrylic monomers by means of gamma-radiation

    NARCIS (Netherlands)

    Mohy Eldin, M.S.; Bencivenga, U.; Rossi, S.; Canciglia, P.; Caeta, F.S.; Tramper, J.; Mita, D.G.


    Penicillin G acylase (PGA) has been immobilized onto nylon membranes grafted with methylmethacrylate (MMA) or diethyleneglycoldimethacrylate (DGDA) monomers by means of -radiation. Hexamethylenediamine (HMDA) has been used as spacer between the grafted membranes and the enzyme. Glutaraldehyde (GA) w

  9. Acrylate Systemic Contact Dermatitis. (United States)

    Sauder, Maxwell B; Pratt, Melanie D


    Acrylates, the 2012 American Contact Dermatitis Society allergen of the year, are found in a range of products including the absorbent materials within feminine hygiene pads. When fully polymerized, acrylates are nonimmunogenic; however, if not completely cured, the monomers can be potent allergens.A 28-year-old woman is presented, who had her teeth varnished with Isodan (Septodont, Saint-Maur-des-Fossés, France) containing HEMA (2-hydroxyethyl methacrylate) with no initial reaction. Approximately 1 month later, the patient developed a genital dermatitis secondary to her feminine hygiene pads. The initial reaction resolved, but 5 months later, the patient developed a systemic contact dermatitis after receiving a second varnishing.The patient was dramatically patch test positive to many acrylates. This case demonstrates a reaction to likely unpolymerized acrylates within a feminine hygiene pad, as well as broad cross-reactivity or cosensitivity to acrylates, and possibly a systemic contact dermatitis with systemic re-exposure to unpolymerized acrylates.

  10. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    LENUS (Irish Health Repository)

    Nagle, Susan


    This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and\\/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength.


    Institute of Scientific and Technical Information of China (English)

    LI Fumian; GU Zhongwei; FENG Xinde(S. T. Voong)


    Several new monomers, β-(acetylsalicylyloxy)ethyl methacrylate, β-(acetylsalicylyloxy)propyl methacrylate, β-(acetylsalicylyloxy)ethyl acrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl methacrylate, β-hydroxy-γ-(acetylsalicylyloxy)propyl acrylate have been synthesized from aspirin with corresponding hydroxyalkyl or glycidyl acrylates, and then polymerized by free radical initiator.

  12. Synthesis of 4-O- and 6-O-monoacryloyl derivatives of sucrose by selective hydrolysis of 4,6-O-(1-ethoxy-2-propenylidene) sucrose. Polymerization and copolymerization with styrene. (United States)

    Fanton, E; Fayet, C; Gelas, J; Deffieux, A; Fontanille, M; Jhurry, D


    The synthesis of an ethylenic orthoester of sucrose by transorthoesterification of an acrylic reagent with sucrose is described. Mild hydrolysis of this orthoester gave sucrose selectively monosubstituted by an acryloyl group at either the 4-O- or the 6-O-position. These acrylates were homopolymerized and copolymerized with styrene, and the corresponding polymers were characterized.

  13. Rare linking hydrogels based on acrylic acid and carbohydrate esters

    Directory of Open Access Journals (Sweden)

    U. Akhmedov


    Full Text Available The process of copolymerization of acrylic acid and esters poliallil sucrose; pentaerythritol and sorbitol, some of its laws are identified. The kinetic regularities of copolymerization and the optimum conditions of synthesis was established.

  14. Photokopolimerisasi monomer akrilat degan kulit kras sapi

    Directory of Open Access Journals (Sweden)

    Dwi Wahini Nurhajati


    Full Text Available The research on photocopolymerization of acrylate monomer with cow crust hide had object to observe the resulted copolymer onto cow crust hide. Crust hides, saturated with aqueous emulsions containing 25 wt % of n-butyl acrylate (n-BA or tripropylene glycol diacrylate (TPGDA were irradiated by cobalt – 60 gamma rays with doses ranges from 5 to 25 kGy. The irradiated hides were washed with water, dried in air and extracted in soxhlet apparatus for 48 hours to remove homopolymer. The highest yield of photocopolymerization of n – butyl acrylate monomer with crust hides was found 17,7878% at dose 25 kGy, and for photocopolymerization of tripropylene glycol diacrylate with crust hides was found 39,4245% at dose 20 kGy.

  15. 新型抗菌型丙烯酸单体的合成及在牙科修复树脂中的应用%Synthesis of New Antibacterial Acrylic Monomer and Its Application in Dental Restoration Resin-based

    Institute of Scientific and Technical Information of China (English)

    赵中令; 连彦青


    Two acrylic monomers 2-(methacryloyloxy) ethyl 6-bromohexanoate pyridinium (MEBH-Py) and 2-(methacryloyloxy) ethyl 11-bromoundecanoate pyridinium(MEBU-Py) with antibacterial property were synthesized and copolymerized with the commercial dental restorative resin Single Bond Ⅱ adhesive (3 M ESPE dental products) to prepare modified binding agent with antibacterial activity to prevent second caries. The two monomers had good solubility in common solvents such as water, methanol. They could be dissolved in methyl methacrylate, hydroxyethyl methacrylate and other common dental resin. The results showed the two monomers could be copolymerized with commercial resin based restoratives. The monomers MEBH-Py and MEBU-Py got decomposed at 267. 6 and 247. 9℃ respectively and the minimal inhibitory concentration (MIC) of MEBH-Py and MEBU-Py were 6 and 1 mg/mL for E. coli JM05, respectively. The surface antibacterial efficiency for E. coli JM05 of the modified cured systems containing 1. 49%-5. 58% monomers were all up to 98%. The residual unpolymerized MEBH-Py or MEBU-Py were detected scarcely in the solution dipped out of the modified binder by UV-Vis analysis. The pyridinium salt groups were enriched on the surface of the modified binder by X-ray photoelectron spectroscopy ( XPS) which could be the reason of high antibacterial efficiency while low content of MEBH-Py or MEBU-Py. Thus, the two monomers have good thermal stability, good bactericidal activity and polymerizable property; they may be used in many other fields to achieve antibacterial materials.%制备了2种具有抗菌活性的丙烯酸酯类单体6-溴己酸-2-(2-甲基丙烯酰氧)乙基酯吡啶盐(MEBH-Py)和11-溴十一酸-2-(2-甲基丙烯酰氧)乙基酯吡啶盐(MEBU-Py),分别将其添加到牙科修复树脂Single BondⅡ纳米黏结剂中共聚,得到具有抗菌活性的改性黏结剂.MEBH-Py和MEBU-Py具有较好的热稳定性;以大肠杆菌JM05 (E.coli JM05)为受试菌,MEBH-Py和MEBU-Py

  16. Poly(meth)acrylate-based coatings. (United States)

    Nollenberger, Kathrin; Albers, Jessica


    Poly(meth)acrylate coatings for pharmaceutical applications were introduced in 1955 with the launch of EUDRAGIT(®) L and EUDRAGIT(®) S, two types of anionic polymers. Since then, by introducing various monomers into their polymer chains and thus altering their properties, diverse forms with specific characteristics have become available. Today, poly(meth)acrylates function in different parts of the gastrointestinal tract and/or release the drug in a time-controlled manner. This article reviews the properties of various poly(meth)acrylates and discusses formulation issues as well as application possibilities.

  17. The study on mechanism of holographic recording in photopolymer with dual monomer (United States)

    Zhai, Qianli; Tao, Shiquan; Wang, Dayong


    In this paper we study the dynamics of refractive index modulation in a dual-monomer photopolymer through grating growth under different experiment stages. By using different sets of parameters for vinyl monomers (NVC) and acrylate monomers (POEA) respectively, a composite dual-monomer model, extended from the uniform post-exposure (UPE) model for single monomer photopolymer, is proposed and fitted with the experiment data very well. Further discussions indicate that the dominant contribution to the total index modulation is made by NVC monomers, and a brief explanation of the function of POEA monomers is given.

  18. Study on Tough Blends of Polylactide and Acrylic Impact Modifier

    Directory of Open Access Journals (Sweden)

    Xiaoli Song


    Full Text Available Acrylic impact modifiers (ACRs with different soft/hard monomer ratios (mass ratios were prepared by semi-continuous seed emulsion copolymerization using the soft monomer butyl acrylate and the hard monomer methyl methacrylate, which were used to toughen polylactide (PLA. The effect of soft/hard ACR monomer ratio on the mechanical properties of PLA/ACR blends was investigated. The results showed that the impact strength and the elongation at break of PLA/ACR blends increased with increasing soft/hard ACR monomer ratio, while the tensile and flexural strengths of PLA had little change. The impact strength of PLA/ACR blends could be increased about 4 times more than that of pure PLA when the soft/hard monomer ratio of ACR was 90/10, which was the optimal ratio for good mechanical properties of PLA. Additionally, the possible mechanism of ACR toughening in PLA was discussed through impact fracture phase morphology analysis.

  19. Testing of residual monomer content reduction possibility on acrilic resins quality

    Directory of Open Access Journals (Sweden)

    Kostić Milena


    Full Text Available Poly (methyl methacrylate (PMMA is material widely used in dentistry. Despite the various methods used to initiate the polymerization of acrylic resins, the conversion of monomer to polymer is not complete thus leaving some unreacted methyl methacrylate (MMA, known as residual monomer (RM, in denture structure. RM in dental acrylic resins has deleterious effects on their mechanical properties and their biocompatibility. The objective of the work was to test the residual monomer reduction possibility by applying the appropriate postpolymerization treatment as well as to determine the effects of this reduction on pressure yields stress and surface structure characteristics of the acrylic resins. Postpolymerization treatments and water storage induced reduction of RM amount in cold-polymerized acrylic resins improved their mechanical properties and the homogenized surface structure. After the polymerization of heat-polymerized acrylic resins the post-polymerization treatments for improving the quality of this material type are not necessary.

  20. Poly(meth)acrylates obtained by cascade reaction. (United States)

    Popescu, Dragos; Keul, Helmut; Moeller, Martin


    Preparation, purification, and stabilization of functional (meth)acrylates with a high dipole moment are complex, laborious, and expensive processes. In order to avoid purification and stabilization of the highly reactive functional monomers, a concept of cascade reactions was developed comprising enzymatic monomer synthesis and radical polymerization. Transacylation of methyl acrylate (MA) and methyl methacrylate (MMA) with different functional alcohols, diols, and triols (1,2,6-hexanetriol and glycerol) in the presence of Novozyme 435 led to functional (meth)acrylates. After the removal of the enzyme by means of filtration, removal of excess (meth)acrylate and/or addition of a new monomer, e.g., 2-hydroxyethyl (meth)acrylate the (co)polymerization via free radical (FRP) or nitroxide mediated radical polymerization (NMP) resulted in poly[(meth)acrylate]s with predefined functionalities. Hydrophilic, hydrophobic as well as ionic repeating units were assembled within the copolymer. The transacylation of MA and MMA with diols and triols carried out under mild conditions is an easy and rapid process and is suitable for the preparation of sensitive monomers.


    Institute of Scientific and Technical Information of China (English)

    Mu-jie Yang; Wei Zhang


    Silicone-acrylate copolymer latex was prepared through three different polymerization processes, i.e., the batch process, preemulsified monomer addition and the monomer addition process. The results revealed that the monomer addition process is a desirable approach to produce narrow particle size distribution latex with higher polymerization conversion and less amount of coagulum. The effect of silicone content on the glossiness and water absorption of latex film was investigated and the results showed that the glossiness of latex film is improved up to a silicone content of 10% of total monomers, but becomes impaired thereafter, whereas water absorption is reduced accordingly.

  2. Synthesis and Demulsibility of the Terpolymer Demulsifier of Acryl Resin

    Institute of Scientific and Technical Information of China (English)

    KANG,Wan-Li; MENG,Ling-Wei; ZHANG,Hong-Yan; LIU,Shu-Ren


    Terpolymer demulsifier of acryl resin has been synthesized through solution polymerization with water as a dissolvent,potassium persulfate as an initiator and the monomers of methyl methacrylate,butyl acrylate and acrylic acid as starting materials.The effects of the reaction temperature,dripping time,the amount of monomers and initiator on the dehydration rate of the demulsifier were investigated by an orthogonal experiment.It shows that the stronger influence on the dehydration rate among six factors is reaction temperature,dripping time,and amount of catalyst,while monomer has weak influence.The performance of the demulsifier was evaluated under different demulsification time,temperatures and concentrations of the screened demulsifiers.The result shows that the dehydration rate of the demulsifier can reach over 67%,which is better than that by the emulsion polymerization way.

  3. Monomers, polymers and articles containing the same from sugar derived compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, James; Reineke, Theresa; Hillmyer, Marc A.


    Disclosed herein are monomers formed by reacting a sugar derived compound(s) comprising a lactone and two hydroxyls with a compound(s) comprising an isocyanate and an acrylate or methacrylate. Polymers formed from such monomers, and articles formed from the polymers are also disclosed.

  4. Advances in acrylic-alkyd hybrid synthesis and characterization (United States)

    Dziczkowski, Jamie


    In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

  5. Iron Sucrose Injection (United States)

    Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due ... and may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called iron ...

  6. Occupational fingertip eczema from acrylates in a manicurist

    Directory of Open Access Journals (Sweden)

    Denitza Zheleva


    Full Text Available Occupational hand eczema due to acrylates present in the workplace is a disease frequently reported among dentists, printers, and fiberglass workers. Acrylate monomers are used in the production of a great variety of polymers, including nail cosmetics. Our case report demonstrates a rare clinical presentations of allergic contact dermatitis from acrylic nails. Our patient was working as a manicurist and the diagnostic analyses revealed sensitation to some of the (meth acrylate compounds of her new nail cosmetics. Sculptured artificial acrylic and UV-hardened nails s are widely used in developed countries and they are gaining more and more popularity. We expect an increase in the number of cases of contact allergic dermatitis among manicurists and customers.

  7. Biocatalytic Synthesis of Maltodextrin-Based Acrylates from Starch and alpha-Cyclodextrin

    NARCIS (Netherlands)

    Kloosterman, Wouter M. J.; Spoelstra-van Dijk, Gerda; Loos, Katja


    Novel 2-(beta-maltooligooxy)-ethyl (meth) acrylate monomers are successfully synthesized by CGTase from Bacillus macerans catalyzed coupling of 2-(beta-glucosyloxy)-ethyl acrylate and methacrylate with a-cyclodextrin or starch. HPLC-UV analysis shows that the CGTase catalyzed reaction yields 2-(beta

  8. Recovery of olefin monomers (United States)

    Golden, Timothy Christoph; Weist, Jr., Edward Landis; Johnson, Charles Henry


    In a process for the production of a polyolefin, an olefin monomer is polymerised said polyolefin and residual monomer is recovered. A gas stream comprising the monomer and nitrogen is subjected to a PSA process in which said monomer is adsorbed on a periodically regenerated silica gel or alumina adsorbent to recover a purified gas stream containing said olefin and a nitrogen rich stream containing no less than 99% nitrogen and containing no less than 50% of the nitrogen content of the gas feed to the PSA process.

  9. Synthesis of novel saccharide-acrylate monomers using biocatalytic approaches

    NARCIS (Netherlands)

    Kloosterman, Wouter Marinus Jacobus


    Polyacrylaten met saccharide zijgroepen (poly saccharide-acrylaten) combineren de eigenschappen van suikers, met de apolaire eigenschappen van polyacrylaten. Deze polymeren worden gemaakt uit polymerizatie van monofunctionele saccharide-acrylaten. De synthese van saccharide-acrylaten, de monomeren v

  10. Review of Preparation and Properties of Polymers from Copolymerization of Aprotic Acrylic Monomers with Protic Acrylic Monomers (United States)



  11. Avaliação de monômero residual em resinas acrílicas de uso ortodôntico e protético: análise por espectroscopia Evaluation of residual monomer in autopolymerizing acrylic resins: spectroscopy analysis

    Directory of Open Access Journals (Sweden)

    Roberto Rocha Filho


    Full Text Available OBJETIVO: duas marcas comerciais de resinas acrílicas ativadas quimicamente (RAAQ, uma de uso ortodôntico (Orto Cril® e outra de uso protético (Jet®, polimerizadas em presença e ausência de pressão, foram analisadas em relação ao conteúdo de monômero (MMA residual liberado em solução, em diferentes intervalos de tempo (0,083; 0,25; 1; 1,25; 2,17; 5; 9; 14 e 21 dias. METODOLOGIA: a espectroscopia de absorção no ultravioleta foi utilizada na análise de soluções aquosas de MMA, com concentrações conhecidas, visando a determinação de uma curva de calibração. Soluções aquosas contendo corpos-de-prova, confeccionados com as citadas RAAQ, foram também submetidas à análise por espectroscopia de absorção no ultravioleta. RESULTADOS E CONCLUSÕES: os resultados foram comparados aos dados da curva de calibração, visando estabelecer a concentração de MMA residual das amostras. Eles permitiram concluir que o nível de MMA residual liberado em solução foi mais elevado durante as primeiras 24 horas, havendo uma tendência à estabilização a partir desse período e que a resina acrílica de uso ortodôntico apresentou níveis mais elevados de MMA em solução do que a de uso protético, em ambas as condições de polimerização empregadas, com presença e ausência de pressão. Além disso, a presença de pressão, durante a polimerização das duas resinas, elevou a concentração de MMA em solução, não havendo, entretanto, efeito da interação entre as marcas das resinas e a presença e ausência de pressão na concentração de MMA em solução, medida ao longo do tempo. Porém, todas as três variáveis (tempo, resina e pressão foram significantes.AIM: Two comercial brands of auto polymerizing acrylic resins (one for orthodontics use, Orto Cril®, and the other for prosthetics use, Jet® were analyzed concerning the amount of methyl methacrilate (MMA monomer dissolved in solution, processed under and not under

  12. UV-crosslinkable photoreactive self-adhesive hydrogels based on acrylics

    Directory of Open Access Journals (Sweden)

    Czech Zbigniew


    Full Text Available Hydrogels are a unique class of macromolecular networks that can hold a large fraction of an aqueous solvent within their structure. They are suitable for biomedical area including controlled drug delivery and for technical applications as self-adhesive materials for bonding of wet surfaces. This paper describes photoreactive self-adhesive hydrogels based on acrylics crosslinked using UV radiation. They are prepared in ethyl acetate through radical polymerization of monomers mixture containing 2-ethylhexyl acrylate (2-EHA, butyl acrylate (BA, acrylic acid (AA and copolymerizable photoinitiator 4-acryloyloxy benzophenone (ABP at presence of radical starter 2.2’-azobis-diisobutyronitrile AIBN. The synthesized acrylic copolymers were determined by viscosity and GPC analysis and later modified using ethoxylated amines. 4-acryloyloxy benzophenone (ABP was used as crosslinking monomer. After UV crosslinking the properties of these novel synthesized hydrogels, such as tack, peel adhesion, shears strength, elongation and water adsorption were also studied.

  13. Performance behavior of modified cellulosic fabrics using polyurethane acrylate copolymer. (United States)

    Zuber, Mohammad; Shah, Sayyed Asim Ali; Jamil, Tahir; Asghar, Muhammad Irfan


    The surface of the cellulosic fabrics was modified using self-prepared emulsions of polyurethane acrylate copolymers (PUACs). PUACs were prepared by varying the molecular weight of polycaprolactone diol (PCL). The PCL was reacted with isophorone diisocyanate (IPDI) and chain was extended with 2-hydroxy ethyl acrylate (HEA) to form vinyl terminated polyurethane (VTPU) preploymer. The VTPU was further co-polymerized through free radical polymerization with butyl acrylate in different proportions. The FT-IR spectra of monomers, prepolymers and copolymers assured the formation of proposed PUACs structure. The various concentrations of prepared PUACs were applied onto the different fabric samples using dip-padding techniques. The results revealed that the application of polyurethane butyl acrylate copolymer showed a pronounced effect on the tear strength and pilling resistance of the treated fabrics.

  14. Biocompatibility of acrylic resin after being soaked in sodium hypochlorite

    Directory of Open Access Journals (Sweden)

    Nike Hendrijatini


    Full Text Available Background: Acrylic resin as basic material for denture will stay on oral mucosa for a very long time. The polymerization of acrylic resin can be performed by conventional method and microwave, both produce different residual monomer at different toxicity. Acrylic resin can absorb solution, porous and possibly absorb disinfectantt as well, that may have toxic reaction with the tissue. Sodium Hypochlorite as removable denture disinfectant can be expected to be biocompatible to human body. The problem is how biocompatible acrylic resin which has been processed by conventional method and microwave method after being soaked in sodium hypochlorite solution. Purpose: The aim of this study was to understand in vitro biocompatibility of acrylic resin which has polimerated by conventional method and microwave after being soaked in sodium hypochlorite using tissue culture. Methods: Four groups of acrylic resin plate were produced, the first group was acrylic resin plate with microwave polymeration and soaked in sodium hypochlorite, the second group was acrylic resin plate with microwave polymeration but not soaked, the thirdwas one with conventional method and soaked and the last group was one with conventional method but not soaked, and in 1 control group. Each group consists of 7 plates. Biocompatibility test was performed in-vitro on each material using fibroblast tissue culture (BHK-21 cell-line. Result: The percentage between living cells and dead cells from materials which was given acrylic plate was wounted. The data was analyzed statistically with T test. Conclusion: The average value of living cells is higher in acrylic resin poimerization using microwave method compared to conventional method, in both soaked and non soaked (by sodium hypochlorite group. This means that sodium hypochlorite 0.5% was biocompatible to the mouth mucosa as removable denture disinfectant for 10 minutes soaking and washing afterwards.

  15. Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    NARCIS (Netherlands)

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.


    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  16. Epoxy-acrylic core-shell particles by seeded emulsion polymerization. (United States)

    Chen, Liang; Hong, Liang; Lin, Jui-Ching; Meyers, Greg; Harris, Joseph; Radler, Michael


    We developed a novel method for synthesizing epoxy-acrylic hybrid latexes. We first prepared an aqueous dispersion of high molecular weight solid epoxy prepolymers using a mechanical dispersion process at elevated temperatures, and we subsequently used the epoxy dispersion as a seed in the emulsion polymerization of acrylic monomers comprising methyl methacrylate (MMA) and methacrylic acid (MAA). Advanced analytical techniques, such as scanning transmission X-ray microscopy (STXM) and peak force tapping atomic force microscopy (PFT-AFM), have elucidated a unique core-shell morphology of the epoxy-acrylic hybrid particles. Moreover, the formation of the core-shell morphology in the seeded emulsion polymerization process is primarily attributed to kinetic trapping of the acrylic phase at the exterior of the epoxy particles. By this new method, we are able to design the epoxy and acrylic polymers in two separate steps, and we can potentially synthesize epoxy-acrylic hybrid latexes with a broad range of compositions.


    Directory of Open Access Journals (Sweden)

    Maya Lyapina


    Full Text Available A multitude of acrylic monomers is used in dentistry, and when dental personnel, patients or students of dental medicine become sensitized, it is of great importance to identify the dental ;acrylic preparations to which the sensitized individual can be exposed. Numerous studies confirm high incidence of sensitization to (meth acrylates in dentatal professionals, as well as in patients undergoing dental treatment and exposed to resin-based materials. Quite a few studies are available aiming to evaluate the incidence of sensitization in students of dental medicineThe purpose of the study is to evaluate the incidence of contact sensitization to some (meth acrylates in students of dental medicine at the time of their education, in dental professionals (dentists, nurses and attendants and in patients, the manifestation of co-reactivity.A total of 139 participants were included in the study, divided into four groups: occupationally exposed to (methacrylates and acrylic monomers dental professionals, 3-4 year-of-education students of dental medicine, 6th year–of-education students of dental medicine and patients with suspected or established sensitization to acrylates, without occupational exposure. All of them were patch-tested with methyl methacrylate (MMA, triethyleneglycol dimethacrylate (TREGDMA, ethyleneglycol dimethacrylate (EGDMA, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy phenyl]propane (bis-GMA, 2-hydroxyethyl methacrylate (2-HEMA, and tetrahidrofurfuril metacrylate. The overall sensitization rates to methacrylates in the studied population are comparative high – from 25.9% for MMA to 31.7% for TREGDMA. Significantly higher incidence of sensitization in the group of 3-4 course students compared to the one in the group of dental professionals for MMA and TREGDMA was observed. Highest was the incidence of sensitization to ethyleneglycol dimethacrylate, BIS-GMA, 2-HEMA and tetrahydrofurfuryl methacrylate in the group of patients, with


    Institute of Scientific and Technical Information of China (English)

    ZHOU Maotang; LI Qian; XU Jiping


    Acrylamide-sodium acrylate copolymer hydrogels have been obtained by radiation techniques.Two different methods have been used to introduce -COONa groups into polymer chains of the gels: (1) by partial hydrolysis of acrylamide homopolymer gel; (2) by direct copolymerization and crosslinking of acrylamide and sodium acrylate in aqueous solutions. It was found that the gels obtained in different ways had different properties, the swelling character of the gels obtained by partial hydrolysis were more sensitive to pH of swelling aqueous media. In order to explain these differences,13 C-NMR techniques were used to investigate the sequence distribution of monomer units of both gels.

  19. Radiation Induced Crosslinking of Polyethylene in the Presence of Bifunctional Vinyl Monomers

    DEFF Research Database (Denmark)

    Joshi, M. S.; Singer, Klaus Albert Julius; Silverman, J.


    Several reports have been published showing that the radiation induced grafting of bifunctional vinyl monomers to low density polyethylene results in a product with an unusually high density of crosslinks. The same grafting reactions are shown to reduce the incipient gel dose by more than a factor...... of fifty. This paper is concerned with the apparent crosslinking produced by the radiation grafting of two monomers to polyethylene: acrylic acid and acrylonitrile....

  20. Photoinduced Graft-Polymerization of Acrylic Acid on Polyethylene and Polypropylene Surfaces: Comparative Study Using IR-ATR Spectroscopy (United States)

    Gorbachev, A. A.; Tretinnikov, O. N.; Shkrabatovskaya, L. V.; Prikhodchenko, L. K.


    Photoinduced graft-polymerization of acrylic acid on the surface of polyethylene and polypropylene films containing a photoinitiator pre-adsorbed from a thin layer of non-de-aerated aqueous monomer solution was investigated. Data about the monomer conversion and grafting depth as functions of the UV irradiation time and polymer nature were obtained using IR-ATR spectroscopy.

  1. Application of reactive acrylate microgels in water-base coatings

    Institute of Scientific and Technical Information of China (English)

    SA Sheng-shu; ZHANG Bao-hua; YANG Qing; WANG Xia-qin; MAO Zhi-ping


    Reactive acrylate microgels with different reactive groups such as carboxyl, hydroxide groups had excellent prop-erties such as quick-dry, low viscosity, high adhesion and hardness, which made them extensively used in preparing paints or in coating-modification. Reactive acrylate microgels were prepared by emulsion co-polymerization with zwitterions surfactant, anionic surfactant and nonionic surfactant as co-emulsifier. The water-base baking paints made from reactive acrylate micro-gels and melamine-formaldehyde resin had excellent combination properties. The aluminium powder can be well-dispersed in the paints. The influences of monomer components on the properties of the water-base baking paints were discussed in this paper. And the baking paints were also compared with the marketing solvent acrylate baking paints. It was found that the water-base acrylate amino baking paints had better combination properties than the organic solvent acrylate baking paints, which means that the water-base baking paints had a bright marketing future.

  2. Effect of post-polymerization heat treatments on the cytotoxicity of two denture base acrylic resins


    Janaina Habib Jorge; Eunice Teresinha Giampaolo; Carlos Eduardo Vergani; Ana Lúcia Machado; Ana Cláudia Pavarina; Iracilda Zeppone Carlos


    INTRODUCTION: Most denture base acrylic resins have polymethylmethacrylate in their composition. Several authors have discussed the polymerization process involved in converting monomer into polymer because adequate polymerization is a crucial factor in optimizing the physical properties and biocompatibility of denture base acrylic resins. To ensure the safety of these materials, in vitro cytotoxicity assays have been developed as preliminary screening tests to evaluate material biocompatibil...

  3. Real-time monitoring of the penetration of amphiphilic acrylate copolymer in leather using a fluorescent copolymer as tracer. (United States)

    Du, Jin-Xia; Shi, Lu; Peng, Bi-Yu


    A fluorescent tracer, poly (acrylic-co-stearyl acrylate-co-3-acryloyl fluorescein) [poly (AA-co-SA-co-Ac-Flu)], used for real-time monitoring the penetration of amphiphilic acrylate copolymer, poly (acrylic-co-stearyl acrylate) [poly (AA-co-SA)], in leather was synthesized by radical polymerization of acrylic, stearyl acrylate and fluorescent monomer, 3-acryloyl fluorescein (Ac-Flu). The structure, molecular weight, introduced fluorescent group content and fluorescent characteristics of the fluorescent tracer and target copolymer, amphiphilic acrylate copolymer, were also characterized. The results show that the tracer presents the similar structural characteristics to the target and enough fluorescence intensity with 1.68 wt % of the fluorescent monomer introduced amount. The vertical section of the leather treated with the target copolymer mixing with 7% of the tracer exhibits evident fluorescence, and the change of fluorescence intensity along with the vertical section with treating time increasing can reflect the penetration depth of the target copolymer. The introduction of the fluorescent group in polymer structure through copolymerization with a limited amount of fluorescent monomer, Ac-Flu, is an effective way to make a tracer to monitor the penetration of the target in leather, which provides a new thought for the penetration research of syntans such as vinyl copolymer materials in leather manufacture.

  4. Polymerization of acrylic acid using atmospheric pressure DBD plasma jet (United States)

    Bashir, M.; Bashir, S.


    In this paper polymerization of acrylic acid was performed using non thermal atmospheric pressure plasma jet technology. The goal of this study is to deposit organic functional coatings for biomedical applications using a low cost and rapid growth rate plasma jet technique. The monomer solution of acrylic acid was vaporized and then fed into the argon plasma for coating. The discharge was powered using a laboratory made power supply operating with sinusoidal voltage signals at a frequency of 10 kHz. The optical emission spectra were collected in order to get insight into the plasma chemistry during deposition process. The coatings were characterized using Fourier transform infrared spectroscopy, atomic force microscopy and growth rates analysis. A high retention of carboxylic functional groups of the monomer was observed at the surface deposited using this low power technique.

  5. Investigation of hydrogen atom addition to vinyl monomers by time resolved ESR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Beckert, D.; Mehler, K.


    By means of time resolved ESR spectroscopy in the microsecond time scale the H atom addition to different vinyl monomers was investigated. The H atoms produced by pulse radiolysis of aqueous solutions show a strong recombination CIDEP effect which also allows the recombination rate constant of H atoms to be determined. By analysis of ESR time profiles with the modified Bloch equations the relaxation times T/sub 1/, T/sub 2/, the polarization factors and the chemical rate constants with scavengers were obtained. Besides the H atom addition rate constants to different vinyl monomers the structure of the monomer radical was determined for acrylic acid.

  6. Penelitian penggunaan monomer n-butil akrilat untuk peningkatan mutu kulit secara iradiasi

    Directory of Open Access Journals (Sweden)

    Dwi Wahini Nurhajati


    Full Text Available Research on the utilization of n-butyl acrylate monomer for quality improvement leather by irradiation cobalt-60 gamma-rays is carried out as follows: Javanese crust hide was impregnated with water emulsions of n-butyl acrylate monomer for 2 hours, packed in to poly ethylene bags, sealed, then irradiated by cobalt-60 gamma rays (doses : 5 to 25 kGy. The irradiated leather was washed by water, dried and then physical tested. The results of physical test of leather modified with n-butyl acrylate showed the increasing of tensile strength and elongation, decreasing of water absorption, resistance against the flexing test of 20,000 times, and PH was constant. Organoleptic test showed that the softly of the modified leather was no different with unmodified leather.

  7. Sucrose Metabolism in Plastids

    NARCIS (Netherlands)

    Gerrits, N.; Turk, S.C.H.J.; Dun, van K.P.M.; Hulleman, H.D.; Visser, R.G.F.; Weisbeek, P.J.; Smeekens, S.C.M.


    The question whether sucrose (Suc) is present inside plastids has been long debated. Low Suc levels were reported to be present inside isolated chloroplasts, but these were argued to be artifacts of the isolation procedures used. We have introduced Suc-metabolizing enzymes in plastids and our experi

  8. Relations structure-propriétés et résistance à l’endommagement de vernis acrylate photo-polymérisables pour substrats thermoplastiques : évaluation de monomères bio-sourcés et de nano-charges



    The aim of this work was to develop 100% solids photo-polymerizable acrylate coatings, intended to protect thermoplastic pieces made of polycarbonate against mechanical damage, in particular scratches. The relationships between the composition, the structure and the properties of these coatings were examined. For this purpose the morphology, the thermomechanical properties and the scratch resistance of the materials, assessed by micro-scratch tests, were studied. The kinetics of the polymer n...

  9. Influence of Solvent Conditons on Average Relative Molecular Weight of Polyoctadecyl Acrylate

    Institute of Scientific and Technical Information of China (English)

    JiangQingzhe; SongZhaozheng; KeMing; ZhaoMifu


    Polymerization of octodecyl acrylate is studied in four solvents -- carbon tetrachloride, chloroform,methylbenzene and tetrachloroethane. Experimental results indicate that the sequence of chain transfer constants in solvents is: carbon tetrachloride>chloroform>methylbenzene>tetrachloroethane in the polymerization of octadecyl acrylate. Influences of four solvents on solubility of polyoctadecyl acrylate prove not the same. In chloroform,polyoctadecyl acrylate shows the highest relative viscosity and the lowest chain termination rate constant. In higher conversion, the average relative molecular weight of polyoctadecyl acrylate depends mainly on the chain transfer constant of the solvent. Under the circumstance of monomer conversion higher than 30%, the viscosity effect induced by polymeric molecular shape in the solvents have a strong influence on the relative molecular weight of the polymer obtained.

  10. The Influence of the Constitution of Acrylate Copolymers on Electrochromic Properties of Their Pan Composite Coatings

    Institute of Scientific and Technical Information of China (English)


    Several polyacrylate matrixes were prepared with monomers such as methyl methacrylate,KH-570,acrylic acid and butyl acrylate,and the electrochromic behavior of their soluble Pan composite coatings was also studied by electrochemical analysis and spectrophotometry.It shows that the constitution of the polymer matrixes have great effects on the electrochromic process and the color change of the composite coatings.When the matrix consists of acrylic acid unit,Pan of both interior and exterior composite possesses the same electrochemical reactivity,shorter responding time and wider color-changing range.But it is contrary when matrixes contain no acrylic acid.Furthermore,the composite containing acrylic acid units has still electrochemical reactivity in distilled water instead of LiClO4-PC electrolyte.

  11. Comparison of Candida Albicans Adherence to Conventional Acrylic Denture Base Materials and Injection Molding Acrylic Materials

    Directory of Open Access Journals (Sweden)

    Masoomeh Aslanimehr


    Full Text Available Statement of the Problem: Candida species are believed to play an important role in initiation and progression of denture stomatitis. The type of the denture material also influences the adhesion of candida and development of stomatitis. Purpose: The aim of this study was comparing the adherence of candida albicans to the conventional and injection molding acrylic denture base materials. Materials and Method: Twenty injection molding and 20 conventional pressure pack acrylic discs (10×10×2 mm were prepared according to their manufacturer’s instructions. Immediately before the study, samples were placed in sterile water for 3 days to remove residual monomers. The samples were then sterilized using an ultraviolet light unit for 10 minutes. 1×108 Cfu/ml suspension of candida albicans ATCC-10231 was prepared from 48 h cultured organism on sabouraud dextrose agar plates incubated at 37oC. 100 μL of this suspension was placed on the surface of each disk. After being incubated at 37oC for 1 hour, the samples were washed with normal saline to remove non-adherent cells. Attached cells were counted using the colony count method after shaking at 3000 rmp for 20 seconds. Finally, each group was tested for 108 times and the data were statistically analyzed by t-test. Results: Quantitative analysis revealed that differences in colony count average of candida albicans adherence to conventional acrylic materials (8.3×103 comparing to injection molding acrylic resins (6×103 were statistically significant (p<0.001. Conclusion: Significant reduction of candida albicans adherence to the injection acrylic resin materials makes them valuable for patients with high risk of denture stomatitis.

  12. Comparison of Candida Albicans Adherence to Conventional Acrylic Denture Base Materials and Injection Molding Acrylic Materials (United States)

    Aslanimehr, Masoomeh; Rezvani, Shirin; Mahmoudi, Ali; Moosavi, Najmeh


    Statement of the Problem: Candida species are believed to play an important role in initiation and progression of denture stomatitis. The type of the denture material also influences the adhesion of candida and development of stomatitis. Purpose: The aim of this study was comparing the adherence of candida albicans to the conventional and injection molding acrylic denture base materials. Materials and Method: Twenty injection molding and 20 conventional pressure pack acrylic discs (10×10×2 mm) were prepared according to their manufacturer’s instructions. Immediately before the study, samples were placed in sterile water for 3 days to remove residual monomers. The samples were then sterilized using an ultraviolet light unit for 10 minutes. 1×108 Cfu/ml suspension of candida albicans ATCC-10231 was prepared from 48 h cultured organism on sabouraud dextrose agar plates incubated at 37oC. 100 μL of this suspension was placed on the surface of each disk. After being incubated at 37oC for 1 hour, the samples were washed with normal saline to remove non-adherent cells. Attached cells were counted using the colony count method after shaking at 3000 rmp for 20 seconds. Finally, each group was tested for 108 times and the data were statistically analyzed by t-test. Results: Quantitative analysis revealed that differences in colony count average of candida albicans adherence to conventional acrylic materials (8.3×103) comparing to injection molding acrylic resins (6×103) were statistically significant (pcandida albicans adherence to the injection acrylic resin materials makes them valuable for patients with high risk of denture stomatitis. PMID:28280761

  13. Sugar (sucrose) holograms (United States)

    Ponce-Lee, E. L.; Olivares-Pérez, A.; Fuentes-Tapia, I.


    Computer holograms made with sugar crystals are reported. This material is well known as a good sweetener; the sugar from sugar cane or sugar beet (sucrose). These sweetener can be applied as honey "water and diluted sugar" easily on any substrate such as plastics or glasses without critical conditions for developed process. This step corresponds only to the cured sucrose as a photopolymer process. The maximum absorption spectra is localized at UV region λ=240 nm. We record with lithographic techniques some gratings, showing a good diffraction efficiency around 45%. This material has good resolution to make diffraction gratings. These properties are attractive because they open the possibility to make phase holograms on candies. Mainly the phase modulation is by refraction index.

  14. Acrylic mechanical bond tests

    Energy Technology Data Exchange (ETDEWEB)

    Wouters, J.M.; Doe, P.J.


    The tensile strength of bonded acrylic is tested as a function of bond joint thickness. 0.125 in. thick bond joints were found to posses the maximum strength while the acceptable range of joints varied from 0.063 in. to almost 0.25 in. Such joints are used in the Sudbury Neutrino Observatory.

  15. Polymerisation by acrylamide and acrylic acid inverse suspension

    Directory of Open Access Journals (Sweden)

    Sergio Alejandro LLoreda Blanco


    Full Text Available This work describes polymerisation by inverse suspension of acrylamide monomers and acrylic acid for forming homopolymers or copolymers This type of polymersitaion's advantages are described and reasons given for why it should be studied. The article stresses the importance of these types of monomer for obtaining materials presenting great affinity for water, such as super-absorbents and controlled liberation mechanism. Important aspects are presented such as type of initiation, monomer composition and continuous phase composition; parameters are described offering an important basis for formulating a system leading to successfully obtaining the desired materials' most relevant characteristics such as particle distribution and size polymerisation kinetics, conversion and water absorption capacity respecting the system's modifiable parameters. The foregoing is important since the product can be modified, bestowing propierties on it which are suitable for its use.

  16. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    Directory of Open Access Journals (Sweden)

    Bojanić Vaso


    Full Text Available Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP, cellulose-poly-1- vinylimidazole (Cell-PVIm and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P and cellulose-poly-9-vinylcarbazole (Cell-P9VK were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass% were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted

  17. Poly(amide-graft-acrylate) interfacial compounds (United States)

    Zamora, Michael Perez

    Graft copolymers with segments of dissimilar chemistries have been shown to be useful in a variety of applications as surfactants, compatibilizers, impact modifiers, and surface modifiers. The most common route to well defined graft copolymers is through the use of macromonomers, polymers containing a reactive functionality and thus capable of further polymerization. However, the majority of the studies thus far have focused on the synthesis of macromonomers capable of reacting with vinyl monomers to form graft copolymers. This study focused on the synthesis of macromonomers capable of participating in condensation polymerizations. A chain transfer functionalization method was utilized. Cysteine was evaluated as a chain transfer agent for the synthesis of amino acid functionalized poly(acrylate) and poly(methacrylate) macromonomers. Low molar mass, functionalized macromonomers were produced. These macromonomers were proven to be capable of reacting with amide precursors to form poly(amide-g-acrylate) graft copolymers. Macromonomers and graft copolymers were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, elemental analysis (EA), inductively coupled plasma (ICP), and differential scanning calorimetry (DSC). The second part of this research involved poly(dimethacrylate) dental restorative materials. Volumetric shrinkage during the cure of these resins results in a poor interface between the resin and the remaining tooth structure, limiting the lifetime of these materials. Cyclic anhydrides were incorporated into common monomer compositions used in dental applications. Volume expansion from the ring opening hydrolysis of these anhydrides was shown to be feasible. The modified dental resins were characterized by swelling, extraction and ultraviolet spectroscopy (UV), and density measurements. Linear poLymers designed to model the crosslinked dental resins were

  18. Synthesis of insecticidal sucrose esters

    Institute of Scientific and Technical Information of China (English)

    Song Zi-juan; Li Shu-jun; Chen Xi; Liu Li-mei; Song Zhan-qian


    Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48:1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg·mL-1. The mortality of first-instar larvae ofLymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg·mL-1 after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates.

  19. Mechanisms of action of (meth)acrylates in hemolytic activity, in vivo toxicity and dipalmitoylphosphatidylcholine (DPPC) liposomes determined using NMR spectroscopy. (United States)

    Fujisawa, Seiichiro; Kadoma, Yoshinori


    We investigated the quantitative structure-activity relationships between hemolytic activity (log 1/H(50)) or in vivo mouse intraperitoneal (ip) LD(50) using reported data for α,β-unsaturated carbonyl compounds such as (meth)acrylate monomers and their (13)C-NMR β-carbon chemical shift (δ). The log 1/H(50) value for methacrylates was linearly correlated with the δC(β) value. That for (meth)acrylates was linearly correlated with log P, an index of lipophilicity. The ipLD(50) for (meth)acrylates was linearly correlated with δC(β) but not with log P. For (meth)acrylates, the δC(β) 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 (meth)acrylates and DPPC liposomes in cell membrane molecular models was investigated using (1)H-NMR spectroscopy and differential scanning calorimetry (DSC). The log 1/H(50) 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 (meth)acrylates.


    Institute of Scientific and Technical Information of China (English)

    WANG Wenjun; YU Zaizhang; LI Bogeng; PAN Zuren


    The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA),2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate(HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solidcontent. The effects of monomer emulsion feed rates (Ra) and (R/E)E values, the ratio ofemulsifier amount between the initial charge (R) and the addition monomer emulsion (E) ,on the polymerization reaction features, the viscosities, surface tensions,particle sizes andparticle sizes distributions of latexes,Tg and the insoluble fractions of films, the 180° peelstrength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, preparedfrom the latexes, were studied. Experimental study shows that the grafting and cross-linking fraction in the PSA tapes must be controlled within a suitable range to keep thebalance of the 180° peel strength, tack and holding power.

  1. Radiation-induced graft copolymerization of binary monomer mixture containing acrylonitrile onto polyethylene films (United States)

    Choi, Seong-Ho; Nho, Young Chang


    Graft copolymerization of acrylonitrile (AN)/acrylic acid (AA), acrylonitrile (AN)/methacrylic acid (MA), and acrylonitrile (AN)/glycidyl methacrylate (GMA) onto pre-irradiated polyethylene (PE) films were studied. The effect of reaction conditions such as solvents, additives, and monomer composition on the grafting yields was investigated. The extent of grafting was found to increase with increasing sulfuric acid concentration when sulfuric acid as an additive was added to the grafting solution. In AN/AA mixture, the proportion of acrylonitrile in the copolymer increased with an increasing AN component in feed monomers. On the other hand, in AN/MA mixture, acrylonitrile component in copolymer was very slight in spite of the increase AN component in feed monomers. In the AN/GMA mixture, the proportion of acrylonitrile in the copolymer increased with increasing acrylonitrile component in AN/GMA feed monomer.

  2. Preparation of Styrene-acrylate Latex Used in Ultra-low VOC Building Internal Wall Coating

    Institute of Scientific and Technical Information of China (English)

    CHEN Lijun; WU Fengqin; ZHUANG Xinyu; YANG Jian; LI Rongxian


    Styrene-acrylate latex with high glass transition temperature(Tg),low minimum film forming temperature(MFT)and good stability was prepared via core-shell emulsion polymerization.With semicontinuous process,high conversion rate of monomer and low gel rate were achieved.The weight ratio of core monomer to shell monomer was approximately 1.35.It is found that many factors such as emulsifiers,initiators,reaction temperature,pH value and polymerization technology have influences on the permormance of styrene-acrylate latex.The prepared latex was characterized by TEM and FTIR.The obtained latex with T of20.57℃,MFT of 5.0℃,and good stability,had good stability of film forming.

  3. Emulsion polymerization of polystyrene-co-acrylic acid with Cu2O incorporation (United States)

    Fahmiati, Sri; Harmami, Sri Budi; Meliana, Yenny; Haryono, Agus


    In this research, poly(styrene-co-acrylic acid-Cu) was prepared via emulsion polymerization.Cu contents were varied as 10%, 15% and 20% and mol ratio of styrene to acrylic acid as 1:1 and 2:1. Structure and surface of poly(styrene-co-acrylic acid-Cu) were characterized by FTIR (Fourier Transformed Infra Red), NMR (Nuclear Magnetic Resonance), and SEM/EDX (Scanning Electron Microcope/ Energy Dispersive X-Ray) spectroscopy. The NMR spectra showed that the polymer was formed, however FTIR spectra showed that there were still unreacted monomers. SEM-EDX confirmed that copper (Cu) was dispersed uniformly on poly(styrene-co-acrylic acid-Cu) matrix.

  4. 大分子不饱和单体法合成具有核壳结构的丙烯酸酯/聚氨酯乳液及表征%Synthesis and Characterization of Core-shell Acrylic/ polyurethane Emulsion with Unsaturated Macromolecule Monomer Method

    Institute of Scientific and Technical Information of China (English)

    李昊; 陈广美; 陈炜; 张明月; 许戈文; 黄毅萍


    Acrylic/polyurethane ( PUA) hybrid emulsion has been prepared by water-borne polyurethane (WPU) modified with acrylic resin. A method for adding different mass fraction of acrylic ( AC) into polyurethane ( PU) polymers is proposed and verified through designed experiments. With increasing the polyacrylate(PA) mass fraction in the copolymer, the appearance of the emulsion changes from transparent to opacity, in the meantime, the particle size is increased. The TEM result reveals that PUA latex particles present clear core-shell structure and regular shape, and the size distribution is within the range of 60 ~ 120 nm. The results of FTIR indicate that the hydrogen bonding effect of PU hard segment first increased and then decreased, while the ordering of hard segment decreased with increasing the AC mass fraction. Compatibility and degree of mixing were developed under 75% AC added in copolymers. With increasing PA mass fraction, one glass transition temperature existed in the copolymers before the content of AC arrived 75%. Thermogravimetric analysis (TGA) shows that the temperatures for the maximal thermal mass-loss rate rose from 363 ℃ to 412℃ , and water absorption for samples decreased from 11. 3% to 5. 7% with the increase of AC fraction. Additionally, the elasticity modulus of PUA was raised from 16.4 to 47. 6 Mpa, while the tensile strength was increased from 9. 0 to 23. 7 Mpa, and the elongation at break changed from 365% to 408%. Furthermore, the composite latex viscosity is decresed, and the drying time is shortened, while glue film adhesion force becomes better.%采用丙烯酸酯(AC)对水性聚氮酯( WPU)进行改性,合成了接枝型丙烯酸酯/聚氨酯(PUA)复合乳液.随着共聚物中丙烯酸酯质量分数的增加,乳液外观由透明变为不透明,乳液粒径随之增大、分布变宽.TEM显示,PUA乳胶粒子呈现清晰的核壳结构,且形态规整,粒径分布在60~120 nm之间.FTIR测试表明,随着丙烯酸酯质量分数

  5. Ionic Liquid Epoxy Resin Monomers (United States)

    Paley, Mark S. (Inventor)


    Ionic liquid epoxide monomers capable of reacting with cross-linking agents to form polymers with high tensile and adhesive strengths. Ionic liquid epoxide monomers comprising at least one bis(glycidyl) N-substituted nitrogen heterocyclic cation are made from nitrogen heterocycles corresponding to the bis(glycidyl) N-substituted nitrogen heterocyclic cations by a method involving a non-nucleophilic anion, an alkali metal cation, epichlorohydrin, and a strong base.

  6. Theoretical investigation on functional monomer and solvent selection for molecular imprinting of tramadol (United States)

    Fonseca, Matheus C.; Nascimento, Clebio S.; Borges, Keyller B.


    The purpose of this Letter was to study for the first time the interaction process of tramadol (TRM) with distinct functional monomers (FM) in the formation of molecular imprinted polymer (MIP), using density functional theory (DFT) calculations at B3LYP/6-31G(d,p). As result we were able to establish that the best MIP synthesis conditions are obtained with acrylic acid as FM in 1:3 molar ratio and with chloroform as solvent. This condition presented the lowest stabilization energy for the pre-polymerization complexes. Besides, the intermolecular hydrogen bonds found between the template molecule and functional monomers play a primary role to the complex stability.

  7. Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

    Institute of Scientific and Technical Information of China (English)

    Li Hua LIU; Zhi Qiang LIU; Zhu Qing GONG


    The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and rDE and rNaAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.

  8. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)


    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  9. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.


    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  10. Self-initiation of UV photopolymerization reactions using tetrahalogenated bisphenol A (meth)acrylates. (United States)

    Pelras, Théophile; Knolle, Wolfgang; Naumov, Sergej; Heymann, Katja; Daikos, Olesya; Scherzer, Tom


    The potential of tetrachlorinated and tetrabrominated bisphenol A diacrylates and dimethacrylates for self-initiation of a radical photopolymerization was investigated. The kinetics of the photopolymerization of an acrylic model varnish containing halogenated monomers was studied by real-time FTIR spectroscopy, whereas the formation of reactive species and secondary products was elucidated by laser flash photolysis and product analysis by GC-MS after steady-state photolysis. The interpretation of the experimental data and the analysis of possible reaction pathways were assisted by quantum chemical calculations. It was shown that all halogenated monomers lead to a significant acceleration of the photopolymerization kinetics at a minimum concentration of 5 wt%. Steady-state and laser flash photolysis measurements as well as quantum chemical calculations showed that brominated and chlorinated samples do not follow the same pathway to generate radical species. Whereas chlorinated (meth)acrylates may cleave only at the C-O bonds of the carboxyl groups resulting in acrolein and oxyl radicals for initiation, brominated monomers may cleave either at the C-O bonds or at the C-Br bonds delivering aryl and bromine radicals. The quantum yields for the photolysis of the halogenated monomers were found to be in the order of 0.1 for acrylates and 0.2 for methacrylates (with an estimated error of 25%), independently of the attached Br and Cl halogens. Finally, the trihalogenated bisphenol A di(meth)acrylate radicals and the acrolein radicals were found to show the highest efficiencies for the reaction with another acrylic double bond leading to the formation of a polymer network.

  11. Monomer Migration and Annihilation Processes

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan; ZHUANG You-Yi


    We propose a two-species monomer migration-annihilation model, in which monomer migration reactions occur between any two aggregates of the same species and monomer annihilation reactions occur between two different species. Based on the mean-field rate equations, we investigate the evolution behaviors of the processes. For the case with an annihilation rate kernel proportional to the sizes of the reactants, the aggregation size distribution of either species approaches the modified scaling form in the symmetrical initial case, while for the asymmetrical initial case the heavy species with a large initial data scales according to the conventional form and the light one does not scale. Moreover,at most one species can survive finally. For the case with aconstant annihilation rate kernel, both species may scale according to the conventional scaling law in the symmetrical case and survive together at the end.

  12. Acrylic Acid and Esters Will Be Oversupply

    Institute of Scientific and Technical Information of China (English)

    Zheng Chengwang


    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  13. Optimization of acrylic acid grafting onto polypropylene using response surface methodology and its biodegradability (United States)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Kushwaha, Jai P.; Chaudhari, Chandrasekhar V.; Dubey, Kumar A.; Varshney, Lalit


    Simultaneous radiation grafting was optimized to graft acrylic acid monomer on the polypropylene (PP) films to make them hydrophilic and enhance their biodegradability. Experiments were designed based on full factorial central composite design (response surface methodology) and influence of monomer concentration, radiation dose, inhibitor concentration, solvent concentration on degree of grafting was investigated. The extent of grafting was found to increase with increasing monomer concentration, inhibitor concentration and radiation dose. The targeted 35% grafting could be achieved at optimum condition viz. monomer concentration 12.09 wt%, radiation dose 12.40 kGy, inhibitor concentration 0.07 M and solvent concentration 0.12 M. The grafted PP films at different degrees of grafting were tested for tensile properties and characterized by swelling studies, fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Successful grafting of acrylic acid onto polypropylene films was indicated by FTIR and confirmed quantitatively by determination of carboxylic groups on the film surface. Tensile strength of grafted PP films decreased with increase in degree of grafting. The crystallinity of the grafted PP films was lower than that of PP film as indicated by DSC studies. Grafting of acrylic acid increased the roughness on the surface of PP films indicated by SEM studies. The maximum biodegradability of the 34.55% grafted film was 5.5%.

  14. Synthesis of Acrylic Acid/Kaoline Powder Superabsorbent Composite by Inverse-suspending Polymerization

    Institute of Scientific and Technical Information of China (English)

    ZHONG Jin-feng; XUE Yi-ming; WU Ji-huai; LIN Jian-ming; WEI Yue-lin


    An acrylic acid/kaoline powder superabsorbent composite with a water absorbency of the superabsorbent composite about 1/800 was synthesized by inverse-suspending polymerization reaction between acrylic acid monomer and kaoline ultrafine powder. The influence of the dispersant agent on the configuration of the products in the inverse suspension polymerization is investigated. The influences of the kaoline powder, cross-linker, initiator, neutralization degree and the volume ratio of oil to water phase on the water absorbency of the superabsorbent composites are discussed in the paper.

  15. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter


    these biosolid/organic systems and thereby make a basis for further theoretical development with respect to filtration.   Poly(N-isopropylacrylamide-co-acrylic acid) microgels are synthesized by free-radical surfactant free emulsion polymerization as an organic model system for biosolids. The model system...... concentrations of acrylic acid as co-monomer. The microgels have a charge density between 0.2 and 0.9 mmol/g.   Preliminary filtration experiments show that filtration properties of the microgel model system significantly differs from the properties for inorganic colloidals such as titaniumdioxid....

  16. 27 CFR 21.131 - Sucrose octaacetate. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Sucrose octaacetate. 21....131 Sucrose octaacetate. (a) Sucrose octaacetate is an organic acetylation product occurring as a.... Sucrose octaacetate 98 percent minimum by weight when determined by the following procedure: Transfer...

  17. 21 CFR 172.869 - Sucrose oligoesters. (United States)


    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sucrose oligoesters. 172.869 Section 172.869 Food... Multipurpose Additives § 172.869 Sucrose oligoesters. Sucrose oligoesters, as identified in this section, may be safely used in accordance with the following conditions: (a) Sucrose oligoesters consist...

  18. Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

    Directory of Open Access Journals (Sweden)


    Full Text Available The acrylate monomer, 7-acryloyloxy-4-methyl coumarin (AMC has been synthesized by reacting 7-hydroxy-4-methyl coumarin, with acryloyl chloride in the presence of NaOH at 0–5°C. Copolymers of 7-acryloyloxy-4-methyl coumarin (AMC with vinyl acetate (VAc were synthesized in DMF (dimethyl formamide solution at 70±1°C using 2,2′-azobisisobutyronitrile (AIBN as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by Fourier transform infra red (FTIR spectroscopy. The copolymer composition was evaluated by 1H-NMR (proton nuclear magnetic resonance and was further used to determine reactivity ratios. The monomer reactivity ratios for AMC (M1-VAc (M2 pair were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 0.6924; r2 = 0.6431, Kelen-Tüdõs (r1 = 0.6776; r2 = 0.6374 and extended Kelen-Tüdõs (r1 = 0.6657; r2 = 0.6256. Thermo gravimetric analysis showed that thermal decomposition of the copolymers occurred in single stage in the temperature range of 263–458°C. The molecular weights of the polymers were determined using gel permeation chromatography. The homo and copolymers were tested for their antimicrobial properties against selected microorganisms.

  19. Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder:. Part I. Grafting conditions and grafting yield (United States)

    Aydinli, Bahattin; Tinçer, Teoman


    Monomers of some water-soluble polymers; acrylic acid, methacrylic acid, acrylamide, N, N -dimethyl acrylamide and 1-vinyl-2 pyrrolidone, were grafted on ultra-high molecular weight polyethylene (UHMWPE) powders by a direct grafting method in an aqueous medium in air. Inhibition of homopolymerisation was achieved by adding various concentrations of Fe 2+ or Cu 2+ ions. It was found that the degree of grafting increases linearly with dose till a gelation state is reached, and varies between 40 and 12% depending on the monomer. Four million molecular weight UHMWPE gave a higher per cent grafting than a 6 million counterpart for the monomers used, with the exception of acrylic acid monomer grafting.

  20. Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder: Part I. Grafting conditions and grafting yield

    Energy Technology Data Exchange (ETDEWEB)

    Aydinli, Bahattin; Tincer, Teoman E-mail:


    Monomers of some water-soluble polymers; acrylic acid, methacrylic acid, acrylamide, N, N-dimethyl acrylamide and 1-vinyl-2 pyrrolidone, were grafted on ultra-high molecular weight polyethylene (UHMWPE) powders by a direct grafting method in an aqueous medium in air. Inhibition of homopolymerisation was achieved by adding various concentrations of Fe{sup 2+} or Cu{sup 2+} ions. It was found that the degree of grafting increases linearly with dose till a gelation state is reached, and varies between 40 and 12% depending on the monomer. Four million molecular weight UHMWPE gave a higher per cent grafting than a 6 million counterpart for the monomers used, with the exception of acrylic acid monomer grafting. (author)

  1. Two decades of occupational (meth)acrylate patch test results and focus on isobornyl acrylate

    NARCIS (Netherlands)

    Christoffers, Wietske A; Coenraads, Pieter Jan; Schuttelaar, Marie-Louise A


    BACKGROUND: Acrylates constitute an important cause of occupational contact dermatitis. Isobornyl acrylate sensitization has been reported in only 2 cases. We encountered an industrial process operator with occupational contact dermatitis caused by isobornyl acrylate. OBJECTIVES: (i) To investigate


    Institute of Scientific and Technical Information of China (English)

    Des-hui Lu; Qi Wu; Xian-fu Lin


    A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymaticallyprepared monomer, 1′-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl adipate inanhydrous pyridine catalyzed by an alkaline protease from Bacillus subtilis at 60℃ for 7 days gave VAS (yield 55%) withoutany blocking/deblocking steps. The vinyl sucrose ester could be polymerized with potassium persulfate and H2O2 as initiatorto give poly(1′-O-vinyladipoyl-sucrose) with Mn = 33,000 and Mw = 53,200, Mw/Mn = 1.61. The polymer was biodegradable.After 6 days in aqueous buffer (pH 7), this alkaline protease could degrade poly(1′-O-vinyladipoyl-sucrose) to Mn of ca.1080, Mw/Mn = 3.30 (37℃), and Mn of ca. 5200, Mw/Mn = 2.44 (4℃). The polymer containing the sucrose branch would be afunctional material in various application fields.

  3. Determination of acrylamide monomer in polyacrylamide degradation studies by high-performance liquid chromatography. (United States)

    Ver Vers, L M


    A high-performance liquid chromatography method using C18 and ion-exchange columns in series is developed for the determination of acrylamide and acrylic acid monomers in polymeric samples. The C18 column acts as a guard column, trapping surfactants and impurities and retaining the nonionic species. The ion-exchange column then separates the monomers according to their respective ionic strengths. This method has been proven in the laboratory to work successfully for all types of acrylamide/acrylic acid polymers and matrices. Detection limits for both monomers can be achieved in the parts-per-billion range. The method is used to study the possible degradation of polyacrylamide to acrylamide monomer in the presence of glyphosate (a herbicide) and sunlight. Polyacrylamide is used as a spray drift reduction aid in combination with glyphosate. In normal applications, the polymer and herbicide are in contact with each other in the presence of sunlight. The results show that the polymer does not degrade to acrylamide in the presence of glyphosate or sunlight or any combination of the two. It is also observed that glyphosate influences the solubility of polyacrylamide, and care must be used when combining the two.

  4. RAFT copolymerization of itaconic anhydride and 2-methoxyethyl acrylate: a multifunctional scaffold for preparation of “clickable” gold nanoparticles

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Kasama, Takeshi; Jankova, Katja Atanasova


    RAFT copolymerization of 2-methoxyethyl acrylate and itaconic anhydride – a monomer derived from renewable resources – is carried out in a controlled fashion. The copolymer allows preparation of gold nanoparticles with abundant surficial carboxyl and alkyne functional groups that are dendronized ...

  5. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability (United States)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.


    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  6. Biocompatibility of alendronate-loaded acrylic cement for vertebroplasty

    Directory of Open Access Journals (Sweden)

    T Calvo-Fernández


    Full Text Available This paper reports a biological evaluation of a non-resorbable acrylic cement loaded with alendronate for the treatment of osteoporotic vertebral compression fractures. The cement formulation was based on polymethyl methacrylate and acrylic monomers; one of these had covalently linked vitamin E residues. The same cement in the absence of alendronate was used as a control. The setting of the charged cement presented a maximum polymerization temperature of 44ºC, a setting time of 24 min, a residual monomer content lower than 3 wt.%, a compressive strength of 99±10 MPa and an elastic modulus of 1.2±0.2 GPa. Cytotoxicity studies using human osteoblast cultures revealed that the leachable substances of the alendronate loaded cement collected between 1 and 7 days decreased cell viability to values lower than 80%. However, morphological changes and cellular damage in cells produced by the extracts decreased with the leak time. Cell adhesion and growth on charged cement was significantly lower than on the control. Implantation of the cement paste in the intra-femoral cavity of rabbits showed that initially the osteogenic activity was evident for the cement charged with alendronate, and the osteosynthesis process took place mainly in the trabeculae and was manifested by the presence of a non-mineralised osseous spicule. The interface between material and adjacent bone tissue was initially characterized by a variable fibrous response that in many cases it appeared reduced to thin connective tissue after a 24-week-period.

  7. Sucrose release from polysaccharide gels. (United States)

    Nishinari, Katsuyoshi; Fang, Yapeng


    Sucrose release from polysaccharide gels has been studied extensively because it is expected to be useful in understanding flavour release from solid foods and to find a new processing method which produces more palatable and healthier foods. We provide an overview of the release of sucrose and other sugars from gels of agar and related polysaccharides. The addition of sucrose to agar solutions leads to the increase in transparency of the resulting gels and the decrease in syneresis, which is attributed to the decrease in mesh size in gels. The syneresis occurring in the quiescent condition and fluid release induced by compression is discussed. The relationship between the sugar release and the structural, rheological and thermal properties of gels is also discussed. Finally, the future research direction is proposed.

  8. 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:; 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:


    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.

  9. Synthesis of radiation crosslinked poly(acrylic acid) in the presence of phenyltriethoxysilane (United States)

    Hassan, Safia; Yasin, Tariq


    Acrylic acid based superabsorbent hydrogel was prepared using phenyltriethoxysilane (PTES) as polyfunctional monomer. Different amounts of PTES were incorporated in acrylic acid and irradiated at different doses upto maximum of 30 kGy. The crosslinked acrylic acid showed hydrogel properties and its swelling kinetics, gel fraction and equilibrium degree of swelling (EDS) were studied. It was found that the increased PTES concentration decreased the EDS of the hydrogels. Infrared spectroscopy confirmed the crosslinking reaction between the feed components and the existence of siloxane bond. Thermogravimetric analysis showed an increase in the stability of the hydrogels having high PTES content. The swelling of the hydrogel was affected by pH, ionic strength and temperature. These hydrogels showed low swelling in acidic and basic pH range and high swelling around neutral pH. This switchable pH response of these hydrogels can be exploited in environmental and biomedical applications.

  10. Hybrid thiol-ene network nanocomposites based on multi(meth)acrylate POSS. (United States)

    Li, Liguo; Liang, Rendong; Li, Yajie; Liu, Hongzhi; Feng, Shengyu


    First, multi(meth)acrylate functionalized POSS monomers were synthesized in this paper. Secondly, FTIR was used to evaluate the homopolymerization behaviors of multi(meth)acrylate POSS and their copolymerization behaviors in the thiol-ene reactions with octa(3-mercaptopropyl) POSS in the presence of photoinitiator. Results showed that the photopolymerization rate of multimethacrylate POSS was faster than that of multiacrylate POSS. The FTIR results also showed that the copolymerizations were dominant in the thiol-ene reactions with octa(3-mercaptopropyl) POSS, different from traditional (meth)acrylate-thiol system, in which homopolymerizations were predominant. Finally, the resulted hybrid networks based on POSS were characterized by XRD, FE-SEM, DSC, and TGA. The characterization results showed that hybrid networks based on POSS were homogeneous and exhibited high thermal stability.

  11. Surface modification of cellulosic substrates via atmospheric pressure plasma polymerization of acrylic acid: Structure and properties (United States)

    Garcia-Torres, Jose; Sylla, Dioulde; Molina, Laura; Crespo, Eulalia; Mota, Jordi; Bautista, Llorenç


    Surface chemical modification of cellulose-based substrates has been carried out by atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD) of acrylic acid. The structure/properties relationship of the samples was studied as a function of the plasma experimental conditions. Acrylic acid monomer/helium ratio and treatment speed clearly influences the wettability properties of the paper substrate: advancing contact angle values were reduced to the half if compare to non-treated paper. Surface morphology of the films did not greatly vary at short polymerization times but fibers were covered by a poly(acrylic acid) film at longer times. FTIR and XPS techniques allowed detecting the retention of carboxylic acid groups/moieties. The possibility to quickly design architectures with tunable carboxylic functions by modifying the plasma processing parameters is shown.

  12. GENERAL: Cluster Growth Through Monomer Adsorption Processes (United States)

    Ke, Jian-Hong; Lin, Zhen-Quan; Chen, Xiao-Shuang


    We propose a monomer adsorption model, in which only the monomers are allowed to diffuse and adsorb onto other clusters. By means of the generalized rate equation we investigate the kinetic behavior of the system with a special rate kernel. For the system without monomer input, the concentration aj(t) of the Aj clusters (j > 1) asymptotically retains a nonzero quantity, while for the system with monomer input, it decays with time and vanishes finally. We also investigate the kinetics of an interesting model with fixed-rate monomer adsorption. For the case without monomer source, the evolution of the system will halt at a finite time; while the system evolves infinitely in time in the case with monomer source. Finally, we also suggest a connection between the fixed-rate monomer adsorption systems and growing networks.

  13. Comparative study between novel self cross-linking and conventional fluorinated acrylic latex

    Institute of Scientific and Technical Information of China (English)

    Li Jun Chen


    Novel self cross-linking fluorinated acrylic latex (SCLFAL) has been successfully prepared via starved seeded semi-batch emulsion polymerization. The resultant SCLFAL is characterized by Fourier transform infrared (FTTR) spectrometry. Contact angle (CA) and glass transition temperature (Tg) of the film are investigated. Results show that CA and Tg of the film can be improved when the moderate amount of HPMA is introduced into the mixed monomers.

  14. Sucrose compared with artificial sweeteners

    DEFF Research Database (Denmark)

    Sørensen, Lone Brinkmann; Vasilaras, Tatjana H; Astrup, Arne;


    There is a lack of appetite studies in free-living subjects supplying the habitual diet with either sucrose or artificially sweetened beverages and foods. Furthermore, the focus of artificial sweeteners has only been on the energy intake (EI) side of the energy-balance equation. The data are from...

  15. Development of a novel oxirane-acrylate composite restorative resin material (United States)

    Sripathi Panditaradhyula, Anuhya

    The need for resin with a long clinical life can be satiated through the novel formulation of varying concentrations of oxirane and acrylate monomers with an increase in filler loading in the sample, which will allow the creation of a resin that is less susceptible to chemical degradation along with improved mechanical properties. Various concentrations of oxirane and acrylate monomers with a three-component photoinitiation system, which is capable of both free radical (acrylate) and cationic (oxirane) initiation, are used. The resin composites were placed in the Speedmixer for 30 seconds and gravitation convection oven for one minute, repeated 5-7 times. The resin composites were used to create a 9.525 mm diameter * 1.5875 mm thick resin mold. The mold was then photocured for twenty seconds on both sides using VALO blue LED light. The Rockwell hardness and shore D durometer hardness served as relative measures of bonding between the monomers. The ideal formulation of oxirane and acrylate concentrations were used to perform the Instron 3 point bend test, as well as contact angle determination. The goal is to identify a resin with a clinical life twice that of the resins being used in practice. Potential findings include ideal oxirane and acrylate concentrations with the highest shore D durometer hardness, Rockwell hardness, contact angle values, and Instron 3 point bend test values. Ideal color, transparency and properties of the resin are taken into account. Optimization of oxirane and acrylate monomers, impact while using various filler components (salination, number of fillers), filler particle size variations and variations in using different filler concentrations are observed. Results of using micro and nano-sized monomers are also studied. Addition of fluorinated acrylate monomer to the micro and nano composite was the next goal. A comparison of all the above stated compositions to the control group 70/30 BisTEG was done. A study on the degradation behavior

  16. PMMA-based composite materials with reactive ceramic fillers: IV. Radiopacifying particles embedded in PMMA beads for acrylic bone cements. (United States)

    Abboud, M; Casaubieilh, L; Morvan, F; Fontanille, M; Duguet, E


    New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS) and embedded in poly(methylmethacrylate-co-ethylacrylate) beads with about 7 mol% of ethyl acrylate repeating units. The encapsulation was performed through a conventional suspension polymerization process. The influence of (i) the concentration of the dispersion stabilizer and (ii) the alumina content upon the shape, size, and size distribution of the acrylic beads was studied. Cements were prepared from each batch by hand-mixing alumina-filled acrylic beads with a liquid monomer mixture containing methyl methacrylate, n-butyl methacrylate, and N,N-dimethyl-p-toluidine. Benzoyl peroxide was previously added to the solid part. The powder-to-liquid ratio was equal to 2 for each formulation. Compressive strength of cured cement decreases with alumina content, whereas compressive modulus remains roughly constant. These results are in contradiction to those obtained for cements based on a mixture of gamma-MPS-treated alumina and unfilled acrylic beads. Nevertheless, they are interpreted in terms of alumina arrangement in the cement. In the first case, alumina particles contribute to the reinforcement of the dispersed acrylic phase, with poor benefits for the whole materials. In the second case, they allow the reinforcement of the continuous acrylic phase and, therefore, the cement's one.

  17. Kekuatan transversa resin akrilik hybrid setelah penambahan glass fiber dengan metode berbeda (The transverse strength of the hybrid acrylic resin after glass fiber reinforcement with different method

    Directory of Open Access Journals (Sweden)

    Intan Nirwana


    Full Text Available Different types of fibers have been added to acrylic resin materials to improve their mechanical properties. The purpose of this study was to know the transverse strength of the hybrid acrylic resins after glass fiber reinforcement with difference method. This study used rectangular specimens of 65 mm in length, 10 mm in width and 2.5 mm in thickness. There were 3 groups consisting of 6 specimens each, hybrid acrylic resin without glass fiber (control, glass fibers dipped in methyl methacrylate monomer for 15 minutes before being reinforced into hybrid acrylic resin (first method, glass fibers reinforced into a mixture of polymer powder and monomer liquid after the hybrid acrylic resin was mixed directly (second method. All of the specimens were cured for 20 minutes at 100° C. Transverse strength was measured using Autograph. The statistical analyses using one way ANOVA and LSD test showed that there were significant differences in transverse strength (p < 0.05 among the groups. The means of transverse strength were 94,94; 118,27; and 116,34 MPa. It meant that glass fibers reinforcement into hybrid acrylic resin enhanced their transverse strength compared with control. Glass fiber reinforcement into hybrid acrylic resin with differenciate method didn’t enhance their transverse strength.

  18. Polymerization of Polar Monomers from a Theoretical Perspective

    KAUST Repository

    Alghamdi, Miasser


    Density functional theory calculations have been used to investigate catalytic mechanism of polymer formation containing polar groups, from the synthesis of the monomer to the synthesis of the macromolecule. In the spirit of a sustainable and green chemistry, we initially focused attention on the coupling of CO2 as economically convenient and recyclable C1 source with C2H4 to form acrylate and/or butirro-lactone, two important polar monomers. In this process formation of a mettallolactone via oxidative coupling of CO2 and C2H4 is an important intermediate. Given this background, we explored in detail (chapter-3) several Ni based catalysts for CO2 coupling with C2H4 to form acrylate. In this thesis we report on the competitive reaction mechanisms (inner vs outer sphere) for the oxidative coupling of CO2 and ethylene for a set of 11 Ni-based complexes containing bisphosphine ligands. In another effort, considering incorporation of a C=C bond into a metal-oxygen-Functional-Group moiety is a challenging step in several polymerization reactions, we explored the details of this reaction (chapter4) using two different catalysts that are capable to perform this reaction in the synthesis of heterocycles. Specifically, the [Rh]-catalyzed intramolecular alkoxyacylation ([Rh] = [RhI(dppp)+] (dppp, 1,3-Bis-diphenylphosphino-propane), and the [Pd]/BPh3 intramolecular alkoxyfunctionalizations. Rest of the thesis we worked on understanding the details of the polymerization of polar monomers using organocatalysts based on N-heterocyclic carbenes (NHC) or N-heterocyclic olefins (NHO). In particular (chapter-5) we studied the polymerization of N-methyl N-carboxy- anhydrides, towards cyclic poly(N-substituted glycine)s, promoted by NHC catalysts. In good agreement with the experimental findings, we demonstrated that NHC promoted ring opening polymerization of N-Me N-Carboxyanhydrides may proceed via two different catalytic pathways. In a similar effort we studied polymerization of

  19. 21 CFR 184.1854 - Sucrose. (United States)


    ... Substances Affirmed as GRAS § 184.1854 Sucrose. (a) Sucrose (C12H22O11, CAS Reg. No. 57-50-11-1) sugar, cane sugar, or beet sugar is the chemical β-D-fructofuranosyl-α-D-glucopyranoside. Sucrose is obtained by... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sucrose. 184.1854 Section 184.1854 Food and...

  20. Isobornyl acrylate contact allergy: Rare or underdiagnosed?

    NARCIS (Netherlands)

    Christoffers, W.A.; Coenraads, P.J.; Schuttelaar, M.L.A.


    Background: Allergic contact dermatitis to isobornyl acrylate has been reported in only two cases in literature. Therefore, isobornyl acrylate is not part of a (meth) acrylates patch test series. At our department an industrial worker presented with therapy-resistant hand eczema and sensitizations f

  1. 40 CFR 721.2805 - Acrylate ester. (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under...

  2. Synthesis of a resin monomer-soluble polyrotaxane crosslinker containing cleavable end groups. (United States)

    Seo, Ji-Hun; Nakagawa, Shino; Hirata, Koichiro; Yui, Nobuhiko


    A resin monomer-soluble polyrotaxane (PRX) crosslinker with cleavable end groups was synthesized to develop degradable photosetting composite resins. The PRX containing 50 α-cyclodextrins (α-CDs) with disulfide end groups was initially modified with n-butylamine to obtain a resin monomer-soluble PRX. The PRX containing 13 n-butyl groups per α-CD molecule was completely soluble in conventional resin monomers such as 2-hydroxyethyl methacrylate (HEMA) and urethane dimethacrylate (UDMA). The synthesized n-butyl-containing PRX was further modified with 2-aminoethyl methacrylate to provide crosslinkable acrylic groups onto PRX. The prepared resin monomer-soluble PRX crosslinker was successfully polymerized with a mixture of HEMA and UDMA to provide photosetting plastic. It was confirmed that the Vickers hardness of the prepared plastic was greatly decreased after treatment with dithiothreitol. This indicates that the resin monomer-soluble PRX crosslinker can be applied to design degradable photosetting plastics potentially used in the industrial or biomedical field.

  3. Synthesis of a resin monomer-soluble polyrotaxane crosslinker containing cleavable end groups

    Directory of Open Access Journals (Sweden)

    Ji-Hun Seo


    Full Text Available A resin monomer-soluble polyrotaxane (PRX crosslinker with cleavable end groups was synthesized to develop degradable photosetting composite resins. The PRX containing 50 α-cyclodextrins (α-CDs with disulfide end groups was initially modified with n-butylamine to obtain a resin monomer-soluble PRX. The PRX containing 13 n-butyl groups per α-CD molecule was completely soluble in conventional resin monomers such as 2-hydroxyethyl methacrylate (HEMA and urethane dimethacrylate (UDMA. The synthesized n-butyl-containing PRX was further modified with 2-aminoethyl methacrylate to provide crosslinkable acrylic groups onto PRX. The prepared resin monomer-soluble PRX crosslinker was successfully polymerized with a mixture of HEMA and UDMA to provide photosetting plastic. It was confirmed that the Vickers hardness of the prepared plastic was greatly decreased after treatment with dithiothreitol. This indicates that the resin monomer-soluble PRX crosslinker can be applied to design degradable photosetting plastics potentially used in the industrial or biomedical field.

  4. The electrospinning of the copolymer of styrene and butyl acrylate for its application as oil absorbent. (United States)

    Xu, Naiku; Cao, Jipeng; Lu, Yuyao


    Electrospun polystyrene materials have been employed as oil absorbents, but they have visible drawbacks such as poor strength at low temperature and unreliable integrity because of brittleness and insufficient cohesive force among fibers. Butyl acrylate can polymerize into flexible chains, and its polymer can be used as elastomer and adhesive material. Thereby it is possible to obtain the material that has better performance in comparison with electrospun polystyrene material through the electrospinning of the copolymer of styrene and butyl acrylate. In this work, a polymer was synthesized through suspension polymerization by using styrene and butyl acrylate as comonomers. The synthesis of the copolymer of styrene and butyl acrylate was verified through dissolution and hydrolysis experimental data; as well through nuclear magnetic resonance spectrometry. The viscous flow activation energy of the solution consisting of copolymer and N, N-dimethylformamide was determined via viscosity method and then adopted to establish the entanglement characteristics of butyl acrylate's chain segments. Finally, in order to electrospin the copolymer solution into fibrous membrane, the effects of monomer feed ratio and spinning parameters were investigated. The prepared fibrous membrane was found to have a potential use as oil absorbent.

  5. Synthesis by Solution Polymerization of Polybehenyl Acrylate as Pour Point Depressant for Crude Oil

    Institute of Scientific and Technical Information of China (English)

    Song Zhaozheng; Ge Jijiang


    Behenyl acrylate is a kind of highly efficient pour point depressants. In order to promote the application of the pour pint depressant in transportation of crude oils, polybehenyl acrylate was synthesized by solution polymerization. These conclusions can be drawn from the experimental results that the sequence of chain transfer constants of four solvents is arranged in the following decreasing order: carbon tetrachloride (6.0×10-5)>chloroform (2.8×10-5)>methylbenzene (2.5×10-5)>tetrachloroethane (1.6×10-5). The average molecular weight of polybehenyl acrylate mainly depends on the chain transfer constant of the solvents. However, if the monomer conversion was higher than 35%, an abnormal phenomenon occurred, resulting in higher average molecular weight of polybehenyl acrylate obtained in methylbenzene solution compared to that obtained in tetrachloroethane solution. It was attributed to the influence of gelation on the average molecular weight of polybehenyl acrylate, which was stronger than the impact of chain transfer in methylbenzene.

  6. Electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite. (United States)

    Abdel-Halim, E S; Al-Deyab, Salem S


    This article describes the synthesis of an electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite hydrogel. The synthesis process started with grafting acrylic acid monomers onto the natural polymer guar gum by the use of ammonium persulphate as a free radical initiator in acid medium. Guar gum/poly(acrylic acid) graft copolymer was separated from the polymerization medium, purified and subjected to crosslinking treatment, using alkaline epichlorohydrin as a crosslinking agent. Silver nitrate solution was added during the crosslinking treatment in varying concentrations, that the reaction conditions affect crosslinking of guar gum/poly(acrylic acid) graft copolymer to a hydrogel, as well as reduction of silver nitrate to silver nanoparticles, giving rise to the formation of silver/guar gum/poly(acrylic acid) nanocomposite. Factors affecting the grafting reaction as well as those affecting the crosslinking/reduction treatment were optimized. The so synthesized nanocomposite hydrogel samples were fully characterized, regarding their contents of silver nanoparticles and swelling ratio. The electrical conductivity of the nanocomposite hydrogel was studied and it was found to be affected by the swelling ratio of the hydrogel as well as its content of silver nanoparticles.

  7. Comparison of impact strength of acrylic resin reinforced with kevlar and polyethylene fibres. (United States)

    Kamath, G; Bhargava, K


    The present study was done to evaluate the impact strengths of heat-activated acrylic resins reinforced with Kevlar fibres, polyethylene fibres and unreinforced heat activated acrylic resin. Each of three groups had 25 specimens. Brass rods of uniform length of 40 mm and diameter of 8 mm were used to prepare the moulds. A combination of long fibres (40 mm length) and short fibres (6 mm length) were used. The total amount of fibres incorporated was limited to 2% by weight of the resin matrix. Short and long fibres of equal weight were incorporated. The short fibres were mixed with polymer and monomer and packed into the mould, while, the long axis of the specimen, perpendicular to the applied force. The specimens were then processed. Impact strength testing was done on Hounsfield's impact testing machine. Kevlar fibre reinforced heat activated acrylic resin specimens recorded higher mean impact strength of 0.8464 Joules, while polyethylene fibres reinforced heat activated acrylic resin recorded mean impact strength of 0.7596 joules. The unreinforced heat activated acrylic resin recorded mean impact strength of 0.3440 Joules.

  8. Graft Polymerization of Acrylic Acid and Acrylamide onto BOPET Corona Films

    Institute of Scientific and Technical Information of China (English)

    SUN Jie; TIAN Hua-yu; BAI Yong-ping


    The graft polymerization of acrylic acid ( A ) and acrylamide (B) was carried out onto bi- ori ented polyester BOPET corona film. The influence of monomer concentration, reducer concentration and reaction time on the graft polymerization was investigated. The surface tension of the films increased with an increase of monomer concentration, till the concentration of monomer A reached 1.5 × 10-2 g/mL and the concentration of monomer B reached 4.0× 10-2 g/ mL. The surface tension of the films reached a maximum value at 7 × 10 4 M of reducer concentration and subsequently decreased with further increase in reducer concentration. The surface tension of the films increased with the increase of the reaction time apparently within 50min. The grafted corona BO PET films were characterized with IR and XPS. The presence of graft on the film surface was confirmed. The atten uation experiments on grafted corona BOPET films in air at 50℃ and in water were carried out to investigate the persistence of graft polymerization of acrylic acid and arylamide onto BOPET corona films.


    Institute of Scientific and Technical Information of China (English)

    Li Jia; Zong-hui Liu; De-qing Wei


    Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-freepolymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reactioncondition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in thehydrosols is 2%. The maximum weight average molecular weight (Mw) of polymer that assures soap-free emulsionconversion into hydrosol is about 1.2 × 105-1.3 × 105. The particle transforming process was investigated, and an obviouschange of particle diameter and morphology was observed.

  10. Preparation and space charge accumulation characteristics of acrylate-grafted polyethylenes using reaction extrusion; Hanno oshidashi ni yoru acrylate polyethylene no seizo to kukan denka chikuseki tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.; Okamoto, T. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Suh, K. [Korea University, Seoul (Korea, Republic of)


    Space charge accumulation characteristics of chemically modified polyethylenes which were grafted with acrylates like acrylic acid and n-butylacrylate using reactive extrusion were investigated. In LDPE-g-Acrylic Acid (LDPE-g-AA), it was showed that the heterocharge found in low-density polyethylenes (LDPE) decreased with the increase of acrylic acid graft ratio and changed to the homocharge formation above 0.1 wt% due to the introduction of carbonyls. Conduction currents and charge mobilities of LDPE-g-AA decreased with the increase of AA graft ratio, while the conduction mechanism remains unchanged. However, in the LDPE-g-n-Buthylacrylate (LDPE-g-nBA), the change of space charge accumulation characteristics were not observed and charge mobilities of them not affected by the graft ratio. The differences of space charge formation between two grafted polyethylenes were closely related to the ability of trap site in monomer grafted to LDPE and the chemical structure of it. 18 refs., 11 figs.

  11. Influencing Solvent Miscibility and Aqueous Stability of Aluminum Nanoparticles through Surface Functionalization with Acrylic Monomers (Postprint) (United States)


    unlimited. where wt % is the weight percentage due to loss of ligand as determined from TGA analysis and MW is the molecular weight for the ligand of...time intervals of 0.5, 1, 1.5, 2, 4, 8, and 16 h. TGA analysis was again used to determine the mass loss attributed to the respective ligands in each of

  12. Cutin and suberin monomers are membrane perturbants. (United States)

    Douliez, Jean-Paul


    The interaction between cutin and suberin monomers, i.e., omega -hydroxylpalmitic acid, alpha, omega -hexadecanedioic acid, alpha, omega --hexadecanediol, 12-hydroxylstearic acid, and phospholipid vesicles biomimicking the lipid structure of plant cell membranes has been studied by optical and transmission electron microscopy, quasielastic light scattering, differential scanning calorimetry, and (31)P solid-state NMR. Monomers were shown to penetrate model membranes until a molar ratio of 30%, modulating their gel to fluid-phase transition, after which monomer crystals also formed in solution. These monomers induced a decrease of the phospholipid vesicle size from several micrometers to about 300 nm. The biological implications of these findings are discussed.

  13. Copolymerization of Propylene and Polar Monomers Using Pd/IzQO Catalysts. (United States)

    Nakano, Ryo; Nozaki, Kyoko


    Palladium catalysts bearing imidazo[1,5-a]quinolin-9-olate-1-ylidene (IzQO) ligands polymerize α-olefins while incorporating polar monomers. The steric environment provided by N-heterocyclic-carbene (NHC) enables regioselective insertion of α-olefins and polar monomers, yielding polypropylene, propylene/allyl carboxylate copolymers, and propylene/methyl acrylate copolymer. Known polymerization catalysts bearing NHC-based ligands decompose rapidly, whereas the present catalyst is durable because of structural confinement, wherein the NHC-plane is coplanar to the metal square plane. The present catalyst system enables facile access to a new class of functionalized polyolefins and helps conceive a new fundamental principle for designing NHC-based ligands.

  14. Surface modification of commercial seawater reverse osmosis membranes by grafting of hydrophilic monomer blended with carboxylated multiwalled carbon nanotubes (United States)

    Vatanpour, Vahid; Zoqi, Naser


    In this study, modification of commercial seawater reverse osmosis membranes was carried out with simultaneous use of surface grafting and nanoparticle incorporation. Membrane grafting with a hydrophilic acrylic acid monomer and thermal initiator was used to increase membrane surface hydrophilicity. The used nanomaterial was carboxylated multiwalled carbon nanotubes (MWCNTs), which were dispersed in the grafting solution and deposited on membrane surface to reduce fouling by creating polymer brushes and hydrodynamic resistance. Effectiveness of the grafting process (formation of graft layer on membrane surface) was proved by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses. Increase of membrane surface hydrophilicity was approved with contact angle test. First, the grafting was performed on the membrane surfaces with different monomer concentrations, various contact times and several membrane curing times (three variables for optimization). The modified membranes were tested by a cross-flow setup using saline solution for permeability and rejection tests, and bovine serum albumin (BSA) solution for fouling test. The results showed that the modified membranes with 0.75 M of monomer, 3 min contact time and 80 min curing time in an oven at 50 °C presented the highest flux and lowest rejection decline related to the commercial reverse osmosis membrane. In the next step, the optimum grafting condition was selected and the nanotubes with different weight percentages were dispersed in the acrylic acid monomer solution. The membrane containing 0.25 wt% COOH-MWCNTs showed the highest fouling resistance.

  15. Synthesis and characterization of copolymers 4,5-dihydroisoxazole and (-)-menthyl acrylates; Sintese e caracterizacao de copolimeros de cadeia lateral derivados de acrilatos de 4,5-di-hidroisoxazol e do (-)-mentol

    Energy Technology Data Exchange (ETDEWEB)

    Passo, Joel A.; Merlo, Aloir A. [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Inst. de Quimica; Eccher, Juliana; Bechtold, Ivan H. [Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil). Campus Universitario Trindade. Dept. de Fisica; Kelly, Stephen M., E-mail: [University of Hull, Hull (United Kingdom). Dept. of Chemistry


    Five monomers 5-[4-(5-cyano-4,5-dihydroisoxazol-3-yl)phenoxy]undecyl acrylate (7a); n-alkyl 3-{l_brace}4-[5-(acryloyloxyundecyl)oxyphenyl]{r_brace}-4,5-dihydroisoxazole-5-carboxylate (7b,c for n-butyl and n-hexyl, respectively); 3-{l_brace}4-[5-(acryloyloxyundecyl) oxyphenyl]{r_brace}-4,5-dihydroisoxazole-5-carboxylic acid (7d) and (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl acrylate (9) and the corresponding copolymers 10a-d,11 and homopolymers 12 from 7a and 13 from 9 were designed and synthesized. Except for acrylate 9 which is derived from (-)-menthol, all of the monomers belong to the series containing the isoxazoline ring linked to the acrylate unit by a flexible spacer chain of eleven methylene units. They presented low glass temperature and despite birefringence behavior, these copolymers showed no mesomorphic properties. (author)

  16. Graft copolymerization of acrylic acid onto polyamide fibers (United States)

    Makhlouf, Chahira; Marais, Stéphane; Roudesli, Sadok


    The grafting of acrylic acid (AA) monomer (CH 2dbnd CH sbnd COOH) on polyamide 6.6 monofilaments (PA 6.6) using benzoyl peroxide (BPO) as initiator was carried out in order to enhance the hydrophilic nature of fibers. The grafting rate depends on the AA concentration, the BPO concentration, the time and the temperature of reaction. The best conditions for optimum rate of grafting were obtained with a AA concentration of 0.5 M, a BPO concentration of 0.03 M, a reaction temperature of T = 85 °C and a reaction time of 120 mn. The fiber surface has been investigated by many experimental techniques of characterization such as Fourier transform infrared spectroscopy (FTIR), calorimetric analysis (DSC), scanning electron microscopy (SEM), and contact angle measurements. The effect of grafting of acrylic acid onto PA 6.6 fibers on their moisture and mechanical resistances was analyzed from water sorption and elongation at break measurements. The analysis of the experimental data shows clearly the efficiency of the grafting reaction used, leading to a significant increase of the hydrophilic character of the PA 6.6 surface.

  17. Controlling monomer-sequence using supramolecular templates


    ten Brummelhuis, Niels


    The transcription and translation of information contained in nucleic acids that has been perfected by nature serves as inspiration for chemists to devise strategies for the creation of polymers with welldefined monomer sequences. In this review the various approaches in which templates (either biopolymers or synthetic ones) are used to influence the monomer-sequence are discussed.

  18. Polyelectrolyte properties of proteoglycan monomers (United States)

    Li, Xiao; Reed, Wayne F.


    Light scattering measurements were made on proteoglycan monomers (PGM) over a wide range of ionic strengths Cs, and proteoglycan concentrations [PG]. At low Cs there were clear peaks in the angular scattering intensity curve I(q), which moved towards higher scattering wave numbers q, as [PG]1/3. This differs from the square root dependence of scattering peaks found by neutron scattering from more concentrated polyelectrolyte solutions. The peaks remained roughly fixed as Cs increased, but diminished in height, and superposed I(q) curves yielded a sort of isosbestic point. Under certain assumptions the static structure factor S(q) could be extracted from the measured I(q), and was found to retain a peak. A simple hypothesis concerning coexisting disordered and liquidlike correlated states is presented, which qualitatively accounts for the most salient features of the peaks. There was evidence of a double component scattering autocorrelation decay at low Cs, which, when resolved into two apparent diffusion coefficients, gave the appearance of simultaneous ``ordinary'' and ``extraordinary'' phases. The extraordinary phase was ``removable,'' however, by filtering. At higher Cs the proteoglycans appear to behave as random nonfree draining polyelectrolyte coils, with a near constant ratio of 0.67 between hydrodynamic radius and radius of gyration. The apparent persistence length varied as roughly the -0.50 power of ionic strength, similar to various linear synthetic and biological polyelectrolytes. Electrostatic excluded volume theory accounted well for the dependence of A2 on Cs.

  19. Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang


    Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

  20. Determination of Residual Monomers in Polycarboxylate Superplasticizer Using High Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    GUO Liping; WANG Shaofeng; ZHANG Anfu; LEI Jiaheng; DU Xiaodi


    A procedure was developed for the determination of residual monomers in polycarboxylate superplasticizer (PCs) by reversed-phase high performance liquid chromatography (RP-HPLC). Four kinds of residual monomers were well separated and determined on a SinoChrom ODS-BP (C18) column with mobile phases composed of acetonitrile and phosphate buffer solution. The monomers were detected by UV detector at 205 nm and quantitatively analyzed with an external standard method. For those residual monomers, the linear response ranged from 4.0× 10-6 mol·L-1 to 2.0× 10-3 mol·L-1. The determination limit of acrylic acid, sodium methylallyl sulfonate and 2-Acrylamido-2-methylpropane sulfonic acid was 0.02× 10-5 mol·L-1, while that of methoxy-polyethylene glycol monoacrylate was 0.1 × 10-5 mol· L-1. The relative standard deviation (RSD) of high concentration samples was less than 1%, while that of the low concentration samples was between 1%-4%. The standard (additional) recovery ratio was 97.4% -104.2%.

  1. Development of ionic gels using thiol-based monomers in ionic liquid (United States)

    Ahmed, Kumkum; Naga, Naofumi; Kawakami, Masaru; Furukawa, Hidemitsu


    Ionic gels (IGs) using ionic liquids (ILs) can propose diverse applications in the field of optics, sensors and separation have opened wide prospects in materials science. ILs have attracted remarkable interest for gel polymer electrolytes and batteries based on their useful properties such as non-volatility, non-flammability, a wide electrochemical window, high thermal stability and a high ionic conductivity. The formation of gel in IL media makes it possible to immobilize ILs within organic or inorganic matrices and to take advantage of their unique properties in the solid state, thus eliminating some shortcomings related to shaping and risk of leakage. In this work for the first time we used multifunctional thiol monomers having uniform structure and good compatibility with the IL of our interest. Therefore we focused on developing thiol monomer-based IGs using multifunctional thiol monomers and acrylate crosslinkers utilizing thiol-ene reaction between monomer and crosslinking molecules in an IL medium and characterize their physico-chemical properties like thermal, conductive, mechanical properties etc.. This work has been focused mainly to improve the mechanical strength of IGs and make prospects of IGs in tribology and lubricants.

  2. Sucrose induces vesicle accumulation and autophagy. (United States)

    Higuchi, Takahiro; Nishikawa, Jun; Inoue, Hiroko


    It has been shown that the treatment of mammalian cells with sucrose leads to vacuole accumulation associated with lysosomes and upregulation of lysosomal enzyme expression and activity. Autophagy is an evolutionarily conserved homeostatic process by which cells deliver cytoplasmic material for degradation into lysosomes, thus it is probable that sucrose affects the autophagic activity. The role of sucrose in autophagy is unknown; however, another disaccharide, trehalose has been shown to induce autophagy. In the current study, we used mouse embryonic fibroblasts to investigate whether sucrose induces autophagy and whether vesicle formation is associated with autophagy. The results showed that sucrose induces autophagy while being accumulated within the endosomes/lysosomes. These vesicles were swollen and packed within the cytoplasm. Furthermore, trehalose and the trisaccharide raffinose, which are not hydrolyzed in mammalian cells, increased the rate of vesicles accumulation and LC3-II level (a protein marker of autophagy). However, fructose and maltose did not show the same effects. The correlation between the two processes, vesicle accumulation and autophagy induction, was confirmed by treatment of cells with sucrose plus invertase, or maltose plus acarbose-the α-glucosidase inhibitor-and by sucrose deprivation. Results also showed that vesicle accumulation was not affected by autophagy inhibition. Therefore, the data suggest that sucrose-induced autophagy through accumulation of sucrose-containing vesicles is caused by the absence of hydrolysis enzymes.

  3. Preparation of molecularly imprinted polymers using anacardic acid monomers derived from cashew nut shell liquid. (United States)

    Philip, Joseph Y N; Buchweishaija, Joseph; Mkayula, Lupituko L; Ye, Lei


    The objective of this work was to use monomers from cashew ( Anacardium occidentale L.) nut shells to develop molecularly imprinted polymers. Cashew nut shell liquid (CNSL) is a cheap and renewable agro byproduct consisting of versatile monomers. Solvent-extracted CNSL contains over 80% anacardic acid (AnAc) with more than 90% degree of unsaturation in its C 15 side chain. From AnAc monomer, anacardanyl acrylate (AnAcr) and anacardanyl methacrylate (AnMcr) monomers were synthesized and their chemical structures were characterized by Fourier transform IR and NMR. Different imprinted bulk polymers based on AnAc, AnAcr, and AnMcr functional monomers have been prepared. In the present study, each functional monomer was separately copolymerized in toluene with ethylene glycol dimethacrylate and divinylbenzene as cross-linkers, using racemic propranolol as a model template. While the AnAc based polymer revealed a meager rebinding ability, the imprinted polymers made from AnAcr and AnMcr displayed highly specific propranolol binding. At a polymer concentration of 2 mg/mL, AnAcr and AnMcr based imprinted polymers were able to bind over 50% of trace propranolol (initial concentration 1.2 nM). Under the same condition propranolol uptake by the two nonimprinted control polymers was less than 20%. Chiral recognition properties of these polymers were further confirmed using tritium-labeled (S)-propranolol as a tracer in displacement experiments, suggesting that the apparent affinity of the imprinted chiral sites for the correct enantiomer is at least 10 times that of the mismatched (R)-propranolol. Moreover, cross reactivity studies of these polymers showed that the (S)-imprinted sites have higher cross-reactivity toward (R, S)-metoprolol than (R)-propranolol and (R)-timolol.

  4. Sucrose accumulation in mature sweet melon fruits. [Cucumis melo

    Energy Technology Data Exchange (ETDEWEB)

    Schaffer, A.A.; Aloni, B.


    Mesocarp tissue from sucrose-accumulating sweet melon (Cucumis melo cv. Galia) showed sucrose synthase activity (ca 1 nkat/gfw) while soluble acid invertase and sucrose phosphate synthase activities were not observed. Sucrose uptake into mesocarp discs was linear with sucrose concentration (1-500 mM) and unaffected by PCMBS and CCCP. Sucrose compartmentation into the vacuole also increased linearly with sucrose concentration as indicated by compartmental efflux kinetics. Mesocarp discs incubated in /sup 14/C-fructose + UDP-glu synthesized /sup 14/C-sucrose and efflux kinetics indicated that the /sup 14/C-sucrose was compartmentalized. These data support the hypothesis that two mechanisms are involved in sucrose accumulation in sweet melon: (1) compartmentation of intact sucrose and (2) synthesis of sucrose via sucrose synthase and subsequent compartmentation in the vacuole.

  5. A study on the effect of the concentration of N,N-methylenebisacrylamide and acrylic acid toward the properties of Dioscorea hispida-starch-based hydrogel (United States)

    Ashri, Airul; Lazim, Azwan


    The research investigated the effects of acrylic acid (monomer) and N,N,-methylenebisacrylamide, MBA (crosslinker) toward the percentage of gel content, swelling ratio and ionic strength of a starch-based hydrogel. Starch grafted on poly (sodium acrylate), St-g-PAANa hydrogel was prepared by incorporating starch extracted from Dioscorea hispida in NaOH/aqueous solution using different composition of acrylic acid (AA) and N,N-methylenebisacrylamide (MBA) in the presence of potassium persulfate (KPS) as chemical initiator. The highest gel content was observed at 1:30 ratio of starch to AA and 0.10 M of MBA. Results showed the highest swelling ratio was observed at 1:15 ratio of starch to acrylic acid and 0.02 M of MBA solution. The same results also gave the highest swelling ratio for the ionic strength study. The FTIR analysis was also conducted in order to confirm the grafting of AA onto starch backbone.


    Institute of Scientific and Technical Information of China (English)

    DING Youjun; QI Daquan


    The copolymerizations of methyl acrylate (MA) with different N- arylmethacrylamide ( N - ArMA )were carried out in benzene solution by free radical initiation.The compositions of the copolymers were deter mined by 1H NMR method. The monomer reactivity ratios were calculated by the Fineman- Ross (F- R)method. The reactivity ratios and the activity of various N- ArMA with MA were investigated.

  7. Sugarcane genes associated with sucrose content

    Directory of Open Access Journals (Sweden)

    Vincentz Michel GA


    Full Text Available Abstract Background - Sucrose content is a highly desirable trait in sugarcane as the worldwide demand for cost-effective biofuels surges. Sugarcane cultivars differ in their capacity to accumulate sucrose and breeding programs routinely perform crosses to identify genotypes able to produce more sucrose. Sucrose content in the mature internodes reach around 20% of the culms dry weight. Genotypes in the populations reflect their genetic program and may display contrasting growth, development, and physiology, all of which affect carbohydrate metabolism. Few studies have profiled gene expression related to sugarcane's sugar content. The identification of signal transduction components and transcription factors that might regulate sugar accumulation is highly desirable if we are to improve this characteristic of sugarcane plants. Results - We have evaluated thirty genotypes that have different Brix (sugar levels and identified genes differentially expressed in internodes using cDNA microarrays. These genes were compared to existing gene expression data for sugarcane plants subjected to diverse stress and hormone treatments. The comparisons revealed a strong overlap between the drought and sucrose-content datasets and a limited overlap with ABA signaling. Genes associated with sucrose content were extensively validated by qRT-PCR, which highlighted several protein kinases and transcription factors that are likely to be regulators of sucrose accumulation. The data also indicate that aquaporins, as well as lignin biosynthesis and cell wall metabolism genes, are strongly related to sucrose accumulation. Moreover, sucrose-associated genes were shown to be directly responsive to short term sucrose stimuli, confirming their role in sugar-related pathways. Conclusion - Gene expression analysis of sugarcane populations contrasting for sucrose content indicated a possible overlap with drought and cell wall metabolism processes and suggested signaling and

  8. 21 CFR 172.859 - Sucrose fatty acid esters. (United States)


    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are...

  9. Preparation and drug-loading properties of Fe3O4/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites (United States)

    Lu, Wensheng; Shen, Yuhua; Xie, Anjian; Zhang, Weiqiang


    Fe3O4/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe3O4 nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50-120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe3O4 nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  10. Blood compatibility of polyurethane surface grafted copolymerization with sulfobetaine monomer. (United States)

    Jiang, Yuan; Rongbing, Bian; Ling, Tong; Jian, Shen; Sicong, Lin


    Surface modification is an effective way to improve the hemocompatibility and remain bulk properties of biomaterials. Recently, polymer tailed with zwitterions was found having good blood compatibility. In this study, the grafting copolymerization of sulfobetaine onto polyurethane surface was obtained through two steps. In the first step, polyurethane film coupled with vinyl groups was obtained through the reaction between the carboxyl group of acrylic acid (AA) and the NH-urethane group of polyurethane by dicyclohexylcarbodiimide (DCC). In the second step, sulfobetaine was grafted copolymerization on the surface using AIBN as an initiator. The reaction process was monitored with ATR-IR spectra and X-ray photoelectron spectroscopy (XPS) spectra. The wettability of films was investigated by water contact angle measurement. The blood compatibility of the grafted films was evaluated by platelet adhesion in platelet rich plasma (PRP) and protein absorption in bovine fibrinogen (BFG). Low platelet adhesion was observed on the grafted films incubated in PRP for 1 and 3 h, respectively. The protein absorption was reduced on the grafted films after incubated in bovine fibrinogen for 2 h. All of these results revealed that the improved blood compatibility was obtained by grafting copolymerization with zwitterionic monomer of sulfobetaine onto polyurethane film. In addition, introducing vinyl groups onto surface through DCC and AA is a novel method to functionalize polyurethane for further modification.

  11. Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem.

    Energy Technology Data Exchange (ETDEWEB)

    Matt Vaughn Greg Harrington Daniel R Bush


    This project was based on our discovery that sucrose acts as a signaling molecule that regulates the activity of a proton-sucrose symporter in sugar beet leaf tissue. A major objective here was determining how sucrose transporter activity is being regulated. When sucrose accumulates in the phloem sucrose transport activity drops dramatically. Western blots of plasma membrane proteins isolated from sucrose treated leaves showed that the loss of sucrose transport activity was proportional to a decline in symporter abundance, demonstrating that sucrose transport is regulated by changes in the amount of BvSUT1 protein. BvSUT1 transcript levels decreased in parallel with the loss of sucrose transport activity. Nuclear run-on experiments demonstrated that BvSUT1 gene transcription was repressed significantly in nuclei from leaves fed 100 mM exogenous sucrose, showing that sucrose-dependent modulation of BvSUT1 mRNA levels is mediated by changes in transcription. To identify which secondary messenger systems might be involved in regulating symporter activity, we used a variety of pharmacological agents to probe for a role of calcium or protein phosphorylation in sucrose signaling. In a detailed analysis, only okadaic acid altered sucrose transport activity. These results suggest a protein phosphatase is involved. We hypothesized that protein kinase inhibitors would have a neutral affect or increase symporter transcription. Transpirational feeding of the protein kinase inhibitor staurosporine had no impact on sucrose transport while calphostin C, an inhibitor of protein kinase C, caused a 60% increase. These data provided good evidence that protein phosphorylation plays a central role in regulating sucrose symporter expression and sucrose transport activity. To determine whether protein phosphorylation is involved in sucrose regulation of proton-sucrose symporter activity, we pre-fed leaves with staurosporine for 4 h and then fed the treated leaves water or 100 mM sucrose

  12. Cyclic Polymer with Alternating Monomer Sequence. (United States)

    Zhu, Wen; Li, Zi; Zhao, Youliang; Zhang, Ke


    Cyclic polymers with alternating monomer sequence are synthesized for the first time based on the ring-closure strategy. Well-defined telechelic alternating polymers are synthesized by reversible addition-fragmentation chain transfer polymerization by copolymerizing the electron acceptor monomer of N-benzylmaleimide and donor monomer of styrene with a feed ratio of 1 between them. The corresponding cyclic alternating polymers are then produced by the UV-induced Diels-Alder click reaction to ring-close the linear alternating polymer precursors under highly diluted reaction solution.

  13. 溶剂条件对聚丙烯酸十八酯的平均相对分子质量的影响%Influence of Solvent Conditons on Average Relative Molecular Weight of Polyoctadecyl Acrylate

    Institute of Scientific and Technical Information of China (English)

    蒋庆哲; 宋昭峥; 柯明; 赵密福


    Polymerization of octodecyl acrylate is studied in four solvents - carbon tetrachloride, chloroform,methylbenzene and tetrachloroethane. Experimental results indicate that the sequence of chain transfer constants in solvents is: carbon tetrachloride>chloroform>methylbenzene>tetrachloroethane in the polymerization of octadecyl acrylate. Influences of four solvents on solubility of polyoctadecyl acrylate prove not the same. In chloroform,polyoctadecyl acrylate shows the highest relative viscosity and the lowest chain termination rate constant. In higher conversion, the average relative molecular weight of polyoctadecyl acrylate depends mainly on the chain transfer constant of the solvent. Under the circumstance of monomer conversion higher than 30%, the viscosity effect induced by polymeric molecular shape in the solvents have a strong influence on the relative molecular weight of the polymer obtained.

  14. Preparation of Conductive Coating Solutions by Blending Waterborne Acrylic Polyurethane Dispersion with Carbon Nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Woo Young; Yun, Dong Gu; Song, Ki Chang [Konyang University, Nonsan (Korea, Republic of)


    Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions.

  15. Local and systemic effects of unpolymerised monomers

    Directory of Open Access Journals (Sweden)

    Sulekha Siddharth Gosavi


    Full Text Available Methyl methacrylate (MMA, a widely used monomer in dentistry and medicine has been reported to cause abnormalities or lesions in several organs. Experimental and clinical studies have documented that monomers may cause a wide range of adverse health effects such as irritation to skin, eyes, and mucous membranes, allergic dermatitis, stomatitis, asthma, neuropathy, disturbances of the central nervous system, liver toxicity, and fertility disturbances.

  16. Self-assembly and UV-curing Property of Polymerized Lyotropic Liquid Crystal Monomer of Sodium 3,4,5-tris(11-acryloxyundecyloxy)benzoate

    Institute of Scientific and Technical Information of China (English)

    Yu-qin Bai; Jin-bao Guo; Ying Wang; Jie Wei


    A polymerized lyotropic liquid crystal monomer of sodium 3,4,5-tris (11-acryloxyundecyloxy)benzoate was synthesized by a convenient route starting from 3,4,5-trihydroxybenzoic acid via esterification followed by etherification,acylation and finally neutralization.The chemical structure was confirmed by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance spectral analysis.The self-organization behavior of the monomer with deionized water in methanol at room temperature was also demonstrated.The assemblies were characterized by polarized optical microscope and X-ray diffraction.The results show that a solution containing 80∶20 of the monomer to water was found to be able to self-organize into Lamellar (La) phase and 92∶8 with inverted hexagonal (HⅡ) phase,which was in accordance with the theoretical calculation of critical packing parameter.It suggests that the concentration of the monomer was the key factor to influence assembly structure.Additionally,the acrylate conversion with different photoinitiators and nanostructure retention after polymerization were investigated.The research shows that the acrylate conversion of the monomer with Darocur2959 could reach up to 78% when irradiated by 30 mW/cm2 UV light of 365 nm for 30 min characterized by Real-time FT-IR as well as the sol-gel method.Meanwhile,the La and HⅡI phase nanostructures were both retained after polymerization.

  17. Size-Dependent Filling Behavior of UV-Curable Di(meth)acrylate Resins into Carbon-Coated Anodic Aluminum Oxide Pores of around 20 nm. (United States)

    Nakagawa, Masaru; Nakaya, Akifumi; Hoshikawa, Yasuto; Ito, Shunya; Hiroshiba, Nobuya; Kyotani, Takashi


    Ultraviolet (UV) nanoimprint lithography is a promising nanofabrication technology with cost efficiency and high throughput for sub-20 nm size semiconductor, data storage, and optical devices. To test formability of organic resist mask patterns, we investigated whether the type of polymerizable di(meth)acrylate monomer affected the fabrication of cured resin nanopillars by UV nanoimprinting using molds with pores of around 20 nm. We used carbon-coated, porous, anodic aluminum oxide (AAO) films prepared by electrochemical oxidation and thermal chemical vapor deposition as molds, because the pore diameter distribution in the range of 10-40 nm was suitable for combinatorial testing to investigate whether UV-curable resins comprising each monomer were filled into the mold recesses in UV nanoimprinting. Although the UV-curable resins, except for a bisphenol A-based one, detached from the molds without pull-out defects after radical photopolymerization under UV light, the number of cured resin nanopillars was independent of the viscosity of the monomer(s) in each resin. The number of resin nanopillars increased and their diameter decreased as the number of hydroxy groups in the aliphatic diacrylate monomers increased. It was concluded that the filling of the carbon-coated pores having diameters of around 20 nm with UV-curable resins was promoted by the presence of hydroxy groups in the aliphatic di(meth)acrylate monomers.

  18. Radiation-induced graft polymerization of acrylamide and acrylic acid onto polyethylene (United States)

    Grushevskaya, L. N.; Aliev, R. E.; Kabanov, V. Ya.

    The radiation-induced grafting of acrylamide onto low-density polyethylene by the different methods and under different conditions was investigated: by the direct liquid phase method from this monomer solution in water (in neutral and acid media) and acetone, and by the pre-irradiation method from aqueous solutions as well as from its sublimated vapour. The molecular masses of polyacrylamide homopolymers were determined. The discussion and comparison of different methods of acrylamide grafting are performed. The relationship between rates of graft polymerization onto polyethylene and homopolymerization of acrylic acid in the presence of metal ions is considered.

  19. Properties of Low Surface Energy Fluorocarbon Polymers with Fluoro-acrylic Resins

    Institute of Scientific and Technical Information of China (English)

    LIU Xiusheng; WANG Can; LIU Lanxuan; LI Jian; GAO Wanzhen


    The low surface energy fluorocarbon polymer from the synthesized fluoro-acrylic resins was developed. Then the molecule orientation principle of nonpolar and polar functional groups in the polymers was analyzed. And the contact angles of pure water drops on the surfaces of various fluoro-monomer homopolymers and interpolymers were measured. So the relation of polymers' fluoro-content with the surface energy was determined. The distribution of fluoric functional groups in the polymers was investigated. And the test results show that though the total fluorine content of the fluorocarbon polymers is relative few, their surface energy is really low due to the enrichment of fluoro-chains on the polymers surface.

  20. Sucrose ingestion induces rapid AMPA receptor trafficking. (United States)

    Tukey, David S; Ferreira, Jainne M; Antoine, Shannon O; D'amour, James A; Ninan, Ipe; Cabeza de Vaca, Soledad; Incontro, Salvatore; Wincott, Charlotte; Horwitz, Julian K; Hartner, Diana T; Guarini, Carlo B; Khatri, Latika; Goffer, Yossef; Xu, Duo; Titcombe, Roseann F; Khatri, Megna; Marzan, Dave S; Mahajan, Shahana S; Wang, Jing; Froemke, Robert C; Carr, Kenneth D; Aoki, Chiye; Ziff, Edward B


    The mechanisms by which natural rewards such as sugar affect synaptic transmission and behavior are largely unexplored. Here, we investigate regulation of nucleus accumbens synapses by sucrose intake. Previous studies have shown that AMPA receptor (AMPAR) trafficking is a major mechanism for regulating synaptic strength, and that in vitro, trafficking of AMPARs containing the GluA1 subunit takes place by a two-step mechanism involving extrasynaptic and then synaptic receptor transport. We report that in rat, repeated daily ingestion of a 25% sucrose solution transiently elevated spontaneous locomotion and potentiated accumbens core synapses through incorporation of Ca(2+)-permeable AMPA receptors (CPARs), which are GluA1-containing, GluA2-lacking AMPARs. Electrophysiological, biochemical, and quantitative electron microscopy studies revealed that sucrose training (7 d) induced a stable (>24 h) intraspinous GluA1 population, and that in these rats a single sucrose stimulus rapidly (5 min) but transiently (<24 h) elevated GluA1 at extrasynaptic sites. CPARs and dopamine D1 receptors were required in vivo for elevated locomotion after sucrose ingestion. Significantly, a 7 d protocol of daily ingestion of a 3% solution of saccharin, a noncaloric sweetener, induced synaptic GluA1 similarly to 25% sucrose ingestion. These findings identify multistep GluA1 trafficking, previously described in vitro, as a mechanism for acute regulation of synaptic transmission in vivo by a natural orosensory reward. Trafficking is stimulated by a chemosensory pathway that is not dependent on the caloric value of sucrose.

  1. Functional Analysis of Arabidopsis Sucrose Transporters

    Energy Technology Data Exchange (ETDEWEB)

    John M. Ward


    Sucrose is the main photosynthetic product that is transported in the vasculature of plants. The long-distance transport of carbohydrates is required to support the growth and development of net-importing (sink) tissues such as fruit, seeds and roots. This project is focused on understanding the transport mechanism sucrose transporters (SUTs). These are proton-coupled sucrose uptake transporters (membrane proteins) that are required for transport of sucrose in the vasculature and uptake into sink tissues. The accomplishments of this project included: 1) the first analysis of substrate specificity for any SUT. This was accomplished using electrophysiology to analyze AtSUC2, a sucrose transporter from companion cells in Arabidopsis. 2) the first analysis of the transport activity for a monocot SUT. The transport kinetics and substrate specificity of HvSUT1 from barley were studied. 3) the first analysis of a sucrose transporter from sugarcane. and 4) the first analysis of transport activity of a sugar alcohol transporter homolog from plants, AtPLT5. During this period four primary research papers, funded directly by the project, were published in refereed journals. The characterization of several sucrose transporters was essential for the current effort in the analysis of structure/function for this gene family. In particular, the demonstration of strong differences in substrate specificity between type I and II SUTs was important to identify targets for site-directed mutagenesis.

  2. Sucrose consumption in Thai undergraduate students. (United States)

    Promdee, Limthong; Trakulthong, Jindara; Kangwantrakul, Wisut


    Highly added sugar diets have been associated with various health problems such as dental caries, dyslipidemia, obesity and poor quality of life. Unfortunately, sugar consumption, especially sucrose, has increased continuously worldwide. The purpose of the study was to examine sources of sugar consumption and amount of added sucrose consumed in Thai undergraduate students. This study was carried out at Khon Kaen University, Thailand, between the years 2004-2005. A complete 3-day record of items and amounts of sweet consumption were obtained from 202 individuals--38 male and 164 female students. Added sucrose content of each sweetened food and drinks referred to in the record was determined by an enzymatic method. Mean intakes of sucrose were calculated from the sucrose content. The average of sucrose consumption in all subjects was 69+/-38 g/day, ranged from 4 to 182 g/day or 17 teaspoons of added sucrose per day. This amount accounted for 13.8% of total daily energy intake. There was a record of 337 kinds of sweetened foods and drinks found. The major source of added sucrose consumption was sweetened beverage, which was consumed 118 g/day averagely, or 60% of daily sugar consumption. Intake of sucrose per day in both male and female was not statistically difference, neither among different BMI groups. Intake of added sugar in the students was higher than the recommendation of the World Health Organization. These data would be helpful in a health promotion campaign aimed at a reduction of sugar consumption in Thai undergraduate students.

  3. Amino-functionalized (meth)acryl polymers by use of a solvent-polarity sensitive protecting group (Br-t-BOC). (United States)

    Ritter, Helmut; Tabatabai, Monir; Herrmann, Markus


    We describe the synthesis of bromo-tert-butyloxycarbonyl (Br-t-BOC)-amino-protected monomers 2-((1-bromo-2-methylpropan-2-yl)oxycarbonylamino)ethyl (meth)acrylate 3a,b. For this purpose, 2-isocyanatoethyl (meth)acrylate 1a,b was reacted with 1-bromo-2-methylpropan-2-ol (2a). The free radical polymerization of (Br-t-BOC)-aminoethyl (meth)acrylates 3a,b yielded poly((Br-t-BOC)-aminoethyl (meth)acrylate) 6a,b bearing protected amino side groups. The subsequent solvolysis of the Br-t-BOC function led to the new polymers poly(2-aminoethyl (meth)acrylate) 8a,b with protonated free amino groups. The monomers and the resulting polymers were thoroughly characterized by (1)H NMR, IR, GPC and DSC methods. The kinetics of the deprotection step was followed by (1)H NMR spectroscopy. The solvent polarity and neighboring group effects on the kinetics of deprotection are discussed.

  4. Synthesis of the diazonium (perfluoroalkyl) benzenesulfonimide monomer from Nafion monomer for proton exchange membrane fuel cells (United States)

    Mei, Hua; D'Andrea, Dan; Nguyen, Tuyet-Trinh; Nworie, Chima


    One diazonium (perfluoroalkyl) benzenesulfonimide monomer, perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide, has been synthesized from Nafion monomer for the first time. With trifluorovinyl ether and diazonium precursors, the partially-fluorinated diazonium PFSI monomer can be polymerized and will provide chemically bonding with carbon electrode in proton exchange membrane fuel cells. A systematic study of the synthesis and characterization of this diazonium PFSI monomer has been conducted by varying reaction conditions. The optimized synthesis method has been established in the lab.

  5. Assessment of preconscious sucrose perception using EEG

    DEFF Research Database (Denmark)

    Rotvel, Camilla Arndal; Møller, Stine; Nielsen, Rene R.

    to the brain cortex. The method complements sensory panel assessment by providing insight to pre-conscious taste perception. In the empirical study the subject was stimulated with an aqueous sucrose solution at two concentrations: 1 mL 0.1g/L sucrose (below detection threshold) and 100g/L sucrose, respectively...... is known to be involved in sensory integration. The proposed method demonstrates promising results in assessing pre-conscious taste perception, suggesting its viability complementing conventional taste panels....

  6. Preparation of hybrid monolithic columns via "one-pot" photoinitiated thiol-acrylate polymerization for retention-independent performance in capillary liquid chromatography. (United States)

    Zhang, Haiyang; Ou, Junjie; Liu, Zhongshan; Wang, Hongwei; Wei, Yinmao; Zou, Hanfa


    A novel "one-pot" approach was developed for ultrarapid preparation of various hybrid monolithic columns in UV-transparent fused-silica capillaries via photoinitiated thiol-acrylate polymerization of an acrylopropyl polyhedral oligomertic silsesquioxane (acryl-POSS) and a monothiol monomer (1-octadecanethiol or sodium 3-mercapto-1-propanesulfonate) within 5 min, in which the acrylate not only homopolymerizes, but also couples with the thiol. This unique combination of two types of free-radical reaction mechanisms offers a simple way to fabricate various acrylate-based hybrid monoliths. The physical characterization, including scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and thermal gravimetric analysis was performed. The results indicated that the monothiol monomers were successfully incorporated into acryl-POSS-based hybrid monoliths. The column efficiencies for alkylbenzenes on the C18-functionalized hybrid monolithic column reached to 60 000-73 500 plates/m at the velocity of 0.33 mm/s in capillary liquid chromatography, which was far higher than that of previously reported POSS-based columns prepared via thermal-initiated free-radical polymerization without adding any thiol monomers. By plotting the plate height (H) of the alkylbenzenes versus the linear velocity (u) of the mobile phase, the results revealed a retention-independent efficient performance of small molecules in the isocratic elution. These results indicated that more homogeneous hybrid monoliths formed via photoinitiated thiol-acrylate polymerization; particularly, the use of the multifunctional cross-linker possibly prevented the generation of gel-like micropores, reducing mass transfer resistance (C-term). Another sulfonate-containing hybrid monolithic column also exhibited hydrophobicity and ion-exchange mechanism, and the dynamic binding capacity was calculated as 71.1 ng/cm (75 μm i.d.).

  7. Study of n-Butyl Acrylate Self-Initiation Reaction Experimentally and via Macroscopic Mechanistic Modeling

    Directory of Open Access Journals (Sweden)

    Ahmad Arabi Shamsabadi


    Full Text Available This paper presents an experimental study of the self-initiation reaction of n-butyl acrylate (n-BA in free-radical polymerization. For the first time, the frequency factor and activation energy of the monomer self-initiation reaction are estimated from measurements of n-BA conversion in free-radical homo-polymerization initiated only by the monomer. The estimation was carried out using a macroscopic mechanistic mathematical model of the reactor. In addition to already-known reactions that contribute to the polymerization, the model considers a n-BA self-initiation reaction mechanism that is based on our previous electronic-level first-principles theoretical study of the self-initiation reaction. Reaction rate equations are derived using the method of moments. The reaction-rate parameter estimates obtained from conversion measurements agree well with estimates obtained via our purely-theoretical quantum chemical calculations.

  8. Monolithic F-16 Uniform Thickness Stretched Acrylic Canopy Transparency Program (United States)


    Thermoforming Finite Strain Analysis Finite Element Modeling Mooney Formulation Tensile Testing Acrylic Material Properties F-16 Transparency Thinning Uniform...OF ACRYLIC TENSILE SPECIMEN ...... 8 MARC ANALYSIS OF ACRYLIC HEMISPHERE ............ 12 IV ACRYLIC MATERIAL PROPERTIES AT THERMOFORMING (necessary for finite element stress analysis work) were generated at temperatures in the range of thermoforming . A finite element code

  9. The synthesis and application of low temperature environment friendly poly-acrylate emulsion%低温环保型聚丙烯酸酯乳液的合成及应用

    Institute of Scientific and Technical Information of China (English)

    刘旭; 习智华


    The low temperature environment friendly poly-acrylate emulsion adhesive is prepared by seed emulsion polymerization method. It means that, with butyl acrylic (BA), ethylhexyl acrylate (EHA), styrene (St) as soft or hard monomer, acrylic acid (AA) as functional monomer, potassium persulfate as initiator, HA as crosslinking monomer, poly-acrylate adhesive provided with excellent performance for pigment printing is synthesized. The effects of the hard monomer to soft monomer ratio, dosage of functional monomer, dosage of crosslinking monomer and chain transfer agent on the emulsion performance and pigment printing property are discussed. Finally, the optimum process condition of emulsion polymerization is confirmed as follows:the ratio of hard monomers to soft monomers is 1.218 8/1, the dosage of functional monomer is 1.8%, the dosage of crosslinking monomer is 2.6%, and chain transfer agent is 0.52%, dosage of adhesive is 30%, the curing time is 4 min.%  采用种子乳液聚合法合成低温环保型聚丙烯酸酯乳液粘合剂,即以丙烯酸丁酯(BA)、丙烯酸异辛酯(EHA)、苯乙烯(ST)为软、硬单体,丙烯酸(AA)为功能单体,过硫酸钾为引发剂,HA为交联单体,合成了一种性能优良的聚丙烯酸酯涂料印花粘合剂。讨论了软硬单体配比、功能单体用量、交联单体用量及链转移剂对乳液性能及涂料印花性能的影响。最终确定了乳液聚合最佳工艺条件:软/硬单体比为1.2188/1,功能单体AA用量为1.8%,交联单体HA用量为2.6%,链转移剂硫醇用量为0.52%。合成粘合剂在涂料印花上应用时,粘合剂用量为30%,焙烘时间为4 min。

  10. Characterization of pH-sensitive Poly (acrylic acid-co-N-vinyl-2-pyrrolidone) Hydrogels Prepared by Gamma Radiation

    Institute of Scientific and Technical Information of China (English)

    YANG Ming-cheng; HE Su-qin; LIU Wen-tao; SONG Hong-yan; ZHU Cheng-shen


    The pH-sensitive copolymer hydrogels were prepared with the monomers of acrylic acid and N-vinyl-2-pyrrolidone based on gamma radiation technique. The morphology of the hydrogels was monitored by using scanning electron microscope. The influence of absorbed dose, monomer compasition and concentration on the swelling ratio (SR) of the hydrogels were investigated in detail. The effect of pH and temperature of the swelling medium on the swelling behavior of the hydrogels were also examined. The results show that the SR of the copolymer hydrogels decreases with the monomer concentration and absorbed dose increasing. The copolymer hydrogels show a better pH-sensitive behavior. In alkaline solution, the SR of the hydrogels is much higher than in acid solution.

  11. Occupational respiratory disease caused by acrylates. (United States)

    Savonius, B; Keskinen, H; Tuppurainen, M; Kanerva, L


    Acrylates are compounds used in a variety of industrial fields and their use is increasing. They have many features which make them superior to formerly used chemicals, regarding both their industrial use and their possible health effects. Contact sensitization is, however, one of their well known adverse health effects but they may also cause respiratory symptoms. We report on 18 cases of respiratory disease, mainly asthma, caused by different acrylates, 10 cases caused by cyanoacrylates, four by methacrylates and two cases by other acrylates.

  12. Synthesis and characterization of copolymers from hindered amines and vinyl monomers

    Directory of Open Access Journals (Sweden)

    Marcelo Aparecido Chinelatto


    Full Text Available New copolymers from hindered amines and vinyl monomers were synthesized by radical chain polymerization. To obtain polymeric HALS, acrylamide-(1ATP and acrylate-(4ATP monomers, derivatives from 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethyl-4-piperidinol were synthesized. The radical chain polymerization of 1ATP with styrene (Sty using 1-butanethiol (BTN resulted in a copolymer with 95 units of Sty and 15 units of 1ATP. The radical chain polymerization of 1ATP and vinyl acetate (VAc has produced only 1ATP homopolymer. In the chain polymerization of 4ATP with Sty or VAc, the hydrogen atom bonded to the nitrogen of 4ATP is labile enough to originate another radical at this site. The steric hindrance imposed by methyl groups on this bonding site hampers its reaction with other propagating species and the formation of a copolymer or network structure will be dependent on the size of the pendent group in the vinyl monomer.

  13. Chemical graft polymerization of sulfobetaine monomer on polyurethane surface for reduction in platelet adhesion. (United States)

    Yuan, Jiang; Chen, Li; Jiang, Xuefeng; Shen, Jian; Lin, Sicong


    Surface modification is an effective way to improve the hemocompatibility and remain bulk properties of biomaterials. Recently, polymer tailored with zwitterions was found having good blood compatibility. In this study, the zwitterionic monomer of sulfobetaine was graft polymerized onto polyurethane (PU) surface in a three-step heterogenous system through the vinyl bonds of acrylic acid (AA) or hydroxyethyl methacrylate (HEMA), which was immobilized with hexamethylene diisocyanate (HDI) beforehand. First, PU was activated with isocyanate groups using HDI as coupling agent. Second, AA or HEMA was introduced through reaction of AA or HEMA with NCO groups bonded on PU surface. Last, zwitterionic monomer of sulfobetain was graft polymerized with vinyl group of AA or HEMA using AIBN as polymerization initiator. The reaction process was monitored with ATR-IR spectra and XPS spectra. Variation of graft yield with temperature and monomer feed concentration was investigated and feasible conditions were optimized. The wettability of films was investigated by water contact angle measurement and water absorbance. Platelet adhesion experiment was conducted as a preliminary test to confirm the improved blood compatibility of PU. The number of platelets adhering to PU decreased greatly comparing with the originals after 1 and 3 h of contact with human plate-rich plasma (PRP).

  14. Vinyl monomers-induced synthesis of polyvinyl alcohol-stabilized selenium nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Chetan P.; Singh, Krishan K. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Kumar, Manmohan, E-mail: [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Bajaj, Parma N. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)


    A simple wet chemical method has been developed to synthesize selenium nanoparticles (size 100-200 nm), by reaction of sodium selenosulphate precursor with different vinyl monomers, such as acrylamide, N,N'-dimethylene bis acrylamide, methyl methacrylate, sodium acrylate, etc., in aqueous medium, under ambient conditions. Polyvinyl alcohol has been used to stabilize the selenium nanoparticles. Average size of the synthesized selenium nanoparticles can be controlled by adjusting concentration of both the precursors and the stabilizer. Rate of the reaction as well as size of the resultant selenium nanoparticles have been correlated with the functional groups of the different monomers. UV-vis optical absorption spectroscopy, X-ray diffraction, energy dispersive X-rays, differential scanning calorimetry, atomic force microscopy, scanning electron microscopy and transmission electron microscopy techniques have been employed to characterize the synthesized selenium nanoparticles. Gas chromatographic analysis of the reaction mixture established the non-catalytic role of the vinyl monomers, which were found to be consumed during the course of the reaction.

  15. Sucrose dependent translational dynamics in Arabidopsis thaliana

    NARCIS (Netherlands)

    Hummel, M.


    Sucrose dependent translational dynamics Gene expression is regulated at several different levels starting from chromatin remodeling and transcription in the nucleus to translation and post-translational modifications in the cytosol. Depending on the gene and circumstances, different regulatory mech

  16. Intracellular sucrose communicates metabolic demand to sucrose transporters in developing pea cotyledons. (United States)

    Zhou, Yuchan; Chan, Katie; Wang, Trevor L; Hedley, Cliff L; Offler, Christina E; Patrick, John W


    Mechanistic inter-relationships in sinks between sucrose compartmentation/metabolism and phloem unloading/translocation are poorly understood. Developing grain legume seeds provide tractable experimental systems to explore this question. Metabolic demand by cotyledons is communicated to phloem unloading and ultimately import by sucrose withdrawal from the seed apoplasmic space via a turgor-homeostat mechanism. What is unknown is how metabolic demand is communicated to cotyledon sucrose transporters responsible for withdrawing sucrose from the apoplasmic space. This question was explored here using a pea rugosus mutant (rrRbRb) compromised in starch biosynthesis compared with its wild-type counterpart (RRRbRb). Sucrose influx into cotyledons was found to account for 90% of developmental variations in their absolute growth and hence starch biosynthetic rates. Furthermore, rr and RR cotyledons shared identical response surfaces, indicating that control of transporter activity was likely to be similar for both lines. In this context, sucrose influx was correlated positively with expression of a sucrose/H(+) symporter (PsSUT1) and negatively with two sucrose facilitators (PsSUF1 and PsSUF4). Sucrose influx exhibited a negative curvilinear relationship with cotyledon concentrations of sucrose and hexoses. In contrast, the impact of intracellular sugars on transporter expression was transporter dependent, with expression of PsSUT1 inhibited, PsSUF1 unaffected, and PsSUF4 enhanced by sugars. Sugar supply to, and sugar concentrations of, RR cotyledons were manipulated using in vitro pod and cotyledon culture. Collectively the results obtained showed that intracellular sucrose was the physiologically active sugar signal that communicated metabolic demand to sucrose influx and this transport function was primarily determined by PsSUT1 regulated at the transcriptional level.

  17. Structural development of sucrose-sweetened and sucrose-free sponge cakes during baking. (United States)

    Baeva, Marianna Rousseva; Terzieva, Vesselina Velichkova; Panchev, Ivan Nedelchev


    The influence of sucrose, wheat starch and sorbitol upon the heat- and mass-exchanging processes forming the structure of sponge cake was studied. Under the influence of wheat starch and sorbitol the structure of the sucrose-free sponge cake was formed at more uniform total moisture release. This process was done at lower temperatures and smoother change of the sponge cake height with respect to the sucrose-sweetened sponge cake. The porous and steady structure of both cakes was finally formed at identical time--between 18th and 19th minute, at the applied conditions for baking of each batter (metal pan with diameter 15.4 cm and depth 6.2 cm containing 300 g of batter and placed in an electric oven "Rahovetz-02", Bulgaria for 30 min at 180 degrees C). The water-losses at the end of baking (10.30% and 10.40% for the sucrose-sweetened cake and sucrose-free cake, respectively) and the final temperatures reached in the crumb central layers (96.6 degrees C and 96.3 degrees C for the sucrose-sweetened cake and sucrose-free cake, respectively) during baking of both samples were not statistically different. The addition of wheat starch and sorbitol in sucrose-free sponge cake lead to the statistically different values for the porosity (76.15% and 72.98%) and the volume (1014.17 cm3 and 984.25 cm3) of the sucrose-sweetened and sucrose-free sponge cakes, respectively. As a result, the sucrose-free sponge cake formed during baking had a more homogeneous and finer microstructure with respect to that ofthe sucrose-sweetened one.

  18. Effect of High Temperature on Sucrose Content and Sucrose Cleaving Enzyme Activity in Rice Grain During the Filling Stage

    Institute of Scientific and Technical Information of China (English)

    LI Tian; LIU Qi-hua; Ryu OHSUGI; Tohru YAMAGISHI; Haruto SASAKI


    Dynamic changes of sucrose, fructose, glucose contents and differences in activities of sucrose synthase, vacuolar invertase, and cell wall bound invertase in rice grain after flowering stage were studied under natural and high temperatures by using two japonica rice varieties Koshihikari and Sasanishiki. In rice grains, the sucrose synthase activity was higher than that of invertase, which was significantly correlated with starch accumulation rate, indicating that the sucrose synthase played an important role in sucrose degradation and starch synthesis. Under high temperature, the significant increase in grain sucrose content without any increase in fructose and glucose contents, suggested that the high temperature treatment enhanced sucrose accumulation, while diminished sucrose degradation in rice grains. Compared with the control plants, the decrease in activities of sucrose synthase, vacuolar invertase, and cell wall bound invertase with high temperature treated plants indicated that the deceleration of sucrose-degradation was related to the decrease in activities of sucrose synthase and invertase.

  19. Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils. (United States)

    Wang, Shu; Robertson, Megan L


    Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

  20. Identification of sucrose binding, membrane proteins using a photolyzable sucrose analog. [P. saccharophila

    Energy Technology Data Exchange (ETDEWEB)

    Ripp, K.G.; Liu, D.F.; Viitanen, P.; Hitz, W.D.


    The sucrose derivative 6'-deoxy-6'-(2-hydroxy-4-azido)benzamidosucrose (6'-HABS) was prepared from sucrose (via 6'-deoxy-6'-aminosucrose) and 4-amino-salicylic acid. 6'-HABS is a competitive inhibitor of sucrose influx into protoplasts from developing soybean cotyledons and of sucrose binding to membranes from the bacteria P. saccharophila. The Ki for inhibition in the soybean protoplasts was 6'-Deoxy-6'-(2-hydroxy-3-/sup 125/Iodo-4-azido)benzamidosucrose was prepared by lactoperoxidase iodination of 6'-HABS. Upon photolysis in the presence of membranes from P saccharophila, label from the photoprobe is incorporated into a sucrose inducible polypeptide of mass 84 KD in SDS-PAGE. The polypeptide is protected from labeling by the inclusion of sucrose in the photolysis mixture. Photolysis conditions which lead to specific labeling of the sucrose protectable polypeptide in bacterial membranes also give sucrose protectable labeling of a 66 KD polypeptide in microsomal preparations made from developing soybeans. The possibility that this is a sucrose transporting protein is being tested.

  1. Crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis.

    NARCIS (Netherlands)

    Sprogoe, D.; Broek, van den L.A.M.; Mirza, O.; Kastrup, J.S.; Voragen, A.G.J.; Gajhede, M.; Skov, L.K.


    Around 80 enzymes are implicated in the generic starch and sucrose pathways. One of these enzymes is sucrose phosphorylase, which reversibly catalyzes the conversion of sucrose and orthophosphate to d-Fructose and a-d-glucose 1-phosphate. Here, we present the crystal structure of sucrose phosphoryla

  2. Cationically polymerizable monomers derived from renewable sources

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.


    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  3. Rapid Output Growth of Special Acrylic Esters

    Institute of Scientific and Technical Information of China (English)

    Wang Lianzhi


    @@ Acrylic esters are usually classified into general-purpose varieties and special varieties. The production and application of general-purpose varieties is already quite matured in the world and their output growth tends to be flat. Owing to the development of coatings, electronics, automobiles,textiles, printing and construction sectors, especially the application of radiation curing technology in various sectors, special acrylic esters have developed rapidly.

  4. Gel time of calcium acrylate grouting material

    Institute of Scientific and Technical Information of China (English)



    Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerization reaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reaction kinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time of calcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and an example is provided to verify the proposed formula.

  5. Gel time of calcium acrylate grouting material

    Institute of Scientific and Technical Information of China (English)



    Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerizationreaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reactionkinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time ofcalcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and anexample is provided to verify the proposed formula.

  6. Novel 2-(ω-phosphonooxy-2-oxaalkylacrylate monomers for self-etching self-priming one part adhesive

    Directory of Open Access Journals (Sweden)

    Joachim E. Klee


    Full Text Available Novel hydrolysis stable 2-(ω-phosphonooxy-2-oxaalkylacrylate monomers 3 with phosphoric acid moieties were synthesized by a three step synthesis via Baylis–Hillman reaction of ethyl acrylate and formaldehyde, and subsequent etherification of the obtained product with diols and phosphorylation using POCl3. The polymerization enthalpy of 2-(ω-phosphonooxy-2-oxaalkylacrylates 3 as measured by DSC ranges from −29 to −53 kJ·mol−1. The shear bond strength of adhesive compositions 4, comprising of polymerizable acids 3, ranges from 5.8 to 19.3 MPa on enamel and from 8.7 to 16.9 MPa on dentin.

  7. Ionic Liquids as Catalysts for the Radical Acrylate Polymerization Co-initiated by Imine Bases (United States)

    Polenz, I.; Spange, S.


    The catalysis of the imine base acrylate (IBA) polymerization by Ionic Liquids (ILs) is reported. Addition of IL traces (~10-50 mM) to an imine base / acrylate mixture leads to both a significant decrease of the activation temperature (40 °C) required for the IBA polymerization process and an increase in the polymerization rate by a factor of 5-40 depending on the IL species. The radical character of the polymerization is proved by copolymerization experiments using methyl methacrylate (MMA) and methacrylonitrile (MAN) and comparison with literature known values of copolymerization parameters rMMA and rMAN of these co-monomers. The influence of the IL on the polymerization kinetics is quantified by the polymerization rate law; the order referring to the IL is 1 indicating its crucial impact on the monomer activation. The IBA activation properties are strongly dependent on the IL interaction strengths with the IBA components verified by the KAMELT-TAFT hydrogen bond donating ability α. The stronger the interaction (higher α) is, the less the IBA polymerization activation. The temperature dependence of four different IL catalysed IBA polymerization is investigated, allows a classification and anomalous non-ARRHENIUS regimes are discussed. Activation energies EA,P span over 20 and 50 kJ·mol-1, which is between the values of thermal- (~80 kJ·mol-1) and photo-initiation (~20 kJ·mol-1).

  8. A Hydrogen Ion-Selective Sensor Based on Non-Plasticised Methacrylic-acrylic Membranes

    Directory of Open Access Journals (Sweden)

    Musa Ahmad


    Full Text Available A methacrylic-acrylic polymer was synthesised for use as a non-plasticised membrane for hydrogen ion-selective sensor incorporating tridodecylamine as an ionophore. The copolymer consisted of methyl methacrylate and n-butyl acrylate monomers in a ratio of 2:8. Characterisation of the copolymer using FTNMR demonstrated that the amount of each monomer incorporated during solution polymerisation was found to be similar to the amount used in the feed before polymerisation. The glass transition temperature of the copolymer determined by differential scanning calorimetry was -30.9 ºC. Potentiometric measurements conducted showed a linear pH response range of 4.3 – 9.6 with the response slope of 56.7 mV/decade. The selectivity of the sensors towards hydrogen ions was similar to other plasticiser based membrane electrodes and the logarithmic selectivity coefficients for discrimination against interference cations is close to –9.7. However, the incorporation of a lipophilic anion as membrane additive is essential in ensuring optimum performance of the hydrogen ion sensor.

  9. Structural rearrangements of sucrose phosphorylase from Bifidobacterium adolescentis during sucrose conversion

    DEFF Research Database (Denmark)

    Mirza, Osman; Henriksen, Lars Skov; Sprogøe, Desiree


    The reaction mechanism of sucrose phosphorylase from Bifidobacterium adolescentis (BiSP) was studied by site-directed mutagenesis and x-ray crystallography. An inactive mutant of BiSP (E232Q) was co-crystallized with sucrose. The structure revealed a substrate-binding mode comparable with that seen...

  10. Producing monomers and polymers from plant oils (United States)

    The integration of biobased industrial products into existing markets, where petrochemically-derived materials currently dominate, is a worthy objective. This chapter reviews some technologies that have been developed including olefins of various chain lengths, photo-curable polymers, vinyl monomers...

  11. Softening and elution of monomers in ethanol

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, Erik; Munksgaard, E Christian;


    The purpose of this study was to investigate the effect of light-curing protocol on softening and elution of monomers in ethanol as measured on a model polymer. It was a further aim to correlate the measured values with previously reported data on degree of conversion and glass transition tempera...

  12. High surface-area amidoxime-based polymer fibers co-grafted with various acid monomers yielding increased adsorption capacity for the extraction of uranium from seawater. (United States)

    Oyola, Yatsandra; Dai, Sheng


    Uranium is dissolved in the ocean at a uniform concentration of 3.34 ppb, which translates to approximately 4-5 billion tons of uranium. The development of adsorbents that can extract uranium from seawater has been a long term goal, but the extremely dilute uranium concentration along with the competition of other metal salts (which are at higher concentrations) has hindered the development of an economical adsorption process. Several acid monomers were co-grafted with acrylonitrile (AN) to help increase the hydrophilicity of the adsorbent to improve access to the metal adsorption sites. Grafting various acid monomers on PE fibers was found to significantly affect the uranium adsorption in simulated seawater in the following order: acrylic acid (AA) uranium adsorption capacity significantly increased when Mohr's salt was added with acrylic acid, most likely due to the reduction of co-polymerization of the monomers. When testing under more realistic conditions, the acid-grafted PE fiber adsorbents were exposed to natural seawater (more dilute uranium), the uranium adsorption capacity increased in the following order: MAA uranium adsorption capacity with each acid monomer was related to higher grafting of AN and therefore a higher conversion to amidoxime (AO).

  13. Surface texture and some properties of acrylic resins submitted to chemical polishing. (United States)

    Braun, K O; Mello, J A N; Rached, R N; Del Bel Cury, A A


    The effects of chemical polishing on dental acrylic resin properties are not well clarified. This study evaluated the effect of chemical and mechanical polishing on the residual monomer release (RM), Knoop hardness (KH), transverse strength (TS) and surface texture (ST) of a heat- and self-cured acrylic resin. Four groups were formed: GI-self-cured resin/mechanical polishing; GII-self-cured resin/chemical polishing; GIII-heat-cured resin/mechanical polishing; GIV-heat-cured resin/chemical polishing. Following the polishing procedures, specimens were stored in distilled water at 37 degrees C. The KH and RM measurements were taken after 1, 2, 8 and 32 days of storage, and TS after 2, 8 and 32 days. Surface texture was observed under SEM evaluation. Results were compared statistically at a confidence level of 95%. The following conclusions were drawn: (1) regardless of the acrylic resin and the period of analysis, chemical polishing increased RM levels, reduced KH, and did not affect TS significantly; (2) water storage increased the surface hardness of GII and GIV; (3) GII and GIV showed a smooth and wavy surface under SEM evaluation.

  14. Hydrophobic acrylic hard coating by surface segregation of hyper-branched polymers (United States)

    Haraguchi, Masayuki; Hirai, Tomoyasu; Ozawa, Masaaki; Miyaji, Katsuaki; Tanaka, Keiji


    The ability of hyperbranched polymers (HBPs) to preferentially segregate to the surface of its matrix owing to its unique structure makes it a good candidate as a surface modifier. One particular challenge in its application as an efficient surface modifier, however, is its possible elimination from the surface due to the lack of attachments between a HBP (modifier) and its host material (polymer matrix). Here, we present a novel approach to efficiently prevent the removal of HBPs from the surface of its host material by directly reacting a HBP containing fluoroalkyl segments (F-HBP) to a multi-functional acrylate monomer prior to curing. We also have characterized surface structure and wettability of the acrylic hard coating material by X-ray photoelectron spectroscopic and contact angle measurements, respectively. The results show that since F-HBP was segregated at the surface, the surface became hydrophobic and more stable. Thus, we claim that our approach results in the formation of a water-repellent acrylic hard coating material.

  15. Properties of solvent-borne acrylic pressure-sensitive adhesives synthesized by a simple approach

    Directory of Open Access Journals (Sweden)


    Full Text Available Acrylic polymers are widely used for fabricating pressure-sensitive adhesives (PSAs with the inherent unique advantages of transparency and superior intrinsic adhesive properties over other polymer-based adhesives. In this study, we have developed and evaluated a method of obtaining by radical copolymerization PSAs for liquid crystalline (LCD applications. Various factors including the amount of monomers, amount of cross-linker, coating weight, dwell time and thermal treatment are investigated for further optimizing the properties of acrylic polymer based PSAs to meet the emerging strict requirements for practical uses related mainly to holding powder and peel strength. The results illustrate that novel crosslinking reagents coupled with the thermal treatment at 70°C can make the resultant PSAs with the improved adhesive properties. The coating weight variation from 10 to 40 g/m2 can significantly enhance the peel strength from 4.0 g/25 mm to 12.5 g/25 mm with about 310% increment. If the dwell time of PSAs with cross-linking reagent is more than 10 hrs, the peel strength can be reduced down to a suitable value to meet the criterion for use. Therefore, acrylic PSAs with peel strength less than 20 g/25 mm and holding power above 120 hrs were successfully synthesized by elaborately designing the reaction system, which are practically applicable for advanced industrial applications.

  16. Synthesis, characterization, swelling and dye adsorption properties of starch incorporated acrylic gels. (United States)

    Mandal, Bidyadhar; Ray, Samit Kumar


    Several hydrogels were prepared by a free radical polymerization of acrylic acid (AA), sodium acrylate (SA) and AA/hydroxy ethyl methacrylate (HEMA) in the presence of starch in water. These starch incorporated acrylic gels were prepared by varying the concentration of the initiator, monomer, crosslinker and the starch. The resulting gels were characterized by FTIR, SEM, XRD, DTA-TGA, pH at point zero charge (PZC), swelling and the diffusion in water. The gels showed high adsorption and removal% of Safranine T (ST) and Brilliant Cresyl Blue (BCB) dyes from water. The swelling and the adsorption data were fitted to different kinetic models and isotherms. Amongst the three kinds of gels, the starch incorporated sodium polyacrylate gel showed the highest adsorption of 9.7-85.3mg/L (97-61% removal) of BCB dye and 9.1-83mg/L (91-60% removal) of ST dye for a feed dye concentration of 10-140mg/L.

  17. Preparation of self-crosslinked acrylate emulsion with high elasticity and its rheological properties

    Institute of Scientific and Technical Information of China (English)

    CHEN Li-jun; WU Feng-qin; LI Dong-shuang; YANG Jian; LI Rong-xian


    Using butyl acrylate (BA), methyl methacrylate (MMA), methacrylic acid (MAA) and mixed emulsifier as raw materials, the self-crosslinked emulsion was prepared via pre-emulsified and semi-continuous seeded emulsion polymerization technology in the presence of N-hydroxymethyl acrylamide and poly solidum maleate. The influence of mass ratio of BA to MMA, amount of N-hydroxymethyl acrylamide and poly solidum maleate on the rheological properties of the self-crosslinked emulsion was studied. Possible cross-linked mechanism of self-crosslinked monomer was investigated. And the relationship between emulsion viscosity and shear rate was investigated. The results show that the self-crosslinked acrylate emulsion with high elasticity can be synthesized when the mass fractions of BA is 60%, MMA is 40%, and added amount of N-hydroxymethyl acrylamide is 2.5%-3.0% and added amount of poly solidum maleate is 0.3%-0.4%. The self-crosslinkage process of N-hydroxymethyl acrylamide involves two steps. One is copolymer zation of N-hydroxymethyl acrylamide and acrylate, the other is cross-linkage among polymer molecules via condensation reaction of methylol. The emulsion is of rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

  18. A novel sucrose synthase pathway for sucrose degradation in cultured sycamore cells. (United States)

    Huber, S C; Akazawa, T


    Enzymes of sucrose degradation and glycolysis in cultured sycamore (Acer pseudoplatanus L.) cells were assayed and characterized in crude extracts and after partial purification, in an attempt to identify pathways for sucrose catabolism. Desalted cell extracts contained similar activities (20-40 nanomoles per milligram protein per minute) of sucrose synthase, neutral invertase, glucokinase, fructokinase, phosphofructokinase, and UDPglucose pyrophosphorylase (assayed with 2 micromolar pyrophosphate (PPi). PPi-linked phosphofructokinase activity was virtually dependent upon fructose 2,6-bisphosphate, and the maximum activity exceeded that of ATP-linked phosphofructokinase. Hexokinase activity, with glucose as substrate, was highly specific for ATP, whereas fructokinase activity was relatively nonspecific. At 1 millimolar nucleoside triphosphate, fructokinase activity decreased in the order: UTP > ATP > CTP > GTP. We propose two pathways for sucrose degradation. One involves invertase action, followed by classical glycolysis of hexose sugars, and the other is a novel pathway initiated by sucrose synthase. The K(m) for sucrose of sucrose synthase was severalfold lower than that of neutral invertase (15 versus 65 millimolar), which may determine carbon partitioning between the two pathways. The sucrose synthase pathway proposed involves cycling of uridylates and PPi. UDPglucose pyrophosphorylase, which is shown to be an effective ;PPi-scavenger,' would consume PPi and form UTP. The UTP could be then utilized in the UTP-linked fructokinase reaction, thereby forming UDP for sucrose synthase. The source of PPi is postulated to arise from the back reaction of PPi-linked phosphofructokinase. Sycamore cells contained a substantial endogenous pool of PPi (about 3 nanomoles per gram fresh weight, roughly 1/10 the amount of ATP in these cells), and sufficient fructose 2,6-bisphosphate (0.09 nanomole per gram fresh weight) to activate the PPi-linked phosphofructokinase. Possible

  19. Linear Copolymer of N-Isopropylacrylamide and 2-Hydroxyethylacrylate: Synthesis, Characterization and Monomer Reactivity Ratios

    Directory of Open Access Journals (Sweden)

    Nakan U


    Full Text Available Сopolymerization of N-isopropylacrylamide (NIPAAm with 2-hydroxyethyl acrylate (2-HEA carried out by solvent ethanol solution method, at 600C, using Azoisobutyronitrile (AIBN as an initiator. The hydrophilic copolymers were characterized by elemental analysis, DSC, TGA and turbidimetric method. The results showed thermal stability increase with increase of NIPAAm in the copolymers. It was found that copolymer solutions have lower critical solution temperature (by turbidimetric analysis. The reactivity ratios of monomers were determined using linear methods like Fineman-Ross and Kelen-Tudos. The reactivity ratios of r1 and r2 were found to be 0,86, 0,72 and 1,02, 1,04 respectively.

  20. Application of Targeted Molecular and Material Property Optimization to Bacterial Attachment-Resistant (Meth)acrylate Polymers. (United States)

    Adlington, Kevin; Nguyen, Nam T; Eaves, Elizabeth; Yang, Jing; Chang, Chien-Yi; Li, Jianing; Gower, Alexandra L; Stimpson, Amy; Anderson, Daniel G; Langer, Robert; Davies, Martyn C; Hook, Andrew L; Williams, Paul; Alexander, Morgan R; Irvine, Derek J


    Developing medical devices that resist bacterial attachment and subsequent biofilm formation is highly desirable. In this paper, we report the optimization of the molecular structure and thus material properties of a range of (meth)acrylate copolymers which contain monomers reported to deliver bacterial resistance to surfaces. This optimization allows such monomers to be employed within novel coatings to reduce bacterial attachment to silicone urinary catheters. We show that the flexibility of copolymers can be tuned to match that of the silicone catheter substrate, by copolymerizing these polymers with a lower Tg monomer such that it passes the flexing fatigue tests as coatings upon catheters, that the homopolymers failed. Furthermore, the Tg values of the copolymers are shown to be readily estimated by the Fox equation. The bacterial resistance performance of these copolymers were typically found to be better than the neat silicone or a commercial silver containing hydrogel surface, when the monomer feed contained only 25 v% of the "hit" monomer. The method of initiation (either photo or thermal) was shown not to affect the bacterial resistance of the copolymers. Optimized synthesis conditions to ensure that the correct copolymer composition and to prevent the onset of gelation are detailed.

  1. Preparation and Application of Crosslinked Poly(sodium acrylate-Coated Magnetite Nanoparticles as Corrosion Inhibitors for Carbon Steel Alloy

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta


    Full Text Available This work presents a new method to prepare poly(sodium acrylate magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate as shell. Fourier transform infrared spectroscopy (FTIR was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM was used to examine the morphology of the modified poly(sodium acrylate magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS. Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  2. Preparation and application of crosslinked poly(sodium acrylate)--coated magnetite nanoparticles as corrosion inhibitors for carbon steel alloy. (United States)

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; El-Saeed, Ashraf M


    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM) was used to examine the morphology of the modified poly(sodium acrylate) magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  3. From the N-Heterocyclic Carbene-Catalyzed Conjugate Addition of Alcohols to the Controlled Polymerization of (Meth)acrylates. (United States)

    Ottou, Winnie Nzahou; Bourichon, Damien; Vignolle, Joan; Wirotius, Anne-Laure; Robert, Fredéric; Landais, Yannick; Sotiropoulos, Jean-Marc; Miqueu, Karinne; Taton, Daniel


    Among various N-heterocyclic carbenes (NHCs) tested, only 1,3-bis(tert-butyl)imidazol-2-ylidene (NHC(tBu) ) proved to selectively promote the catalytic conjugate addition of alcohols onto (meth)acrylate substrates. This rather rare example of NHC-catalyzed 1,4-addition of alcohols was investigated as a simple means to trigger the polymerization of both methyl methacrylate and methyl acrylate (MMA and MA, respectively). Well-defined α-alkoxy poly(methyl (meth)acrylate) (PM(M)A) chains, the molar masses of which could be controlled by the initial [(meth)acrylate]0/[ROH]0 molar ratio, were ultimately obtained in N,N-dimethylformamide at 25 °C. A hydroxyl-terminated poly(ethylene oxide) (PEO-OH) macro-initiator was also employed to directly access PEO-b-PMMA amphiphilic block copolymers. Investigations into the reaction mechanism by DFT calculations revealed the occurrence of two competitive concerted pathways, involving either the activation of the alcohol or that of the monomer by NHC(tBu) .

  4. Preparation and drug-loading properties of Fe{sub 3}O{sub 4}/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wensheng [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China); Shen, Yuhua, E-mail: [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Xie, Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Zhang, Weiqiang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China)


    Fe{sub 3}O{sub 4}/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe{sub 3}O{sub 4} nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50–120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe{sub 3}O{sub 4} nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  5. Systematic investigation of the synthesis of core-shell poly(styrene-co-acrylic acid) colloids with varying shell thickness and core diameter

    DEFF Research Database (Denmark)

    Hinge, Mogens; Keiding, Kristian


    the morphology of the material for an specific application is going on. It is known from SFEP of styrene that the final colloidal size can be controlled by adjusting the ionic strength of the synthesis feed [1] and it is suggested that adding acrylic acid to the synthesis will result in a change...... in polymerization locus from the core to the surface [2]. There is at present not performed a systematically investigation in controlling the core size and shell thickness of poly(styrene-co-acrylic acid) core-shell colloids  (poly(ST-co-AA)).   Poly(ST-co-AA) colloids were synthesized by free-radical surfactant......-free emulsion co-polymerization (SFECP) at 70°C, using styrene as monomer and acrylic acid as co-monomer. Different batches of poly(ST-co-AA) colloids were synthesized with varying ionic strength and acrylic acid concentrations in the synthesis feed. The produced poly(ST-co-AA) colloids were analysed...

  6. Relationships Between Base-Catalyzed Hydrolysis Rates or Glutathione Reactivity for Acrylates and Methacrylates and Their NMR Spectra or Heat of Formation

    Directory of Open Access Journals (Sweden)

    Yoshinori Kadoma


    Full Text Available The NMR chemical shift, i.e., the π-electron density of the double bond, of acrylates and methacrylates is related to the reactivity of their monomers. We investigated quantitative structure-property relationships (QSPRs between the base-catalyzed hydrolysis rate constants (k1 or the rate constant with glutathione (GSH (log kGSH for acrylates and methacrylates and the 13C NMR chemical shifts of their α,β-unsaturated carbonyl groups (δCα and δCβ or heat of formation (Hf calculated by the semi-empirical MO method. Reported data for the independent variables were employed. A significant linear relationship between k1 and δCβ, but not δCα, was obtained for methacrylates (r2 = 0.93, but not for acrylates. Also, a significant relationship between k1 and Hf was obtained for both acrylates and methacrylates (r2 = 0.89. By contrast, log kGSH for acrylates and methacrylates was linearly related to their δCβ (r2 = 0.99, but not to Hf. These findings indicate that the 13C NMR chemical shifts and calculated Hf values for acrylates and methacrylates could be valuable for estimating the hydrolysis rate constants and GSH reactivity of these compounds. Also, these data for monomers may be an important tool for examining mechanisms of reactivity.

  7. Plant Sucrose Transporters from a Biophysical Point of View

    Institute of Scientific and Technical Information of China (English)

    Dietmar Geiger


    T The majority of higher plants use sucrose as their main mobile carbohydrate. Proton-driven sucrose transporters play a crucial role in cell-to-cell and long-distance distribution of sucrose throughout the plant. A very negative plant membrane potential and the ability of sucrose transporters to accumulate sucrose concentrations of more than 1 M indicate that plants evolved transporters with unique structural and functional features. The knowledge about the transport mechanism and structural/functional domains of these nano-machines is, however, still fragmentary. In this review,the current knowledge about the biophysical properties of plant sucrose transporters is summarized and discussed.

  8. Functionalization of nanodiamond with epoxy monomer

    Institute of Scientific and Technical Information of China (English)

    Huan Huan Zhang; Ya Ting Liu; Rong Wang; Xiao Yan Yu; Xiong Wei Qu; Qing Xin Zhang


    A novel nanodiamond-epoxy derivative (ND-EP) was synthesized by grafting epoxy monomers onto the surface of nanodiamond (ND), and characterized by FTIR and TGA. The ratio of grafted epoxy groups was determined to be 32.5 wt% by TGA. The developed methodology provides an efficient method for the functionalization of nanodiamond material, which enables a variety of advanced engineering and biomedical applications of ND.

  9. Photochemistry of acrylates at 222 nm (United States)

    Knolle, Wolfgang; Naumov, Sergej; Madani, Mohamed; von Sonntag, Clemens


    Excimer lamps as monochromatic UV sources with an intense short-wavelength emission (especially KrCl∗, 222 nm) allow a photoinitiator-free initiation of the acrylate polymerisation. Laser photolysis (KrCl∗ excimer laser, pulse width 20 ns, up to 5 mJ per pulse) gives rise to similar transient spectra (λmax ≈ 280 nm) for all acrylates studied. As the rather unspecific spectra do not allow conclusions as to the main reaction channel, a product study has been performed by GC-MS following steady-state photolysis of acrylate solutions in acetonitrile, methanol and n-hexane. Somewhat unexpected, α-cleavage seems to be a main reaction channel, and quantum chemical calculations show that such a reaction can occur from either the excited singlet state or the unrelaxed triplet state, but not from the relaxed triplet state that is observed spectroscopically. A reaction scheme accounting for the observed products is presented.

  10. Synthesis and characterization of a sphere-like modified chitosan and acrylate resin composite for organics absorbency (United States)

    Xin, S. S.; Wang, Y. H.; Li, Q. R.; Zhang, Q.; Wang, X. P.


    In this study, the chitosan (deacetylation degree >95%) was modified with vinyltriethoxysilane (A151) and became hydrophobic. The modified chitosan and acrylate resin composite can be synthesized by butyl methacrylate (BMA), butyl acrylate (BA), poly vinyl alcoho(PVA), N,N’-methylene bisacrylamide (MBA), benzoyl peroxide (BPO), and ethyl acetate under microwave irradiation. The optimal synthetic condition was as follows: the molar ratio of BA and BMA was 1.5:1, the dosage of ethyl acetate, PVA, MBA, BPO and modified chitosan were 50 wt.%, 10 wt.%, 1.5 wt.%, 2.0 wt.% and 1.0 wt.% of monomers, respectively. The adsorption capacity of the composite for CHCl3 and CCl4 were approximate to 53 g/g and 44 g/g, respectively. The organics absorbency and regeneration of the samples were also tested, and the samples were characterized by analysis of the scanning electron microscope and simultaneous thermo gravimetric/differential thermal.

  11. Fabrication and Characterization of Gd-DTPA-Loaded Chitosan-Poly(Acrylic Acid) Nanoparticles for Magnetic Resonance Imaging. (United States)

    Ahmed, Arsalan; Zhang, Chao; Guo, Jian; Hu, Yong; Jiang, Xiqun


    Gd-DTPA-loaded chitosan-poly(acrylic acid) nanoparticles (Gd-DTPA@CS-PAA NPs) were formulated based on the reaction system of water-soluble polymer-monomer pairs of acrylic acid in chitosan solution followed by sorption of Gd-DTPA. Morphological investigations revealed the spherical shape of these NPs with about 220 nm particle size. These NPs showed charge reversal characteristic in acidic solution. In vitro and in vivo magnetic characteristics of these NPs were explored to estimate their utilization in targeted enhanced magnetic resonance imaging. Relaxation studies showed that these NPs possessed pH susceptible relaxation properties, which could introduce in vivo-specific distribution of contrast agent. MRI experiment showed that these nanoparticles had better results in contrast enhancement, and the concentration of contrast agent increased in liver and brain with increment in time. Thus, these NPs could maintain in vivo long circulation and high relaxation rate and were suitable agents for magnetic resonance imaging.

  12. A Facile Strategy for Catalyst Separation and Recycling Suitable for ATRP of Hydrophilic Monomers Using a Macroligand. (United States)

    Jiang, Xiaowu; Wu, Jian; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin


    How to simply and efficiently separate and recycle catalyst has still been a constraint for the wide application of atom transfer radical polymerization (ATRP), especially for the polymerization systems with hydrophilic monomers because the polar functional groups may coordinate with transition metal salts, resulting in abundant catalyst residual in the resultant water-soluble polymers. In order to overcome this problem, a latent-biphasic system is developed, which can be successfully used for ATRP catalyst separation and recycling in situ for various kinds of hydrophilic monomers for the first time, such as poly(ethylene glycol) monomethyl ether methacrylate (PEGMA), 2-hydroxyethyl methacrylate (HEMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), N,N-dimethyl acrylamide (DMA), and N-isopropylacrylamide (NIPAM). Herein, random copolymer of octadecyl acrylate (OA), MA-Ln (2-(bis(pyridin-2-ylmethyl)amino)ethyl acrylate), and POA-ran-P(MA-Ln) is designed as the macroligand, and heptane/ethanol is selected as the biphasic solvent. Copper(II) bromide (CuBr2 ) is employed as the catalyst, PEG-bound 2-bromo-2-methylpropanoate (PEG350 -Br) as the water-soluble ATRP initiator and 2,2'-azobis(isobutyronitrile) (AIBN) as the azo-initiator to establish an ICAR (initiators for continuous activator regeneration) ATRP system. Importantly, well-defined water-soluble polymers are obtained even though the recyclable catalyst is used for sixth times.

  13. Concepts for stereoselective acrylate insertion

    KAUST Repository

    Neuwald, Boris


    Various phosphinesulfonato ligands and the corresponding palladium complexes [{((PaO)PdMeCl)-μ-M}n] ([{( X1-Cl)-μ-M}n], (PaO) = κ2- P,O-Ar2PC6H4SO2O) with symmetric (Ar = 2-MeOC6H4, 2-CF3C6H4, 2,6-(MeO)2C6H3, 2,6-(iPrO)2C 6H3, 2-(2′,6′-(MeO)2C 6H3)C6H4) and asymmetric substituted phosphorus atoms (Ar1 = 2,6-(MeO)2C6H 3, Ar2 = 2′-(2,6-(MeO)2C 6H3)C6H4; Ar1 = 2,6-(MeO)2C6H3, Ar2 = 2-cHexOC 6H4) were synthesized. Analyses of molecular motions and dynamics by variable temperature NMR studies and line shape analysis were performed for the free ligands and the complexes. The highest barriers of ΔGa = 44-64 kJ/mol were assigned to an aryl rotation process, and the flexibility of the ligand framework was found to be a key obstacle to a more effective stereocontrol. An increase of steric bulk at the aryl substituents raises the motional barriers but diminishes insertion rates and regioselectivity. The stereoselectivity of the first and the second methyl acrylate (MA) insertion into the Pd-Me bond of in situ generated complexes X1 was investigated by NMR and DFT methods. The substitution pattern of the ligand clearly affects the first MA insertion, resulting in a stereoselectivity of up to 6:1 for complexes with an asymmetric substituted phosphorus. In the consecutive insertion, the stereoselectivity is diminished in all cases. DFT analysis of the corresponding insertion transition states revealed that a selectivity for the first insertion with asymmetric (P aO) complexes is diminished in the consecutive insertions due to uncooperatively working enantiomorphic and chain end stereocontrol. From these observations, further concepts are developed. © 2012 American Chemical Society.

  14. 40 CFR 721.324 - Alkoxylated acrylate polymer (generic). (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxylated acrylate polymer (generic... Substances § 721.324 Alkoxylated acrylate polymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkoxylated acrylate...

  15. 21 CFR 573.120 - Acrylamide-acrylic acid resin. (United States)


    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid...

  16. 21 CFR 176.110 - Acrylamide-acrylic acid resins. (United States)


    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in...

  17. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic). (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated benzyl ester acrylate... Specific Chemical Substances § 721.329 Halogenated benzyl ester acrylate (generic). (a) Chemical substance... halogenated benzyl ester acrylate (PMN P-90-1527) is subject to reporting under this section for...

  18. 40 CFR 721.10180 - Trifunctional acrylic ester (generic). (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Trifunctional acrylic ester (generic... Specific Chemical Substances § 721.10180 Trifunctional acrylic ester (generic). (a) Chemical substance and... acrylic ester (PMN P-04-692) is subject to reporting under this section for the significant new...

  19. 21 CFR 175.210 - Acrylate ester copolymer coating. (United States)


    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section... COATINGS Substances for Use as Components of Coatings § 175.210 Acrylate ester copolymer coating. Acrylate ester copolymer coating may safely be used as a food-contact surface of articles intended for...

  20. Investigation of Acrylic Acid at High Pressure using Neutron Diffraction

    DEFF Research Database (Denmark)

    Johnston, Blair F.; Marshall, William G.; Parsons, Simon


    This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalised using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a n...


    Institute of Scientific and Technical Information of China (English)

    Qiang Shi; Lian-chao Zhu; Chuan-lun Cai; Jing-hua Yin


    The kinetics of melt grafting acrylic acid (AA) onto linear low density polyethylene (LLDPE) by using reactive extrusion was investigated. The polymeric peroxides (POOP and POOH) generated by electron beam irradiation were used to initiate the graft reaction. The samples taken out from the barrel at five ports along screw axis were analyzed by FTIR. The spectra show that both the graft copolymerization and homopolymerization proceed in two stages: the graft degree (or mass of homopolymer) increases linearly with the reaction time in the initial stage, and then gradually in the second stage. The rate of graft copolymerization Rg is always faster than that of homopolymerization Rh in the present system and the activation interpreted in terms of solubility and diffusion of monomer, as well as the reactivity and the concentration of reactive species.The relationships between reaction rate and monomer concentration and peroxide concentration were found to be. Rg ∝ [M]1.46[POOP+POOH]0.53 and Rh ∝ [M]1.08[POOH]0.51, which indicate that the addition of monomer to polymeric radicals is a slow step for the graft copolymerization.

  2. Surface properties and self-cleaning ability of the fluorinated acrylate coatings modified with dodecafluoroheptyl methacrylate through two adding ways

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xin [Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education), School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Zhu, Liqun, E-mail: [Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education), School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Zhang, Yang [Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education), School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Chen, Yichi [Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Bao, Baiqing; Xu, Jinlong; Zhou, Weiwei [Jiangsu Baihe Coatings Co., Ltd, Changzhou 213136 (China)


    Highlights: • A self-cleaning test is used to evaluate the self-cleaning ability of coatings. • Adding way of fluorine monomer has an influence on the self-cleaning ability. • The fluorine content of coating surface increases by changing modification method. • High contact angles and low sliding angles are advantageous for self-cleaning. • The self-cleaning ability of coatings is analyzed after scrubbing. - Abstract: The fluorine-modified acrylate resin was synthesized by solution radical polymerization using dodecafluoroheptyl methacrylate (DFMA) and other acrylate monomers. The same weight of DFMA was added into the reaction through two different ways: (1) adding DFMA as bottom monomer (AFBM); (2) adding DFMA drop by drop (AFDD). The different coatings were prepared by blending the fluorine-modified acrylate resin with the curing agent. Compared with AFDD coating, the AFBM coating exhibited better self-cleaning ability which was confirmed by the self-cleaning test through measuring the specular gloss of coatings before contamination and after water droplets flushing. The fluorine content at the surface of AFBM coating increased from 15.1 at.% to 23.1 at.%, while the water contact angles increased by 8° and the sliding angles decreased obviously. Furthermore, the contact angles and self-cleaning ability of the coatings prepared with DFMA through two adding ways both decreased after scrubbing by wet cotton because of the decrease of the surface fluorine atom content. It could be concluded that high contact angles and low sliding angles were advantageous for coatings to obtain excellent self-cleaning ability.

  3. 21 CFR 888.4220 - Cement monomer vapor evacuator. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or...

  4. The Optimization of Synthesizing Graft Copolymer of Starch with Vinyl Monomers

    Institute of Scientific and Technical Information of China (English)

    WANG Zhiyu; LIU Zuoxin


    The graft copolymerization of acrylamide (AM)/acrylic acid (AA) onto starch (St-g-pAA and St-g-p(AA-co-AM)) was carried out using an orthogonal test method. The combined effects of different reaction conditions on the water absorbency of the graft copolymers were optimized through mathematical statistical methods of range and square variance analysis. The maximum water absorbency was obtained when the ratio of dried starch to distilled water was 1∶8 (w/w), the ratio of starch to monomer 1∶6 (w/w), the initiator concentration 4.40×10-3 mol/L, the crosslinker concentration 10.86×10-2 mol/L, and the basicity to AA 0.70(mol/mol). Both the graft copolymers have an excellent water absorption capacity in distilled water and in 0.9wt% NaCl solution. It was also found that in distilled water the water absorbency of St-g-pAA was higher than that of St-g-p(AA-co-AM), while in 0.9wt% NaCl solution, the situation was just the reverse. The correlation between the water absorbency and the nature of the solution and the properties of the copolymers, which is related to the properties of the monomers, was discussed. The grafting of AA and AM onto starch was confirmed by the IR spectra of St-g-pAA and St-g-p(AA-co-AM).

  5. Synthesis of Molecularly Imprinted Polymers for Amino Acid Derivates by Using Different Functional Monomers

    Directory of Open Access Journals (Sweden)

    Sonia Scorrano


    Full Text Available Fmoc-3-nitrotyrosine (Fmoc-3-NT molecularly imprinted polymers (MIPs were synthesized to understand the influence of several functional monomers on the efficiency of the molecular imprinting process. Acidic, neutral and basic functional monomers, such as acrylic acid (AA, methacrylic acid (MAA, methacrylamide (MAM, 2-vinylpyridine (2-VP, 4-vinylpyridine (4-VP, have been used to synthesize five different polymers. In this study, the MIPs were tested in batch experiments by UV-visible spectroscopy in order to evaluate their binding properties. The MIP prepared with 2-VP exhibited the highest binding affinity for Fmoc-3NT, for which Scatchard analysis the highest association constant (2.49 × 104 M−1 was obtained. Furthermore, titration experiments of Fmoc-3NT into acetonitrile solutions of 2-VP revealed a stronger bond to the template, such that a total interaction is observed. Non-imprinted polymers as control were prepared and showed no binding affinities for Fmoc-3NT. The results are indicative of the importance of ionic bonds formed between the –OH residues of the template molecule and the pyridinyl groups of the polymer matrix. In conclusion, 2-VP assists to create a cavity which allows better access to the analytes.

  6. IPN's of acrylic acid and N-isopropylacrylamide by gamma and electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, UNAM, Ciudad Universitaria, 04510 Mexico DF (Mexico)], E-mail:; Briones, M. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, UNAM, Ciudad Universitaria, 04510 Mexico DF (Mexico); Adem, E. [Instituto de Fisica UNAM, Apartado Postal 20-364, 01000 Mexico DF (Mexico)


    Interpenetrating networks (IPN) of temperature sensitive N-isopropylacrylamide (NIPAAm) and pH sensitive acrylic acid (AAc) monomer were prepared in two consecutive steps. Hydrogels of AAc were synthesized by gamma radiation from a {sup 60}Co gamma source and an electron beam from a Van de Graaff accelerator. A second hydrogel of NIPAAm was synthesized within the first AAc hydrogel by polymerization and cross-linking with a redox initiator and cross-linking agent. The thermal and pH sensitivity of the hydrogels were determined by measuring the swelling, and the morphology and composition by SEM.

  7. Preparation and characterization of acrylic acid-grafted poly (vinyl alcohol) hydrogel actuators using γ-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    An, Sung Jun; Lim, Youn Mook; Gwon, Hui Jeong; Kim, Yun Hye; Youn, Min Ho; Nho, Young Chang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Han, Dong Hyun; Kim, Chong Yeal [Dept. of Radiation Science AND Technology, Graduate School of Chonbuk National University, Jeonju (Korea, Republic of)


    Active polymer gels expand and contract in response to certain environmental stimuli, such as the application of an electric field or a change in the pH level of the surroundings. This ability to achieve large, reversible deformations with no external mechanical loading has generated much interest in the use of these gels as biomimetic actuators and artificial muscles. In this study, poly (vinyl alcohol)(PVA) grafted acrylic acid monomer (PVA-g-AAc) hydrogels were prepared by {sup 60}Co γ-ray irradiation and their properties such as degree of grafting and weight swelling in electrostimulation as an artificial muscle and actuator were investigated.

  8. Effect of sucrose on adventitious root regeneration in apple

    NARCIS (Netherlands)

    Calamar, A.; Klerk, de G.J.M.


    We have examined the effect of sucrose on adventitious root formation in apple microcuttings and in 1-mm stem slices cut from apple microcuttings. The sucrose concentration influenced the number of adventitious roots, but at a broad range of sucrose concentrations (1¿9%) the effect was small. In add

  9. Sham-feeding response of rats to Polycose and sucrose. (United States)

    Nissenbaum, J W; Sclafani, A


    Adult female rats were fitted with gastric fistulas and maintained at 85% of their ad lib body weight. Their real-feeding (fistula closed) and sham-feeding (fistula open) responses to polysaccharide (Polycose) and sucrose solutions were measured during 30 min/day one-bottle tests. The rats consumed similar amounts of a 1% Polycose solution during real- and sham-feeding tests, but their sham-intakes of 4%, 16% and 32% Polycose solutions greatly exceeded their real-intakes of these solutions. Similar results were obtained with sucrose solutions. The rats sham-fed more Polycose than sucrose at the 1% and 4% concentrations, while their sham-intakes of the 16% and 32% Polycose and sucrose solutions were comparable. In subsequent two-solution sham-feeding tests, the rats preferred 1% Polycose to 1% sucrose, but preferred sucrose to Polycose at 4%, 16% and 32% concentrations. These preference results indicate that rats find Polycose more palatable than sucrose at low concentrations, but sucrose more palatable at high concentrations. In addition, the findings that the rats preferred 4% sucrose to 4% Polycose in the two-bottle test, but sham-fed more 4% Polycose than 4% sucrose in the one-bottle tests, suggest that sucrose is more "orally-satiating" than is Polycose. These results provide further evidence for qualitative differences in the tastes of sucrose and polysaccharide. They also indicate that the amount of solution sham-fed does not necessarily reflect the palatability of the solution.

  10. Acrylic Tanks for Stunning Chemical Demonstrations (United States)

    Mirholm, Alexander; Ellervik, Ulf


    We describe the use of acrylic tanks (400 x 450 x 27 mm) for visualization of chemical demonstrations in aqueous solutions. Examples of well-suited demonstrations are oscillating reactions, pH indicators, photochemical reduction of Lauth's violet, and chemoluminiscent reactions. (Contains 1 figure.)


    thoracic and abdominal aorta. The use of a composite construction utilizing acrylate-amide foam is being evaluated in prostheses for mitral valve ...bleeding. The success of the initial experimental work has led to a clinical trial in which 99 replacement , bypass, or patch-angioplasty procedures... replacement , superior vena cava patch venoplasty, and esophageal replacement . (Author)

  12. Static and dynamical critical behavior of the monomer-monomer reaction model with desorption (United States)

    da Costa, E. C.; Rusch, Flávio Roberto


    We studied in this work the monomer-monomer reaction model on a linear chain. The model is described by the following reaction: A + B → AB, where A and B are two monomers that arrive at the surface with probabilities yA and yB, respectively, and we have considered desorption of the monomer B with probability α. The model is studied in the adsorption controlled limit where the reaction rate is infinitely larger than the adsorption rate. We employ site and pair mean-field approximations as well as static and dynamical Monte Carlo simulations. We show that the model exhibits a continuous phase transition between an active steady state and an A-absorbing state, when the parameter yA is varied through a critical value, which depends on the value of α. Monte Carlo simulations and finite-size scaling analysis near the critical point are used to determine the static critical exponents β and ν⊥ and the dynamical critical exponents ν∥ and z. The results found for the monomer-monomer reaction model with B desorption, in the linear chain, are different from those found by E. V. Albano (Albano, 1992) and are in accordance with the values obtained by Jun Zhuo and Sidney Redner (Zhuo and Redner, 1993), and endorse the conjecture of Grassberger, which states that any system undergoing a continuous phase transition from an active steady state to a single absorbing state, exhibits the same critical behavior of the directed percolation universality class.

  13. 水性丙烯酸乳液的合成%Synthesis of water-based acrylic emulsion

    Institute of Scientific and Technical Information of China (English)

    官仕龙; 陈协; 胡登华; 陈思


    An aqueous acrylic emulsion was synthesized by the method of emulsion polymerization with methacrylate as a functional monomer, styrene as a hard monomer and n-butyl acrylate as a soft monomer. The methacrylic acid as the functional monomer achieved water-soluble and increased the adhesion. The effects of the monomer ratio, kind and amount of initiator agent, reaction temperature, stirring speed , monomer dropping time and the holding time on the emulsion and film properties were discussed. The experimental results show that the mass proportion of methacrylate, styrene and n-butyl acrylate is 5 : 17 : 20, the dropping time of the monomer mixture is from 2 to 3 h, the use amount of initiator ammonium persulfate is 0. 7% of the monomer mass, adding dropwise simultaneously with the monomer, OP-10 and sodium lauryl sulfate were selected as the emulsifier content with 2% and 1% of the monomer mass respectively, the reaction temperature is from 75 ℃ to 85 ℃ and the stirring speed is from 200 to 300 r/min, white emulsion with obviously blue light and good stability is obtained; under 100 ℃ , colourless and transparent film with good hardness, adhesion and flexibility is obtained.%以甲基丙烯酸为功能性单体、苯乙烯为硬单体和丙烯酸正丁酯为软单体,通过3种基本丙烯酸酯类单体用乳液聚合的方法合成了一种水性丙烯酸乳液.甲基丙烯酸作为功能单体实现水溶性并增加了附着力.研究了单体配比、引发剂种类及用量、反应温度、搅拌速度、单体滴加时间和保温时间对乳液及涂膜性能的影响.实验结果表明,单体甲基丙烯酸、苯乙烯和丙烯酸正丁酯的质量配比为5∶17∶20,单体混合物的的滴加时间为2~3 h,引发剂过硫酸铵其用量为单体质量的0.7%,加入方式为与单体同时逐滴加入,乳化剂选用OP-10和十二烷基硫酸钠的复合乳化剂,其用量分别为单体质量的2%和1%,反应温度为75~85


    Institute of Scientific and Technical Information of China (English)

    GUOTianying; SONGMoudao; 等


    The semibatch emulsifier-free emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate(BA) in the presence of 2-hydroxyethyl methacrylate(HEMA) initiated by K2S2O8(PSP) was studied.The latex particles can maintain an appreciable stability during the emulsifier-free emulsion copolymerization of MMA and BA in the presence of HEMA.The average particle diameter increase with an increase of total solids content,HEMA content,PSP content,ionic strength of the system and monomer feed rate,and decrease with the monomer feed ration from 3/1 (MMA/BA:molar ration).to 1/3.The stability of this reaction system is improved by adding HEMA as nonionic comonomer,High solids content (50%) latex with monodisperse particle can be obtained using this process.

  15. Large Acrylic Spherical Windows In Hyperbaric Underwater Photography (United States)

    Lones, Joe J.; Stachiw, Jerry D.


    Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

  16. Prenatal ethanol increases sucrose reinforcement, an effect strengthened by postnatal association of ethanol and sucrose. (United States)

    Culleré, Marcela Elena; Spear, Norman E; Molina, Juan Carlos


    Late prenatal exposure to ethanol recruits sensory processing of the drug and of its motivational properties, an experience that leads to heightened ethanol affinity. Recent studies indicate common sensory and neurobiological substrates between this drug and sweet tastants. Using a recently developed operant conditioning technique for infant rats, we examined the effects of prenatal ethanol history upon sucrose self-administration (postnatal days, PDs 14-17). Prior to the last conditioning session, a low (0.5 g/kg) or a high (2.5 g/kg) ethanol dose were paired with sucrose. The intention was to determine if ethanol would inflate or devalue the reinforcing capability of the tastant and if these effects are dependent upon prenatal ethanol history. Male and female pups prenatally exposed to ethanol (2.0 g/kg) responded more when reinforced with sucrose than pups lacking this antenatal experience. Independently of prenatal status, a low ethanol dose (0.5 g/kg) enhanced the reinforcing capability of sucrose while the highest dose (2.5 g/kg) seemed to ameliorate the motivational properties of the tastant. During extinction (PD 18), two factors were critical in determining persistence of responding despite reinforcement omission. Pups prenatally exposed to ethanol that subsequently experienced the low ethanol dose paired with sucrose, showed higher resistance to extinction. The effects here reported were not associated with differential blood alcohol levels across prenatal treatments. These results indicate that fetal ethanol experience promotes affinity for a natural sweet reinforcer and that low doses of ethanol are also capable of enhancing the positive motivational consequences of sucrose when ethanol and sucrose are paired during infancy.

  17. Antifungal Effect of Henna against Candida albicans Adhered to Acrylic Resin as a Possible Method for Prevention of Denture Stomatitis. (United States)

    Nawasrah, Amal; AlNimr, Amani; Ali, Aiman A


    Denture stomatitis is a very common disease affecting the oral mucosa of denture wearers. The aim of this study was to measure the antifungal effect of henna against Candida albicans adhered to acrylic resin as a possible method for prevention of denture stomatitis. One-hundred-eighty acrylic plates were prepared of heat-cured acrylic denture resin. The specimens were divided into six groups of 30 samples each. The first group was only polymer and monomer following the conventional manufacturer instruction for processing complete dentures. The other five groups were processed by adding different concentration of Yamani henna powder (Harazi) to the polymer in a concentration of henna: polymer 1%, 2.5%, 5%, 7.5% and 10%, respectively. Samples were incubated in artificial saliva rich with Candida albicans at 37 °C, and the effect of henna on Candida albicans was evaluated in two different methods: semi-quantitative slide count and a culture-based quantitative assay (quantitative). Variation in the number of live Candida was observed with the increase in the concentration of Yamani henna powder. It was observed that the variation in live Candida, between control group and group B (concentration of Yamani henna powder was 1%), was statistically significant with a p-value of 0.0001. Similarly, variations in live Candida were significant, when the concentration of powder was 7.5% or 10% in contrast with control group and p-values were 0.0001 and 0.001 respectively. Adding henna to acrylic resin denture could be effective in controlling Candida albicans proliferation on the denture surface; however, its effects on the physical properties of acrylic resin denture need further studies.

  18. Antifungal Effect of Henna against Candida albicans Adhered to Acrylic Resin as a Possible Method for Prevention of Denture Stomatitis

    Directory of Open Access Journals (Sweden)

    Amal Nawasrah


    Full Text Available Denture stomatitis is a very common disease affecting the oral mucosa of denture wearers. The aim of this study was to measure the antifungal effect of henna against Candida albicans adhered to acrylic resin as a possible method for prevention of denture stomatitis. One-hundred-eighty acrylic plates were prepared of heat-cured acrylic denture resin. The specimens were divided into six groups of 30 samples each. The first group was only polymer and monomer following the conventional manufacturer instruction for processing complete dentures. The other five groups were processed by adding different concentration of Yamani henna powder (Harazi to the polymer in a concentration of henna: polymer 1%, 2.5%, 5%, 7.5% and 10%, respectively. Samples were incubated in artificial saliva rich with Candida albicans at 37 °C, and the effect of henna on Candida albicans was evaluated in two different methods: semi-quantitative slide count and a culture-based quantitative assay (quantitative. Variation in the number of live Candida was observed with the increase in the concentration of Yamani henna powder. It was observed that the variation in live Candida, between control group and group B (concentration of Yamani henna powder was 1%, was statistically significant with a p-value of 0.0001. Similarly, variations in live Candida were significant, when the concentration of powder was 7.5% or 10% in contrast with control group and p-values were 0.0001 and 0.001 respectively. Adding henna to acrylic resin denture could be effective in controlling Candida albicans proliferation on the denture surface; however, its effects on the physical properties of acrylic resin denture need further studies.

  19. Withanolides and Sucrose Esters from Physalis neomexicana. (United States)

    Cao, Cong-Mei; Wu, Xiaoqing; Kindscher, Kelly; Xu, Liang; Timmermann, Barbara N


    Four withanolides (1-4) and two sucrose esters (5, 6) were isolated from the aerial parts of Physalis neomexicana. The structures of 1-6 were elucidated through a variety of spectroscopic techniques. Cytotoxicity studies of the isolates revealed that 2 inhibited human breast cancer cell lines (MDA-MB-231 and MCF-7) with IC50 values of 1.7 and 6.3 μM, respectively.


    Institute of Scientific and Technical Information of China (English)

    LIU Zhongdong; LIU Huihua; LUO Peng; LIU Peng; Xiao Fugang


    Orthogonal test was used to evaluate the effects of synthetic such as temperature (120~140 ℃), reaction time (4-6) and substrate molar ratio of methyl oleate to sucrose (8:1-12:1) on the percent quantity conversion to sucrose polyester. Sucrose polyester was synthesized by a solvent-free one-stage interesterification. The optimum reaction conditions are as follows: methyl oleate/sucrose = 10∶1 (mol/mol); reaction temperature is 140 ℃;yield reaches 88.15%, and the degree of esterification (DE) is over 7 in the conditions. Thin layer chromatography (TLC), column chromatography (CC), High-performance liquid chromatography (HPLC) were used to analyze the product, the results show that the percent of sucrose polyoleate is over 70% in the product. The physicochemical properties of sucrose polyesters were compared with cooking oil. The results show that the qualities of sucrose polyesters are all up to the triglyceride.

  1. Crystallization inhibition of an amorphous sucrose system using raffinose

    Institute of Scientific and Technical Information of China (English)



    The shelf life of pure amorphous sucrose systems, such as cotton candy, can be very short. Previous studies have shown that amorphous sucrose systems held above the glass transition temperature will collapse and crystallize. One study,however, showed that adding a small percent of another type of sugar, such as trehalose, to sucrose can extend the shelf life of the amorphous system by slowing crystallization. This study explores the hypothesis that raffinose increases the stability of an amorphous sucrose system. Cotton candy at 5 wt% raffinose and 95 wt% sucrose was made and stored at room temperature and three different relative humidities (%RH) 11%RH, 33%RH, and 43%RH. XRD patterns, and glass transition temperatures were obtained to determine the stability as a function of %RH. The data collected showed that raffinose slows sucrose crystallization in a low moisture amorphous state above the glass transition temperature and therefore improves the stability of amorphous sucrose systems.

  2. One step graft copolymerization of acrylic acid and sodium styrene sulfonate onto high-density polyethylene film by preirradiation method

    Institute of Scientific and Technical Information of China (English)


    High-density polyethylene (HDPE) films were irradiated by 60Co gamma ray with a dose of 100 kGy in air and then immersed in aqueous solution of acrylic acid (AA) and sodium styrene sulfonate (SSS) at different temperature. The effects of grafting conditions such as temperature, reaction time, Mohr's salt concentration, and total concentration of monomer on grafting yield were studied. Both grafting yield of AA and SSS onto HDPE respectively increases with total concentration of monomers. The highest grafting yield was observed at 3 mol/L monomers where the grafted PE swelled to the largest extent in the monomers mixture. The grafting yield increases with reaction time and then levels off. At higher temperature, the grafting yield decreases with Mohr's salt concentration, but increases at low temperature when Mohr's salt concentration is 0.083%. Which can be interpreted that in the presence of Fe2+ diperoxides and hydroperoxides may decompose at low temperature to form radical which can initiate the grafting. The physical and chemical properties of grafting films were also investigated.

  3. Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    Sari Fouad


    Full Text Available We reported in this work that the cationic copolymerization in one step takes place between carbon–carbon double-bond monomer styrene with cyclic monomer tetrahydrofuran. The comonomers studied belong to different families: vinylic and cyclic ether. The reaction is initiated with maghnite-H+ an acid exchanged montmorillonite as acid solid ecocatalyst. Maghnite-H+ is already used as catalyst for polymerization of many vinylic and heterocyclic monomers. The oxonium ion of tetrahydrofuran and carbonium ion of styrene propagated the reaction of copolymerization. The acetic anhydride is essential for the maintenance of the ring opening of tetrahydrofuran and the entry in copolymerization. The temperature was kept constant at 40°C in oil bath heating for 6 hours. A typical reaction product was analyzed by 1H-NMR, 13C-NMR and IR and the formation of the copolymer was confirmed. The reaction was proved by matched with analysis. The maghnite-H+ allowed us to obtain extremely pure copolymer in good yield by following a simples operational conditions. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 29th October 2012; Revised: 29th November 2012; Accepted: 29th November 2012[How to Cite: S. Fouad, M.I. Ferrahi, M. Belbachir. (2012. Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 165-171. (doi:10.9767/bcrec.7.2.4074.165-171][How to Link / DOI: ] | View in 

  4. Synthesis of Acrylate Microemulsion Modified by Alkoxy Silane

    Institute of Scientific and Technical Information of China (English)

    SUN Zhijuan; ZHANG Xinya; HUANG Hong; FU Heqing; CHEN Huanqin


    An acrylate emulsion was modified by adding vinyltriisopropoxy silane (trade name C-1706).By adding the multiple emulsifier which consists of an anionic emulsifier, sodium dodecyl benzene sulfonate(SDBS) and nonionic emulsifier, octyl phenolic divinyl oxide (OP-10), the acryiosilane microemulsiun was synthesized by seeded emulsion polymerization. The influential factors including the kind and the adding amount of emulsifiers and the monomer variety of alkoxy silane and the added methods which influence on the properties of the microemulsion were investigated. It is found that SDBS and OP-10 as multiple emulsifiers with mass ratio of hl and the adding amount of 2.5%-3.5% can act on co-effect for emulsion polymerization. The C-1706 possesses bulky isopropoxy substituent that can reduce hydrolysis reactivity during the polymerization process, So as to not only make the process smoothly but also advance the store stability of the emulsion.Moreover, the latter-addition mode of C-1706 can restrain its hydrolysis activity and polycondensation reaction during the polymerization process of the emulsion. The structure, the film cross section, the particle size and its distribution of the microemulsion were analyzed by the Fourier Transform Infrared Ray Spectrum (FT-IR), Scanning Electron Microscopy (SEM) and a particle size analyzer, respectively. The results show that the particle diameter of the modified microemulsion can be controlled between 50 and 70 nm and its film hardness is 7.3. Only adding 1.5% of C-1706 into the system of emulsion polymerization can apparently improve the weathering resistance of the microemulsion, which undergo degradation with chromatism(△E) is 1.6 after 3 600 hours of QUV-aging.

  5. Synthesis of acrylate guar-gum for delivery of bio-active molecules

    Indian Academy of Sciences (India)

    Ajeet Kumar; Arnab De; Subho Mozumdar


    Modification of natural polymers by graft copolymerization is a promising technique as it functionalizes these biopolymer to their potential, imparting desirable properties onto them. Grafting with vinyl monomers is the route for modifying the properties of the naturally occurring guar-gum for their better industrial exploitation and development of various commercial products. Acrylated guar-gum chain is synthesized and analysed using Fourier transform infrared, differential scanning calorimetry and X-ray diffraction techniques to gain an insight into the particle size and structural features. Chlorpyrifos is then entrapped into the polymer, and its release is studied under various conditions. Critical factors influencing the size, entrapment efficiency and release behaviour of entrapped chlorpyrifos have been studied.

  6. Electron-beam initiated polymerization of acrylate compositions 1 : FTIR monitoring of incremental irradiation

    CERN Document Server

    Patacz, C; Coqueret, X


    The electron-beam induced polymerization of some representative formulations including acrylate functional oligomers and diluents has been investigated by means of FTIR spectroscopy applied to films that were cured under a nitrogen flow. In order to gain a deeper insight into the reactivity of the polymerizable systems, the conversion-dose relationship was examined with emphasis on the following points : depth cure profile of the films, and the additivity of effects of incremental radiation doses on monomer conversion. It was shown to be possible to reproduce the actual polymerization profile from discontinuous measurements. This remarkable result is tentatively explained by the geometry of the samples causing limited thermal effects and by the minor influence of possible inhibition and post-polymerization that could influence each of the incremental transformations compared to a single large dose treatment. This method provides a fine tool for revealing differences in kinetic behavior between polymerizable m...


    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  8. Transcription factors, sucrose, and sucrose metabolic genes interact to regulate potato phenylpropanoid metabolism. (United States)

    Payyavula, Raja S; Singh, Rajesh K; Navarre, Duroy A


    Much remains unknown about how transcription factors and sugars regulate phenylpropanoid metabolism in tuber crops like potato (Solanum tuberosum). Based on phylogeny and protein similarity to known regulators of phenylpropanoid metabolism, 15 transcription factors were selected and their expression was compared in white, yellow, red, and purple genotypes with contrasting phenolic and anthocyanin profiles. Red and purple genotypes had increased phenylalanine ammonia lyase (PAL) enzyme activity, markedly higher levels of phenylpropanoids, and elevated expression of most phenylpropanoid structural genes, including a novel anthocyanin O-methyltransferase. The transcription factors Anthocyanin1 (StAN1), basic Helix Loop Helix1 (StbHLH1), and StWD40 were more strongly expressed in red and purple potatoes. Expression of 12 other transcription factors was not associated with phenylpropanoid content, except for StMYB12B, which showed a negative relationship. Increased expression of AN1, bHLH1, and WD40 was also associated with environmentally mediated increases in tuber phenylpropanoids. Treatment of potato plantlets with sucrose induced hydroxycinnamic acids, flavonols, anthocyanins, structural genes, AN1, bHLH1, WD40, and genes encoding the sucrose-hydrolysing enzymes SUSY1, SUSY4, and INV2. Transient expression of StAN1 in tobacco leaves induced bHLH1, structural genes, SUSY1, SUSY4, and INV1, and increased phenylpropanoid amounts. StAN1 infiltration into tobacco leaves decreased sucrose and glucose concentrations. In silico promoter analysis revealed the presence of MYB and bHLH regulatory elements on sucrolytic gene promoters and sucrose-responsive elements on the AN1 promoter. These findings reveal an interesting dynamic between AN1, sucrose, and sucrose metabolic genes in modulating potato phenylpropanoids.

  9. Sucrose secreted by the engineered cyanobacterium and its fermentability (United States)

    Duan, Yangkai; Luo, Quan; Liang, Feiyan; Lu, Xuefeng


    The unicellular cyanobacterium, Synechococcus elongatus PCC 7942 (Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps (encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and cscB (encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing cscB only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.

  10. Superiorly Plasticized PVC/PBSA Blends through Crotonic and Acrylic Acid Functionalization of PVC

    Directory of Open Access Journals (Sweden)

    Arturo Salazar Avalos


    Full Text Available Superior plasticization efficiency was achieved by a grafting from functionalization of the PVC backbone. This was deduced to a synergistic effect of internal plasticization and improved intermolecular interactions between PVC and an oligomeric poly(butylene succinate-co-adipate (PBSA plasticizer. A mild grafting process for functionalization of the PVC chain by crotonic acid (CA or acrylic acid (AA was used. The formation of PVC-g-CA and PVC-g-AA was confirmed by FTIR and 1H NMR. Grafting with the seemingly similar monomers, CA and AA, resulted in different macromolecular structures. AA is easily homopolymerized and long hydrophilic poly(acrylic acid grafts are formed resulting in branched materials. Crotonic acid does not easily homopolymerize; instead, single crotonic acid units are located along the PVC chain, leading to basically linear PVC chains with pendant crotonic acid groups. The elongation of PVC-g-CA and PVC-g-AA in comparison to pure PVC were greatly increased from 6% to 128% and 167%, respectively, by the grafting reactions. Blending 20% (w/w PBSA with PVC, PVC-AA or PVC-CA further increased the elongation at break to 150%, 240% and 320%, respectively, clearly showing a significant synergistic effect in the blends with functionalized PVC. This is a clearly promising milestone towards environmentally friendly flexible PVC materials.

  11. Synthesis and properties of acrylate latex modified by vinyl alkoxy siloxane

    Institute of Scientific and Technical Information of China (English)


    Acrylate latex modified by vinyl triisopropoxy silane (C-1706) was synthesized by seeded emulsion polymerization with anionic emulsifier sodium dodecyl sulphonate(SDS) and nonionic emulsifier OP-10 as the multiple emulsifiers at (78±2) ℃. The effects of different factors, such as the emulsifier, C-1706 monomer and its feeding manner on the properties of aciylate latex modified by C-1706 were investigated. The particle size distribution and the structure, the configuration, the weather durability and stain resistance of copolymer latex were characterized by particle size analyzer, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope(TEM), scanning electron microscope(SEM) and ultraviolet aging instrument respectively. The results show that SDS to OP-10 as multiple emulsifiers can lead to coordinated efficiency, the optimal emulsifier dosage is 2.4%-3.2%(mass fraction), and the mass ratio of SDS to OP-10 is 1:1- 1:2. The seeded emulsion polymerization can effectively introduce a organic-siloxane bonding in a macromolecule inter polymer, and the obtained acrylate latex modified by organic-siloxane possesses narrow distribution of particle size with mean diameter of 51.8-76.6 nm and has the excellent properties in weather durability and stain-resistance especially.

  12. Rheology and adhesion of poly(acrylic acid)/laponite nanocomposite hydrogels as biocompatible adhesives. (United States)

    Shen, Muxian; Li, Li; Sun, Yimin; Xu, Jun; Guo, Xuhong; Prud'homme, Robert K


    Biocompatible nanocomposite hydrogels (NC gels) consisting of poly(acrylic acid) (PAA) and nanosized clay (Laponite) were successfully synthesized by in situ free-radical polymerization of acrylic acid (AA) in aqueous solutions of Laponite. The obtained NC gels were uniform and transparent. Their viscosity, storage modulus G', and loss modulus G″ increased significantly upon increasing the content of Laponite and the dose of AA, while exhibiting a maximum with increasing the neutralization degree of AA. They showed tunable adhesion by changing the dose of Laponite and monomer as well as the neutralization degree of AA, as determined by 180° peel strength measurement. The maximal adhesion was shown when reaching a balance between cohesion and fluidity. A homemade Johnson-Kendall-Roberts (JKR) instrument was employed to study the surface adhesion behavior of the NC gels. The combination of peel strength, rheology, and JKR measurements offers the opportunity of insight into the mechanism of adhesion of hydrogels. The NC gels with tunable adhesion should be ideal candidates for dental adhesive, wound dressing, and tissue engineering.

  13. Influence of Glyoxal on Preparation of Poly(Vinyl Alcohol)/Poly(Acrylic Acid) Blend Film. (United States)

    Park, Ju-Young; Hwang, Kyung-Jun; Yoon, Soon-Do; Lee, Ju-Heon; Lee, In-Hwa


    The preparation of a poly(vinyl alcohol)/poly(acrylic acid)/glyoxal film (PVA = poly(vinyl alcohol); PAA = poly(acrylic acid)) with high tensile strength and hydrophobic properties by using the crosslinking reaction for OH group removal is reported herein. PAA was selected as a crosslinking agent because the functional carboxyl group in each monomer unit facilitates reaction with PVA. The OH groups on unreacted PVA were removed by the addition of glyoxal to the PVA/PAA solution. The chemical properties of the PVA/PAA films were investigated using Fourier transformation infrared spectroscopy and the thermal properties of the PVA/PAA/glyoxal films were investigated by means of differential scanning calorimetry and thermogravimetric analysis. A tensile strength of 48.6 N/mm2 was achieved at a PVA/PAA ratio of 85/15 for the PVA/PAA film. The tensile strength of the cross-linked PVA/PAA/glyoxal film (10 wt% glyoxal) was increased by 55% relative to the pure PVA/PAA (85/15) film. The degree of swelling (DS) and solubility (S) of the 10 wt% (PVA/PAA = 85/15, wt%) film added 10 wt% glyoxal were 1.54 and 0.6, respectively.

  14. Synthesis and photoactivity of phenylazonaphthalene peptide nucleic acid monomers

    Institute of Scientific and Technical Information of China (English)

    Jin Du Li; Miao Chen; Sheng Liu; Hao Bo Zhang; Zhi Lu Liu


    Phenylazonaphthalene peptide nucleic acid (PNA) monomers were successfully synthesized,and their photoisomerization was examined.The new PNA monomers showed reversible trans-cis isomerization with UV and visible light irradiation,which might be the foundation of photo-regulating the hybridization between PNA containing phenylazonaphthalene unit and DNA.Simultaneously,the fluorescence of the new PNA monomers might make them especially useful as structural probes.

  15. Biocompatibility and other properties of acrylic bone cements prepared with antiseptic activators. (United States)

    de la Torre, B; Fernández, M; Vázquez, B; Collía, F; de Pedro, J A; López-Bravo, A; San Román, J


    Acrylic bone cements prepared with activators of reduced toxicity have been formulated with the aim of improving the biocompatibility of the final material. The activators used were N,N-dimethylaminobenzyl alcohol (DMOH) and 4,4'-dimethylamino benzydrol (BZN). The toxicity, cytotoxicity, and antiseptic action of these activators were first studied. DMOH and BZN presented LD50 values 3-4 times higher than DMT, were less cytotoxic against polymorphonuclear leucocytes, and possessed an antimicrobial character, with a high activity against the most representative microorganisms involved in postoperative infections. The properties of the acrylic bone cements formulated with DMOH and BZN were evaluated to determine the influence of these activators on the curing process and the physicochemical characteristics of the cements. A decrease of the peak temperature was observed for the curing with DMOH or BZN with respect to that of one commercially available formulation (CMW 3). However, residual monomer content and mechanical properties in tension and compression were comparable to those of CMW 3. The biocompatibility of acrylic bone cements containing DMOH or BZN was studied and compared with CMW 3. To that end, intramuscular and intraosseous implantation procedures were carried out and the results were obtained from the histological analysis of the surrounding tissues at different periods of time. Implantation of rods of cement into the dorsal muscle of rats showed the presence of a membrane of connective tissue, which increased in collagen fibers with time of implantation, for all formulations. The intraosseous implantation of the cements in the dough state in the femur of rabbits, revealed a higher and early osseous neoformation, with the presence of osteoid material surrounding the rest of the cured material, for the cement prepared with the activator BZN in comparison with that obtained following the implantation of the cement cured with DMOH or DMT (CMW 3).

  16. Can the hydrophilicity of functional monomers affect chemical interaction? (United States)

    Feitosa, V P; Ogliari, F A; Van Meerbeek, B; Watson, T F; Yoshihara, K; Ogliari, A O; Sinhoreti, M A; Correr, A B; Cama, G; Sauro, S


    The number of carbon atoms and/or ester/polyether groups in spacer chains may influence the interaction of functional monomers with calcium and dentin. The present study assessed the chemical interaction and bond strength of 5 standard-synthesized phosphoric-acid ester functional monomers with different spacer chain characteristics, by atomic absorption spectroscopy (AAS), ATR-FTIR, thin-film x-ray diffraction (TF-XRD), scanning electron microscopy (SEM), and microtensile bond strength (μTBS). The tested functional monomers were 2-MEP (two-carbon spacer chain), 10-MDP (10-carbon), 12-MDDP (12-carbon), MTEP (more hydrophilic polyether spacer chain), and CAP-P (intermediate hydrophilicity ester spacer). The intensity of monomer-calcium salt formation measured by AAS differed in the order of 12-MDDP=10-MDP>CAP-P>MTEP>2-MEP. FTIR and SEM analyses of monomer-treated dentin surfaces showed resistance to rinsing for all monomer-dentin bonds, except with 2-MEP. TF-XRD confirmed the weaker interaction of 2-MEP. Highest µTBS was observed for 12-MDDP and 10-MDP. A shorter spacer chain (2-MEP) of phosphate functional monomers induced formation of unstable monomer-calcium salts, and lower chemical interaction and dentin bond strength. The presence of ester or ether groups within longer spacer carbon chains (CAP-P and MTEP) may affect the hydrophilicity, μTBS, and also the formation of monomer-calcium salts.

  17. Interference of functional monomers with polymerization efficiency of adhesives. (United States)

    Hanabusa, Masao; Yoshihara, Kumiko; Yoshida, Yasuhiro; Okihara, Takumi; Yamamoto, Takatsugu; Momoi, Yasuko; Van Meerbeek, Bart


    The degree of conversion (DC) of camphorquinone/amine-based adhesives is affected by acidic functional monomers as a result of inactivation of the amine co-initiator through an acid-base reaction. During bonding, functional monomers of self-etch adhesives chemically interact with hydroxyapatite (HAp). Here, we tested in how far the latter interaction of functional monomers with HAp counteracts the expected reduction in DC of camphorquinone/amine-based adhesives. The DC of three experimental adhesive formulations, containing either of the two functional monomers [10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) or 4-methacryloxyethyl trimellitic acid anhydride (4-META)] or no functional monomer (no-FM; control), was measured with and without HAp powder added to the adhesive formulations. Both the variables 'functional monomer' and 'HAp' were found to be significant, with the functional monomer reducing the DC and HAp counteracting this effect. It is concluded that the functional monomers 10-MDP and 4-META interfere with the polymerization efficiency of adhesives. This interference is less prominent in the presence of HAp, which would clinically correspond to when these two functional monomers of the adhesive simultaneously interact with HAp in tooth tissue.

  18. The practice of using Phenol inhibitors in obtaining monomers

    Energy Technology Data Exchange (ETDEWEB)

    Kurbatov, V.A.; Kirpichnikov, P.A.; Likumovich, A.G.


    Phenol antioxidants are promising stabilizers for the industrial production of monomers. Their potential may be considerably improved by searching for optimum compositions and conditions of application.

  19. Study of Graft Copolymerization of Acrylic Acid Onto Nata De Coco and its Application as Microfiltration Membrane

    Directory of Open Access Journals (Sweden)

    T. Puspitasari


    Full Text Available Chemical and physical modifications of membrane can be carried out by radiation induced graft copolymerization. The aim of this research is to prepare graft copolymers of acrylic acid onto nata de coco (NDC-g-AAc by radiation and to study the performance of grafted copolymer as microfiltration membrane. Using a total dose of 30 kGy, the highest degree of grafting obtained were 209% and 142% for r (weight ratio of monomers to nata de coco equal to 61.3 and 35.7 respectively. The increasing degree of grafting resulted in decreasing flux due to high hydrogen bonding between grafted acrylic groups and water. It was found that the degree of swelling of NDC-g-AAc membrane with r = 35.7 was higher than that of r = 63.1. The changes of chemical structure of membrane were characterized by FTIR spectroscopy which showed a new band at 1720 cm-1 attributed to the carbonyl group of acrylic acid

  20. Properties of Eco-friendly Acrylic Resin/Clay Nanocomposites Prepared by Non-aqueous Dispersion (NAD) Polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeongho; Lee, Minho; Jeon, Hyeon Yeol; Min, Byong Hun; Kim, Jeong Ho [Univ. of Suwon, Hwaseong (Korea, Republic of); Lee, Young Chul [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)


    Eco-friendly acrylic resin/clay nanocomposites containing pristine montmorillonite (PM) or modified clays (30B and 25A) were prepared from acrylic and styrenic monomers using non-aqueous dispersion (NAD) polymerization. Effect of nanoclays on physical properties of polymerization product and resulting nanocomposites was investigated. In view of NAD particle stability, addition of nanoclay at the beginning of polymerization is proved to be good. Results of gel fraction, acid value and viscosity of the NAD product showed that nanocomposites containing clay 25A showed better physical properties than the ones with other clays. GPC results exhibit the increase in molecular weight and decrease in polydispersity index for the 25A nanocomposite. Increase in layer distance confirmed from XRD analysis showed good dispersion of 25A in the nanocomposite. Thermal and dynamic mechanical analysis showed that highest glass transition temperature and storage modulus for 25A nanocomposites. These results indicate that 25A nanoclay gives the best properties in the process of non-aqueous dispersion polymerization of acrylic resin/nanoclay nanocomposites.

  1. Polymerization time for a microwave-cured acrylic resin with multiple flasks Tempo de polimerização de resina acrílica em microondas, utilizando múltiplas muflas


    Daniela Maffei Botega; Tatiana de Souza Machado; José Antônio Nunes de Mello; Renata Cunha Matheus Rodrigues Garcia; Altair Antoninha Del Bel Cury


    This study aimed at establishing the polymerization time of a microwave-cured acrylic resin (AcronTM MC), simultaneously processing 2, 4, and 6 flasks. Required time was measured according to the parameters: monomer release in water, Knoop hardness, and porosity. Samples were made with AcronTM MC in different shapes: rectangular (32 x 10 x 2.5 mm) for monomer release and porosity; and half-disc (30 mm in diameter x 4 mm in height) for Knoop hardness. There were four experimental groups (n = 2...

  2. Pulse radiolysis of aqueous solutions of ethyl acrylate and hydroxy ethyl acrylate (United States)

    Safrany, A.; Biro, A.; Wojnarovits, L.


    Ethyl- and hydroxy ethyl acrylate show high reactivities with hydrated electron and hydroxyl radical intermediates of water radiolysis. The electron adduct reversibly protonate with pK values of 5.7 and 7.3. The adducts may take part in irreversible protonation at the β carbon atom forming α-carboxyl alkyl radicals. Same type of radical forms in reaction of acrylates with OH: at low concentration the adduct mainly disappear in self termination reactions. Above 5 mmol dm -1 the signals showed the startup of oligomerization.

  3. Analysis and protease-catalysed synthesis of sucrose alkanoate regioisomers

    DEFF Research Database (Denmark)

    Lie, Aleksander


    The aims of the presented research were to develop quantifiable methods for reversed-phase high-performance liquid chromatography analysis of sucrose alkanoate regioisomers and to investigate the activity and regioisomeric distribution in the biocatalytic esterification of sucrose with vinyl...... formulations. Differences in regioisomeric distribution after 48 hours appeared partly to stem from differences in overall reaction rates, as the different reaction conditions resulted in similar distributions after different reaction times. The esterification of sucrose with vinyl laurate with no protein...

  4. Effect of salt on the response of birds to sucrose (United States)

    Rogers, J.G.; Maller, O.


    The preference of male red-winged blackbirds for solutions of sucrose and sucrose with 0.03 M sodium chloride was tested, using a two-bottle choice test. Preliminary experiments demonstrated that the birds were indifferent to 0.03 M NaCl in water. Both control and experimental animals exhibited indifference to the solutions at the lowest concentration and aversion at the highest. The data suggest that the added sodium chloride makes the sucrose stimulus more discriminable.

  5. A review of the developments of multi-purpose primers and adhesives comprising novel dithiooctanoate monomers and phosphonic acid monomers. (United States)

    Ikemura, Kunio; Endo, Takeshi; Kadoma, Yoshinori


    This paper reviews the developments of dithiooctanoate monomers and acidic adhesive monomers, and their roles in multi-purpose primers and adhesives in promoting adhesion to multiple substrate materials. Novel dithiooctanoate monomers exhibited excellent bonding to precious metals and alloys when compared against conventional sulfur-containing monomers. Newly developed phosphonic acid monomers, endowed with a water-soluble nature, enabled sufficient demineralization of dental hard tissues and thus improved bonding to both ground enamel and dentin. The optimal combination for bonding to dental hard tissues and precious and non-precious metals and alloys was 5.0 wt% 10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT) and 1.0 wt% 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA). For bonding to dental porcelain, alumina, zirconia, and gold (Au) alloy, a ternary combination of silane coupling agent, acidic adhesive monomers, and dithiooctanoate monomers seemed promising. The latest development was a single-bottle, multi-purpose, self-etching adhesive which contained only acidic adhesive monomers and dithiooctanoate monomers but which produced strong adhesion to ground enamel and dentin, sandblasted zirconia, and Au alloy.

  6. Enhancing fermentative hydrogen production from sucrose. (United States)

    Perera, Karnayakage Rasika J; Nirmalakhandan, Nagamany


    This study evaluated the hypothesis that fermentative hydrogen production from organic-rich feedstock could be enhanced by supplementing with waste materials such as cattle manure that could provide nutritional needs, buffering capacity, and native hydrogen-producing organisms. This hypothesis was tested in batch reactors fed with sucrose blended with cattle manure run at 25 degrees C without any nutrient supplements, pH adjustments, buffering, or gas-sparging. Hydrogen production rates in these reactors ranged 16-30 mL H(2)/g DeltaCOD-day, while hydrogen content in the biogases ranged 50-59%. Compared to literature studies conducted at higher temperatures, hydrogen yields found in this study at 25 degrees C were higher in the range of 3.8-4.7 mol H(2)/mol sucrose added, with higher positive net energy yields (>14 kJ/L). This study demonstrated that cattle manure as a supplement could not only provide hydrogen-producing seed, nutritional needs, and buffering capacity, but also increase hydrogen yield by approximately 10%, improving the economic viability of fermentative biohydrogen production from sugary wastes.

  7. Linear sucrose transport in protoplasts from developing soybean cotyledons. (United States)

    Lin, W


    Previous studies with isolated soybean cotyledon protoplasts revealed the presence of a saturable, simple diffusion, and nonsaturating carrier-mediated uptake of sucrose into soybean cotyledon cells. A proton/sucrose cotransport may be involved in the saturable sucrose uptake (Lin et al. 1984 Plant Physiol 75: 936-940 and Schmitt et al. 1984 Plant Physiol 75: 941-946). In this study, we investigated the linear sucrose uptake mechanism by treating isolated protoplasts with 15 micromolar p-trifluoromethoxy-carbonylcyanide phenylhydrazone (FCCP) or 100 micromolar p-chloromecuribenzenesulfonic acid to eliminate the saturable uptake. We found: (a) increasing external pH decreases the linear sucrose uptake; (b) fusicoccin at 20 micromolar stimulates and FCCP at 15 micromolar inhibits this linear sucrose uptake; and (c) the ratio of the initial influx of proton to sucrose is close to one in both saturable and nondiffusive linear (difference between the total linear and diffusive components) uptakes. The results suggest that a proton/sucrose cotransport is also involved in the nondiffusive linear sucrose uptake into soybean cotyledon cells.

  8. Sucrose metabolism in halotolerant methanotroph Methylomicrobium alcaliphilum 20Z. (United States)

    But, Sergey Y; Khmelenina, Valentina N; Reshetnikov, Alexander S; Mustakhimov, Ildar I; Kalyuzhnaya, Marina G; Trotsenko, Yuri A


    Sucrose accumulation has been observed in some methylotrophic bacteria utilizing methane, methanol, or methylated amines as a carbon and energy source. In this work, we have investigated the biochemical pathways for sucrose metabolism in the model halotolerant methanotroph Methylomicrobium alcaliphilum 20Z. The genes encoding sucrose-phosphate synthase (Sps), sucrose-phosphate phosphatase (Spp), fructokinase (FruK), and amylosucrase (Ams) were co-transcribed and displayed similar expression levels. Functional Spp and Ams were purified after heterologous expression in Escherichia coli. Recombinant Spp exhibited high affinity for sucrose-6-phosphate and stayed active at very high levels of sucrose (K i  = 1.0 ± 0.6 M). The recombinant amylosucrase obeyed the classical Michaelis-Menten kinetics in the reactions of sucrose hydrolysis and transglycosylation. As a result, the complete metabolic network for sucrose biosynthesis and re-utilization in the non-phototrophic organism was reconstructed for the first time. Comparative genomic studies revealed analogous gene clusters in various Proteobacteria, thus indicating that the ability to produce and metabolize sucrose is widespread among prokaryotes.

  9. Sucrose-mediated giant cell formation in the genus Neisseria. (United States)

    Johnson, K G; McDonald, I J


    Growth of Neisseria perflava, Neisseria cinerea, and Neisseria sicca strain Kirkland in media supplemented with sucrose (0.5 to 5.0% w/v) resulted in the formation of giant cells. Response to sucrose was specific in that a variety of other carbohydrates did not mediate giant cell formation. Giant cells appeared only under growth conditions and did not lyse upon transfer to medium lacking sucrose or upon resuspension in hypotonic media. Reversion of giant to normal cells occurred when giant cells were used as inocula and allowed to multiply in media lacking sucrose.

  10. Optical spectroscopy of Nd{sup 3+} ions in poly(acrylic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Lara, F [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); C, A Lira [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); Ramirez, M O [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Flores, M [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); Arroyo, R [Departamento de Quimica, Universidad Autonoma Metropolitana-Iztapalapa, PO Box 55-534, 09340 Mexico, DF (Mexico); Caldino, U [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)


    Nd{sup 3+} dissolved in solid poly(acrylic acid) was synthesized by polymerization of the monomer partially neutralized with neodymium hydroxide in aqueous solution. The monomer modification and the coordination of ligands to Nd{sup 3+} were confirmed by {sup 1}H NMR spectroscopy. The measured oscillator strengths for transitions from the ground state to the main excited state manifolds compared favourably with calculated electric dipole oscillator strengths. The spontaneous emission rates, the fluorescence branching ratios and the stimulated emission cross sections of the {sup 4}F{sub 3/2} {yields} {sup 4}I{sub 9/2}, {sup 4}F{sub 3/2} {yields} {sup 4}I{sub 11/2} and {sup 4}F{sub 3/2} {yields} {sup 4}I{sub 13/2} transitions, as well as the radiative lifetime and the quantum efficiency of the {sup 4}F{sub 3/2} emitting level, were determined.


    Institute of Scientific and Technical Information of China (English)

    Feng Bai; Xin-lin Yang; Wen-qiang Huang


    Divinylbenzene-80 (DVB-80) and polar monomer acrylic acid (AA) having hydrogen bonding at a total monomer loading of 5 vol% were precipitated-copolymerized in a variety of organic solvents with 2,2'-azobis(isobutyronitrile) (AIBN) as initiator. The experiments were investigated from a two-dimensional matrix, i.e., the actual crosslinking degree of DVB varying from 0 to 80% and the solvent composition varying from 0 to 100% of toluene mixture with acetonitrile, when the mixture of acetonitrile and toluene was used as the reaction solvent. Under various reaction conditions, six distinct morphologies including soluble polymers, swellable microgels, coagulum, irregular microparticles, and nano-/micrometer microspheres were formed and the structures of these polymer architectures were described. A morphological map was utilized to discuss the effects of both crosslinking degree of DVB and composition of solvent on the transitions between morphology domains. The results demonstrated that the microspheres are formed by an internal contraction due to the marginal solvency of the continuous phase and the crosslinking of the polymer network through the covalent bonding from DVB as well as the interchain hydrogen-bonding between the carboxylic acid units.

  12. Plasma-Enhanced Copolymerization of Amino Acid and Synthetic Monomers (United States)


    end cap containing a second inlet for the liquid monomer delivery (Scheme 1). The solid L-tyrosine monomer was placed in a resistively heated tantalum ...microroughness, which is indicative of uniform cross-linking and wetting of the deposits of all components. These films are free of pinhole defects as well

  13. Research progress of acrylate modified waterborne polyurethane%丙烯酸酯改性水性聚氨酯的研究进展

    Institute of Scientific and Technical Information of China (English)

    高国生; 任筱芳; 杜郢; 蔡小燕


    介绍了丙烯酸酯改性水性聚氨酯乳液(PUA)的制备方法,其中包括乳液型丙烯酸酯改性水性聚氨酯、单体丙烯酸酯改性水性聚氨酯、溶剂型丙烯酸酯低聚物改性水性聚氨酯,指出了各改性方法的优缺点;概述了国内外的研究现状,对丙烯酸酯改性水性聚氨酯前景进行了展望.%In this paper.the preparation methods of acrylate modified waterborne polyurethanes (PUA) were fully reviewed.including the acrylic emulsion modified waterborne polyurethane.the acrylic monomer modified waterborne polyurethane and the solvent-based acrylic oligomer modified waterborne polyurethane. On the basis of the advantages and disadvantages of these methods and the overseas and domestic research situation,the prospects of PUA was discussed.

  14. Monomer-dimer tatami tilings of square regions

    CERN Document Server

    Erickson, Alejandro


    We prove that the number of monomer-dimer tilings of an $n\\times n$ square grid, with $mmonomers in which no four tiles meet at any point is $m2^m+(m+1)2^{m+1}$, when $m$ and $n$ have the same parity. In addition, we present a new proof of the result that there are $n2^{n-1}$ such tilings with $n$ monomers, which divides the tilings into $n$ classes of size $2^{n-1}$. The sum of these tilings over all monomer counts has the closed form $2^{n-1}(3n-4)+2$ and, curiously, this is equal to the sum of the squares of all parts in all compositions of $n$. We also describe two algorithms and a Gray code ordering for generating the $n2^{n-1}$ tilings with $n$ monomers, which are both based on our new proof.

  15. An investigation on the effects of different polymerization techniques on dimensional changes ofAcropars, an Iranian autopolymerizing acrylic resin

    Directory of Open Access Journals (Sweden)

    Ebadian B


    Full Text Available Iranian product, Acropars autopolymerizing acrylic resin is nowadays widely used in"ndental prostheses. Dimensional change is a common problem among Iranian made acrylic resins in making"ncustom trays and record bases, seems to be more than the similar foreign products. In order to achieve a"ntechnique for making a record base with minimum dimensional changes, more research is necessary."nPurpose: The aim of the present study was to determine a curing technique for Iranian autopolymerizing"nacrylic resins leading to the least polymerization shrinkage and the most adaptation between record bases and"nstone casts."nMaterials and Methods: In this experimental study, 40 stone casts were divided into four 10- member group."nFor each group, polymerization shrinkage was determined at three points with one of the following"ntechniques: Bench curing, Curing under a coat of petroleum jelly , Curing in a monomer saturated"natmosphere, Curing in boiled water. Adaptation between bases and stone casts were measured at three points"n(the right and left crests of the ridge and the midpalatal region with a light-measuring microscope. To analyze"nthe data, Variance analysis was used."nResults: The monomer atmosphere technique showed the minimum dimensional changes and the samples in"nboiled water group had the maximum dimensional changes. No statistical differences were observed between"nother groups."nConclusion: More adaptation between record bases and stone casts was observed in monomer atmosphere"npolymerization technique. The differences between bench curing and curing under a coat of petroleum jelly"ntechniques with this method were not statistically significant. Therefore, it is suggested for making base"nrecords with maximum adaptation.

  16. Compartmentation of sucrose during radial transfer in mature sorghum culm

    Directory of Open Access Journals (Sweden)

    Vietor Donald M


    Full Text Available Abstract Background The sucrose that accumulates in the culm of sorghum (Sorghum bicolor (L. Moench and other large tropical andropogonoid grasses can be of commercial value, and can buffer assimilate supply during development. Previous study conducted with intact plants showed that sucrose can be radially transferred to the intracellular compartment of mature ripening sorghum internode without being hydrolysed. In this study, culm-infused radiolabelled sucrose was traced between cellular compartments and among related metabolites to determine if the compartmental path of sucrose during radial transfer in culm tissue was symplasmic or included an apoplasmic step. This transfer path was evaluated for elongating and ripening culm tissue of intact plants of two semidwarf grain sorghums. The metabolic path in elongating internode tissue was also evaluated. Results On the day after culm infusion of the tracer sucrose, the specific radioactivity of sucrose recovered from the intracellular compartment of growing axillary-branch tissue was greater (nearly twice than that in the free space, indicating that sucrose was preferentially transferred through symplasmic routes. In contrast, the sucrose specific radioactivity in the intracellular compartment of the mature (ripening culm tissue was probably less (about 3/4's than that in free space indicating that sucrose was preferentially transferred through routes that included an apoplasmic step. In growing internodes of the axillary branch of sorghum, the tritium label initially provided in the fructose moiety of sucrose molecules was largely (81% recovered in the fructose moiety, indicating that a large portion of sucrose molecules is not hydrolysed and resynthesized during radial transfer. Conclusion During radial transfer of sucrose in ripening internodes of intact sorghum plants, much of the sucrose is transferred intact (without hydrolysis and resynthesis and primarily through a path that includes an

  17. 78 FR 66743 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose; Availability (United States)


    ... iron sucrose injection. The draft guidance is a revised version of a previously issued draft guidance... sucrose injection (Draft Iron Sucrose Injection BE Recommendations of 2013). Venofer (iron sucrose... the Agency's recommendations for BE studies to support ANDAs for iron sucrose injection (Draft......

  18. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers. (United States)


    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... this section are not applicable to ethylene-acrylic acid copolymers used in food-packaging adhesives... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310...

  19. Artificial saliva effect on toxic substances release from acrylic resins

    Directory of Open Access Journals (Sweden)

    Kostić Milena


    Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

  20. 40 CFR 721.8082 - Polyester polyurethane acrylate. (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane...

  1. Functionality of Inulin as a Sucrose Replacer in Cookie Baking (United States)

    Inulin was evaluated as a sucrose replacer for healthy cookie production with benefits of low glycemic impact and prebiotic soluble fiber. Sucrose (as a reference) and three inulin products of different concentrations (as soluble fibers) were used to explore the effects of sugar-replacer type on so...

  2. Citrate increases glass transition temperature of vitrified sucrose preparations

    NARCIS (Netherlands)

    Kets, E.P.W.; Lipelaar, P.J.; Hoekstra, F.A.; Vromans, H.


    The aim of this study was to investigate the effect of sodium citrate on the properties of dried amorphous sucrose glasses. Addition of sodium citrate to a sucrose solution followed by freeze-drying or convective drying resulted in a glass transition temperature (T-g) that was higher than the well-s

  3. Sucrose and Saccharomyces cerevisiae: a relationship most sweet. (United States)

    Marques, Wesley Leoricy; Raghavendran, Vijayendran; Stambuk, Boris Ugarte; Gombert, Andreas Karoly


    Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is focused on sucrose metabolism in S. cerevisiae, a rather unexplored subject in the scientific literature. An analysis of sucrose availability in nature and yeast sugar metabolism was performed, in order to understand the molecular background that makes S. cerevisiae consume this sugar efficiently. A historical overview on the use of sucrose and S. cerevisiae by humans is also presented considering sugarcane and sugarbeet as the main sources of this carbohydrate. Physiological aspects of sucrose consumption are compared with those concerning other economically relevant sugars. Also, metabolic engineering efforts to alter sucrose catabolism are presented in a chronological manner. In spite of its extensive use in yeast-based industries, a lot of basic and applied research on sucrose metabolism is imperative, mainly in fields such as genetics, physiology and metabolic engineering.

  4. Comparative sucrose responsiveness in Apis mellifera and A. cerana foragers. (United States)

    Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y; Miao, Xiaoqing


    In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.

  5. Switching the mode of sucrose utilization by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Miletti Luiz C


    Full Text Available Abstract Background Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. Results We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Conclusion Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by

  6. Injectable biocompatible and biodegradable pH-responsive hollow particle gels containing poly(acrylic acid): the effect of copolymer composition on gel properties. (United States)

    Halacheva, Silvia S; Adlam, Daman J; Hendow, Eseelle K; Freemont, Tony J; Hoyland, Judith; Saunders, Brian R


    The potential of various pH-responsive alkyl (meth)acrylate ester- and (meth)acrylic acid-based copolymers, including poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) and poly(n-butyl acrylate-co-methacrylic acid) (PBA-MAA), to form pH-sensitive biocompatible and biodegradable hollow particle gel scaffolds for use in non-load-bearing soft tissue regeneration have been explored. The optimal copolymer design criteria for preparation of these materials have been established. Physical gels which are both pH- and redox-sensitive were formed only from PMMA-AA copolymers. MMA is the optimal hydrophobic monomer, whereas the use of various COOH-containing monomers, e.g., MAA and AA, will always induce a pH-triggered physical gelation. The PMMA-AA gels were prepared at physiological pH range from concentrated dispersions of swollen, hollow, polymer-based particles cross-linked with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP). A linear relationship between particle swelling ratios, gel elasticity, and ductility was observed. The PMMA-AA gels with lower AA contents feature lower swelling ratios, mechanical strengths, and ductilities. Increasing the swelling ratio (e.g., through increasing AA content) decreased the intraparticle elasticity; however, intershell contact and gel elasticity were found to increase. The mechanical properties and performance of the gels were tuneable upon varying the copolymers' compositions and the structure of the cross-linker. Compared to PMMA-AA/CYS, the PMMA-AA/DTP gels were more elastic and ductile. The biodegradability and cytotoxicity of the new hollow particle gels were tested for the first time and related to their composition, mechanical properties, and morphology. The new PMMA-AA/CYS and PMMA-AA/DTP gels have shown good biocompatibility, biodegradability, strength, and interconnected porosity and therefore have good potential as a tissue repair agent.

  7. Sucrose behenate as a crystallization enhancer for soft fats. (United States)

    Domingues, Maria Aliciane Fontenele; da Silva, Thaís Lomonaco Teodoro; Ribeiro, Ana Paula Badan; Chiu, Ming Chih; Gonçalves, Lireny Aparecida Guaraldo


    The addition of sucrose behenate for the modification of the physical properties of soft fats, such as soybean oil-based interesterified fat, refined palm oil, and palm mid fraction was studied. The addition of sucrose behenate was verified to affect the crystalline network of fats, changing the hardness and solids profile. The isothermal crystallization behaviors of the fat blends with 1% sucrose behenate were analyzed at 20 and 25 °C. Temperature had a greater effect on the speed of crystallization (k) than the presence of the emulsifier. Sucrose behenate did, however, influence the crystallization mechanism, with changes observed in the Avrami exponent (n). These changes were also observed in the microstructure of the fats. Changes in the polymorphic behavior were observed with the addition of sucrose behenate, such as a possible delay in the α → β transition for interesterified fat, and the initial formation of the β polymorph in palm oil.

  8. Antibiotic-loaded acrylic cement: current concepts. (United States)

    Buchholz, H W; Elson, R A; Heinert, K


    Antibiotic-loaded acrylic cement has been used routinely since 1972 at the authors' hospitals, where a series of some 22,000 joint arthroplasty operations was performed from 1964-1983. The current status of the material is presented with up-to-date follow-up statistics on prophylactic therapy and on established deep infections. The results of 869 exchange arthroplasties are compared with results published in 1981. In the future, results will be presented in the form of survival curves. The method by which survival tables and curves are constructed is critical. Investigators should use survival curves for ease of comparison and because of the wide range of possibilities in an analysis of covariable factors. A retrospective actuarial analysis was made of 825 one-stage reimplantations in which antibiotic-loaded acrylic cement was used for infected total hip arthroplasties. Staphylococcus aureus was the most commonly encountered organism. Failure rates of prostheses infected by S. aureus, S. species, and anaerobic corynebacteria did not differ statistically. A factor that significantly contributed to failure of this method of treatment was Pseudomonas infection. By actuarial analysis five years after operation, a success (survival) rate of 77% was calculated.

  9. Surface functionalization of an osteoconductive filler by plasma polymerization of poly(ε-caprolactone) and poly(acrylic acid) films (United States)

    Petisco-Ferrero, S.; Sánchez-Ilárduya, M. B.; Díez, A.; Martín, L.; Meaurio Arrate, E.; Sarasua, J. R.


    One of the major limitations found in the use of nanocomposites based on synthetic hydroxyapatite and polymeric matrix for bone-tissue regeneration lies in the poor interfacial adhesion between the inorganic filler and the polymer matrix. The integrity of the nanocomposite is severely compromised since, on the one hand, high surface fillers tend to form aggregates and on the other, there is no chemical bonding between these two different categories of materials. Thus, customized surface functionalization stands as an effective route to improve the interfacial behaviour between particles and polymeric matrices. Amongst the current state of development of coating technologies, the high film-chemistry controllability offered by plasma polymerization technology enhances the synthesis of polymeric films from virtually any starting organic monomer. In this sense, the work presented here provides strong evidences of surface functionalization achieved by plasma polymerization starting respectively from ε-caprolactone and acrylic acid monomers. The chemistry of the deposited films has been descriptively analysed by XPS demonstrating outstanding retention of monomer functionalities and FTIR spectra of the deposited films revealed a high resemblance to those obtained by conventional synthesis. Results provided thereof are expected to significantly contribute to improve the interfacial behaviour in terms of matrix-reinforcement compatibilization, of crucial importance for bone-tissue engineering applications.

  10. Production of bone cement composites: effect of fillers, co-monomer and particles properties

    Energy Technology Data Exchange (ETDEWEB)

    Santos Junior, J.G.F.; Melo, P.A.; Pinto, J.C., E-mail: jjunior@peq.coppe.ufrj.b, E-mail: melo@peq.coppe.ufrj.b, E-mail: pinto@peq.coppe.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia. (PEQ/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Quimica; Pita, V.J.R.R., E-mail: vjpita@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Eloisa Mano; Nele, M. [Universidade Federal do Rio de Janeiro (EQ/UFRJ), RJ (Brazil). Escola de Quimica


    Artificial bone cements (BCs) based on poly(methyl methacrylate) (PMMA) powders and methyl methacrylate (MMA) liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the addition of hydroxyapatite (HA) and acrylic acid (AA) to the bone cement recipe can be beneficial for the mechanical performance of the final material. It is also shown that particle morphology can exert a tremendous effect upon the performance of test pieces, indicating that the suspension polymerization step should be carefully controlled when optimization of the bone cement formulation is desired. (author)

  11. Characterization of a Low Shrinkage Dental Composite Containing Bismethylene Spiroorthocarbonate Expanding Monomer

    Directory of Open Access Journals (Sweden)

    Jing Fu


    Full Text Available In this study, a novel dental composite based on the unsaturated bismethylene spiroorthocarbonate expanding monomer 3,9-dimethylene-1,3,5,7-tetraoxa-spiro[5,5]undecane (BMSOC and bisphenol-S-bis(3-meth acrylate-2-hydroxypropylether (BisS-GMA was prepared. CQ (camphorquinone of 1 wt % and DMAEMA (2-(dimethylaminoethyl methacrylate of 2 wt % were used in a photoinitiation system to initiate the copolymerization of the matrix resins. Distilled water contact angle measurements were performed for the wettability measurement. Degree of conversion, volumetric shrinkage, contraction stress and compressive strength were measured using Fourier Transformation Infrared-FTIR spectroscopy, the AccuVol and a universal testing machine, respectively. Within the limitations of this study, it can be concluded that the resin composites modified by bismethylene spiroorthocarbonate and BisS-GMA showed a low volumetric shrinkage at 1.25% and a higher contact angle. The lower contraction stress, higher degree of conversion and compressive strength of the novel dental composites were also observed.

  12. Study on the preirradiation polymerization of vinyl monomers (United States)

    Yu-Ming, Liu; Yue-Qi, Yang; Zue-Teh, Ma

    This paper presents mainly the polymerization, copolymerization and crosslinking of monomers off-source induced by peroxides which are formed by high energy irradiation of vinyl monomers such as styrene (St), acrylonitrile (AN), methylmethacrylate (MMA), vinyl acetate (VAc) and 2-hydroxyethyl methacrylate (HEMA). The peroxides produced by irradiation of the above-mentioned monomers can not only induce the monomers themselves, but also another non-irradiated monomer to carry out copolymerization efficiently. The activation energy of peroxide formation, the apparent activation energy of polymerization and the activation energy of peroxide initiation by irradiation of vinyl monomers are: Ef(MMA) = 11, Ef(St) = 9.6, Ef(AN) = 8.5, EMMA = EVA = 11.4, Ei(MMA) = Ei(VA) = 13 kcal/mol. The rate of decomposition of monomer peroxides is smoother than that of BPO during the polymerization and so a smooth kinetic progress is obtained. The initiating ability of forming peroxides by irradiation of the vinyl monomers depends mainly on the chemical structure of the monomers. For instance, the main structure of peroxides formed during preirradiation MMA are: alternating peroxy-copolymer ? and random peroxy-copolymer ? Owing to the peroxy-bond which is unstable and in which homolytic breakage easily occurs to yield a pair of radicals, RO . is formed within the above-mentioned structural compounds, so that they possess stronger initiating reactivity. It is quite evident that the initiating reactivity of AN peroxide will be greatly reduced because of the conjugate double bond. In other words, the initiating ability of AN peroxide is lower than MMA peroxide and St peroxide.

  13. Highly Efficient Synthesis of Allopurinol Locked Nucleic Acid Monomer by C6 Deamination of 8-Aza-7-bromo-7-deazaadenine Locked Nucleic Acid Monomer

    DEFF Research Database (Denmark)

    Kosbar, Tamer Reda El-Saeed; Sofan, M.; Abou-Zeid, L.;


    An allopurinol locked nucleic acid (LNA) monomer was prepared by a novel strategy through C6 deamination of the corresponding 8-aza-7-bromo-7-deazaadenine LNA monomer with aqueous sodium hydroxide. An 8-aza-7-deazaadenine LNA monomer was also synthesized by a modification of the new synthetic pat...... the required LNA monomers. © Georg Thieme Verlag....

  14. Sucrose- and H-dependent charge movements associated with the gating of sucrose transporter ZmSUT1.

    Directory of Open Access Journals (Sweden)

    Armando Carpaneto

    Full Text Available BACKGROUND: In contrast to man the majority of higher plants use sucrose as mobile carbohydrate. Accordingly proton-driven sucrose transporters are crucial for cell-to-cell and long-distance distribution within the plant body. Generally very negative plant membrane potentials and the ability to accumulate sucrose quantities of more than 1 M document that plants must have evolved transporters with unique structural and functional features. METHODOLOGY/PRINCIPAL FINDINGS: To unravel the functional properties of one specific high capacity plasma membrane sucrose transporter in detail, we expressed the sucrose/H(+ co-transporter from maize ZmSUT1 in Xenopus oocytes. Application of sucrose in an acidic pH environment elicited inward proton currents. Interestingly the sucrose-dependent H(+ transport was associated with a decrease in membrane capacitance (C(m. In addition to sucrose C(m was modulated by the membrane potential and external protons. In order to explore the molecular mechanism underlying these C(m changes, presteady-state currents (I(pre of ZmSUT1 transport were analyzed. Decay of I(pre could be best fitted by double exponentials. When plotted against the voltage the charge Q, associated to I(pre, was dependent on sucrose and protons. The mathematical derivative of the charge Q versus voltage was well in line with the observed C(m changes. Based on these parameters a turnover rate of 500 molecules sucrose/s was calculated. In contrast to gating currents of voltage dependent-potassium channels the analysis of ZmSUT1-derived presteady-state currents in the absence of sucrose (I =  Q/τ was sufficient to predict ZmSUT1 transport-associated currents. CONCLUSIONS: Taken together our results indicate that in the absence of sucrose, 'trapped' protons move back and forth between an outer and an inner site within the transmembrane domains of ZmSUT1. This movement of protons in the electric field of the membrane gives rise to the presteady

  15. Comparison of the Retinal Straylight in Pseudophakic Eyes with PMMA, Hydrophobic Acrylic, and Hydrophilic Acrylic Spherical Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Ya-wen Guo


    Full Text Available Purpose. To investigate the intraocular straylight value after cataract surgery. Methods. In this study, 76 eyes from 62 patients were subdivided into three groups. A hydrophobic acrylic, a hydrophilic acrylic, and a PMMA IOL were respectively, implanted in 24 eyes, 28 eyes, and 24 eyes. Straylight was measured using C-Quant at 1 week and 1 month postoperatively in natural and dilated pupils. Results. The hydrophilic acrylic IOLs showed significantly lower straylight values than those of the hydrophobic acrylic IOLs in dilated pupils at 1 week and 1 month after surgery (P0.05. Moreover, no significant difference was found in straylight between natural and dilated pupils in each group at 1 week and 1 month postoperatively (P>0.05. Conclusions. Although the hydrophobic acrylic IOL induced more intraocular straylight, straylight differences among the 3 IOLs were minimal. Pupil size showed no effect on intraocular straylight; the intraocular straylight was stable 1 week after surgery.

  16. Synthetic Technology and Application of the Waterborne Fluoro-Silicon Modified Acrylic Resin and Coating%水性氟硅改性丙烯酸树脂的合成及涂膜性能研究

    Institute of Scientific and Technical Information of China (English)

    黄守成; 刘晓国


    The waterborne fluoro modified acrylic synthesized fully with fluorinated acrylate monomer will provide both hydrophobic and oleophobic properties,but cause the problems of foaming and foam stabilization at the same time.In order to avoid this problem,a cyclic siloxane prepolymer was synthesized by ring opening polymerization,which was then introduced into the fluoro-contaning acrylic resin chain acrylic by free radical polymerization,eliminating the defect of foaming and foam stabilization.In addition,the devlopment of waterbone of fluorine silicone modified acrylic resin has a significance on environmental protection.%合成具有足够疏水和疏油性能的水性含氟丙烯酸树脂,全部采用含氟丙烯酸酯单体,其在提供树脂具有疏水和疏油性能的同时,也会带来树脂容易起泡和稳泡的缺陷,为此,采用开环聚合合成环硅氧烷预聚物,将环硅氧烷预聚物引入水性含氟丙烯酸树脂分子链中,可以消除因含氟单体引入产生的起泡和稳泡缺陷.

  17. Hyperbranched Acrylated Aromatic Polyester Used as a Modifier in UV-Curable Epoxy Acrylate Resins

    Institute of Scientific and Technical Information of China (English)

    KOU,Hui-Guang; ASIF,Anila; SHI,Wen-Fang


    The viscosity, the shrinkage degree and the photoplymerization rate of the epoxy acrylate (EB600 ) blended with hyperbranched acrylated aromatic polyester ( HAAPE ) were investigated. The addition of HAAPE into EB600 largely reduces the viscosity of the blend formulation and the shrinkage degree. For example, EB600resin with 50% weight fraction of HAAPE has the 1250 cps of the viscosity and 2.0% of shrinkage degree, while the pure EB600 resin has 3000 cps of the viscosity and 10.5% of shrinkage degree. The photopolymerization rate of the rein is also promoted by HAAPE addition. The good miscibility between HAAPE and EB600 was also observed from the dynamic mechanical analysis. The tensile, flexural and compressive strength, and the thermal properties of the UVcured films are greatly improved.

  18. 21 CFR 864.7300 - Fibrin monomer paracoagulation test. (United States)


    ... to detect fibrin monomer in the diagnosis of disseminated intravascular coagulation (nonlocalized clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class...

  19. Viscous properties of microparticulated dairy proteins and sucrose. (United States)

    Onwulata, C I; Konstance, R P; Tomasula, P M


    Slurries of whey protein concentrate (WPC) or sodium caseinate (Na-CN) mixed with sucrose (36% T.S.) were subjected to microparticulation by a high shear homogenizer operated at 27,000 rpm for 2, 4, and 6 min to facilitate gel formation. After microparticulation treatment, the milk protein and sucrose slurries were evaporated at 85 degrees C for 60 min under a partial vacuum (20 to 45 mm of Hg) to form composite gels. Particle sizes and viscoelastic properties were determined before microparticulation treatment. Microparticulation reduced the particle size of WPC-sucrose slurries from an average size of 330 to 188 nm after 4 min and NaCN-sucrose slurries from 270 to 35 nm after 2 min. The WPC-sucrose composites were gel-like, but NaCN-sucrose composites did not gel. Viscoelastic properties of heated WPC-sucrose composites were liquid-like, exhibiting significant reduction in storage modulus and complex viscosity. Microparticulation reduced particle sizes, which resulted in softer gels as time of shearing increased.

  20. Cariogenic Potential of Sucrose Associated with Maltodextrin on Dental Enamel. (United States)

    Rezende, Gabriela; Arthur, Rodrigo A; Grando, Debora; Hashizume, Lina N


    Maltodextrin is a hydrolysate of cornstarch and has been widely used in the food industry associated with sucrose. The addition of starch can increase the cariogenic potential of sucrose; however, there are sparse data regarding the cariogenicity of sucrose associated with maltodextrin. Therefore, the aim of this study was to test in situ if maltodextrin could increase the cariogenic potential of sucrose. This was an in situ, randomized, crossover, split-mouth, and double-blind study. Volunteers wore palatal appliances containing bovine enamel blocks for 2 periods of 14 days. They dripped the following solutions on the enamel blocks 8 times per day: deionized distilled water (DDW), maltodextrin (M), sucrose + maltodextrin (S+M), or sucrose (S). At the end of each experimental period, biofilms were collected and analyzed for microbiological (mutans streptococci, lactobacilli, and total microorganisms counts) and biochemical (calcium, inorganic phosphate, fluoride, and insoluble extracellular polysaccharides concentrations) compositions. The enamel demineralization was assessed by microhardness. Treatments S and S+M resulted in a lower inorganic composition and higher concentration of insoluble extracellular polysaccharides in the biofilms, and higher enamel mineral loss compared to DDW and M. It can be concluded that the cariogenic potential of sucrose is not changed when this carbohydrate is associated with maltodextrin (dextrose equivalent 13-17).

  1. Characterization of Sucrose Thin Films for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    S. L. Iconaru


    Full Text Available Sucrose is a natural osmolyte accumulated in the cells of organisms as they adapt to environmental stress. In vitro sucrose increases protein stability and forces partially unfolded structures to refold. Thin films of sucrose (C12H22O11 were deposited on thin cut glass substrates by the thermal evaporation technique (P∼10−5 torr. Characteristics of thin films were put into evidence by Fourier Transform Infrared Spectroscopy (FTIR, X-ray Photoelectron Spectroscopy (XPS, scanning electron microscopy (SEM, and differential thermal analysis and thermal gravimetric analysis (TG/DTA. The experimental results confirm a uniform deposition of an adherent layer. In this paper we present a part of the characteristics of sucrose thin films deposited on glass in medium vacuum conditions, as a part of a culture medium for osteoblast cells. Osteoblast cells were used to determine proliferation, viability, and cytotoxicity interactions with sucrose powder and sucrose thin films. The osteoblast cells have been provided from the American Type Culture Collection (ATCC Centre. The outcome of this study demonstrated the effectiveness of sucrose thin films as a possible nontoxic agent for biomedical applications.

  2. Sucrose and IQ induced mutations in rat colon by independent

    DEFF Research Database (Denmark)

    Hansen, Max; Hald, M. T.; Autrup, H.


    Sucrose-rich diets have repeatedly been observed to have co-carcinogenic actions in colon and liver of rats and to increase the number of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) induced aberrant crypt foci in rat colon. To investigate a possible interaction between sucrose and IQ...... on the genotoxicity in rat liver and colon, we gave Big Blue rats(TM) a diet containing sucrose (0%, 3.45% or 13.4% w/w) and/or IQ (70 ppm) for a period of 3 weeks. Sucrose and IQ increased the mutation frequency in the colon. The effect of combined treatments with IQ and sucrose on the mutation frequencies...... was additive indicating that sucrose and IQ act independently. This was supported by the mutation spectra where sucrose expands the background mutations in the colon, whereas IQ, in other studies, more specifically has induced G:C --> T:A transversions. In the liver IQ increased the mutation frequency, whereas...

  3. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Directory of Open Access Journals (Sweden)

    Pudji Rahardjo


    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  4. Poly(lauryl acrylate) and poly(stearyl acrylate) grafted multiwalled carbon nanotubes for polypropylene composites

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Hvilsted, Søren


    in loading after 12 h of polymerization. The modified nanomaterials were melt mixed into polypropylene composites with very low filler loading (0.3 wt%), whereafter both the thermal and electrical properties were investigated by DSC and dielectric resonance spectroscopy. The electrical properties were found...... to be substantially improved, where poly(lauryl acrylate) was found to be the superior surface modification, resulting in a conductive composite....

  5. Synthesis of Functional Polyethylene Copolymers via Reactive Monomer

    Institute of Scientific and Technical Information of China (English)

    Hua-yi Li; Shu-qing Zhang; Ling-zhi Wang; You-liang Hu


    @@ 1Introduction Polyolefins are used widely due to their good performance and low price, but the poor compatibility and adhesion with other materials limits their applications in broader areas. Reactive monomer approach is effective to synthesize functional polyolefins[1]. In this case, olefin is copolymerized with a reactive comonomer to produce reactive intermediary which is then converted to functional group or initiator to initiate graft-from polymerization of polar monomer.

  6. Functional Relationship between Sucrose and a Cariogenic Biofilm Formation.

    Directory of Open Access Journals (Sweden)

    Jian-Na Cai

    Full Text Available Sucrose is an important dietary factor in cariogenic biofilm formation and subsequent initiation of dental caries. This study investigated the functional relationships between sucrose concentration and Streptococcus mutans adherence and biofilm formation. Changes in morphological characteristics of the biofilms with increasing sucrose concentration were also evaluated. S. mutans biofilms were formed on saliva-coated hydroxyapatite discs in culture medium containing 0, 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, or 40% (w/v sucrose. The adherence (in 4-hour biofilms and biofilm composition (in 46-hour biofilms of the biofilms were analyzed using microbiological, biochemical, laser scanning confocal fluorescence microscopic, and scanning electron microscopic methods. To determine the relationships, 2nd order polynomial curve fitting was performed. In this study, the influence of sucrose on bacterial adhesion, biofilm composition (dry weight, bacterial counts, and water-insoluble extracellular polysaccharide (EPS content, and acidogenicity followed a 2nd order polynomial curve with concentration dependence, and the maximum effective concentrations (MECs of sucrose ranged from 0.45 to 2.4%. The bacterial and EPS bio-volume and thickness in the biofilms also gradually increased and then decreased as sucrose concentration increased. Furthermore, the size and shape of the micro-colonies of the biofilms depended on the sucrose concentration. Around the MECs, the micro-colonies were bigger and more homogeneous than those at 0 and 40%, and were surrounded by enough EPSs to support their structure. These results suggest that the relationship between sucrose concentration and cariogenic biofilm formation in the oral cavity could be described by a functional relationship.

  7. Electrochemical characterization of aminated acrylic conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)


    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  8. Flexible, stretchable electroadhesives based on acrylic elastomers (United States)

    Duduta, Mihai; Wood, Robert J.; Clarke, David R.


    Controllable adhesion is a requirement for a wide variety of applications including robotic manipulation, as well as locomotion including walking, crawling and perching. Electroadhesives have several advantages such as reversibility, low power consumption and controllability based on applied voltage. Most demonstrations of electroadhesive devices rely on fairly rigid materials, which cannot be stretched reversibly, as needed in some applications. We have developed a fast and reliable method for building soft, stretchable electroadhesive pads based on acrylic elastomers and electrodes made of carbon nanotubes. The devices produced were tested pre-deformation and in a stretched configuration. The adhesive force was determined to be in the 0.1 - 3.0 N/cm2 range, depending on the adhering surface. The electroadhesive devices were integrated with pre-stretched dielectric elastomer actuators to create a device in which the adhesion force could be tuned by changes in either the applied voltage or total area.

  9. Perturbation of the Monomer-Monomer Interfaces of the Benzoylformate Decarboxylase Tetramer

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Forest H.; Rogers, Megan P.; Paul, Lake N.; McLeish, Michael J. [IUPUI; (Purdue)


    The X-ray structure of benzoylformate decarboxylase (BFDC) from Pseudomonas putida ATCC 12633 shows it to be a tetramer. This was believed to be typical of all thiamin diphosphate-dependent decarboxylases until recently when the structure of KdcA, a branched-chain 2-keto acid decarboxylase from Lactococcus lactis, showed it to be a homodimer. This lent credence to earlier unfolding experiments on pyruvate decarboxylase from Saccharomyces cerevisiae that indicated that it might be active as a dimer. To investigate this possibility in BFDC, we sought to shift the equilibrium toward dimer formation. Point mutations were made in the noncatalytic monomer–monomer interfaces, but these had a minimal effect on both tetramer formation and catalytic activity. Subsequently, the R141E/Y288A/A306F variant was shown by analytical ultracentrifugation to be partially dimeric. It was also found to be catalytically inactive. Further experiments revealed that just two mutations, R141E and A306F, were sufficient to markedly alter the dimer–tetramer equilibrium and to provide an ~450-fold decrease in kcat. Equilibrium denaturation studies suggested that the residual activity was possibly due to the presence of residual tetramer. The structures of the R141E and A306F variants, determined to <1.5 Å resolution, hinted that disruption of the monomer interfaces will be accompanied by movement of a loop containing Leu109 and Leu110. As these residues contribute to the hydrophobicity of the active site and the correct positioning of the substrate, it seems that tetramer formation may well be critical to the catalytic activity of BFDC.

  10. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)


    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  11. Characteristics of Sucrose Transport through the Sucrose-Specific Porin ScrY Studied by Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Liping eSun


    Full Text Available Sucrose-specific porin (ScrY is a transmembrane protein that allows for the uptake of sucrose under growth-limiting conditions. The crystal structure of ScrY was resolved before by X-ray crystallography, both in its uncomplexed form and with bound sucrose. However, little is known about the molecular characteristics of the transport mechanism of ScrY. To date, there has not yet been any clear demonstration for sucrose transport through the ScrY.Here, the dynamics of the ScrY trimer embedded in a phospholipid bilayer as well as the characteristics of sucrose translocation were investigated by means of atomistic molecular dynamics (MD simulations. The potential of mean force (PMF for sucrose translocation through the pore showed two main energy barriers within the constriction region of ScrY. Energy decomposition allowed to pinpoint three aspartic acids as key residues opposing the passage of sucrose, all located within the L3 loop. Mutation of two aspartic acids to uncharged residues resulted in an accordingly modified electrostatics and decreased PMF barrier. The chosen methodology and results will aid in the design of porins with modified transport specificities.

  12. Microbial transformation of 8:2 fluorotelomer acrylate and methacrylate in aerobic soils. (United States)

    Royer, Laurel A; Lee, Linda S; Russell, Mark H; Nies, Loring F; Turco, Ronald F


    Biotransformation of fluorotelomer (FT) compounds, such as 8:2 FT alcohol (FTOH) is now recognized to be a source of perfluorooctanoic acid (PFOA) as well as other perfluoroalkyl acids. In this study, microbially mediated hydrolysis of FT industrial intermediates 8:2 FT acrylate (8:2 FTAC) and 8:2 FT methacrylate (8:2 FTMAC) was evaluated in aerobic soils for up to 105d. At designated times, triplicate microcosms were sacrificed by sampling the headspace for volatile FTOHs followed by sequential extraction of soil for the parent monomers as well as transient and terminal degradation products. Both FTAC and FTMAC were hydrolyzed at the ester linkage as evidenced by 8:2 FTOH production. 8:2 FTAC and FTMAC degraded rapidly with half-lives ⩽5d and 15d, respectively. Maximum 8:2 FTOH levels were 6-13mol% within 3-6d. Consistent with the known biotransformation pathway of 8:2 FTOH, FT carboxylic acids and perfluoroalkyl carboxylic acids were subsequently generated including up to 10.3mol% of PFOA (105d). A total mass balance (parent plus metabolites) of 50-75mol% was observed on the last sampling day. 7:2 sFTOH, a direct precursor to PFOA, unexpectedly increased throughout the incubation period. The likely, but unconfirmed, concomitant production of acrylic acids was proposed as altering expected degradation patterns. Biotransformation of 8:2 FTAC, 8:2 FTMAC, and previously reported 8:2 FT-stearate for the same soils revealed the effect of the non-fluorinated terminus group linked to the FT chain on the electronic differences that affect microbially-mediated ester cleavage rates.

  13. 丙烯酸抗菌涂料的研制%Preparation of Acrylic Antibaterial Coatings

    Institute of Scientific and Technical Information of China (English)

    杨保平; 谭生; 郭军红; 崔锦峰; 杨宏斌; 孙宁宁


    The acrylic resin was synthetized with an antibacterial monomer propylene ethyl dimethyl ammonium bromide (PEDAB), MMA, BMA and BA by free radical polymerization. The coating was prepared with the acrylic resin and antibiotic text was detected. Experimental results showed the optimum technological conditions of synthetic resin: temperature 100 ℃, n - butyl alcohol as solvent, and dosage of the initiator (BPO) 1%. The antimicrobial tests showed that the antibacterial rate of polymer was 99% for staphylo-coccus aureus, escherichia coli, pseudomonas aeruginosa, and aspergillus niger when the amount of PEDAB was added 8% by wt. In the process of resin polymerization.%以具有抗菌性的功能单体丙烯酰氧乙基二甲基乙基溴化铵(PEDAB)与甲基丙烯酸甲酯、甲基丙烯酸丁酯及丙烯酸丁酯自由基聚合,合成了丙烯酸树脂.以此树脂配制涂料,并进行抗菌性检测.实验结果表明:合成树脂的最佳工艺条件为:在100 qC以正丁醇为溶剂、引发剂(BPO)的用量为1%.抗菌性检测结果表明在合成树脂过程中功能单体的用量为8%,涂膜对金黄色葡萄球菌、大肠杆菌、绿脓杆菌及黑曲霉的抗菌率均达到99%.

  14. Durability to oxygen reactive ion etching enhanced by addition of synthesized bis(trimethylsilyl)phenyl-containing (meth)acrylates in ultraviolet nanoimprint lithography (United States)

    Ito, Shunya; Sato, Hiroki; Tasaki, Yuhei; Watanuki, Kimihito; Nemoto, Nobukatsu; Nakagawa, Masaru


    We investigated the selection of bis(trimethylsilyl)phenyl-containing (meth)acrylates as additives to improve the durability to oxygen reactive ion etching (O2 RIE) of sub-50 nm imprint resist patterns suitable for bubble-defect-free UV nanoimprinting with a readily condensable gas. 2,5-Bis(2-acryloyloxyethoxy)-1,4-bis(trimethylsilyl)benzene, which has a diacrylate chemical structure similar to that of glycerol 1,3-diglycerolate diacrylate used as a base monomer, and 3-(2-methacryloyloxyethoxy)-1-(hydroxylethoxy)-2-propoxy-3,5-bis(trimethylsilyl)benzene, which has a hydroxy group similar to the base monomer, were synthesized taking into consideration the Ohnishi and ring parameters, and the oxidization of the trimethylsilyl moiety to inorganic species during O2 RIE. The addition of the latter liquid additive to the base monomer decreased etching rate owing to the good miscibility of the additive in the base monomer, while the addition of the former crystalline additive caused phase separation after UV nanoimprinting. The latter additive worked as a compatibilizer to the former additive, which is preferred for etching durability improvement. The coexistence of the additives enabled the fabrication of a 45 nm line-and-space resist pattern by UV nanoimprinting, and its residual layer could be removed by O2 RIE.

  15. New sucrose esters from the fruits of Physalis solanaceus. (United States)

    Pérez-Castorena, Ana-Lidia; Luna, Minerva; Martínez, Mahinda; Maldonado, Emma


    Three new sucrose esters (1-3) along with several known compounds were isolated from the fruits of Physalis solanaceus. The structural elucidation of the isolates was based on their spectroscopic characteristics mainly those of MS and NMR.

  16. Sucrose And Saccharomyces Cerevisiae: A Relationship Most Sweet.


    Marques, Wesley Leoricy; Raghavendran, Vijayendran; Stambuk,Boris Ugarte; Gombert, Andreas Karoly


    Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is f...

  17. Sucrose Improves Insecticide Activity Against Drosophila suzukii (Diptera: Drosophilidae). (United States)

    Cowles, Richard S; Rodriguez-Saona, Cesar; Holdcraft, Robert; Loeb, Gregory M; Elsensohn, Johanna E; Hesler, Steven P


    The addition of sucrose to insecticides targeting spotted wing drosophila, Drosophila suzukii (Matsumura), enhanced lethality in laboratory, semifield, and field tests. In the laboratory, 0.1% sucrose added to a spray solution enhanced spotted wing drosophila feeding. Flies died 120 min earlier when exposed to spinosad residues at label rates enhanced with sucrose. Added sucrose reduced the LC50 for dried acetamiprid residues from 82 to 41 ppm in the spray solution. Laboratory bioassays of spotted wing drosophila mortality followed exposure to grape and blueberry foliage and/or fruit sprayed and aged in the field. On grape foliage, the addition of 2.4 g/liter of sugar with insecticide sprays resulted in an 11 and 6% increase of spotted wing drosophila mortality at 1 and 2 d exposures to residues, respectively, averaged over seven insecticides with three concentrations. In a separate experiment, spinetoram and cyantraniliprole reduced by 95-100% the larval infestation of blueberries, relative to the untreated control, 7 d after application at labeled rates when applied with 1.2 g/liter sucrose in a spray mixture, irrespective of rainfall; without sucrose infestation was reduced by 46-91%. Adding sugar to the organically acceptable spinosyn, Entrust, reduced larval infestation of strawberries by >50% relative to without sugar for five of the six sample dates during a season-long field trial. In a small-plot field test with blueberries, weekly applications in alternating sprays of sucrose plus reduced-risk insecticides, spinetoram or acetamiprid, reduced larval infestation relative to the untreated control by 76%; alternating bifenthrin and phosmet (without sucrose) reduced infestation by 65%.


    Institute of Scientific and Technical Information of China (English)

    YANG Zhenghua; LI Yuesheng


    A series of acrylonitrile (AN) copolymers with methyl acrylate (MA) or ethyl acrylate (EA) as comonomer (5-23 wt%) was prepared by free-radical copolymerization. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at 1.0 MPa and at 30 ℃, and those to water vapor also measured at 100% relative humidity and at 30 ℃. All the AN/acrylic copolymers are semicrystalline. As the acrylate content increase, the permeability coefficients of the copolymers to oxygen and carbon dioxide are increased progressively, but those to water vapor are decreased progressively. The gas permeability coefficients of the polymers were correlated with free-volume fractions or the ratio of free volume to cohesive energy.

  19. Improvement in the behavior of bromelain coupled to pNIPAm polymers containing acrylamide or acrylic acid

    Directory of Open Access Journals (Sweden)

    Rubab Mahmood


    Full Text Available Bromelain was coupled to N-isopropyl acrylamide (NIPAmpolymers, synthesized using NIPAm and various concentrations of acrylamide (Ac or acrylic acid (AAc. Incorporation of Ac/AAcinto the polymer increased the LCST (lower critical solutiontemperature in a concentration dependent manner but AAc wasmore effective in this regard; the LCST rose to 40°C when 6 percent AAc was used. Incorporation of Ac/AAc increased the coupling of enzyme to the polymer and the η (effectiveness factor of the coupled enzyme, moderately. Various studies indicate that such incorporation of hydrophilic monomers into the polymer does not impair its capacity to couple enzyme or expression of the activity of bound enzyme but seems to actually improve the stability of the enzyme against heat induced inactivation and alkaline pH.


    Institute of Scientific and Technical Information of China (English)

    Dong Zou; Xiu-fen Li; Xiao-li Zhu; Xiang-zheng Kong


    Cationic latexes were prepared through emulsion copolymerization of styrene (St) and butyl acrylate (BA) with a cationic surfactant,cetyl trimethyl ammonium bromide (CTAB).Latex properties,including particle size,size distribution,ζ potential,surface tension and monomer conversion,were determined for latexes prepared with different CTAB amounts.Evolution of these properties during emulsion polymerization was followed in order to understand the mechanism of the particles formation.Results showed that both particle size and ζpotential were function of polymerization time and latex solids.Parallel emulsion polymerizations with cationic,anionic charged initiator and charge-free initiators were also carried out,the latex properties were determined at different polymerization time.All these results were attentively interpreted based on the mechanisms of emulsion polymerization,surfactant adsorption and latex particle stabilization.

  1. Surface properties of latex film and solvent-borne film resulted from fluorinated acrylate copolymers prepared by emulsion polymerization

    Directory of Open Access Journals (Sweden)


    Full Text Available The fluorinated acrylate copolymer, poly (BMA-co-DFHMA, was prepared by emulsion polymerization using a preemulsified monomer addition process. The FTIR and 1H –NMR were used to characterize the copolymer structure. The contact angle of water on the solvent-borne film increased dramatically and reached an equilibrium value (103° when the PDFHMA content in the copolymer was only 0.97 mol%. However, the contact of water on the latex film increased slowly, and reached the equilibrium value of 99° until the fluorinated component content was as highly as 9 mol%. A similar result was observed for the oil contact angle on the two types of films. XPS results showed that when the F/C ratio on film surfaces reached equilibrium, the required content of fluorinated component in the copolymer for the solvent-borne film was much lower than that for the latex film.

  2. Synthesis, characterization and swelling behavior investigation of gela-tin-g-poly(acrylic acid-co-itaconic acid

    Directory of Open Access Journals (Sweden)

    Hossein Hosseinzadeh


    Full Text Available A novel pH-responsive superabsorbent hydrogel based on gelatin was prepared through crosslinking copolymerization of poly (acrylic acid and poly (itaconic acid. The copolymerization conditions including monomers, initiator, gelatin and crosslinker concentration, reaction temperature, and neutralization percent were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The hydrogels structure was confirmed using Fourier-transform infrared, thermogravimetric analysis, differential scanning calorimetric and scanning electron microscopy. The swelling of the superabsorbing hydrogel was examined in buffer solutions with pH ranged 3-12. Moreover, the swelling of the hydrogel was conducted in 0.15 M aqueous solutions of NaCl, CaCl2, and AlCl3. Due to the high swelling capacity in salt solutions, the hydrogel may be referred to as "low-salt sensitive" superabsorbent.

  3. Altered sucrose metabolism impacts plant biomass production and flower development. (United States)

    Coleman, Heather D; Beamish, Leigh; Reid, Anya; Park, Ji-Young; Mansfield, Shawn D


    Nicotiana tabacum (tobacco) was transformed with three genes involved in sucrose metabolism, UDP-glucose pyrophosphorylase (UGPase, EC, sucrose synthase (SuSy, EC and sucrose phosphate synthase (SPS, EC Plants harbouring the single transgenes were subsequently crossed to produce double and triple transgenic lines, including: 2 x 35S::UGPase x SPS, 4CL::UGPase x SPS, 2 x 35S::SuSy x SPS, 4CL::SuSy x SPS, 2 x 35S::UGPase x SuSy x SPS, and 4CL::UGPase x SuSy x SPS. The ultimate aim of the study was to examine whether it is possible to alter cellulose production through the manipulation of sucrose metabolism genes. While altering sucrose metabolism using UGPase, SuSy and SPS does not have an end effect on cellulose production, their simultaneous overexpression resulted in enhanced primary growth as seen in an increase in height growth, in some cases over 50%. Furthermore, the pyramiding strategy of simultaneously altering the expression of multiple genes in combination resulted in increased time to reproductive bud formation as well as altered flower morphology and foliar stipule formation in 4CL lines. Upregulation of these sucrose metabolism genes appears to directly impact primary growth and therefore biomass production in tobacco.

  4. Effects of Soil Salinity on Sucrose Metabolism in Cotton Leaves.

    Directory of Open Access Journals (Sweden)

    Jun Peng

    Full Text Available This study investigated sucrose metabolism of the youngest fully expanded main-stem leaf (MSL and the subtending leaf of cotton (Gossypium hirsutum L. boll (LSCB of salt-tolerant (CCRI-79 and salt-sensitive (Simian 3 cultivars and its relationship to boll weight under low, medium and high soil salinity stress in Dafeng, China, in 2013 and 2014. The results showed that with increased soil salinity, 1 both the chlorophyll content and net photosynthetic rate (Pn decreased, while the internal CO2 concentration firstly declined, and then increased in the MSL and LSCB; 2 carbohydrate contents in the MSL reduced significantly, while sucrose and starch contents in the LSCB increased, as did the activities of sucrose phosphate synthase (SPS and sucrose synthase (SuSy in both the MSL and LSCB; 3 but invertase activity in both the MSL and LSCB did not change significantly. Our study also showed that the LSCB was more sensitive to soil salinity than was the MSL. Of the measured physiological indices, higher SPS activity, mainly controlled by sps3, may contribute to adaption of the LSCB to soil salinity stress because SPS is beneficial for efficiently sucrose synthesis, reduction of cellular osmotic potential and combined actions of Pn, and sucrose transformation rate and SPS may contribute to the reduction in boll weight under soil salinity stress.

  5. Nucleophilic Addition of Reactive Dyes on Amidoximated Acrylic Fabrics



    Seven reactive dyes judiciously selected based on chemical structures and fixation mechanisms were applied at 2% owf of shade on amidoximated acrylic fabrics. Amidoximated acrylic fabric has been obtained by a viable amidoximation process. The dyeability of these fabrics was evaluated with respect to the dye exhaustion, fixation, and colour strength under different conditions of temperature and dyeing time. Nucleophilic addition type reactive dyes show higher colour data compared to nucleophi...

  6. Monomers of cutin biopolymer: sorption and esterification on montmorillonite surfaces (United States)

    Olshansky, Yaniv; Polubesova, Tamara; Chefetz, Benny


    One of the important precursors for soil organic matter is plant cuticle, a thin layer of predominantly lipids that cover all primary aerial surfaces of vascular plants. In most plant species cutin biopolymer is the major component of the cuticle (30-85% weight). Therefore cutin is the third most abundant plant biopolymer (after lignin and cellulose). Cutin is an insoluble, high molecular weight bio-polyester, which is constructed of inter-esterified cross linked hydroxy-fatty acids and hydroxyepoxy-fatty acids. The most common building blocks of the cutin are derivatives of palmitic acid, among them 9(10),16 dihydroxy palmitic acid (diHPA) is the main component. These fatty acids and their esters are commonly found in major organo-mineral soil fraction-humin. Hence, the complexes of cutin monomers with minerals may serve as model of humin. Both cutin and humin act as adsorption efficient domains for organic contaminants. However, only scarce information is available about the interactions of cutin with soil mineral surfaces, in particular with common soil mineral montmorillonite. The main hypothesize of the study is that adsorbed cutin monomers will be reconstituted on montmorillonite surface due to esterification and oligomerization, and that interactions of cutin monomers with montmorillonite will be affected by the type of exchangeable cation. Cutin monomers were obtained from the fruits of tomato (Lycopersicon esculentum). Adsorption of monomers was measured for crude Wyoming montmorillonites and montmorillonites saturated with Fe3+ and Ca2+. To understand the mechanism of monomer-clay interactions and to evaluate esterification on the clay surface, XRD and FTIR analyses of the montmorillonite-monomers complexes were performed. Our results demonstrated that the interactions of cutin monomers with montmorillonite are affected by the type of exchangeable cation. Isotherms of adsorption of cutin monomers on montmorillonites were fitted by a dual mode model of

  7. Stabilizing effects of estertins mercaptide (methyl acrylate) for PVC degradation (United States)

    Zhang, S. H.; Liu, T. M.; Li, J. L.; Wang, C. R.; Li, C.; Wang, Z. Q.


    The thermal and UV light (ultraviolet light) stability of PVC films with estertins mercaptide (methyl acrylate), methyltins mercaptide and the compound consisted of estertins mercaptide (methyl acrylate) and hydrotalcite (2:2.5) were investigated by ageing in a circulation oven at 190 °C and irradiating with 72W UV light for 96h, respectively, and then the yellowness and transmission rate were tested by Color Quest XE. Hydrotalcite was proved to have good synergies with estertins mercaptide (methyl acrylate) on improving the thermal stability and UV light stability. The retarding effects of the heat stabilizers to PVC degradation were tested by TGA from 50°C to 600°C. The results show that temperature of HCl evolution from PVC film was improved obviously by compounding with estertins mercaptide(methyl acrylate) and hydrotalcite and estertins mercaptide(methyl acrylate) was found to have a better long term stability. Sn4+ consistence of water and seawater in which films before and after UV light irradiation were soaked for 60 days was analyzed by ICP; the results indicate that the Sn4+ consistence from the films with estertins mercaptide(methyl acrylate) as thermal stabilizer was lower than that from the film with methyltins mercaptide. The crosslink moderately by UV irradiation for PVC films can hold back the dissolution of organotin heat stabilizers from PVC products into water and seawater.

  8. Antimicrobial activity of poly(acrylic acid) block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Gratzl, Günther, E-mail: [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Paulik, Christian [Johannes Kepler University Linz, Institute for Chemical Technology of Organic Materials, Altenberger Str. 69, 4040 Linz (Austria); Hild, Sabine [Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Str. 69, 4040 Linz (Austria); Guggenbichler, Josef P.; Lackner, Maximilian [AMiSTec GmbH and Co. KG, Leitweg 13, 6345 Kössen, Tirol (Austria)


    The increasing number of antibiotic-resistant bacterial strains has developed into a major health problem. In particular, biofilms are the main reason for hospital-acquired infections and diseases. Once formed, biofilms are difficult to remove as they have specific defense mechanisms against antimicrobial agents. Antimicrobial surfaces must therefore kill or repel bacteria before they can settle to form a biofilm. In this study, we describe that poly(acrylic acid) (PAA) containing diblock copolymers can kill bacteria and prevent from biofilm formation. The PAA diblock copolymers with poly(styrene) and poly(methyl methacrylate) were synthesized via anionic polymerization of tert-butyl acrylate with styrene or methyl methacrylate and subsequent acid-catalyzed hydrolysis of the tert-butyl ester. The copolymers were characterized via nuclear magnetic resonance spectroscopy (NMR), size-exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, and acid–base titrations. Copolymer films with a variety of acrylic acid contents were produced by solvent casting, characterized by atomic force microscopy (AFM) and tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antimicrobial activity of the acidic diblock copolymers increased with increasing acrylic acid content, independent of the copolymer-partner, the chain length and the nanostructure. - Highlights: • Acrylic acid diblock copolymers are antimicrobially active. • The antimicrobial activity depends on the acrylic acid content in the copolymer. • No salts, metals or other antimicrobial agents are needed.

  9. Removal of monomer delignification products by laccase from Trametes versicolor. (United States)

    Kolb, Michaela; Sieber, Volker; Amann, Manfred; Faulstich, Martin; Schieder, Doris


    The influence of a laccase from Trametes versicolor on the removal of phenolic monomers in liquid hot water pretreated wheat straw supernatants (LHW-S) was examined. Beside the total phenol content derived by Folin-Ciocalteu (FC-) assay, phenolic monomers were measured via headspace-solid phase micro-extraction (HS-SPME)/GC-MS. A notable decrease of the phenols was achieved using 0.2 and 0.5 U/mL laccase whilst higher dosage showed no improvement. Nearly all kind of monomer phenolic compounds identified in the LHW-S were found to be removed after 24h. However, acetophenone and 4-hydroxybenzaldehyde (HBA) were obviously not affected by laccase. Summarizing, three laccase reaction groups (LRG) of phenolic monomers could be classified: immediate removal (LRG-A), degradation after 1 day (LRG-B), no effect of laccase (LRG-C). Additionally, HS-SPME/GC was found to be a powerful tool to study the reaction of laccase and phenolic monomers in complex lignocellulose derived solutions.

  10. Comparative study on adhesive performance of functional monomers. (United States)

    Yoshida, Y; Nagakane, K; Fukuda, R; Nakayama, Y; Okazaki, M; Shintani, H; Inoue, S; Tagawa, Y; Suzuki, K; De Munck, J; Van Meerbeek, B


    Mild self-etch adhesives demineralize dentin only partially, leaving hydroxyapatite around collagen within a submicron hybrid layer. We hypothesized that this residual hydroxyapatite may serve as a receptor for chemical interaction with the functional monomer and, subsequently, contribute to adhesive performance in addition to micro-mechanical hybridization. We therefore chemically characterized the adhesive interaction of 3 functional monomers with synthetic hydroxyapatite, using x-ray photoelectron spectroscopy and atomic absorption spectrophotometry. We further characterized their interaction with dentin ultra-morphologically, using transmission electron microscopy. The monomer 10-methacryloxydecyl dihydrogen phosphate (10-MDP) readily adhered to hydroxyapatite. This bond appeared very stable, as confirmed by the low dissolution rate of its calcium salt in water. The bonding potential of 4-methacryloxyethyl trimellitic acid (4-MET) was substantially lower. The monomer 2-methacryloxyethyl phenyl hydrogen phosphate (phenyl-P) and its bond to hydroxyapatite did not appear to be hydrolytically stable. Besides self-etching dentin, specific functional monomers have additional chemical bonding efficacy that is expected to contribute to their adhesive potential to tooth tissue.

  11. Study on acrylic acid bentonite of high amount/poly(sodium acrylate) superabsorbent composite Ⅰ :the preparation process and morphology%高含量丙烯酸膨润土/聚丙烯酸钠高吸水性复合材料的研究Ⅰ:制备工艺与形貌

    Institute of Scientific and Technical Information of China (English)

    付丽华; 彭英知; 韦藤幼; 童张法


    Superabsorbent composite of high amount of acrylic acid bentonite/poly(sodium acrylic) was synthesized through solution polymerization with acrylic acid bentonite(ABT) and sodium acrylic and acrylic acid. The morphology of the composite was observed by scanning electron microscope(SEM). The results show that a-crylic acid bentonite is evenly and disorder dispersed in the composite with the sheets of 20-30 nm thickness. The preparation process are optimized. The results are as follows. The amount of ABT, crosslinker and initiator are 30wt% , 0. 3wt% , 1. lwt% of the monomer mass respectively. The total water in the system is 340 % of the monomer mass, the neutralization degree is 64 %). The absorbency of the composite is 1103 g/g in deionized water in the conditions. At the same time, the water retention property of the superabsorbent composite(PAA) is better compared to that of PAA.%通过特殊工艺将丙烯酸膨润土(简称ABT)和丙烯酸钠单体采用溶液聚合法制备出高含量丙烯酸膨润土/聚丙烯酸钠高吸水性复合材料(简称HABT/PAA).SEM考察材料的形貌得知,ABT以20~30nm的尺寸较均匀、无序地分散在聚合物基体中,且与聚合物有很好的相容性.对合成工艺进行了优化得到较优的工艺:ABT用量为单体质量的30%(质量分数),交联剂用量为单体质量的0.3%(质量分数),引发剂用量为单体质量的1.1%(质量分数),体系总水量为单体质量的340%(质量分数),中和度为64%,在此条件下,材料吸附去离子水的能力为1103g/g.同时,HABT/PAA的保水性能较聚丙烯酸钠(PAA)好.

  12. Study on preparation of alcohol-acid crosslinking type acrylate emulsion%醇酸交联型丙烯酸酯乳液的制备研究

    Institute of Scientific and Technical Information of China (English)

    任先艳; 田恐虎; 刘才林; 杨海君; 王胜


    以丙烯酸丁酯(BA)、丙烯酸甲酯(MA)和丙烯腈(AN)为主要原料,烷基酚聚氧乙烯醚(OP-10)和十二烷基磺酸钠(SDS)为复合乳化剂,过硫酸铵(APS)和亚硫酸氢钠(NaHSO3)为氧化还原型引发剂,采用种子乳液聚合法制备了丙烯酸酯乳液;然后以多元醇A作为丙烯酸酯乳液的交联改性剂,制备了醇酸交联型丙烯酸酯乳液,实现了热交联体系无甲醛化.结果表明:当聚合温度为70℃、ω(引发剂)=2.4%、m(BA):m(MA):m(AN)=33:11:6、ω(复合乳化剂)=5%且m(OP-10):m(SDS)=1:1.5时,丙烯酸酯乳液的综合性能较好;当n(丙烯酸):n(多元醇A)=30:1、ω(丙烯酸)=1.0%时,交联改性乳液的固含量为51.40%、单体转化率为98.3%;交联改性乳液的胶膜吸水率(10.08%)比未改性乳液降低了82.4%,但两者的热稳定性均较高且相差不大.%With butyl acrylate(BA),methyl acrylate(MA) and acrylonitrile(AN) as main materials, alkyl phenol polyoxyethylene ether(OP-10) and sodium dodecyl sulphonate(SDS) as composite emulsifier, sodium bisulfite (NaHSO3) and ammonium persulfate(APS) as redox initiator, so a new acrylate emulsion was prepared by seeded emulsion polymerization. Then an alcohol-acid crosslinking type acrylate emulsion(namely heat-crosslinking system without formaldehyde) was prepared with polyol A as cross linker and modifier of the acrylate emulsion. The results showed that the acrylate emulsion had well combination property when polymerization temperature was 70 ℃, mass ratio of m(BA)∶m(MA)∶m(AN) was 33∶11∶6, mass fractions of initiator and composite emulsifier were 2.4% and 5% respectively,and mass ratio of m(OP-10)∶m(SDS) was 1∶1.5. The solid content and monomer conversion rate of crosslinking modified acrylate emulsion were 51.40% and 98.3% respectively when molar ratio of n (acrylic acid)∶n (polyol A) was 30∶1 and mass fraction of acrylic acid was 1.0%. The water absorption of crosslinking modified acrylate emulsion film

  13. Swelling properties of cassava starch grafted with poly (potassium acrylate-co-acrylamide) superabsorbent hydrogel prepared by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Barleany, Dhena Ria, E-mail:; Ulfiyani, Fida; Istiqomah, Shafina; Rahmayetty [Department of Chemical Engineering, University of Sultan Ageng Tirtayasa, Cilegon, Banten (Indonesia); Heriyanto, Heri; Erizal [Centre for Application of Isotopes and Radiation, Jakarta (Indonesia)


    Natural and synthetic hydrophylic polymers can be phisically or chemically cross-linked in order to produce hydrogels. Starch based hydrogels grafted with copolymers from acrylic acid or acrylamide have become very popular for water absorbent application. Superabsorbent hydrogels made from Cassava starch grafted with poly (potassium acrylate-co-acrylamide) were prepared by using of ϒ-irradiation method. Various important parameters such as irradiation doses, monomer to Cassava starch ratio and acrylamide content were investigated. The addition of 7,5 % w w{sup −1} acrylamide into the reaction mixture generated a starch graft copolymer with a water absorption in distilled water as high as 460 g g{sup −1} of its dried weight. The effectivity of hydrogel as superabsorbent for aqueous solutions of NaCl and urea was evaluated. The obtained hydrogel showed the maximum absorptions of 317 g g{sup −1} and 523 g g{sup −1} for NaCl and urea solution, respectively (relative to its own dry weight). The structure of the graft copolymer was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM)

  14. Synthesis, characterization and swelling properties of guar gum-g-poly(sodium acrylate-co-styrene)/muscovite superabsorbent composites (United States)

    Wang, Wenbo; Kang, Yuru; Wang, Aiqin


    A series of novel guar gum-g-poly(sodium acrylate-co-styrene)/muscovite (GG-g-P(NaA-co-St)/MVT) superabsorbent composites were prepared by free-radical grafting copolymerization of natural guar gum (GG), partially neutralized acrylic acid (NaA), styrene (St) and muscovite (MVT) using ammonium persulfate (APS) as the initiator and N,N-methylene-bis-acrylamide (MBA) as the crosslinker. Optical absorption spectra confirmed that NaA and St had been grafted onto the GG main chain and MVT participated in the polymerization reaction. The simultaneous introduction of St and MVT into the GG-g-PNaA matrix could clearly improve the surface morphologies of the composites, and MVT led to better dispersion in the polymeric matrix without agglomeration, as revealed by electron microscopy. The effects of St and MVT on the water absorption and swelling behavior in various saline solutions, aqueous solutions of hydrophilic organic solvents and surfactant solutions were investigated. Results indicated that the swelling rate and capabilities of the composites were markedly enhanced by the incorporation of the hydrophobic monomer St and inorganic MVT clay mineral. The superabsorbent composite showed a clearer deswelling characteristic in solutions of multivalent saline, acetone and ethanol, and cationic surfactant than that in the solutions of multivalent saline, methanol and anionic surfactant.

  15. Synthesis, characterization and swelling properties of guar gum-g-poly(sodium acrylate-co-styrene)/muscovite superabsorbent composites

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wenbo; Kang Yuru; Wang Aiqin, E-mail: aqwang@licp.cas.c [Center for Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)


    A series of novel guar gum-g-poly(sodium acrylate-co-styrene)/muscovite (GG-g-P(NaA-co-St)/MVT) superabsorbent composites were prepared by free-radical grafting copolymerization of natural guar gum (GG), partially neutralized acrylic acid (NaA), styrene (St) and muscovite (MVT) using ammonium persulfate (APS) as the initiator and N,N-methylene-bis-acrylamide (MBA) as the crosslinker. Optical absorption spectra confirmed that NaA and St had been grafted onto the GG main chain and MVT participated in the polymerization reaction. The simultaneous introduction of St and MVT into the GG-g-PNaA matrix could clearly improve the surface morphologies of the composites, and MVT led to better dispersion in the polymeric matrix without agglomeration, as revealed by electron microscopy. The effects of St and MVT on the water absorption and swelling behavior in various saline solutions, aqueous solutions of hydrophilic organic solvents and surfactant solutions were investigated. Results indicated that the swelling rate and capabilities of the composites were markedly enhanced by the incorporation of the hydrophobic monomer St and inorganic MVT clay mineral. The superabsorbent composite showed a clearer deswelling characteristic in solutions of multivalent saline, acetone and ethanol, and cationic surfactant than that in the solutions of multivalent saline, methanol and anionic surfactant.

  16. Synthesis, characterization and swelling properties of guar gum-g-poly(sodium acrylate-co-styrene/muscovite superabsorbent composites

    Directory of Open Access Journals (Sweden)

    Wenbo Wang, Yuru Kang and Aiqin Wang


    Full Text Available A series of novel guar gum-g-poly(sodium acrylate-co-styrene/muscovite (GG-g-P(NaA-co-St/MVT superabsorbent composites were prepared by free-radical grafting copolymerization of natural guar gum (GG, partially neutralized acrylic acid (NaA, styrene (St and muscovite (MVT using ammonium persulfate (APS as the initiator and N,N-methylene-bis-acrylamide (MBA as the crosslinker. Optical absorption spectra confirmed that NaA and St had been grafted onto the GG main chain and MVT participated in the polymerization reaction. The simultaneous introduction of St and MVT into the GG-g-PNaA matrix could clearly improve the surface morphologies of the composites, and MVT led to better dispersion in the polymeric matrix without agglomeration, as revealed by electron microscopy. The effects of St and MVT on the water absorption and swelling behavior in various saline solutions, aqueous solutions of hydrophilic organic solvents and surfactant solutions were investigated. Results indicated that the swelling rate and capabilities of the composites were markedly enhanced by the incorporation of the hydrophobic monomer St and inorganic MVT clay mineral. The superabsorbent composite showed a clearer deswelling characteristic in solutions of multivalent saline, acetone and ethanol, and cationic surfactant than that in the solutions of multivalent saline, methanol and anionic surfactant.

  17. Synthesis and Characterization of Encapsulated Nanosilica Particles with an Acrylic Copolymer by in Situ Emulsion Polymerization Using Thermoresponsive Nonionic Surfactant

    Directory of Open Access Journals (Sweden)

    Daryoosh Vashaee


    Full Text Available Nanocomposites of encapsulated silica nanoparticles were prepared by in situ emulsion polymerization of acrylate monomers. The synthesized material showed good uniformity and dispersion of the inorganic components in the base polymer, which enhances the properties of the nanocomposite material. A nonionic surfactant with lower critical solution temperature (LCST was used to encapsulate the silica nanoparticles in the acrylic copolymer matrix. This in situ method combined the surface modification and the encapsulation in a single pot, which greatly simplified the process compared with other conventional methods requiring separate processing steps. The morphology of the encapsulated nanosilica particles was investigated by dynamic light scattering (DLS and transmission electron microscopy (TEM, which confirmed the uniform distribution of the nanoparticles without any agglomerations. A neat copolymer was also prepared as a control sample. Both the neat copolymer and the prepared nanocomposite were characterized by Fourier transform infrared spectroscopy (FTIR, thermal gravimetric analyses (TGA, dynamic mechanical thermal analysis (DMTA and the flame resistance test. Due to the uniform dispersion of the non-agglomerated nanoparticles in the matrix of the polymer, TGA and flame resistance test results showed remarkably improved thermal stability. Furthermore, DMTA results demonstrated an enhanced storage modulus of the nanocomposite samples compared with that of the neat copolymer, indicating its superior mechanical properties.


    Institute of Scientific and Technical Information of China (English)

    Zhao Dai; Xin-lin Yang; Wen-qiang Huang


    Monodisperse poly(poly(ethyleneglycol) methyl ether acrylate-co-acrylic acid) (poly(PEGMA-co-AA))microspheres were prepared by distillation-precipitation polymerization with divinylbenzene (DVB) as crosslinker with 2,2'-azobisisobutyronitrile (AIBN) as initiator in neat acetonitrile without stirring. Under various reaction conditions, four distinct morphologies including the sol, microemulsion, microgels and microspheres were formed during the distillation of the solvent from the reaction system. A 2D morphological map was established as a function of crosslinker concentration and the polar monomer AA concentration, in comonomer feed in the transition between the morphology domains. The effect of the covalent crosslinker DVB on the morphology of the polymer network was investigated in detail at AA fraction of 40 vol%.The ratios of acid to ethylene oxide units presenting in the comonomers dramatically affected the polymer-polymer interaction and hence the morphology of the resultant polymer network. The covalent crosslinking by DVB and the hydrogen bonding crosslinking between two acid units as well as between the acid and ethylene oxide unit played key roles in the formation of monodisperse polymer microspheres.

  19. Swelling properties of cassava starch grafted with poly (potassium acrylate-co-acrylamide) superabsorbent hydrogel prepared by ionizing radiation (United States)

    Barleany, Dhena Ria; Ulfiyani, Fida; Istiqomah, Shafina; Heriyanto, Heri; Rahmayetty, Erizal


    Natural and synthetic hydrophylic polymers can be phisically or chemically cross-linked in order to produce hydrogels. Starch based hydrogels grafted with copolymers from acrylic acid or acrylamide have become very popular for water absorbent application. Superabsorbent hydrogels made from Cassava starch grafted with poly (potassium acrylate-co-acrylamide) were prepared by using of ϒ-irradiation method. Various important parameters such as irradiation doses, monomer to Cassava starch ratio and acrylamide content were investigated. The addition of 7,5 % w w-1 acrylamide into the reaction mixture generated a starch graft copolymer with a water absorption in distilled water as high as 460 g g-1 of its dried weight. The effectivity of hydrogel as superabsorbent for aqueous solutions of NaCl and urea was evaluated. The obtained hydrogel showed the maximum absorptions of 317 g g-1 and 523 g g-1 for NaCl and urea solution, respectively (relative to its own dry weight). The structure of the graft copolymer was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM).

  20. The Study of Fluoroacrylate Modified Hydroxyl Acrylic Emulsion%氟改性羟基丙烯酸乳液的研究

    Institute of Scientific and Technical Information of China (English)

    贺亮洪; 梁亮; 曾凡初; 齐增清; 弋天宝


    以丙烯酸全氟烷基酯(Zonyl TM)为功能单体,阴离子、非离子乳化剂为复合乳化剂,采用预乳化半连续乳液聚合法合成了氟改性羟基丙烯酸乳液,并将合成的乳液与氨基树脂制得性能优异的丙烯酸氨基清漆.系统地研究了氟单体、交联单体、丙烯酸含量及苯乙烯和甲基丙烯酸甲酯的配比等因素对涂膜性能的影响,对影响清漆的混容性及贮存稳定性的各因素进行了讨论.此外,含氟乳胶膜对水的接触角及红外光谱表征结果表明,Zonyl TM有效参与了共聚反应,提高了涂膜的耐水性及耐化学品性.%Fluoroacrylate modified hydroxyl acrylic emulsion was synthesized by pre - emulsion and semi - continuous emulsion polymerization, with perfluoroalky acrylate(Zonyl TM) as functional monomer, and a mixture of anionic and nonionic emulsifier as emulsifier, which was then used together with melamine resin to give high performance acrylic - melamine varnish. The effects of fluorine - containing monomer, crosslinking monomer, acrylic acid amount and the ratio of styrene and methyl methacrylate on the film performance were systematically investigated. And the factors influencing the compatibility and storage stability of varnish were discussed. Additionally, water contact and the FT - IR of the fluorine - containing emulsion film were analyzed. The results showed that Zonyl TM was effectively involved in the eopolymerization and improved the water resistance and chemical resistance of'the film.

  1. 含氟自交联丙烯酸树脂皮革涂饰剂的制备与性能%Synthesis and Properties of Self-crosslinking Fluorinated Acrylic Resin Leather Finishing Agent

    Institute of Scientific and Technical Information of China (English)

    邱超超; 吕生华; 马宇娟; 巨浩波


    A fluorine-containing self-crosslinking acrylic resin was synthesized by emulsion polymerization using butyl acrylate (BA), methyl methacrylate (MMA), hydroxypropyl acrylate (HPA), dodecafluoroheptyl methacrylate (DFMA), diacetone acrylamide (DAAM) and methacrylic acid(MAA)as monomers which pre-emulsified, SDS, AEO-9 and C16-18 mixed alcohol as mixed emulsifier and ammonium persulfate (ASP) as initiator. The influence of different monomer ratio on emulsion stability and coat performances was in-vestigated. The results showed that the stable fluorinated acrylic latex was obtained with the highest monomer conversion rate when monomer ratio (BA):(MMA):(DFMA):(HPA)is 46.6:32.2:6:3, (DAAM) is 1.2%,and (MA) is from 1.0% to 1.3%. It confers leather coat superior tensile strength and resistance to wet rubbing compared with conventional acrylic resin.%院用丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸羟丙酯(HPA)、甲基丙烯酸十二氟庚酯(DF原MA)、双丙酮丙烯酰胺(DAAM)、甲基丙烯酸(MAA)为单体,经过混合单体的预乳化,用十二烷基硫酸钠(SDS)、AEO-9、16~18醇为乳化剂,在过硫酸铵(ASP)引发剂作用下通过乳液聚合法合成了一种含氟自交联型丙烯酸树脂乳液。探讨了不同单体配比对乳液及涂膜性能的影响。研究发现当主要单体配比为(BA)颐(MMA)颐(DFMA)颐(HPA)=46.6颐32.2颐6颐3、DAAM用量(DAAM)=2.0%、MAA用量(MAA)=1.0%1.3%时,乳液反应稳定,单体转化率最高,用于皮革涂饰时涂膜的拉伸强度、耐湿擦性能等优于常规丙烯酸树脂涂饰剂。

  2. Biosynthesis of Polyhydroxyalkanoates Consisting of Short-chain-length Monomers and Medium-chain-length Monomers by Pseudomonas YS1

    Institute of Scientific and Technical Information of China (English)


    A strain capable of producing polyhydroxyalkanoates (PHAs) consisting of short- and medium-chain-length monomers was identified as Pseudomonas sp.coded as YS1.The strain synthesized PHAs containing monomers of hydroxybutyrate(HB or C4) and/or hydroxyoctanoate (HO or C8) and/or hydroxydecanoate (HD or C10) when grown in various substrates including glucose, raw sugar, molasses and various fatty acids.It was found that growth temperature affected the HB and HO monomer contents in the PHA.HB content in PHA increased from mole fraction 69% at 26℃ to mole fraction 85% at 37℃ while HO content decreased from mole fraction 29% at 26℃ to mole fraction 12% at 37℃.The temperature effect provides a simple and effective way to control the PHA composition and hence control the PHA mechanical and other physical properties.Also, the fermentor experiment indicated that PHB formation was growth associated and HO monomer production was in fact promoted by N-limitation.This conclusion was further supported by the fact that the formation of PHB only polyester was observed only when C/N molar ratio was smaller than 20.Higher C/N ratio led to the formation of HO monomers in the polyesters.

  3. Monomer release from nanofilled and microhybrid dental composites after bleaching.

    Directory of Open Access Journals (Sweden)

    Masumeh Hasani Tabatabaee


    Full Text Available The aim of this study was to assess the effect of bleaching on elution of monomers from nanofilled and microhybrid composites.80 samples (5mm diameter and 3mm thickness of each composite were prepared. After curing, half of them were randomly polished. Each group was divided into 8 subgroups and immersed in water or 10%, 20% and 30% H2O2 for 3 or 8 hours. Eluted Bis-GMA (Bis-phenol A Glycidyl Dimethacrylate, TEGDMA (Triethyleneglycol Dimethacrylate, UDMA (Urethane Dimethacrylate and BisEMA (Bis-phenol A ethoxylate Dimethacrylate were quantified by high performance liquid chromatography and the results were analyzed by univariate ANOVA and t-test (P<0.05.Bleach significantly increased the overall release of monomers (P<0.001; TEGDMA was released more than Bis-GMA (P<0.001. Supreme released more TEGDMA compared to Z250 (P<0.001. Bleaching increased the release of this monomer (P<0.001. Increasing both the concentration of H2O2, and the immersion time, increased the release of TEGDMA (P<0.001. Polishing had no effect on release of this monomer (P=0.952. Supreme released more Bis-GMA than Z250 (P=0.000. The more concentrated H2O2 caused more elution of Bis-GMA (P= 0.003; while the effect of immersion time was not significant (P=0.824. Polishing increased the release of Bis-GMA (P=0.001. Neither the type of composite nor Bleaching had any effect on release of UDMA (P=0.972 and (P=0.811 respectively. Immersion duration increased the release of UDMA (P=0.002, as well as polishing (P=0.024.Bleaching increased the release of monomers. Nanofilled composites released more monomer than the microfilled.

  4. Study on Preparation Fluorine-containing and Properties of Acrylic Emulsion%含氟丙烯酸酯乳液的制备及性能研究

    Institute of Scientific and Technical Information of China (English)

    王伟; 孙祥山; 刘彦军


    以全氟辛基丙烯酸乙酯为主要单体,制备了核壳型含氟丙烯酸酯乳液,采用红外光谱和激光粒度对聚合物进行了表征,并对纯棉织物进行了拒水拒油整理,研究了聚合方法、整理工艺对纯棉织物表面拒水拒油性能的影响,通过SEM对整理后织物表面进行了分析。结果表明含氟丙烯酸酯乳液作为织物整理剂整理后的织物具有良好的拒水拒油性。%Core/shell structure fluorine-containing acrylic emulsion was prepared by using perfluoroalkyl octyl ethyl acrylate as main monomer. The polymer was characterized by using infrared spectroscopy and laser particle size analyzer and cotton textile was finished with water and oil repellent finishment. The influence of polymerization process and finishing technology to the properties of water and oil repellent finishment were studied. The textile surface was analyzed by SEM after finishing. The results show that the fluorine- containing acrylic emulsion textile finishing agent has good water-repellent and oil-repellent properties.

  5. Poly(met)acrylates as reducers of pour point of Brazilian crude oil; Poli(met)acrilatos como redutores de ponto de fluidez de petroleo cru brasileiro

    Energy Technology Data Exchange (ETDEWEB)

    Cesar-Oliveira, Maria Aparecida Ferreira; Zawadzki, Sonia Faria [Parana Univ., Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Polimeros Sinteticos (LABPOL)]. E-mail:;; Tabak, David [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Quimica Organica. Lab. de Polimeros e Catalise (LAPOCAT)]. E-mail:; Lucas, Elizabete Fernandes [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas. Lab. de Macromoleculas e Coloides na Industria de Petroleo (LMCP)]. E-mail:


    Several types of crude oil have a large amount of wax, which can crystallize, at low temperatures, reducing the oil flow. Polymeric additives are able to prevent the wax deposition and to reduce the pour point of the oil, what improves the oil flow at low temperatures. Some acrylic polymers containing C{sub 12+} pendant groups are found in the literature as efficient additives for crude oils. Nevertheless, this type of polymer has not yet been used in Brazilian crude oils. In this work, octadecyl acrylate (ODA) was synthesized by transe esterification of methyl acrylate (MA). By using these monomers, several copolymers of MA-ODA (containing different compositions and different molecular weights) were obtained by solution copolymerization. The performance of the copolymers as pour point depressants was verified by using a crude oil from Bacia de Campos, RJ, Brazil. Increasing the ODA content in the copolymer, its efficiency increases and the best results were obtained with the copolymer MA:ODA (36:64). The crude oil containing this copolymer as additive presented a pour point reduction of 26 deg C but the lower the copolymer molecular weight the worse the polymeric additive performance. (author)

  6. Viabilitas sel fibroblas BHK-21 pada permukaan resin akrilik rapid heat cured (Viability of fibroblast BHK-21 cells to the surface of rapid heat cured acrylic resins

    Directory of Open Access Journals (Sweden)

    Anita Yuliati


    Full Text Available Acrylic resins are widely used in the fabrication of denture bases and have been shown to be cytotoxic as a result of substances that leach from the resin. Numerous reports suggest that residual monomer may be responsible for mucosal irritation and sensitization of tissues. This information is important in eddition to the information of the biologiced effect of such materials. The purpose of this study was to know the viability of fibroblast BHK-21cells to the surface of rapid heat cured acrylic resins. The sample of 5 mm in diameter and 1 mm thickness was cured in water bath for 20, 30, and 40 minutes at 100° C. BHK-21 cells were grown in medium eagle to be 2 × 105 cell/ml in 96 well micro titer plates as the added sample and incubated at 37° C for 24 hour. Five hours before the end of the incubation MTT solutionwas added from step one to each well containing cells. Viability cells were measured by spectrophotometer at 550 nm. The data were statistically analyzed by using one-way analysis of variance followed by LSD test. The result indicated that viability of fibroblast BHK-21 cells did not decrease to the surface of resin acrylic rapid heat cured.

  7. Sitotoksisitas resin akrilik hybrid setelah penambahan glass fiber dengan metode berbeda (Cytotoxicity of the hybrid acrylic resin after glass fiber reinforcement with difference method

    Directory of Open Access Journals (Sweden)

    Intan Nirwana


    Full Text Available Glass fiber reinforcement of the hybrid acrylic resin with difference method can enhance residual monomer content of the material; it can cause cytotoxic effect on fibroblast cells. The purpose of this study was to know the cytotoxicity of hybrid acrylic resins after glass fiber reinforcement with difference method on the cultured fibroblasts. The squared specimens of 10 mm in length, 10 mm in width and 1.5 mm in thickness were cured for 20 minutes at 100° C. The fibroblast cells were grown in Eagle's Minimum Essential Medium to be 2 × 105 cells/ml, then the cells were added to the samples in the plates and incubated at 37° C. After 48 hours, the cytotoxic effect was determined by direct cell number count using microscope and a hemocytometer. The statistical analyses using one way ANOVA and LSD test showed that there were significant difference in cell viability (p < 0.05 among the groups. The means percentage of cell viability were 90.00%, 99.,11%, 98.66%, it could be concluded that glass fiber reinforcement into hybrid acrylic resin with either first method or second method was not toxic.

  8. Cationically polymerizable monomers derived from renewable sources. Annual performance report

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.


    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year`s research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  9. [Influence Factors on Monomer Conversion of Dental Composite Resin]. (United States)

    Wang, Shuang; Gao, Yan; Wang, Jing; Zhang, Yan; Zhang, Yuntao; Wang, Fanghui; Wang, Qingshan


    Dental composite resin is a kind of material which has been widely used in dental restoration. Research has found that the influence of residual monomer on the material mechanical, chemical and biological properties cannot be ignored. This paper elaborates these harms of residual monomers. The effects of resin matrix, inorganic filler and initiating system, illumination, secondarily treatment on the degree of conversion were also analyzed. The paper also discusses the effective measures to increase the conversion, and offers theoretical basis for the clinical application and development of composite resin.

  10. PMR polyimide composites for aerospace applications. [Polymerization of Monomer Reactants (United States)

    Serafini, T. T.


    A novel class of addition-type polyimides has been developed in response to the need for high temperature polymers with improved processability. The new plastic materials are known as PMR (for in situ polymerization of monomer reactants) polyimides. The highly processable PMR polyimides have made it possible to realize much of the potential of high temperature resistant polymers. Monomer reactant combinations for several PMR polyimides have been identified. The present investigation is concerned with a review of the current status of PMR polyimides. Attention is given to details of PMR polyimide chemistry, the processing of composites and their properties, and aerospace applications of PMR-15 polyimide composites.

  11. Breathing zone concentrations of methylmethacrylate monomer during joint replacement operations

    DEFF Research Database (Denmark)

    Darre, E; Jørgensen, L G; Vedel, P;


    By use of a methylmethacrylate (MMA) Dräger tube and bellow bump, the breathing zone concentrations of MMA monomer were measured for the operating surgeon during cementation of the components of hip and knee joint prostheses. The highest recordings (50-100 p.p.m.) were encountered during cementat......By use of a methylmethacrylate (MMA) Dräger tube and bellow bump, the breathing zone concentrations of MMA monomer were measured for the operating surgeon during cementation of the components of hip and knee joint prostheses. The highest recordings (50-100 p.p.m.) were encountered during...

  12. Synthesis and Ethoxylation of Poly Methyl Acrylate%聚丙烯酸甲酯齐聚物的合成及乙氧基化

    Institute of Scientific and Technical Information of China (English)

    杜鹏飞; 孙永强; 康保安; 田春花; 刘广宇; 史修启; 张勇


    以四氩呋喃为溶剂,正十二硫醇为链转移剂,采用自由基溶液聚合的方法合成了聚丙烯酸甲酯齐聚物.考察了单体滴加时闻对黏均分子量的影响,确定滴加时间为40 min可以得到较低黏均分子量的聚丙烯酸甲酯齐聚物.在自制的插入式酯基乙氧基化催化荆MCT-09催化下成功地对聚丙烯酸甲酯齐聚物进行了乙氧基化反应.反应结果显示,随着反应进行,催化剂活性下降,乙氧基化反应速度逐渐降低.采用红外光谱对聚丙烯酸甲酯齐聚物及其乙氧基化物进行了结构表征.%Poly methyl acrylate(PMA) was synthesized by the method of free radical solvent polymerization using the tetrahydrofuran as solvent and the n-dodecyl mercaptan as chain transfer agent. The effect of the monomer dropping time on the viscosity molecular weight was tested. The results show that poly methyl acrylate with low viscosity molecular weight can be obtained when the monomer dropping time is set to be 40 minutes approximately.Following, with the help of self-made inserting ester ethoxylation catalyst MCT-09 the poly methyl acrylate is carriedout the ethoxylation successfully. The reaction results demonstrate that with the reaction carried through, the reaction rate decreases gradually due to the catalyst activity decline. Finally, the structure of the PMA and PMA ethoxylate was characterized by infrared spectrum(IR).

  13. Application of modified styrene-acrylate latex as surface sizing agent%改性苯丙乳液表面施胶剂的应用

    Institute of Scientific and Technical Information of China (English)

    曹辉波; 何静; 朱磊; 全晟


    By using functional monomer maleic anhydride, modified hydroxy-ethyl methacrylate emulsion, and taking styrene, methyl methacrylate, ethyl acrylate as main monomers, polystyrene-methyl methacrylate-ethyl acrylate-maleic anhydride (PSMEM), polystyrene-methyl methacrylate-ethyl acrylate-hydroxy-ethyl methacrylate (PSMEH) polymer surface sizing agent has been synthesized respectively. Application results indicate that after dried, and sized with the 70% emulsion on the paper surface, the testing paper reached the best physical properties; PSMEH was superior to PSMEM in wet strength of the paper. PSMEH and PSMEM both made the paper good hydrophobicity.%利用功能单体马来酸酐、甲基丙烯酸羟乙酯改性苯丙乳液,苯乙烯、甲基丙烯酸甲酯、丙烯酸乙酯为主单体,分别合成聚苯乙烯-甲基丙烯酸甲酯-丙烯酸乙酯-马来酸酐(PSMEM)、聚苯乙烯-甲基丙烯酸甲酯-丙烯酸乙酯-甲基丙烯酸羟乙酯(PSMEH)聚合物表面施胶剂.应用表明:选择纸样烘干后70%乳液涂布法进行施胶对纸张的物理性质作用效果最优;PSMEH对纸张湿强度的影响优于PSMEM;PSMEH、PSMEM可使纸张具有很好的憎水性.

  14. Textural and sensory properties of spreads with sucrose and maltitol

    Directory of Open Access Journals (Sweden)

    Šoronja-Simović Dragana M.


    Full Text Available Spreads are confectionery products based on sugar, vegetable fat, cocoa powder, milk powder and other ingredients. Basic properties of these products are good spreadability in wide temperature range (from ambience to fridge temperature, rich creamy chocolate taste, and homogenous smooth structure without oil phase migration. Undesirable attribute of these products is their relatively high energy value (2300 kJ/100 g. In recent years, cocoa cream products with reduced energy values have become very popular among consumers and today they are present in the assortment of many confectionery manufacturers. One way to produce spreads with reduced energy value is the replacement of sugar (sucrose with adequate sweetener. Maltitol is a low-energy poliol capable to qualitatively and quantitatively replace sucrose. Cocoa spreads with maltitol and with the combination of maltitol and sucrose (produced at different temperatures and mixer rotation speeds have similar texture and rheological properties compared to the spreads with sucrose. The spreads with maltitol have about 15% lower energy value in comparison to the same product with sucrose.

  15. Sucrose metabolism gene families and their biological functions. (United States)

    Jiang, Shu-Ye; Chi, Yun-Hua; Wang, Ji-Zhou; Zhou, Jun-Xia; Cheng, Yan-Song; Zhang, Bao-Lan; Ma, Ali; Vanitha, Jeevanandam; Ramachandran, Srinivasan


    Sucrose, as the main product of photosynthesis, plays crucial roles in plant development. Although studies on general metabolism pathway were well documented, less information is available on the genome-wide identification of these genes, their expansion and evolutionary history as well as their biological functions. We focused on four sucrose metabolism related gene families including sucrose synthase, sucrose phosphate synthase, sucrose phosphate phosphatase and UDP-glucose pyrophosphorylase. These gene families exhibited different expansion and evolutionary history as their host genomes experienced differentiated rates of the whole genome duplication, tandem and segmental duplication, or mobile element mediated gene gain and loss. They were evolutionarily conserved under purifying selection among species and expression divergence played important roles for gene survival after expansion. However, we have detected recent positive selection during intra-species divergence. Overexpression of 15 sorghum genes in Arabidopsis revealed their roles in biomass accumulation, flowering time control, seed germination and response to high salinity and sugar stresses. Our studies uncovered the molecular mechanisms of gene expansion and evolution and also provided new insight into the role of positive selection in intra-species divergence. Overexpression data revealed novel biological functions of these genes in flowering time control and seed germination under normal and stress conditions.


    Energy Technology Data Exchange (ETDEWEB)

    Steven C. Huber


    Studies have focused on the enzyme sucrose synthase, which plays an important role in the metabolism of sucrose in seeds and tubers. There are three isoforms of SUS in maize, referred to as SUS1, SUS-SH1, and SUS2. SUS is generally considered to be tetrameric protein but recent evidence suggests that SUS can also occur as a dimeric protein. The formation of tetrameric SUS is regulated by sucrose concentration in vitro and this could also be an important factor in the cellular localization of the protein. We found that high sucrose concentrations, which promote tetramer formation, also inhibit the binding of SUS1 to actin filaments in vitro. Previously, high sucrose concentrations were shown to promote SUS association with the plasma membrane. The specific regions of the SUS molecule involved in oligomerization are not known, but we identified a region of the SUS1 moelcule by bioinformatic analysis that was predicted to form a coiled coil. We demonstrated that this sequence could, in fact, self-associate as predicted for a coiled coil, but truncation analysis with the full-length recombinant protein suggested that it was not responsible for formation of dimers or tetramers. However, the coiled coil may function in binding of other proteins to SUS1. Overall, sugar availability may differentially influence the binding of SUS to cellular structures, and these effects may be mediated by changes in the oligomeric nature of the enzyme.

  17. Polymerization rate and mechanism of ultrasonically initiated emulsion polymerization of n-butyl acrylate. (United States)

    Xia, Hesheng; Wang, Qi; Liao, Yongqin; Xu, Xi; Baxter, Steven M; Slone, Robert V; Wu, Shuguang; Swift, Graham; Westmoreland, David G


    The factors affecting the induction period and polymerization rate in ultrasonically initiated emulsion polymerization of n-butyl acrylate (BA) were investigated. The induction period takes only an instant in ultrasonically initiated emulsion polymerization of BA without any added initiator by enhancing the N2 flow rate. Increasing temperature, power output and SDS concentration, decreasing the monomer concentration results in further decreasing induction period and enhanced polymerization rate. Under optimized reaction conditions the conversion of BA reaches 92% in 11 min. The polymerization rate can be controlled by varying reaction parameters. The apparatus of ultrasonically initiated semi-continuous and continuous emulsion polymerization were set up and the feasibility was first studied. Based on the experimental results, a free radical polymerization mechanism for ultrasonically initiated emulsion polymerization was proposed, including the sources of the radicals, the process of radical formation, the locus of polymerization and the polymerization process. Compared with conventional emulsion polymerization, where the radicals come from thermal decomposition of a chemical initiator, ultrasonically initiated emulsion polymerization has attractive features such as no need for a chemical initiator, lower reaction temperature, faster polymerization rate, and higher molecular weight of the polymer prepared.

  18. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Directory of Open Access Journals (Sweden)

    Fangfang LIU


    Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

  19. Impact of Packing and Processing Technique on Mechanical Properties of Acrylic Denture Base Materials

    Directory of Open Access Journals (Sweden)

    Touraj Nejatian


    Full Text Available The fracture resistance of polymethylmethacrylate (PMMA as the most popular denture base material is not satisfactory. Different factors can be involved in denture fracture. Among them, flexural fatigue and impact are the most common failure mechanisms of an acrylic denture base. It has been shown that there is a correlation between the static strength and fatigue life of composite resins. Therefore, the transverse strength of the denture base materials can be an important indicator of their service life. In order to improve the fracture resistance of PMMA, extensive studies have been carried out; however, only a few promising results were achieved, which are limited to some mechanical properties of PMMA at the cost of other properties. This study aimed at optimizing the packing and processing condition of heat-cured PMMA as a denture base resin in order to improve its biaxial flexural strength (BFS. The results showed that the plain type of resin with a powder/monomer ratio of 2.5:1 or less, packed conventionally and cured in a water bath for 2 h at 95 °C provides the highest BFS. Also, it was found that the performance of the dry heat processor is inconsistent with the number of flasks being loaded.

  20. Synthesis and characterization of polycaprolactone/acrylic acid (PCL/AA) hydrogel for controlled drug delivery

    Indian Academy of Sciences (India)

    Nazar Mohammad Ranjha; Jahanzeb Mudassir; Sajid Majeed


    In the present work biodegradable pH-sensitive polycaprolactone/acrylic acid (PCL/AA) hydrogels have been developed using ethylene glycol dimethacrylate (EGDMA) as a cross-linker and benzoyl peroxide as initiator. For these prepared hydrogels swelling studies, sol–gel fraction analysis and porosity measurements were performed. Results show that swelling of the hydrogels decreases on increasing the concentration of PCL and EGDMA, however swelling of hydrogels increases on increasing the concentration of AA. Results of sol–gel fraction analysis show that gel fraction increases on increasing concentration of monomer AA, polymer PCL as well as cross-linker EGDMA. As far as porosity is concerned, it increases on increasing the concentration of AA and PCL while porosity decreases on increasing the concentration of EGDMA. Hydrogels were characterized by measuring diffusion coefficient () and equilibrium water content (EWC). Network formation, morphology and crystallinity of PCL/AA hydrogels were investigated using FTIR, SEM and XRD, respectively. Tramadol hydrochloride was loaded as model drug and its release pattern was analysed using various kinetic models like zero order, first order, Higuchi and Peppas. Results indicated that most of the samples followed non-Fickian release mechanism.

  1. Photocurable biodegradable liquid copolymers: synthesis of acrylate-end-capped trimethylene carbonate-based prepolymers, photocuring, and hydrolysis. (United States)

    Matsuda, Takehisa; Kwon, Il Keun; Kidoaki, Satoru


    Various photocurable liquid biodegradable trimethylene carbonate (TMC)-based (co)oligomers were prepared by ring-opening (co)polymerization of TMC with or without L-lactide (LL) using low molecular weight poly(ethylene glycol) (PEG) (mol wt 200, 600, or 1000) or trimethylolpropane (TMP) as an initiator. Resultant (co)oligomers were pastes, viscous liquids, or liquids at room temperature, depending on the monomer composition and monomer/initiator ratio. Liquid (co)oligomers were subsequently end-capped with acrylate groups. Upon visible-light irradiation in the presence of camphorquinone as a radical generator, rapid liquid-to-solid transformation occurred to produce photocured solid. The photocuring yield increased with photoirradiation time, photointensity, and camphorquinone concentration. The photocured polymers derived from low molecular weight PEG (PEG200) and TMP exhibited much reduced hydrolysis potential compared with PEG1000-derived polymers in terms of weight loss, water uptake, and swelling depth. Force-distance curve measurements by nanoindentation using atomic force microscopy clearly showed that Young's moduli of the photocured polymer films decreased with increasing hydrolysis time. Their potential biomedical applications are discussed.

  2. Enhancing antibiofouling performance of Polysulfone (PSf) membrane by photo-grafting of capsaicin derivative and acrylic acid (United States)

    Wang, Jian; Sun, Haijing; Gao, Xueli; Gao, Congjie


    Biofouling is a critical issue in membrane water and wastewater treatment. Herein, antibiofouling PSf membrane was prepared by UV-assisted graft polymerization of acrylic acid (AA) and a capsaicin derivative, N-(5-methyl-3-tert-butyl-2-hydroxy benzyl) acrylamide (MBHBA), on PSf membrane. AA and MBHBA were used as hydrophilic monomer and antibacterial monomer separately. The membranes were characterized by FTIR-ATR, contact angle, SEM, AFM, cross-flow filtration unit, antifouling and antibacterial measurements. Verification of MBHBA and AA that photo-chemically grafted onto the PSf membrane surface is confirmed by carbonyl stretching vibration at ∼1655 cm-1 and ∼1730 cm-1, separately. The increasing AA concentration accelerates the graft-polymerization of MBHBA and resulted in a more hydrophilic surface. Consequently, antifouling property of the membranes was improved on a large level. The flux recovery rate can achieve 100% during the cyclic test, which may be attributed to the more hydrophilic and smooth surface, as well as the decreased membrane pore size. Most importantly, the presence of AA in graft co-polymer does not affect the antibacterial activity of MBHBA. That may be induced by the increasing chain length and flexibility of the grafted polymer chains.

  3. Synthesis of a benzoxazine monomer containing maleimide and allyloxy groups

    Institute of Scientific and Technical Information of China (English)


    A novel benzoxazine monomer 3-(4-allyloxy)phenyl-3,4-dihydro-2H-6-(N-maleimido)-1,3-benzoxazine (AMB) was synthesized and structure was confirmed by FT-IR, 1H NMR. Thermal analysis (DSC) of AMB showed the introduction of allyloxy group decreased melting point and exhibited a narrow and symmetric curing exothermic window.

  4. WH2 domain: a small, versatile adapter for actin monomers. (United States)

    Paunola, Eija; Mattila, Pieta K; Lappalainen, Pekka


    The actin cytoskeleton plays a central role in many cell biological processes. The structure and dynamics of the actin cytoskeleton are regulated by numerous actin-binding proteins that usually contain one of the few known actin-binding motifs. WH2 domain (WASP homology domain-2) is a approximately 35 residue actin monomer-binding motif, that is found in many different regulators of the actin cytoskeleton, including the beta-thymosins, ciboulot, WASP (Wiskott Aldrich syndrome protein), verprolin/WIP (WASP-interacting protein), Srv2/CAP (adenylyl cyclase-associated protein) and several uncharacterized proteins. The most highly conserved residues in the WH2 domain are important in beta-thymosin's interactions with actin monomers, suggesting that all WH2 domains may interact with actin monomers through similar interfaces. Our sequence database searches did not reveal any WH2 domain-containing proteins in plants. However, we found three classes of these proteins: WASP, Srv2/CAP and verprolin/WIP in yeast and animals. This suggests that the WH2 domain is an ancient actin monomer-binding motif that existed before the divergence of fungal and animal lineages.

  5. Influence of the diene monomer on devulcanization of EPDM rubber

    NARCIS (Netherlands)

    Verbruggen, M.; Does, van der L.; Noordermeer, J.W.M.; Duin, van M.


    Ethylene–propylene–diene rubbers (EPDM) with 2-ethylidene-5-norbornene (ENB), dicyclopentadiene (DCPD), and 1,4-hexadiene (HD) as third monomers have been vulcanized with peroxide and with a conventional sulfur vulcanization recipe, and their devulcanization was subsequently investigated for recycli

  6. Base-catalyzed depolymerization of lignin : separation of monomers

    Energy Technology Data Exchange (ETDEWEB)

    Vigneault, A. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; Johnson, D.K. [National Renewable Energy Laboratory, Golden, CO (United States); Chornet, E. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; National Renewable Energy Laboratory, Golden, CO (United States)


    Biofuels produced from residual lignocellulosic biomass range from ethanol to biodiesel. The use of lignin for the production of alternate biofuels and green chemicals has been studied with particular emphasis on the structure of lignin and its oxyaromatic nature. In an effort to fractionate lignocellulosic biomass and valorize specific constitutive fractions, the authors developed a strategy for the separation of 12 added value monomers produced during the hydrolytic base catalyzed depolymerization (BCD) of a Steam Exploded Aspen Lignin. The separation strategy was similar to vanillin purification to obtain pure monomers, but combining more steps after the lignin depolymerization such as acidification, batch liquid-liquid-extraction (LLE), followed by vacuum distillation, liquid chromatography (LC) and crystallization. The purpose was to develop basic data for an industrial size process flow diagram, and to evaluate both the monomer losses during the separation and the energy requirements. Experimentally testing of LLE, vacuum distillation and flash LC in the laboratory showed that batch vacuum distillation produced up to 4 fractions. Process simulation revealed that a series of 4 vacuum distillation columns could produce 5 distinct monomer streams, of which 3 require further chromatography and crystallization operations for purification. 22 refs., 4 tabs., 8 figs.

  7. Epoxy resin monomers with reduced skin sensitizing potency. (United States)

    O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese


    Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis.

  8. Aggregation processes with catalysis-driven monomer birth/death

    Institute of Scientific and Technical Information of China (English)

    Chen Yu; Han An-Jia; Ke Jian-Hong; Lin Zhen-Quan


    We propose two solvable cluster growth models, in which an irreversible aggregation spontaneously occurs between any two clusters of the same species; meanwhile, monomer birth or death of species A occurs with the help of species B. The system with the size-dependent monomer birth/death rate kernel K(i,j) = Jijv is then investigated by means of the mean-field rate equation. The results show that the kinetic scaling behaviour of species A depends crucially on the value of the index v. For the model with catalysis-driven monomer birth, the cluster-mass distribution of species A obeys the conventional scaling law in the v ≤ 0 case, while it satisfies a generalized scaling form in the v>0 case; moreover, the total mass of species A is a nonzero value in the v< 0 case while it grows continuously with time in the v>0 case. For the model with catalysis-driven monomer death, the cluster-mass distribution also approaches the conventional scaling form in the v < 0 case, while the conventional scaling description of the system breaks down in the v ≥ 0 case. Additionally, the total mass of species A retains a nonzero quantity in the v <0 case, but it decreases to zero with time in the v ≥ 0 case.

  9. Microstructure Control in the emulsion polymerization of fluorinated monomers

    Energy Technology Data Exchange (ETDEWEB)

    Apostolo, Marco [Ausimont R and D, Bollate (Italy); Morbidelli, Massimo [ETH Zentrum, Zuerich (Switzerland)


    In this paper a mathematical model able to evaluate the microstructure of fluorinated polymers is presented. The model uses the pseudo-homo polymerization approach to describe the kinetic evolution of polymerization reactions involving any number of monomer species. The molecular weight distribution is evaluated combining the classical leading moments method with a recently proposed model based on the numerical fractionation technique.

  10. Oligonucleotides with 1,4-dioxane-based nucleotide monomers

    DEFF Research Database (Denmark)

    Madsen, Andreas S; Wengel, Jesper


    An epimeric mixture of H-phosphonates 5R and 5S has been synthesized in three steps from known secouridine 1. Separation of the epimers has been accomplished by RP-HPLC, allowing full characterization and incorporation of monomers X and Y into 9-mer oligonucleotides using H-phosphonates building ...

  11. Large deformation micromechanics of particle filled acrylics at elevated temperatures (United States)

    Gunel, Eray Mustafa

    The main aim of this study is to investigate stress whitening and associated micro-deformation mechanism in thermoformed particle filled acrylic sheets. For stress whitening quantification, a new index was developed based on image histograms in logarithmic scale of gray level. Stress whitening levels in thermoformed acrylic composites was observed to increase with increasing deformation limit, decreasing forming rate and increasing forming temperatures below glass transition. Decrease in stress whitening levels above glass transition with increasing forming temperature was attributed to change in micro-deformation behavior. Surface deformation feature investigated with scanning electron microscopy showed that source of stress whitening in thermoformed samples was a combination of particle failure and particle disintegration depending on forming rate and temperature. Stress whitening level was strongly correlated to intensity of micro-deformation features. On the other hand, thermoformed neat acrylics displayed no surface discoloration which was attributed to absence of micro-void formation on the surface of neat acrylics. Experimental damage measures (degradation in initial, secant, unloading modulus and strain energy density) have been inadequate in describing damage evolution in successive thermoforming applications on the same sample at different levels of deformation. An improved version of dual-mechanism viscoplastic material model was proposed to predict thermomechanical behavior of neat acrylics under non-isothermal conditions. Simulation results and experimental results were in good agreement and failure of neat acrylics under non-isothermal conditions ar low forming temperatures were succesfully predicted based on entropic damage model. Particle and interphase failure observed in acrylic composites was studied in a multi-particle unit cell model with different volume fractions. Damage evolution due to particle failure and interphase failure was simulated

  12. Impact Delamination and Fracture in Aluminum/Acrylic Sandwich Plates (United States)

    Liaw, Benjamin; Zeichner, Glenn; Liu, Yanxiong; Bowles, Kenneth J. (Technical Monitor)


    Impact-induced delamination and fracture in 6061-T6 aluminum/cast acrylic sandwich plates adhered by epoxy were generated in an instrumented drop-weight impact machine. Although only a small dent was produced on the aluminum side when a hemispherical penetrator tup was dropped onto it from a couple of inches, a large ring of delamination at the interface was observed. The delamination damage was often accompanied by severe shattering in the acrylic substratum. Damage patterns in the acrylic layer include radial and ring cracks and, together with delamination at the interface, may cause peeling-off of acrylic material from the sandwich plate. Theory of stress-wave propagation can be used to explain these damage patterns. The impact tests were conducted at various temperatures. The results also show clearly that temperature effect is very important in impact damage. For pure cast acrylic nil-ductile transition (NDT) occurs between 185-195 F. Excessive impact energy was dissipated into fracture energy when tested at temperature below this range or through plastic deformation when tested at temperature above the NDT temperature. Results from this study will be used as baseline data for studying fiber-metal laminates, such as GLARE and ARALL for advanced aeronautical and astronautical applications.

  13. Taste preference thresholds for Polycose, maltose, and sucrose in rats. (United States)

    Sclafani, A; Nissenbaum, J W


    The taste preference thresholds of adult female rats for polysaccharide (Polycose), maltose, and sucrose were compared. The nondeprived animals were given 24-hr two-bottle preference tests (saccharide solution vs. water) and, starting at 0.008%, the saccharide concentration was increased daily. The rats first preferred the Polycose solution to water at 0.01% (0.0001 M), the maltose solution to water at 0.09% (0.0025 M), and the sucrose solution to water at 0.09% (0.0026 M). Thus, on a molar basis the rats' Polycose threshold was 25 to 26 times lower than their maltose and sucrose threshold. It was postulated that the low taste threshold for polysaccharides allows the rat to detect starch which, unlike sugar, is very low in solubility.

  14. Fatal anaphylactic reaction to iron sucrose in pregnancy

    Directory of Open Access Journals (Sweden)

    Ajay Mishra


    Full Text Available Iron-deficiency anemia in pregnancy can have serious deleterious effects for both mother and fetus. Parenteral iron therapy in iron-deficiency anemia is recommended in patients where oral iron therapy is ineffective due to malabsorption states and non-compliance. Compared to oral iron therapy, intravenous iron results in much more rapid resolution of iron-deficiency anemia with minimal adverse reactions. Iron sucrose has a favorable safety profile and is an alternative to other forms of parenteral iron therapy in correction of iron stores depletion. Immune mechanisms and iron agent releasing bioactive, partially unbound iron into the circulation, resulting in oxidative stress appears to cause severe adverse reactions. Although iron sucrose has a favorable safety profile in comparison to other parenteral iron preparations, this report highlights a fatal anaphylactic shock to iron sucrose in a pregnant woman with severe iron deficiency non-compliant to oral iron therapy.

  15. The Structure of Sucrose Synthase-1 from Arabidopsis thaliana and Its Functional Implications

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yi; Anderson, Spencer; Zhang, Yanfeng; Garavito, R. Michael (MSU); (NWU)


    Sucrose transport is the central system for the allocation of carbon resources in vascular plants. During growth and development, plants control carbon distribution by coordinating sites of sucrose synthesis and cleavage in different plant organs and different cellular locations. Sucrose synthase, which reversibly catalyzes sucrose synthesis and cleavage, provides a direct and reversible means to regulate sucrose flux. Depending on the metabolic environment, sucrose synthase alters its cellular location to participate in cellulose, callose, and starch biosynthesis through its interactions with membranes, organelles, and cytoskeletal actin. The x-ray crystal structure of sucrose synthase isoform 1 from Arabidopsis thaliana (AtSus1) has been determined as a complex with UDP-glucose and as a complex with UDP and fructose, at 2.8- and 2.85-{angstrom} resolutions, respectively. The AtSus1 structure provides insights into sucrose catalysis and cleavage, as well as the regulation of sucrose synthase and its interactions with cellular targets.

  16. Binding interactions between suberin monomer components and pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Olivella, M.À., E-mail: [Department of Chemical Engineering, Escola Politècnica Superior, Universitat de Girona, Maria Aurèlia Capmany, 61, 17071 Girona (Spain); Bazzicalupi, C.; Bianchi, A. [Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia, 3, 50019 Sesto Fiorentino (Italy); Río, J.C. del [Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, P.O. Box 1052, 41080 Seville (Spain); Fiol, N.; Villaescusa, I. [Department of Chemical Engineering, Escola Politècnica Superior, Universitat de Girona, Maria Aurèlia Capmany, 61, 17071 Girona (Spain)


    Understanding the role of biomacromolecules and their interactions with pollutants is a key for elucidating the sorption mechanisms and making an accurate assessment of the environmental fate of pollutants. The knowledge of the sorption properties of the different constituents of these biomacromolecules may furnish a significant contribution to this purpose. Suberin is a very abundant biopolymer in higher plants. In this study, suberin monomers isolated from cork were analyzed by thermally-assisted methylation with tetramethylammonium hydroxide (TMAH) in a pyrolysis unit coupled to gas chromatography–mass spectrometry (GC/MS). The isolated monomer mixture was used to study the sorption of three pesticides (isoproturon, methomyl and oxamyl). The modes of pesticide–sorbent interactions were analyzed by means of two modeling calculations, the first one representing only the mixture of suberin monomers used in the sorption study, and the second one including glycerol to the mixture of suberin monomers, as a building block of the suberin molecule. The results indicated that the highest sorption capacity exhibited by the sorbent was for isoproturon (33%) being methomyl and oxamyl sorbed by the main suberin components to a lesser extent (3% and < 1%, respectively). In addition to van der Waals interactions with the apolar region of sorbent and isoproturon, modeling calculations evidenced the formation of a hydrogen bond between the isoproturon NH group and a carboxylic oxygen atom of a suberin monomer. In the case of methomyl and oxamyl only weak van der Waals interactions stabilize the pesticide–sorbent adducts. The presence of glycerol in the model provoked significant changes in the interactions with isoproturon and methomyl. - Highlights: • Suberin has low affinity to retain pesticides of aliphatic character. • Suberin has a moderate affinity to adsorb isoproturon. • Modeling calculations show that apolar portion of suberin interacts with isoproturon.

  17. Deregulation of sucrose-controlled translation of a bZIP-type transcription factor results in sucrose accumulation in leaves.

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Thalor

    Full Text Available Sucrose is known to repress the translation of Arabidopsis thaliana AtbZIP11 transcript which encodes a protein belonging to the group of S (S--stands for small basic region-leucine zipper (bZIP-type transcription factor. This repression is called sucrose-induced repression of translation (SIRT. It is mediated through the sucrose-controlled upstream open reading frame (SC-uORF found in the AtbZIP11 transcript. The SIRT is reported for 4 other genes belonging to the group of S bZIP in Arabidopsis. Tobacco tbz17 is phylogenetically closely related to AtbZIP11 and carries a putative SC-uORF in its 5'-leader region. Here we demonstrate that tbz17 exhibits SIRT mediated by its SC-uORF in a manner similar to genes belonging to the S bZIP group of the Arabidopsis genus. Furthermore, constitutive transgenic expression of tbz17 lacking its 5'-leader region containing the SC-uORF leads to production of tobacco plants with thicker leaves composed of enlarged cells with 3-4 times higher sucrose content compared to wild type plants. Our finding provides a novel strategy to generate plants with high sucrose content.

  18. New rat models of iron sucrose-induced iron overload. (United States)

    Vu'o'ng Lê, Bá; Khorsi-Cauet, Hafida; Villegier, Anne-Sophie; Bach, Véronique; Gay-Quéheillard, Jérôme


    The majority of murine models of iron sucrose-induced iron overload were carried out in adult subjects. This cannot reflect the high risk of iron overload in children who have an increased need for iron. In this study, we developed four experimental iron overload models in young rats using iron sucrose and evaluated different markers of iron overload, tissue oxidative stress and inflammation as its consequences. Iron overload was observed in all iron-treated rats, as evidenced by significant increases in serum iron indices, expression of liver hepcidin gene and total tissue iron content compared with control rats. We also showed that total tissue iron content was mainly associated with the dose of iron whereas serum iron indices depended essentially on the duration of iron administration. However, no differences in tissue inflammatory and antioxidant parameters from controls were observed. Furthermore, only rats exposed to daily iron injection at a dose of 75 mg/kg body weight for one week revealed a significant increase in lipid peroxidation in iron-treated rats compared with their controls. The present results suggest a correlation between iron overload levels and the dose of iron, as well as the duration and frequency of iron injection and confirm that iron sucrose may not play a crucial role in inflammation and oxidative stress. This study provides important information about iron sucrose-induced iron overload in rats and may be useful for iron sucrose therapy for iron deficiency anemia as well as for the prevention and diagnosis of iron sucrose-induced iron overload in pediatric patients.

  19. Sucrose: A Prospering and Sustainable Organic Raw Material (United States)

    Peters, Siegfried; Rose, Thomas; Moser, Matthias

    Sucrose (α-d-glucopyranosyl-(1→2)-β-d-fructofuranoside) is an inexpensive chemical produced by sugar cane and sugar beet cultivation. Chemical and/or biochemical transformations convert it into highly valuable synthetic intermediates such as 5-hydroxymethylfurfural (HMF), bioethylene, 1,2-propylene glycol and levulinic acid. Sucrose can also be converted into biodegradable polymers such as polyesters and polyurethanes, as well as into novel carbohydrates such as isomaltulose, trehalulose, inulin, levan, Neo-amylose, and dextran, highly valuable additives for food and cosmetics and materials for separation and purification technologies.

  20. Anharmonicity and hydrogen bonding in electrooptic sucrose crystal (United States)

    Szostak, M. M.; Giermańska, J.


    The polarized absorption spectra of the sucrose crystal in the 5300 - 7300 cm -1 region have been measured. The assignments of all the eight OH stretching overtones are proposed and their mechanical anharmonicities are estimated. The discrepancies from the oriented gas model (OGM) in the observed relative band intensities, especially of the -CH vibrations, are assumed to be connected with vibronic couplings enhanced by the helical arrangement of molecules joined by hydrogen bondings. It seems that this kind of interactions might be important for the second harmonic generation (SHG) by the sucrose crystal.

  1. 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


    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.

  2. 无皂苯丙防锈乳液的合成研究%Study on the Synthesis of Soap-free Styrene-acrylic Anti-rust Emulsion

    Institute of Scientific and Technical Information of China (English)

    张洁; 闫福安


    以苯乙烯(st)、丙烯酸丁酯(BA)为主要单体,甲基丙烯酸(MAA)、甲基丙烯酸缩水甘油酯(GMA)、乙烯基三乙氧基硅烷(A-151)为交联单体合成了无皂苯丙乳液。研究了反应型乳化剂的种类及用量、交联单体的用量对乳液及涂膜性能的影响。确定反应型乳化剂的最佳用量为单体总量的3%。试验发现:当甲基丙烯酸缩水甘油酯与甲基丙烯酸的用量分别为单体总量的3%和3%时,二者可进行交联,能提高苯丙乳液的交联度和致密性。通过加入缓蚀剂PD—star-102,解决了苯丙乳液初期的闪锈问题,同时对涂膜的耐盐水性能有所提高。%With styrene (St), butyl acrylate (BA) as main monomers, methacrylic acid (MAA), glycidyl methacrylate (GMA) and vinyltriethoxysilane(A-151) as crosslinking monomers, the soap-free emulsion is synthesized. This paper studies the influence of the type and the amount of reactive emulsifier and the amount of crosslinking monomer on the emulsion and film performance. It is determined that the best amount of the reactive emulsifier is 3% of total amount. Experiments show: when the amount of glycidyl methacrylate monomer and methacrylic acid monomer is respectively 3% and 3% of the total monomer, they can be cross-linked and the crosslinking degree and density of styrene-acrylic emulsion can be improved. By adding corrosion inhibitor PD-star-102, the problem of initial flash rust of styrene-acrylic emulsion can be solved; and at the same time, the property of salt water resistance can be improved.

  3. Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins

    Directory of Open Access Journals (Sweden)

    Nour M. Ajaj-ALKordy


    Conclusion: Within the limitations of this study, it can be concluded that the high-impact acrylic resin is a suitable denture base material for patients with clinical fracture of the acrylic denture.

  4. 固体酸Amberlyst 15催化合成丙烯酸异冰片酯%Synthesis of Isobornyl Acrylate in the Presence of Amberlyst 15

    Institute of Scientific and Technical Information of China (English)

    徐晓维; 徐徐; 王石发; 花宇


    以莰烯和丙烯酸为原料,用强酸性阳离子树脂Amberlyst 15作催化剂合成了功能单体丙烯酸异冰片酯,考察了物料比、催化剂用量、阻聚剂种类及用量、反应温度、反应时间等因素对反应的影响,同时采用正交试验对工艺条件进行了优化,结果表明,较适宜的反应条件是n(丙烯酸)∶n(莰烯)为1.3∶1,催化剂Amberlyst 15用量占原料总质量的12%,阻聚剂吩噻嗪用量占原料总质量的0.03%,反应温度为60℃,在此条件下制备的丙烯酸异冰片酯得率为83.3%,选择性为94.6%.利用傅立叶变换红外光谱及气相色谱-质谱等分析手段对产物的结构进行了鉴定.%Functional monomer-isobornyl acrylate was prepared from camphene and acrylic acid using cation exchange resin-Amberlyst 15 as catalyst.Effects of material ratio of camphene to acrylic acid,content of catalyst,types and content of inhibitors,the temperature,and the reaction time on reaction were investigated.Experimental results showed that the optimum conditions were material ratio of acrylic acid to camphene 1.3∶ 1,content of catalyst 12 %,content of phenothiazine 0.03 %,and the reaction temperature 60 ℃.The yield of isobornyl acrylate was 83.3 %,and the selectivity was 94.6 % under the above conditions.The structure of isobornyl acrylate was characterized by FT-IR and GC-MS.

  5. Nucleophilic Addition of Reactive Dyes on Amidoximated Acrylic Fabrics

    Directory of Open Access Journals (Sweden)

    Reda M. El-Shishtawy


    Full Text Available Seven reactive dyes judiciously selected based on chemical structures and fixation mechanisms were applied at 2% owf of shade on amidoximated acrylic fabrics. Amidoximated acrylic fabric has been obtained by a viable amidoximation process. The dyeability of these fabrics was evaluated with respect to the dye exhaustion, fixation, and colour strength under different conditions of temperature and dyeing time. Nucleophilic addition type reactive dyes show higher colour data compared to nucleophilic substitution ones. FTIR studies further implicate the binding of reactive dyes on these fabrics. A tentative mechanism is proposed to rationalize the high fixation yield obtained using nucleophilic addition type reactive dyes. Also, the levelling and fastness properties were evaluated for all dyes used. Excellent to good fastness and levelling properties were obtained for all samples irrespective of the dye used. The result of investigation offers a new method for a viable reactive dyeing of amidoximated acrylic fabrics.

  6. Nucleophilic addition of reactive dyes on amidoximated acrylic fabrics. (United States)

    El-Shishtawy, Reda M; El-Zawahry, Manal M; Abdelghaffar, Fatma; Ahmed, Nahed S E


    Seven reactive dyes judiciously selected based on chemical structures and fixation mechanisms were applied at 2% of of shade on amidoximated acrylic fabrics. Amidoximated acrylic fabric has been obtained by a viable amidoximation process. The dyeability of these fabrics was evaluated with respect to the dye exhaustion, fixation, and colour strength under different conditions of temperature and dyeing time. Nucleophilic addition type reactive dyes show higher colour data compared to nucleophilic substitution ones. FTIR studies further implicate the binding of reactive dyes on these fabrics. A tentative mechanism is proposed to rationalize the high fixation yield obtained using nucleophilic addition type reactive dyes. Also, the levelling and fastness properties were evaluated for all dyes used. Excellent to good fastness and levelling properties were obtained for all samples irrespective of the dye used. The result of investigation offers a new method for a viable reactive dyeing of amidoximated acrylic fabrics.

  7. Lightweight bonded acrylic facing at the Vitra VSL Factory

    Directory of Open Access Journals (Sweden)



    Full Text Available Corresponding author: Matthias Michel, E-mail: Acrylic glass is omnipresent in the industrialised world; but as a building material most architects, facade planners and engineers are still unfamiliar with this material. In most cases it is applied as a substitute for glass which leads to inappropriate joints and fixtures. During the years of the path toward the digital era, the authors were in the fortunate position to be involved in several unconventional glass and acrylic glass projects. On the basis of their most recent project, the facade of the Vitra VSL Factory by SANAA Architekten, they describe the development of a facade for which they chose acrylic glass not as a substitute for glass but rather as a conscious material choice. Since the entire facade is it was possible to apply the manufacturing technology of deep-drawing, allowing for very thin wall thicknesses.

  8. Lightweight bonded acrylic facing at the Vitra VSL Factory

    Directory of Open Access Journals (Sweden)

    Matthias Michel


    Full Text Available Acrylic glass is omnipresent in the industrialised world; but as a building material most architects, facade planners and engineers are still unfamiliar with this material. In most cases it is applied as a substitute for glass which leads to inappropriate joints and fixtures. During the years of the path toward the digital era, the authors were in the fortunate position to be involved in several unconventional glass and acrylic glass projects.On the basis of their most recent project, the  facade of the Vitra VSL Factory by SANAA Architekten, they describe the development of a facade for which they chose acrylic glass not as a substitute for glass but rather as a conscious material choice. Since the entire facade is it was possible to apply the manufacturing technology of deep-drawing, allowing for very thin wall thicknesses.


    Institute of Scientific and Technical Information of China (English)

    张诚; 孟琴; 吕德伟


    For the aim of getting macromolecular flocculant,we studied the copolymerization of acrylic acid onto Rhi.oryzae cell wall structural polysaccharide by the initiation of ceric ammonium nitrate.The effect of concentration of initiator and monomer,reaction temperature and reaction time on grafting percentage was investigated.To Rhi.oryzae cell wall structural polysaccharide the maximal grafting percentage of 135.5% was achieved at [Ce+4]=5mmol/L,[AA]=1mol/L,T=60℃,t=3h.Then choosing organic dyes as the flocculated substances,by comparing with the chitosan,polyacrylamide and Rhi.oryzae cell wall structural polysaccharide before grafting,we studied the flocculent capability of Rhi.oryzae cell wall structural polysaccharide after grafting acrylic acid.The grafting product had excellent flocculent effect on basic and neutral dyes.

  10. The effect of sucrose on unfrozen water and syneresis of acidified sodium caseinate-xanthan gels. (United States)

    Braga, A L M; Cunha, R L


    The influence of the ingredients of acidified Na caseinate-xanthan-sucrose gels on thermophysical properties and syneresis of the gels was studied. Sucrose concentration affected all of the gel equilibrium properties and the rate of syneresis. The positive effect of sucrose on syneresis and unfrozen water (UFW) values was attributed to different effects. The amount of UFW was governed mainly by the colligative properties of sucrose whereas the equilibrium syneresis behaviour was associated with the changes in network dynamics caused by the kosmotropic properties of sucrose. The latter could enhance xanthan-sucrose association or favour xanthan-protein interactions.

  11. Ultrasonic velocities, densities, and excess molar volumes of binary mixtures of N,N-dimethyl formamide with methyl acrylate, or ethyl acrylate, or butyl acrylate, or 2-ethyl hexyl acrylate at T = 308.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Kondaiah, M. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Sravana Kumar, D. [Dr. V.S. Krishna Govt. Degree College, Visakhapatnam, Andhra Pradesh (India); Sreekanth, K. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India); Krishna Rao, D., E-mail: [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, Andhra Pradesh (India)


    Highlights: > Positive values of V{sub m}{sup E}, indicate dispersion forces between acrylic esters and DMF. > V{sub m}{sup E} values compared with Redlich-Kister polynomial. > Partial molar volumes data conclude that weak interactions exist in the systems. > Measured velocity values compared with theoretical values obtained by polynomials. - Abstract: Ultrasonic velocities, u, densities, {rho}, of binary mixtures of N,N-dimethyl formamide (DMF) with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), and 2-ethyl hexyl acrylate (EHA), including pure liquids, over the entire composition range have been measured at T = 308.15 K. Using the experimental results, the excess molar volume, V{sub m}{sup E}, partial molar volumes, V-bar {sub m,1}, V-bar{sub m,2}, and excess partial molar volumes, V-bar{sub m,1}{sup E}, V-bar{sub m,2}{sup E} have been calculated. Molecular interactions in the systems have been studied in the light of variation of excess values of calculated properties. The excess properties have been fitted to Redlich-Kister type polynomial and the corresponding standard deviations have been calculated. The positive values of V{sub m}{sup E} indicate the presence of dispersion forces between the DMF and acrylic ester molecules. Further theoretical values of sound velocity in the mixtures have been evaluated using various theories and have been compared with experimental sound velocities to verify the applicability of such theories to the systems studied. Theoretical ultrasonic velocity data have been used to study molecular interactions in the binary systems investigated.

  12. Comparison of classical dermatoscopy and acrylic globe magnifier dermatoscopy

    DEFF Research Database (Denmark)

    Lorentzen, Henrik F; Eefsen, Rikke Løvendahl; Weismann, Kaare


    Dermatoscopic asymmetry of melanocytic skin lesion is pivotal in most algorithms assessing the probability of melanoma. Larger lesions cannot be assessed by dermatoscopy and the Dermaphot in a single field of vision, but this can be performed using the acrylic globe magnifier. We examined......% confidence interval 83-97%). Sensitivity for melanoma, benign melanocytic naevi and basal cell carcinoma was 100%, 98% and 85%, respectively. Specificity was 95%, 94% and 100% for melanoma, naevi and basal cell carcinoma. Acrylic globe dermatoscopy enables a diagnostic accuracy similar to epiluminescence...

  13. Evaluation of Cellular Toxicity of Three Denture Base Acrylic Resins


    Ebrahimi Saravi, M.; M. Vojdani; Bahrani, F


    Objective This study aimed to evaluate the cellular toxicity of two newly-released acrylic resins (Futura Gen and GC Reline Hard) in comparison with the conventional heat-cure resin (Meliodent). Materials and Methods: Sample discs from each acrylic resin were placed in 24-well culture plates along with L929 mouse fibroblast cell line. A mixture of the RPMI 1640 medium, antibiotics and 10% FBS was added to the plates and the specimens were incubated in a CO2 incubator. The amount of light abso...

  14. The creep behavior of acrylic denture base resins. (United States)

    Sadiku, E R; Biotidara, F O


    The creep behavior of acrylic dental base resins, at room temperature and at different loading conditions, has been examined. The behaviors of these resins are similar to that of "commercial perspex" at room temperature over a period of 1000 seconds. The pseudo-elastic moduli of the blends of PMMA VC show a significant increase compared with PMMA alone. The addition of the PVC powder to the heat-cured acrylic resin increased the time-dependent elastic modulus. This increase in elastic modulus is advantageous in the production of denture based resins of improv mechanical properties.

  15. Triphenylphosphine-Catalyzed Michael Addition of Alcohols to Acrylic Compounds

    Institute of Scientific and Technical Information of China (English)

    LIU, Hai-Ling; JIANG, Huan-Feng; WANG, Yu-Gang


    A facile triphenylphosphine-catalyzed Michael addition of alcohols to acrylic compounds was described. The reaction was carried out in open air at refluxing temperature in the presence of 10 mol% PPh3. Michael addition of saturated and unsaturated alcohols to acrylonitrile or acrylates has been examined. The reaction gaveβ-alkoxy derivatives with isolated yields of 5%-79%. PPh3 is cheaper and more stable than those trialkylphosphines previously used for the similar reactions, and the products can be easily separated from the reaction mixture via distillation.

  16. 40 CFR 180.1162 - Acrylate polymers and copolymers; exemption from the requirement of a tolerance. (United States)


    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Acrylate polymers and copolymers... RESIDUES IN FOOD Exemptions From Tolerances § 180.1162 Acrylate polymers and copolymers; exemption from the requirement of a tolerance. (a) Acrylate polymers and copolymers are exempt from the requirement of...

  17. 40 CFR 721.9640 - Salt of an acrylic acid - acrylamide terpolymer (generic). (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Salt of an acrylic acid - acrylamide... Specific Chemical Substances § 721.9640 Salt of an acrylic acid - acrylamide terpolymer (generic). (a... generically as salt of an acrylic acid - acrylamide terpolymer (PMN P-99-817) is subject to reporting...

  18. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates. (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  19. The effect of acrylic resin functionality on the curing process and properties of acrylic-hexamethoxymethylmelamine coatings

    Directory of Open Access Journals (Sweden)

    Prendžov Slobodan J.


    Full Text Available In this paper the effect of the functionality of synthesized thermosetting acrylic resins (with hydroxy and carboxy groups and the cure temperature on the process of crosslinking and properties of the coatings was investigated. Methylated melamine resin, characterized by 1H and C NMR was used as the crosslinking agent. The degree of crosslinking was studied by infrared spectroscopy by determining the conversion of functional groups and the sol fraction. On the basis of the results obtained it was found that compositions with lower functionality of the acrylic resin had a higher conversion of functional groups, during which cocondensation reactions occurred (acrylic melamine crosslinks in a wide temperature crosslinking range. Consequently better control of the coating properties was achieved. The degree of crosslinking was in good correlation to the sol fraction content and the resin hardness.

  20. Enzymatic synthesis and NMR studies of acylated sucrose acetates

    NARCIS (Netherlands)

    Steverink-De Zoete, M.C.; Kneepkens, M.F.M.; Waard, de P.; Woudenberg-van Oosterom, M.; Gotlieb, K.F.; Slaghek, T.


    The lipase-catalyzed esterification of partially acetylated sucrose has been studied. It was shown that the chemical acetylation increased the reaction rate of the subsequent enzymatic acylation. Thus it was possible to perform the enzymatic acylation in the absence of solvents while underivatized s

  1. Crystal structure of sucrose phosphorylase from Bifidobacterium adolescentis

    DEFF Research Database (Denmark)

    Sprogøe, Desiree; van den Broek, Lambertus A M; Mirza, Osman


    phosphorylase from Bifidobacterium adolescentis (BiSP) refined at 1.77 A resolution. It represents the first 3D structure of a sucrose phosphorylase and is the first structure of a phosphate-dependent enzyme from the glycoside hydrolase family 13. The structure of BiSP is composed of the four domains A, B, B...

  2. Sucrose Responsiveness, Learning Success, and Task Specialization in Ants (United States)

    Perez, Margot; Rolland, Uther; Giurfa,, Martin; d'Ettorre, Patrizia


    Social insects possess remarkable learning capabilities, which are crucial for their ecological success. They also exhibit interindividual differences in responsiveness to environmental stimuli, which underlie task specialization and division of labor. Here we investigated for the first time the relationships between sucrose responsiveness,…

  3. [The applicability of sucrose laurate in hot-melt technology]. (United States)

    Lang, Péter; Szuts, Angéla; Ambrus, Rita; Szabóné, Révész Piroska


    Nowadays, one of the most important task of the pharmaceutical technology is to optimize the dissolution of active ingredients, because most of the drug candidates have a poorly water solubility and hence a slow absorption. According to the latest examinations, the bioavailability of poorly water soluble drugs can be increased significantly by using surfactants or the mixture of surfactants and polymers. Nowadays, surfactants (like polysorbates) are generally used in the production of solid dispersions, so the use of surface-active sucrose esters can be resulted an innovative solution in the pharmaceutical technology. The aim of our investigation was to examine the applicability of sucrose laurate in hot-melt technology in order to influence the crystalline structure and dissolution rate of a poorly water soluble drug (gemfibrosil) having low-melting point. The results of the X-ray powder diffractometry have showed that the sucrose laurate had no significant effect on the crystallization degree of the drug which is important in case of the stability. On the bases of the results of in-vitro dissolution studies, it can be concluded that the sucrose laurate (using minimum 5%) can be well applied in hot-melt technology with carriers having characteristic melting point (e.g. Macrogol) to increase the dissolution rate of poorly soluble drugs.

  4. Tensile bond strength between auto-polymerized acrylic resin and acrylic denture teeth treated with MF-MA solution (United States)


    PURPOSE This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (α=.05). RESULTS The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05). CONCLUSION 15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth. PMID:27555897

  5. Polymer as a function of monomer: Analytical quantum modeling

    CERN Document Server

    Nakhaee, Mohammad


    To identify an analytical relation between the properties of polymers and their's monomer a Metal-Molecule-Metal (MMM) junction has been presented as an interesting and widely used object of research in which the molecule is a polymer which is able to conduct charge. The method used in this study is based on the Green's function approach in the tight-binding approximation using basic properties of matrices. For a polymer base MMM system, transmission, density of states (DOS) and local density of states (LDOS) have been calculated as a function of the hamiltonian of the monomer. After that, we have obtained a frequency for LDOS variations in pass from a subunit to the next one which is a function of energy.

  6. Dynamics of Aggregate Growth Through Monomer Birth and Death

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan


    @@ We investigate the kinetic behaviour of the growth of aggregates through monomer birth and death and propose a simple model with the rate kernels K(k) ∝ ku and K′(k) ∝ kv at which the aggregate Ak of size k respectively yields and loses a monomer. For the symmetrical system with K(k) = K′(k), the aggregate size distribution approaches the conventional scaling form in the case of u < 2, while the system may undergo a gelation-like transition in the u > 2 case. Moreover, the typical aggregate size S(t) grows as t1/(2-u) in the u < 2 case and increases exponentially with time in the u = 2 case. We also investigate several solvable systems with asymmetrical rate kernels and find that the scaling of the aggregate size distribution may break down in most cases.

  7. 腈纶基牛奶纤维与腈纶纤维性能比较%Comparison of the performance of acrylic milk fiber and acrylic fiber

    Institute of Scientific and Technical Information of China (English)

    耿琴玉; 吴佩云


    为了比较腈纶基牛奶纤维与腈纶纤维的基本性能,对腈纶基牛奶纤维的表观形态、力学性能、摩擦性能、卷曲弹性等进行了试验.结果表明,腈纶基牛奶纤维的纵向形态有隐条纹和不规则斑点,截面近似圆形并有明显的海岛状凹凸结构和细微孔隙;红外吸收光谱具有羊毛纤维典型的酰胺吸收谱带和腈纶纤维丙烯腈特征谱带;回潮率为4.34%,干、湿态下的断裂强度是腈纶纤维的67%~69%,断裂伸长率是腈纶纤维的1.26~1.27倍;干、湿态初始模量小于腈纶纤维;静、动态摩擦因数也小于腈纶纤维,而卷曲弹性回复率和残留卷曲率均大于腈纶纤维.%In order to compare the basic performance of acrylic milk fiber and acrylic fiber, surface morphology, mechanical properties, friction properties and crimp elasticity of acrylic milk fiber were tested. The results showed that the longitudinal morphology of acrylic milk fiber had hidden stripe and irregular spots, and the section of acrylic milk fiber was nearly circular and had obvious insular concave-convex structure and fine pores. The infrared absorption spectroscopy of acrylic milk fiber had typical amide absorption bands of wool fiber and acrylonitrile absorption bands of acrylic fiber. Moisture regain of acrylic milk fiber was 4.34%, the dry and wet breaking strength of acrylic milk fiber was 67%-69% of acrylic fiber; the elongation of acrylic milk fiber was 1.26-1.27 times of acrylic fiber. Dry and wet initial modulus of acrylic milk fiber were less than those of acrylic fiber. Static and dynamic friction factor of acrylic milk fiber were less than those of acrylic fiber, and the crimp recovery rate and residual crimp rate were larger than acrylic fiber.

  8. Synthesis of a new aromatic dianhydride monomer and related polyimide

    Institute of Scientific and Technical Information of China (English)

    Yun Xia Wei; Ming Guang Ma; Guo Hu Zhao; Sheng Ying Li; Ming Kai Chen


    A novel aromatic dianhydride monomer,3,3'-oxybis[(3,4-dicarboxyphenoxy)phenol]dianhydride,was successfully synthe-sized in three steps using 3,3'-oxybis(phenol)as starting material,which was reacted with 4,4'-oxydianiline(ODA)via a conventional thermal or chemical imidization method to produce a new polyimide.The resulting polyimide exhibited excellent solubility,and film-forming capability.

  9. Development of high performance vinyl acetate monomer (VAM) catalysts



    The focus of this study was to develop high performance catalysts for the synthesis of vinyl acetate monomer (VAM). By systematic variation of different preparation parameters a multitude of shell catalysts consisting of PdAu nanoparticles supported on a bentonite carrier was explored. In order to investigate the influence of these alterations on catalytic performance, a catalyst classification was accomplished in a high-throughput Temkin test unit by comparison with a highly efficient commer...

  10. Syntheses of New Functionalized Monomers for π-Conjugated Polymers

    Institute of Scientific and Technical Information of China (English)



    1 Results Tailored monomers based on the activated esters of 2,5-dibromobenzoic (sulfonic) acid derivatives, the 3-substituted 2,5-dibromothiophenes, the 9-substituted 2,7-dibromocarbazoles, and on the brominated 1,10-phenanthrolines suitable for Suzuki, Yamamoto or Grignard metathesis (GRIM) coupling reactions were synthesized and characterized by melting point, elemental analysis, 1H NMR, FTIR and TLC. The Horner-Wadsworth-Emmons reaction mechanism was utilized for the preparation of the 3-[2-(pyren-1...

  11. Novel fluoro-carbon functional monomer for dental bonding. (United States)

    Yoshihara, K; Yoshida, Y; Hayakawa, S; Nagaoka, N; Kamenoue, S; Okihara, T; Ogawa, T; Nakamura, M; Osaka, A; Van Meerbeek, B


    Among several functional monomers, 10-methacryloxydecyl dihydrogen phosphate (10-MDP) bonded most effectively to hydroxyapatite (HAp). However, more hydrolysis-resistant functional monomers are needed to improve bond durability. Here, we investigated the adhesive potential of the novel fluoro-carbon functional monomer 6-methacryloxy-2,2,3,3,4,4,5,5-octafluorohexyl dihydrogen phosphate (MF8P; Kuraray Noritake Dental Inc., Tokyo, Japan) by studying its molecular interaction with powder HAp using solid-state nuclear magnetic resonance ((1)H MAS NMR) and with dentin using x-ray diffraction (XRD) and by characterizing its interface ultrastructure at dentin using transmission electron microscopy (TEM). We further determined the dissolution rate of the MF8P_Ca salt, the hydrophobicity of MF8P, and the bond strength of an experimental MF8P-based adhesive to dentin. NMR confirmed chemical adsorption of MF8P onto HAp. XRD and TEM revealed MF8P_Ca salt formation and nano-layering at dentin. The MF8P_Ca salt was as stable as that of 10-MDP; MF8P was as hydrophobic as 10-MDP; a significantly higher bond strength was recorded for MF8P than for 10-MDP. In conclusion, MF8P chemically bonded to HAp. Despite its shorter size, MF8P possesses characteristics similar to those of 10-MDP, most likely to be associated with the strong chemical bond between fluorine and carbon. Since favorable bond strength to dentin was recorded, MF8P can be considered a good candidate functional monomer for bonding.

  12. Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms. (United States)

    Durso, S C; Vieira, L M; Cruz, J N S; Azevedo, C S; Rodrigues, P H; Simionato, M R L


    Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge.

  13. New insight into the catalytic properties of rice sucrose synthase. (United States)

    Huang, Yu-Chiao; Hsiang, Erh-Chieh; Yang, Chien-Chih; Wang, Ai-Yu


    Sucrose synthase (SuS), which catalyzes the reversible conversion of sucrose and uridine diphosphate (UDP) into fructose and UDP-glucose, is a key enzyme in sucrose metabolism in higher plants. SuS belongs to family 4 of the glycosyltransferases (GT4) and contains an E-X7-E motif that is conserved in members of GT4 and two other GT families. To gain insight into the roles of this motif in rice sucrose synthase 3 (RSuS3), the two conserved glutamate residues (E678 and E686) in this motif and a phenylalanine residue (F680) that resides between the two glutamate residues were changed by site-directed mutagenesis. All mutant proteins maintained their tetrameric conformation. The mutants E686D and F680Y retained partial enzymatic activity and the mutants E678D, E678Q, F680S, and E686Q were inactive. Substrate binding assays indicated that UDP and fructose, respectively, were the leading substrates in the sucrose degradation and synthesis reactions of RSuS3. Mutations on E678, F680, and E686 affected the binding of fructose, but not of UDP. The results indicated that E678, F680, and E686 in the E-X7-E motif of RSuS3 are essential for the activity of the enzyme and the sequential binding of substrates. The sequential binding of the substrates implied that the reaction catalyzed by RSuS can be controlled by the availability of fructose and UDP, depending on the metabolic status of a tissue.

  14. Sucrose Diffusion in Decellularized Heart Valves for Freeze-Drying. (United States)

    Wang, Shangping; Oldenhof, Harriëtte; Goecke, Tobias; Ramm, Robert; Harder, Michael; Haverich, Axel; Hilfiker, Andres; Wolkers, Willem Frederik


    Decellularized heart valves can be used as starter matrix implants for heart valve replacement therapies in terms of guided tissue regeneration. Decellularized matrices ideally need to be long-term storable to assure off-the-shelf availability. Freeze-drying is an attractive preservation method, allowing storage at room temperature in a dried state. However, the two inherent processing steps, freezing and drying, can cause severe damage to extracellular matrix (ECM) proteins and the overall tissue histoarchitecture and thus impair biomechanical characteristics of resulting matrices. Freeze-drying therefore requires a lyoprotective agent that stabilizes endogenous structural proteins during both substeps and that forms a protective glassy state at room temperature. To estimate incubation times needed to infiltrate decellularized heart valves with the lyoprotectant sucrose, temperature-dependent diffusion studies were done using Fourier transform infrared spectroscopy. Glycerol, a cryoprotective agent, was studied for comparison. Diffusion of both protectants was found to exhibit Arrhenius behavior. The activation energies of sucrose and glycerol diffusion were found to be 15.9 and 37.7 kJ·mol(-1), respectively. It was estimated that 4 h of incubation at 37°C is sufficient to infiltrate heart valves with sucrose before freeze-drying. Application of a 5% sucrose solution was shown to stabilize acellular valve scaffolds during freeze-drying. Such freeze-dried tissues, however, displayed pores, which were attributed to ice crystal damage, whereas vacuum-dried scaffolds in comparison revealed no pores after drying and rehydration. Exposure to a hygroscopic sucrose solution (80%) before freeze-drying was shown to be an effective method to diminish pore formation in freeze-dried ECMs: matrix structures closely resembled those of control samples that were not freeze-dried. Heart valve matrices were shown to be in a glassy state after drying, suggesting that they can

  15. Healing effect of Sodium-Sucrose-Octasulfate and EGF on epithelial corneal abrasions in rabbits

    DEFF Research Database (Denmark)

    Johansen, Sven; Heegaard, Steffen; Bjerrum, Kirsten Birgitte;


    ophthalmology, Sjögrens syndrome, cornea, abrasion, epidermal growth factor, sodium-sucrose-octasulfate......ophthalmology, Sjögrens syndrome, cornea, abrasion, epidermal growth factor, sodium-sucrose-octasulfate...

  16. The Path of Carbon in Photosynthesis XIX. The Identification of Sucrose Phosphate in Sugar Beet Leaves (United States)

    Buchanan, J. G.


    The recognition and characterization of a sucrose phosphate as an intermediate in sucrose by synthesis by green plants is described. A tentative structure for this phosphate is proposed and its mode of formation suggested.


    Institute of Scientific and Technical Information of China (English)

    Chang-you Gao; Jian-jun Guan; Jia-cong Shen


    Two grafting methods, i.e. solution grafting and pre-adsorbing, are introduced to covalently immobilize hydrophilic polymers on segmented polyurethane (SPU) to modify its hydrophilicity and to improve its cell compatibility. Solution grafting results in higher degree of grafting and rougher surface morphology. Cell culture evaluation demonstrates that the modified membranes thus obtained are disadvantageous to the endothelial cell (ECs) growth probably because the hydrophilic groups on the surface are over-crowded. However, pre-absorbing grafting generates lower degree of grafting, which is detected and confirmed by ATR-FTIR spectra and water contact angle. Scanning electron microscopic (SEM) measurement shows that the latter method produces a plane and smooth morphology, which is similar to the SPU control sample controlled. When grafting with lower monomer concentration, ECs could grow on SPU-g-PHEA [poly(2-hydroxyethyl acrylate)], SPU-g-PAAm (polyacrylamide), SPU-g-PDMA [poly(2-(dimethylamino)ethyl methacrylate)] or quaternized SPU-g-PDMA surface with elongated cell shapes. Hence, the cell compatibility of SPU is improved and a useful method to construct a cell compatible layer on the polymer surface has been developed. ``

  18. Thermally stable drilling fluid additive comprised of a copolymer of catechol-based monomer

    Energy Technology Data Exchange (ETDEWEB)

    Patel, A.D.


    A water soluble polymer is described having thermal stability and exhibiting utility as an aqueous drilling fluid additive comprising: (a) a major portion of a catechol based monomer; (b) a minor portion of a dicarboxylic acid monomer.

  19. Regio- and stereoselective glucosylation of diols by sucrose phosphorylase using sucrose or glucose 1-phosphate as glucosyl donor

    NARCIS (Netherlands)

    Renirie, R.; Pukin, A.; Lagen, van B.; Franssen, M.C.R.


    Previously it has been shown that glycerol can be regioselectively glucosylated by sucrose phosphorylase from Leuconostoc mesenteroides to form 2-O-alpha-D-glucopyranosyl-glycerol (Coedl et al., Angew. Chem. Int. Ed. 47 (2008) 10086-10089). A series of compounds related to glycerol were investigated

  20. Study on the preparation of soap-free styrene-acrylic latex%无皂苯丙乳液的制备工艺研究

    Institute of Scientific and Technical Information of China (English)

    丁长波; 赵振河; 杨少艳


    通过将反应型乳化剂DNS-86与DNS-1035复配,引入交联单体丙烯酸羟乙酯(HEA),合成了一系列性能优异的无皂苯丙乳液粘合剂。结果表明:固含量为(45±2)%,单体转化率较高,乳液凝胶率较小,且乳液离心稳定性、储存稳定性、稀释稳定性、电解质(Ca2+)稳定性和酸碱稳定性均良好;采用无皂苯丙乳液印花的织物耐干、湿摩擦色牢度和耐皂洗色牢度等级与市售涂料印花粘合剂相当;红外光谱(FT-IR)分析表明:优化后的苯丙乳液中没有C C双键存在,即没有反应型乳化剂的剩余,实现了无皂乳液聚合。—%A series of soap- free styrene- acrylic latex with excel ent performance were synthesized through the compound of reactive emulsifier DNS- 86 and DNS- 1035 and the introduction of cross- linking monomer hydroxyethyl acrylate (HEA). The results showed that solids content was (45 ± 2)%, the monomer conversion rate was higher, and the emulsion coagulation rate was lower. In addition, the emulsion centrifugal stability, storage stability, dilution stability, electrolytes (Ca2+) stability, and pH stability were good. The dry and wet rubbing fastness and soaping fastness of soap- free styrene- acrylic latex printed fabric were similar with those of pigment printing binder on market. Final y, infrared spectrum (FT- IR) analysis indicated that C C functional group did not existed in the optimized styrene and butyl- acrylic emulsion, namely there was no re⁃maining reactive emulsifier. Thus soap- free emulsion polymerization was realized.

  1. Acrylic acid and electric power cogeneration in an SOFC reactor. (United States)

    Ji, Baofeng; Wang, Jibo; Chu, Wenling; Yang, Weishen; Lin, Liwu


    A highly efficient catalyst, MoV(0.3)Te(0.17)Nb(0.12)O, used for acrylic acid (AA) production from propane, was used as an anodic catalyst in an SOFC reactor, from which AA and electric power were cogenerated at 400-450 degrees C.

  2. Design and Synthesis of Novel Fluorine-containing Acrylates

    Institute of Scientific and Technical Information of China (English)


    A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed.

  3. Decarboxylation-based traceless linking with aroyl acrylic acids

    DEFF Research Database (Denmark)

    Nielsen, John


    beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

  4. Oil-acrylic hybrid latexes as binders for waterborne coatings

    NARCIS (Netherlands)

    Hamersveld, van E.M.S.; Es, van J.; German, A.L.; Cuperus, F.P.; Weissenborn, P.; Hellgren, A.C.


    The combination of the characteristics of oil, or alkyd, emulsions and acrylic latexes in a waterborne binder has been the object of various studies in the past. Strategies for combining the positive properties of alkyds, e.g. autoxidative curing, gloss and penetration in wood, with the fast drying

  5. Lightweight bonded acrylic facing at the Vitra VSL Factory

    NARCIS (Netherlands)

    Michel, M.T.; Techen, H.


    Acrylic glass is omnipresent in the industrialised world; but as a building material most architects, facade planners and engineers are still unfamiliar with this material. In most cases it is applied as a substitute for glass which leads to inappropriate joints and fixtures. During the years of the

  6. 21 CFR 173.5 - Acrylate-acrylamide resins. (United States)


    ... additive consists of one of the following: (1) Acrylamide-acrylic acid resin (hydrolyzed polyacrylamide) is... or cane sugar juice and liquor or corn starch hydrolyzate in an amount not to exceed 5 parts per million by weight of the juice or 10 parts per million by weight of the liquor or the corn...

  7. Nanopigmented Acrylic Resin Cured Indistinctively by Water Bath or Microwave Energy for Dentures

    Directory of Open Access Journals (Sweden)

    L. S. Acosta-Torres


    Full Text Available The highlight of this study was the synthesis of nanopigmented poly(methyl methacrylate nanoparticles that were further processed using a water bath and/or microwave energy for dentures. The experimental acrylic resins were physicochemically characterized, and the adherence of Candida albicans and biocompatibility were assessed. A nanopigmented acrylic resin cured by a water bath or by microwave energy was obtained. The acrylic specimens possess similar properties to commercial acrylic resins, but the transverse strength and porosity were slightly improved. The acrylic resins cured with microwave energy exhibited reduced C. albicans adherence. These results demonstrate an improved noncytotoxic material for the manufacturing of denture bases in dentistry.

  8. Sensitization capacity of acrylated prepolymers in ultraviolet curing inks tested in the guinea pig. (United States)

    Björkner, B


    One commonly used prepolymer in ultraviolet (UV) curing inks is epoxy acrylate. Of 6 men with dermatitis contracted from UV-curing inks, 2 had positive patch test reaction to epoxy acrylate. None reacted to the chemically related bisphenol A dimethacrylate. The sensitization capacity of epoxy acrylate and bisphenol A dimethacrylate performed with the "Guinea pig maximization test" (GPM) shows epoxy acrylate to be an extreme sensitizer and bisphenol A dimethacrylate a moderate sensitizer. Cross-reaction between the two substances occurs. The epoxy resin oligomer MW 340 present in the epoxy acrylate also sensitized some animals.


    Institute of Scientific and Technical Information of China (English)

    Jiang-hong Wang; Jian-feng Zhai; Jia-yun Zhou; Yu-xia Zhao; Yu-quan Shen


    A novel monomer,(trans)-7-[4-N,N-(di-β-hydroxyethyl) amino-benzene]-ethenyl-3,5-dinitro-thiophene (HBDT), was synthesized and characterized. The details of synthesizing the monomer and prepolymer, polyurethane with the monomer covalently incorporated are presented. The prepolymer and polyurethane exhibited good solubility in common organic solvents. Molecular nonlinear optical properties of the monomer (HBDT) substituted thiophene based stilbenes is presented.

  10. 77 FR 18827 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose Injection... (United States)


    ... Recommendations for Iron Sucrose Injection; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice...) for iron sucrose injection. DATES: Although you can comment on any guidance at any time (see 21 CFR 10... recommendations. This notice announces the availability of draft BE recommendations for iron sucrose......

  11. Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia (United States)

    Belke, Terry W.; Duncan, Ian D.; Pierce, W. David


    Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior…

  12. Synthesis of Self - Crosslinking Modified Styrene -Acrylate Emulsion and Its Performance for Wood Paints%木器漆用自交联改性苯丙乳液的合成以及性能研究

    Institute of Scientific and Technical Information of China (English)

    李顺; 兰支利; 尹笃林; 邓靖; 黄波


    Using styrene,butyl acrylate,acrylic acid,HEMA,N -MA.DAAM and siloxane monomer as raw materials, ammonium persulfate(APS) as initiator to prepare the title self - crosslinking modified styrene - acrylate emulsion through pre - emulsification technology and semi - continuous seed emulsion polymerization process. The influences of the amount and percentage of crosslinking monomers, amount of siloxane monomer,and amount of initiator and temperature on the emulsion performance were discussed. The results showed that the better comprehensive performance of emulsion could be obtained when the amount of crosslinking monomer was 5% ,m(DAAM): m(N - MA) =3:2,amount of siloxane monomer between 0. 5% to 1. 0% , initiator 0. 4% and polymerization temperature between 83-87 ℃.%以苯乙烯、丙烯酸丁酯、丙烯酸、甲基丙烯酸羟乙酯、N-羟甲基丙烯酰胺(N -MA)、双丙酮丙烯酰胺(DAAM)及有机硅单体为主要原料,过硫酸铵(APS)为引发剂,采用预乳化工艺和半连续种子乳液聚合法制备自交联改性苯丙乳液.考察了交联单体用量、交联单体配比、有机硅单体用量、引发剂用量以及聚合温度等因素对乳液性能的影响.研究结果表明:当交联单体用量为单体总量的5%,m(DAAM):m(N - MA) =3:2,有机硅加入量为0.5%~1.O%,引发剂用量为单体用量的0.4%,聚合温度为83~87℃时,所得乳液的综合性能优良.

  13. Efficient microwave assisted synthesis of novel 1,2,3-triazole-sucrose derivatives by cycloaddition reaction of sucrose azides and terminal alkynes. (United States)

    Potewar, Taterao M; Petrova, Krasimira T; Barros, M Teresa


    Novel 1-(1',2,3,3',4,4',6-hepta-O-acetyl-6'-deoxy-sucros-6'-yl)-4-substituted-1,2,3-triazoles were synthesized by microwave assisted copper catalyzed 1,3-dipolar cycloaddition of sucrose derived azides with terminal alkynes in excellent yields and in short reaction times. The compound 1',2,3,3',4,4',6-hepta-O-acetyl-6'-azido-6'-deoxy-sucrose was regioselectively synthesized from sucrose by improved procedure and used for the cycloadditions. By combining carbohydrate and 1,2,3-triazole structural motifs, a library of 1,2,3-triazole-sucrose conjugates have been obtained.

  14. Effects of a high sucrose diet and intragastric sucrose feeding on the dentinogenesis, dental caries, and mineral excretion of the young rat. (United States)

    Pekkala, E; Hietala, E L; Puukka, M; Larmas, M


    Previous studies show that a high sucrose diet reduces the rate of primary dentinogenesis and increases dental caries, although their cause-effect relationship is still obscure. The purpose of this study was to explore whether the effect of sucrose load on the dentinogenesis and dental caries of young rat molars is mediated by systemic (intragastric) or by systemic and local (dietary) factors. At weaning (19 days), animals were randomized into the control, intragastric sucrose, and dietary sucrose groups for 4 weeks. The areas of dentin appositions and dentinal caries lesions were measured planimetrically. Caries was also determined with Shiffs staining and the width of predentin by histology. Urinary Ca, K, and Na levels were measured by flame photometry, urinary P levels using an UV method, and serum insulin levels using radioimmunoassay. Systemic and local sucrose load reduced dentin appositions and intragastric sucrose increased urinary Ca excretion. No differences in the width of predentin were noticed. Only dietary sucrose enhanced the occurrence and progression of caries. The present findings show that sucrose load reduces dentinogenesis by impairing the synthesis of dentin matrix, but also point out the crucial importance of the local sucrose challenge in the initiation of dental caries.

  15. Synthesis of lithium iron phosphate/carbon microspheres by using polyacrylic acid coated iron phosphate nanoparticles derived from iron(III) acrylate. (United States)

    Xu, Dongwei; He, Yan-Bing; Chu, Xiaodong; Ding, Zhaojun; Li, Baohua; He, Jianfu; Du, Hongda; Qin, Xianying; Kang, Feiyu


    Lithium iron phosphate/carbon (LiFePO4 /C) microspheres with high rate and cycling performance are synthesized from iron phosphate/polyacrylic acid (FePO4 /PAA) nanoparticles. Iron(III) acrylate is used as a precursor for both the iron and carbon sources. FePO4 nanoparticles are first produced by a coprecipitation reaction. The byproduct, acrylic acid ions, is polymerized in situ to form a uniform PAA layer on the surface of the FePO4 nanoparticles. The as-prepared LiFePO4 /C microspheres are composed of primary nanoparticles with sizes of 40-50 nm. The nanoparticles are fully coated with a thin, uniform carbon layer derived from the decomposition of the PAA layer. The uniform carbon-coating layer cooperates with interstitial and boundary carbon derived from sucrose successfully to construct an excellent interconnecting conductive network in the microspheres. As a result of the unique structure, the as-prepared LiFePO4 /C microspheres display both high electronic and ionic conductivities, which contribute to their high rate performance (162.9 mAh g(-1) at 0.1C and 126.1 mAh g(-1) at 5C) and excellent cycling stability (97.1% of capacity retention after 500 cycles at 5C/5C).

  16. A Sucrose Solution Application to the Study of Model Biological Membranes

    CERN Document Server

    Kiselev, M A; Kisselev, A M; Lombardo, D; Killany, M; Lesieur, S; Ollivon, M


    The small-angle X-ray and neutron scattering, time resolved X-ray small-angle and wide-angle diffraction coupled with differential scanning calorimetry have been applied to the investigation of unilamellar and multilamellar dimyristoylphosphatidylcholine (DMPC) vesicles in sucrose buffers with sucrose concentrations from 0 to 60%. Sucrose buffer decreased vesicle size and polydispersity and increased an X-ray contrast between phospholipid membrane and bulk solvent sufficiently. No influence of sucrose on the membrane thickness or mutual packing of hydrocarbon chains has been detected. The region of sucrose concentrations 30%-40% created the best experimental conditions for X-ray small-angle experiments with phospholipid vesicles.

  17. Evaluation of Polyethylene Glycol Mono-acrylate/Acrylate/Organosilicone Functional Polymer Synthesis and Its Coating Performance%聚乙二醇单丙烯酸酯/丙烯酸酯/有机硅功能聚合物合成及其涂层性能评价

    Institute of Scientific and Technical Information of China (English)

    于世长; 王巧玲


    In order to reduce the low surface energy of functional coatings, three acryloyl oxygen radicals isopropyl silane monomer, polyethylene glycol single methyl ether, butyl acrylate, ethyl methacrylate andγ-methyl acryloxy trimethyl silane are selected as monomers to prepare copolymer with low surface energy and organic silicon function. The appropriate monomer ratio, molecular weight and glass transition temperature are obtained through the properties characterization of the polymers. The optimal formula was obtained through the evaluation on the contact angle, adhesion strength, water resistance and antifouling property of coatings.%为了降低功能涂层的低表面能,选择丙烯酰氧基三异丙基硅烷单体与聚乙二醇单甲醚、丙烯酸丁酯、甲基丙烯酸乙酯、γ-甲基丙烯酰氧基三甲基硅烷作为共聚单体,制备低表面能有机硅功能共聚物。通过聚合物性能表征,得到适宜的单体配比、分子量和玻璃化温度。通过对涂层接触角、附着强度、耐水性、防污性评价,得出涂层最佳配方。

  18. [Migration of monomers and primary aromatic amines from nylon products]. (United States)

    Mutsuga, Motoh; Yamaguchi, Miku; Ohno, Hiroyuki; Kawamura, Yoko


    Migration of 2 kinds of monomer and 21 kinds of primary aromatic amines (PAAs) from 21 kinds of nylon products such as turners, ladles and wrap film were determined. Samples were classified as regards materials by mean of pyrolysis-GC/MS. One sample was classified as nylon 6, 15 samples as nylon 66 and three samples as nylon 6/66 copolymers, while two samples were laminate of nylon 6 with polyethylene or polypropylene. All of the nylon 66 samples contained a small amount of ε-caprolactam (CPL), which is the nylon 6 monomer. Migration levels of monomers and PAAs at 60°C for 30 min into 20% ethanol were measured by LC/MS/MS. CPL was detected at the level of 0.015-38 µg/mL from all samples, excluding one wrap film sample, and 1,6-hexamethylenediamine was detected at the level of 0.002-0.013 µg/mL from all nylon 66 samples and one nylon 6/66 sample. In addition, 0.006-4.3 µg/mL of 4,4'-diaminodiphenylmethane from three samples, 0.032-0.23 µg/mL of aniline from four samples, 0.001 µg/mL of 4-chloroaniline from two samples, and 0.002 µg/mL of 2-toluidine and 0.066 mg/mL of 1-naphthylamine from one sample each were detected. The migration levels at 95 or 121°C were about 3 and 10 times the 60°C levels, respectively.

  19. Susceptibility of Adult Mosquitoes to Insecticides in Aqueous Sucrose Baits (United States)


    of the lack of ingestion as a result of repellency due to high survival of water-deprived control mosquitoes at 24 hr and the abundance of abdomens...Vol. 36, no. 1 Journal of Vector Ecology 59 Susceptibility of adult mosquitoes to insecticides in aqueous sucrose baits Sandra A. Allan Center for...2010 ABSTRACT: Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence and intermittently during their

  20. Low phytic acid, low stachyose, high sucrose soybean lines



    The present invention provides novel soybean lines having high sucrose content and low phytic acid and low stachyose content. The soybeans are easily digested and provide high energy content for animals and humans. The low phytic acid content permits animal feed to be produced that does not require phytase, yet does not result in significant production of pollution to the environment from excretion by farm animals.

  1. Sucrose polyesters from poultry fat as non-ionic emulsifiers

    Directory of Open Access Journals (Sweden)

    Megahed, Mohamed G.


    Full Text Available Poultry fats are rich in palmitic and oleic acids are produced as by-products from poultry industries. These fats can be utilized in the preparation of emulsifiers. Sucrose esters of poultry fat are prepared from low-cost poultry fat and sucrose by esterification. The yield of sucrose esters prepared in this work exceeds than 85%. The hydrophilic-lipophilic balance (HLB, surface tension, interfacial tension and stability index (SI were evaluated and compared with standard emulsifiers prepared from pure palmitate and oleate esters. Concerning the stability of emulsions, the values of interfacial tension and HLB were higher for the sucrose esters of poultry fat.Las grasas de aves de corral son ricas en ácidos palmítico y oleico y son producidas como subproductos de las industrias avícolas. Estas grasas pueden ser utilizadas en la preparación de emulsionantes. Los ésteres de sacarosa de grasas de aves de corral fueron preparadas a partir de grasas de bajo coste y sacarosa por esterificación. El rendimiento de los ésteres de sacarosa preparados en este trabajo superó el 85%. El balance hidrofílicolipofílico (HLB, tensión superficial, tensión interfacial e índice de estabilidad (SI fueron evaluados y comparados con emulsionantes estandar preparados de ésteres de palmitato y oleato puros. Los valores de tensión interfacial y el HLB fueron más altos en los poliésteres de sacarosa de las grasas de aves de corral.

  2. Central melanocortins regulate the motivation for sucrose reward.

    Directory of Open Access Journals (Sweden)

    Rahul Pandit

    Full Text Available The role of the melanocortin (MC system in feeding behavior is well established. Food intake is potently suppressed by central infusion of the MC 3/4 receptor agonist α-melanocyte stimulating hormone (α-MSH, whereas the MC 3/4 receptor inverse-agonist Agouti Related Peptide (AGRP has the opposite effect. MC receptors are widely expressed in both hypothalamic and extra-hypothalamic brain regions, including nuclei involved in food reward and motivation, such as the nucleus accumbens (NAc and the ventral tegmental area. This suggests that MCs modulate motivational aspects of food intake. To test this hypothesis, rats were injected intracerebroventricularly with α-MSH or AGRP and their motivation for sucrose was tested under a progressive ratio schedule of reinforcement. Food motivated behavior was dose-dependently decreased by α-MSH. Conversely, AGRP increased responding for sucrose, an effect that was blocked by pretreatment with the dopamine receptor antagonist α-flupenthixol. In contrast to progressive ratio responding, free intake of sucrose remained unaltered upon α-MSH or AGRP infusion. In addition, we investigated whether the effects of α-MSH and AGRP on food motivation were mediated by the NAc shell. In situ hybridization of MC3 and MC4 receptor expression confirmed that the MC4 receptor was expressed throughout the NAc, and injection of α-MSH and AGRP into the NAc shell caused a decrease and an increase in motivation for sucrose, respectively. These data show that the motivation for palatable food is modulated by MC4 receptors in the NAc shell, and demonstrate cross-talk between the MC and dopamine system in the modulation of food motivation.

  3. Chelating compounds as potential flash rust inhibitors and melamine & aziridine cure of acrylic colloidal unimolecular polymers (CUPs) (United States)

    Mistry, Jigar Kishorkumar

    Waterborne coatings on ferrous substrates usually show flash rusting which decreases the adhesion of the coating and the corrosion products can form a stain. Chelating compounds were investigated as potential flash rust inhibitors. Compounds being evaluated include amine alcohols, diamines and sulfur containing amines. A new corrosion inhibitor 2,5-bis(thioaceticacid)-1,3,4-thiadiazole (H2ADTZ) was synthesized and its performance characteristics were evaluated. It was noted that the observed structure of 1,3,4-thiadiazolidine-2,5-dithione (also known as 2,5-dimercapto-1,3,4-thiadiazole (DMTD or DMcT)) has been previously reported in three different tautomeric forms including -dithiol and -dithione. The relative stability of each form as well as the synthesis and characterization of the structures of mono- and dialkylated forms of 5-mercapto-1,3,4-thiadiazole-2(3H)-thione (MTT) were examined. The methods of X-ray crystallography, NMR spectroscopy and ab-initio electronic structure calculations were combined to understand the reactivity and structure of each compound. Polymers were synthesized with a 1:7 or 1:8 ratio of acrylic acid to acrylate monomers to produce an acid rich resin. The polymers were reduced and solvent stripped to produce Colloidal Unimolecular Polymers (CUPs). These particles are typically 3-9 nanometers in diameter depending upon the molecular weight. They were then formulated into a clear coating with either a melamine (bake) or an aziridine (ambient cure) and then cured. The melamine system was solvent free, a near zero VOC and the aziridine system was very low to near zero VOC. The coatings were evaluated for their MEK resistance, adhesion, hardness, gloss, flexibility, wet adhesion, abrasion and impact resistance properties.

  4. Interpenetrating polymer network (IPN) nanogels based on gelatin and poly(acrylic acid) by inverse miniemulsion technique: synthesis and characterization. (United States)

    Koul, Veena; Mohamed, Raja; Kuckling, Dirk; Adler, Hans-Jürgen P; Choudhary, Veena


    Novel interpenetrating polymer network (IPN) nanogels composed of poly(acrylic acid) and gelatin were synthesised by one pot inverse miniemulsion (IME) technique. This is based on the concept of nanoreactor and cross-checked from template polymerization technique. Acrylic acid (AA) monomer stabilized around the gelatin macromolecules in each droplet was polymerized using ammonium persulfate (APS) and tetramethyl ethylene diamine (TEMED) in 1:5 molar ratio and cross-linked with N,N-methylene bisacrylamide (BIS) to form semi-IPN (sIPN) nanogels, which were sequentially cross-linked using glutaraldehyde (Glu) to form IPNs. Span 20, an FDA approved surfactant was employed for the formation of homopolymer, sIPN and IPN nanogels. Formation of stable gelatin-AA droplets were observed at 2% surfactant concentration. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) studies of purified nanogels showed small, spherical IPN nanogels with an average diameter of 255 nm. In contrast, sIPN prepared using the same method gave nanogels of larger size. Fourier-transform infrared (FT-IR) spectroscopy, SEM, DLS, X-ray photoelectron spectroscopy (XPS) and zeta potential studies confirm the interpenetration of the two networks. Leaching of free PAA chains in sIPN upon dialysis against distilled water leads to porous nanogels. The non-uniform surface of IPN nanogels seen in transmission electron microscopy (TEM) images suggests the phase separation of two polymer networks. An increase of N/C ratio from 0.07 to 0.17 (from PAA gel to IPN) and O/C ratio from 0.22 to 0.37 (from gelatin gel to IPN) of the nanogels by XPS measurements showed that both polymer components at the nanogel surface are interpenetrated. These nanogels have tailoring properties in order to use them as high potential drug delivery vehicles for cancer targeting.

  5. Recovery of Monomer from Nylon waste powder for its Recycling

    Directory of Open Access Journals (Sweden)

    Dilip B.Patil


    Full Text Available Recovery of monomer hexamethylene diamine(HMD in the form of dibenzoyl derivative of hexamethylene diamine (DBHMD from Nylon waste rope powder was carried out by degradation of Nylon waste powder of nylon rope waste.The molecular weight of nylon waste powder was found to be 26582.The minimum amount of nylon waste powder and hydrochloric acid required for maximum recovery of HMD and DBHMD was found to be 5g and 5N,50ml hydrochloric acid respectively. Further it was observed that the maximum time and temperature required for getting maximum yield of DBHMD was 120 minutes and 800C respectively.

  6. Structural analyses of sucrose laurate regioisomers by mass spectrometry techniques

    DEFF Research Database (Denmark)

    Lie, Aleksander; Stensballe, Allan; Pedersen, Lars Haastrup


    6- And 6′-O-lauroyl sucrose were isolated and analyzed by matrix-assisted laser desorption/ionisation (MALDI) time-of-flight (TOF) mass spectrometry (MS), Orbitrap high-resolution (HR) MS, and electrospray-ionization (ESI) tandem mass spectrometry (MS/MS). The analyses aimed to explore.......8, respectively, and Orbitrap HRMS confirmed the mass of [M+Na]+ (m/z 547.2712). ESI-MS/MS on the precursor ion [M+Na]+ resulted in product ion mass spectra showing two high-intensity signals for each sample. 6-O-Lauroyl sucrose produced signals located at m/z 547.27 and m/z 385.21, corresponding to the 6-O......-lauroyl glucose sodium adduct ions, while the signals for 6′-O-lauroyl sucrose were located at m/z 385.22 and 367.20, respectively corresponding to the sodium adduct ions with 6-O-lauroyl fructose and 6-O-lauroyl fructosyl. The mass spectra of the two regioisomers were clearly different, and the investigation...

  7. Sucrose-replacement by rebaudioside a in a model beverage. (United States)

    Majchrzak, Dorota; Ipsen, Annika; Koenig, Juergen


    Rebaudioside A (RA), a component of Stevia rebaudiana, is a non-caloric sweetener of natural origin, suitable to meet consumers' demand for sweet taste, but undesirable flavors were reported at high concentrations. Aim of this study was to create a model beverage (ice-tea) in which sucrose was replaced increasingly by RA to identify optimal sensory profile for consumer acceptance. Samples with 20 % and 40 % sucrose replacement by RA, respectively, showed very similar sensory profiles but were significantly higher in some flavor attributes, such as artificial sweetness, licorice-like and metallic, as well as in sweet and bitter aftertaste (p < 0.05) compared to the reference ice-tea. In both hedonic tests, preference and acceptance samples with RA have been judged as comparable to the reference despite perception of some undesirable notes. In view of the results of our study it can be stated that a replacement of 20 % or 40 % sucrose by RA in an ice-tea is achievable.

  8. Comparison of monofunctional and multifunctional monomers in phosphate binding molecularly imprinted polymers. (United States)

    Wu, Xiangyang; Goswami, Kisholoy; Shimizu, Ken D


    In this study, molecularly imprinted polymers (MIPs) prepared using a multifunctional and a monofunctional monomer were compared with respect to their affinities, selectivities, and imprinting efficiencies for organophosphates. This is of interest because multifunctional monomers have higher affinities than traditional monofunctional monomers for their target analytes and thus should yield MIPs with higher affinities and selectivities. However, polymers containing multifunctional monomer may also have a higher number of unselective, non-templated binding sites. This increase in background binding sites could lead to a decrease in the magnitude of the imprinting effect and in the selectivity of the MIP. Therefore, phosphate selective imprinted and non-imprinted polymers (NIPs) were prepared using a novel multifunctional triurea monomer. The binding properties of these polymers were compared with polymers prepared using a monofunctional monourea monomer. The binding affinities and selectivities of the monomers, imprinted polymers, and NIPs were characterized by NMR titration, binding uptake studies, and binding isotherms. MIPs prepared with the triurea monomer showed higher binding affinity and selectivity for the diphenylphosphate anion in organic solvents than the MIPs prepared with the monofunctional monomer. Surprisingly, the binding properties of the NIPs revealed that the polymers prepared using the multifunctional and monofunctional monomers were very similar in affinity and selectivity. Thus, the multifunctional monomers increase not only the affinity of the MIP but also enhance the imprinting effect.

  9. Bond of acrylic teeth to different denture base resins after various surface-conditioning methods. (United States)

    Lang, Reinhold; Kolbeck, Carola; Bergmann, Rainer; Handel, Gerhard; Rosentritt, Martin


    The study examined the bond between different denture base resins and highly cross-linked acrylic denture teeth with different base surface-conditioning methods. One hundred fifty highly cross-linked resin denture teeth (SR-Antaris, No. 11, Ivoclar-Vivadent, FL) were divided into five groups with different surface-conditioning methods of the base surfaces of the teeth (C = control, no surface conditioning, MM = application of methyl methacrylate monomer, SB = sand blasting, SBB = sand blasting + bonding agent, TSS = tribochemical silica coating + silanization). Teeth were bonded to either a cold-cured denture base resin (ProBase Cold, Ivoclar-Vivadent, FL) or heat-cured denture base resins (SR Ivocap Plus, Ivoclar-Vivadent, FL and Lucitone 199, Dentsply, USA). After 24 h of storage in distilled water, compressive load was applied at 90° on the palatal surface of each tooth until fracture. Median failure load ranged between 103 and 257 N for Probase Cold groups, 91 to 261 N for Lucitone 199, and 149 to 320 N for SR Ivocap Plus. For Probase Cold, significant highest failure loads resulted when teeth were treated with SB, SBB, or TSS. For Lucitone 199, significant highest failure loads has been found with MM and TSS treatment. For SR Ivocap Plus, highest failure loads resulted using SBB and TSS. Conditioning of the base surfaces of the teeth prior to denture base processing is highly recommended. Tooth bond is significantly affected by the surface-conditioning method and applied denture base resin. Tribochemical silica coating + silanization method can be recommended for pre-treatment of teeth applying either heat-cured or cold-cured denture base resin.

  10. Effect of chemical surface treatments and repair material on transverse strength of repaired acrylic denture resin

    Directory of Open Access Journals (Sweden)

    Vojdani Mahroo


    Full Text Available Purpose: This study was performed to evaluate the transverse strength of a denture base resin (H, repaired with an autopolymerizing acrylic resin (A or a visible light-curing (VLC resin (T following the use of three chemical solvents: methyl methacrylate monomer, aceton or chloroform. Materials and Methods: Eighty specimens (65.0 x 10.0 x 3.3 mm of H were fabricated and stored in distilled water at 37°C for seven days. Specimens were divided into eight equal groups of 10. In each group, specimens were sectioned in the middle to create a 10 mm gap. Two groups served as controls and had no surface treatment. They were repaired with A or T materials. In the remaining six experimental groups, specimen surfaces were treated with ac for 30 sec or mma for 180 sec or ch for 5 sec. Then A or T material was placed on the treated surfaces, using the same preparation molds. After seven days′ storage at 37°C, the transverse bond strength (MPa of the specimens was measured using a three-point bending test. A two-way ANOVA and a Tukey HSD were performed to identify significant differences ( P < 0.05. The nature of the failures was noted as adhesive, cohesive or mixed. Results: Significant differences were found between the controls and experimental groups ( P < 0.05. In the control groups, repair with A showed significantly higher strength (60.3 MPa than those repaired with T (51.3 MPa. Mean transverse strength of experimental specimens repaired with A was (75.06 MPa which was significantly greater than those repaired with T (67.9 MPa. Although surface treatment increased repair strength, no significant differences were detected between the effects of the chemical etchants. Conclusions: The autopolymerizing resin exhibited significantly higher repair strength than VLC resin. The transverse strength of the repaired specimens was increased significantly after chemical treatments.

  11. CuS-poly (N-isopropylacryl-amide-co-acrylic acid) composite microspheres with patterned surface structures:preparation and characterization

    Institute of Scientific and Technical Information of China (English)

    YANG Juxiang; FANG Yu; BAI Chaoliang; HU Daodao; ZHANG Ying


    N-isopropylacrylamide (NIPAM) and acrylic acid (AA) copolymer microspheres with various compositions were prepared by reverse suspension polymerization technique. The microspheres thus prepared were employed as micro-reactors for the deposition of CuS. In this way, several CuS-P(NIPAM-co-AA) composite microspheres with different surface morphologies were prepared. It was demonstrated that the surface structures of the composite microspheres can be tailored to a certain extent by varying the ratio of the two monomer units in the template (microgels) and/or the amount of CuS deposited. It is in prospect that the inherent advantages of microgel templates (the size, composition, charge nature and density, and crosslinking density could be easily controlled) would make the microgel template method extremely useful in the preparation of composite microspheres with different patterned surface structures.

  12. Radiation-induced copolymerization of styrene/ n-butyl acrylate in the presence of ultra-fine powdered styrene-butadiene rubber (United States)

    Yu, Haibo; Peng, Jing; Zhai, Maolin; Li, Jiuqiang; Wei, Genshuan; Qiao, Jinliang


    Styrene (St)/ n-butyl acrylate (BA) copolymers were prepared by two-stage polymerization: St/BA was pre-polymerized to a viscous state by bulk polymerization with initiation by benzoyl peroxide (BPO) followed by 60Co γ-ray radiation curing. The resultant copolymers had higher molecular weight and narrower molecular weight distribution than conventional methods. After incorporation of ultra-fine powdered styrene-butadiene rubber (UFSBR) with a particle size of 100 nm in the monomer, the glass transition temperature ( Tg) of St-BA copolymer increased at low rubber content. Both the St-BA copolymer and the St-BA copolymer/UFSBR composites had good transparency at BA content below 40%.

  13. Fatigue crack propagation of acrylic bone cements. Influence of the radio-opaque agents; Propagacion de grietas por fatiga de cementos oseos acrilicos. Influencia de los agentes radiopacos

    Energy Technology Data Exchange (ETDEWEB)

    Ginebra, M. P.; Albuixech, L.; Fernandez-Barragan, E.; Gil, F. J.; Planell, J. A.; San Roman, J.; Vazquez, B.


    In this work the 2,5-diiodo-8-quinolyl methacrylate (IHQM), is proposed as a new radiopaque agent. The addition of the iodine containing methacrylate provided a statistically significant increase in the tensile strength, fracture toughness and ductility, with respect to the barium sulphate containing cement. This effect was attributed to the fact that the use of a radiopaque monomer eliminated the porosity associated to the barium sulphate particles. However, since fatigue resistance is one of the main properties required to ensure a good long-term performance of permanent pros these, as is the case of acrylic bone cements, it is important to compare the fatigue properties of this new bone cement formulation with the radiolucent and the BaSO{sub 4} containing bone cements. The results show that the absence of inorganic particles with no matrix adhesion plays a negative role when the fatigue crack propagation is considered. (Author) 26 refs.

  14. A new approach in copolymerization: Monte Carlo method for the reactivity ratios calculation in copolymerization of furfuryl acrylate with 2-hydroxyethyl methacrylate

    Directory of Open Access Journals (Sweden)

    D. Zaldívar


    Full Text Available Copolymers of furfuryl acrylate (A with 2-hydroxyethyl methacrylate (H were prepared by free radical copolymerization in DMF solution at 50°C, using 2,2'-azobisisobutyronitrile (AIBN as initiator. The reactivity ratios of both monomers were calculated according to the general copolymerization equation using the Fineman-Röss and Kelen-Tüdos 1inearization methods, as well as the Tidwell-Mortimer non linear least-squares treatment and the Monte Carlo random method. The reactivity ratios obtained were rA = 0.93 and rH = 1.42. Similar results were obtained by both, the Monte Carlo and the non-linear least squares methods. The microstructure of copolymer chains based on the first order Markov statistics is described.

  15. 新型含氟丙烯酸酯拒水剂的合成及应用%Synthesis and application of new fluorinated acrylate water repellent

    Institute of Scientific and Technical Information of China (English)

    安恩来; 党会茹; 习智华


    采用甲基丙烯酸十二氟庚酯(Actyflon-G04)、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主要单体,脂肪醇聚氧乙烯醚(AEO-9)和十二烷基硫酸钠(SDS)为复配乳化剂,过硫酸铵(APS)为引发剂,通过半连续种子乳液聚合法,制备出新型含氟丙烯酸酯共聚物乳液.分析了该含氟丙烯酸酯拒水剂的最佳合成工艺,并应用到棉织物上.最佳合成工艺为:m(BA)∶m(MMA)=5∶3,Actyflon-G0430%(对单体总质量),乳化剂2.5%(对单体总质量),引发剂0.9%(对单体总质量),聚合反应温度80℃,保温时间3 h.将拒水剂处理到棉织物上,整理后织物对水的接触角可达125.0°,耐静水压为145.8 mm,具有良好的拒水效果,并且织物手感、透气性能变化不大.%New fluorinated acrylate copolymer emulsion was prepared using dodecafluoroheptyl methacry⁃late (Actyflon- G04), methyl methacrylate (MMA), butyl acrylate (BA) as the monomers, fatty alcohol polyoxy⁃ethylene ether (AEO- 9) and sodium dodecyl sulfate (SDS) as emulsifier, ammonium persulfate as initiator through semi- continuous seed emulsion polymerization method. The optimal synthesis process of new fluori⁃nated acrylate water repel ent was analyzed. The prepared copolymer was applied in cotton fabric. The results showed that the optimum synthesis conditions were 5∶3 of BA and MMA mass ratio, 30% of Actyflon- G04 (on the total mass of monomers), 2.5% of emulsifier (on the total mass of monomers), 0.9% of initiator (on the total mass of monomers), 80 ℃ of polymerization temperature, 3 h of holding time. And the synthetic co⁃polymers was applied in cotton fabric, the water contact angle of finished cotton fabric was up to 125.0° , the hydrostatic pressure was up to 145.8 mm. The prepared fluorinated acrylate emulsion had good water repel en⁃cy and little effect on the handle and air permeability of cotton fabric.

  16. Episodic sucrose intake during food restriction increases synaptic abundance of AMPA receptors in nucleus accumbens and augments intake of sucrose following restoration of ad libitum feeding. (United States)

    Peng, X-X; Lister, A; Rabinowitsch, A; Kolaric, R; Cabeza de Vaca, S; Ziff, E B; Carr, K D


    Weight-loss dieting often leads to loss of control, rebound weight gain, and is a risk factor for binge pathology. Based on findings that food restriction (FR) upregulates sucrose-induced trafficking of glutamatergic AMPA receptors to the nucleus accumbens (NAc) postsynaptic density (PSD), this study was an initial test of the hypothesis that episodic "breakthrough" intake of forbidden food during dieting interacts with upregulated mechanisms of synaptic plasticity to increase reward-driven feeding. Ad libitum (AL) fed and FR subjects consumed a limited amount of 10% sucrose, or had access to water, every other day for 10 occasions. Beginning three weeks after return of FR rats to AL feeding, when 24-h chow intake and rate of body weight gain had normalized, subjects with a history of sucrose intake during FR consumed more sucrose during a four week intermittent access protocol than the two AL groups and the group that had access to water during FR. In an experiment that substituted noncontingent administration of d-amphetamine for sucrose, FR subjects displayed an enhanced locomotor response during active FR but a blunted response, relative to AL subjects, during recovery from FR. This result suggests that the enduring increase in sucrose consumption is unlikely to be explained by residual enhancing effects of FR on dopamine signaling. In a biochemical experiment which paralleled the sucrose behavioral experiment, rats with a history of sucrose intake during FR displayed increased abundance of pSer845-GluA1, GluA2, and GluA3 in the NAc PSD relative to rats with a history of FR without sucrose access and rats that had been AL throughout, whether they had a history of episodic sucrose intake or not. A history of FR, with or without a history of sucrose intake, was associated with increased abundance of GluA1. A terminal 15-min bout of sucrose intake produced a further increase in pSer845-GluA1 and GluA2 in subjects with a history of sucrose intake during FR

  17. Engineering topology and kinetics of sucrose metabolism in Saccharomyces cerevisiae for improved ethanol yield. (United States)

    Basso, Thiago O; de Kok, Stefan; Dario, Marcelo; do Espirito-Santo, Júlio Cézar A; Müller, Gabriela; Schlölg, Paulo S; Silva, Carlos P; Tonso, Aldo; Daran, Jean-Marc; Gombert, Andreas K; van Maris, Antonius J A; Pronk, Jack T; Stambuk, Boris U


    Sucrose is a major carbon source for industrial bioethanol production by Saccharomyces cerevisiae. In yeasts, two modes of sucrose metabolism occur: (i) extracellular hydrolysis by invertase, followed by uptake and metabolism of glucose and fructose, and (ii) uptake via sucrose-proton symport followed by intracellular hydrolysis and metabolism. Although alternative start codons in the SUC2 gene enable synthesis of extracellular and intracellular invertase isoforms, sucrose hydrolysis in S. cerevisiae predominantly occurs extracellularly. In anaerobic cultures, intracellular hydrolysis theoretically enables a 9% higher ethanol yield than extracellular hydrolysis, due to energy costs of sucrose-proton symport. This prediction was tested by engineering the promoter and 5' coding sequences of SUC2, resulting in predominant (94%) cytosolic localization of invertase. In anaerobic sucrose-limited chemostats, this iSUC2-strain showed an only 4% increased ethanol yield and high residual sucrose concentrations indicated suboptimal sucrose-transport kinetics. To improve sucrose-uptake affinity, it was subjected to 90 generations of laboratory evolution in anaerobic, sucrose-limited chemostat cultivation, resulting in a 20-fold decrease of residual sucrose concentrations and a 10-fold increase of the sucrose-transport capacity. A single-cell isolate showed an 11% higher ethanol yield on sucrose in chemostat cultures than an isogenic SUC2 reference strain, while transcriptome analysis revealed elevated expression of AGT1, encoding a disaccharide-proton symporter, and other maltose-related genes. After deletion of both copies of the duplicated AGT1, growth characteristics reverted to that of the unevolved SUC2 and iSUC2 strains. This study demonstrates that engineering the topology of sucrose metabolism is an attractive strategy to improve ethanol yields in industrial processes.

  18. Intermittent access to a sucrose solution for rats causes long-term increases in consumption. (United States)

    Eikelboom, Roelof; Hewitt, Randelle


    Intermittent access to palatable food can elevate consumption beyond an animal's immediate needs. If adult male rats (with ad lib access to food and water) are provided with a 4% sucrose solution, daily sucrose consumption is determined by the sucrose access schedule: access that is intermittent leads to high levels of consumption. In Experiment 1, sucrose solutions were first provided continuously or every second, third, or fourth day for 23.5h over 49days. Continuous-access sucrose consumption averaged 102g per day, while that for access every fourth day averaged 294g. Daily consumption averages for access every second and third day fell between these two extremes. When all rats were then given alternate-day access to sucrose for 24days in Phase II, the previously established consumption differences were maintained. Body weight was unaffected by sucrose access; rats adjusted their food consumption so that total calorie intake remained constant. In Experiment 2, compared to continuous 4% sucrose solution access, access every third day markedly elevated daily sucrose consumption after only four sucrose exposures. With this shorter Phase I, sucrose intake in the continuous group increased markedly when in Phase II all rats were given alternate day access. In Experiment 3, a lick-by-lick analysis of the difference in sucrose consumption between access every third day and continuous access revealed that all rats were consuming a similar number of sucrose meals; however, the meals were larger both in the first hour and over the whole 24h with intermittent access. This suggests a change in satiety as a mechanism underlying sucrose consumption difference.

  19. Nitrosative stress and apoptosis in non-anemic healthy rats induced by intravenous iron sucrose similars versus iron sucrose originator. (United States)

    Toblli, Jorge E; Cao, Gabriel; Angerosa, Margarita


    Iron can both induce and inhibit nitrosative stress. Intracellular iron levels play an important role in nitric oxide (NO(•)) signaling mechanisms. Depending on various factors, such as the cell's redox state and transition metal levels, NO(•) generation may lead to lipid peroxidation and DNA damage as well as both anti- and pro-apoptotic effects. Administration of intravenous iron sucrose originator (IS(ORIG)) has been shown not to cause significant tyrosine nitration or significantly increased caspase 3 levels in non-anemic rats. In this study, the potential of several marketed iron sucrose similars (ISSs) to induce tyrosine nitration and caspase 3 expression in non-anemic rats was assessed. Although the physico-chemical properties of most of the analyzed ISSs complied with the United States Pharmacopeia for iron sucrose injection, all ISSs resulted in higher levels of tyrosine nitration and increased the expression of caspase 3 versus IS(ORIG). Moreover, significant differences were detected in tissue iron distribution between IS(ORIG)- and ISS-treated animals. In general, ISORIG resulted in higher levels of ferritin deposits versus ISSs whereas ISSs showed higher Prussian blue-stainable iron(III) deposits than IS(ORIG). This result suggests that some iron from ISSs bypassed the tightly regulated pathway through resident macrophages of the liver, spleen and bone marrow thus, ending up in the cellular compartment that favors oxidative and or nitrosative stress as well as apoptosis. The results also confirm that polynuclear iron(III)-oxyhydroxide carbohydrates, such as iron sucrose, cannot be fully characterized by physico-chemical methods alone.

  20. Energetic Binder Poly (2,2-Dinitrobutyl Acrylate) :Synthesis, Structure and Properties%含能黏合剂聚2,2-二硝基丁基丙烯酸酯的合成与性能

    Institute of Scientific and Technical Information of China (English)

    张公正; 李海华; 黄云霞; 赵姗


    以1-硝基丙烷为原料,经过氧化硝化和羟甲基化反应合成了2,2二硝基-1-丁醇.2,2-二硝基丁醇与丙烯酸进行酯化反应得到2,2-二硝基丁基丙烯酸酯.以2,2-二硝基丁基丙烯酸酯为单体,偶氮二异丁腈为引发剂,甲苯为溶剂,按自由基聚合机理,合成了含能黏合剂聚2,2-二硝基丁基丙烯酸酯,确定了2,2-二硝基丁基丙烯酸酯的均聚动力学.用FTIR,1 HNMR,TG,DSC等方法表征了聚2,2-二硝基丁基丙烯酸酯的结构和热性能.结果表明,2,2-二硝基丁基丙烯酸酯均聚速率方程为Rp=k[M]1.27 [I]0.63,说明链终止为单基终止和双基终止并存.聚2,2-二硝基丁基丙烯酸酯热分解峰温为260℃,质量损失21%.%2, 2-Dinitro-l-butanol was obtained using 1-nitropropane as a raw material through the reaction of the oxidative-nitration and methylolation. 2,2-Ehnitrobutyl acrylate was prepared from 2,2-dinitro-1-butanol and acrylic acid through direct esterification. The energetic binder poly (2, 2-dinitrobutyl acrylate) was synthesized by the free radical polymerization of 2,2-dinitrobutyl acrylate in toluene and using azobisiosbutyronitrile as initiator. The polymerization rate equation was determined experimentally. The structure and thermal properties of poly (2, 2-dinitrobutyl acrylate) were also characterized by the methods of FTIR, ' HNMR,TG,DSC. The results show that the polymerization rate equation for 2, 2-dinitrobutyl acrylate is Rp =r[M]1.27 [I]063, which displays that the chain termination reaction is the coexistence mode of mono- and bi-molecular termination, and the initiating process is dependent on monomer concentration. The thermal decomposition temperature of poly (2,2-dinitrobutyl acrylate) is 260 °C with mass loss of 21%.

  1. Shelf Life of PMR Polyimide Monomer Solutions and Prepregs Extended (United States)

    Alston, William B.; Scheiman, Daniel A.


    PMR (Polymerization of Monomeric Reactants) technology was developed in the mid-1970's at the NASA Glenn Research Center at Lewis Field for fabricating high-temperature stable polyimide composites. This technology allowed a solution of polyimide monomers or prepreg (a fiber, such as glass or graphite, impregnated with PMR polyimide monomers) to be thermally cured without the release of volatiles that cause the formation of voids unlike the non-PMR technology used for polyimide condensation type resins. The initial PMR resin introduced as PMR 15 is still commercially available and is used worldwide by aerospace industries as the state-of-the-art resin for high-temperature polyimide composite applications. PMR 15 offers easy composite processing, excellent composite mechanical property retention, a long lifetime at use temperatures of 500 to 550 F, and relatively low cost. Later, second-generation PMR resin versions, such as PMR II 50 and VCAP 75, offer improvements in the upper-use temperature (to 700 F) and in the useful life at temperature without major compromises in processing and property retention but with significant increases in resin cost. Newer versions of nontoxic (non-methylene dianiline) PMR resins, such as BAX PMR 15, offer similar advantages as originally found for PMR 15 but also with significant increases in resin cost. Thus, the current scope of the entire PMR technology available meets a wide range of aeronautical requirements for polymer composite applications.

  2. Induced DNA damage by dental resin monomers in somatic cells. (United States)

    Arossi, Guilherme Anziliero; Lehmann, Mauricio; Dihl, Rafael Rodrigues; Reguly, Maria Luiza; de Andrade, Heloisa Helena Rodrigues


    The present in vivo study investigated the genotoxicity of four dental resin monomers: triethyleneglycoldimethacrylate (TEGDMA), hydroxyethylmethacrylate (HEMA), urethanedimethacrylate (UDMA) and bisphenol A-glycidylmethacrylate (BisGMA). The Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster was applied to analyse their genotoxicity expressed as homologous mitotic recombination, point and chromosomal mutation. SMART detects the loss of heterozygosity of marker genes expressed phenotypically on the fly's wings. This fruit fly has an extensive genetic homology to mammalians, which makes it a suitable model organism for genotoxic investigations. The present findings provide evidence that the mechanistic basis underlying the genotoxicity of UDMA and TEGDMA is related to homologous recombination and gene/chromosomal mutation. A genotoxic pattern can correspondingly be discerned for both UDMA and TEGDMA: their genotoxicity is attributed respectively to 49% and 44% of mitotic recombination, as well as 51% and 56% of mutational events, including point and chromosomal alterations. The monomer UDMA is 1.6 times more active than TEGDMA to induce mutant clones per treatment unit. BisGMA and HEMA had no statistically significant effect on total spot frequencies - suggesting no genotoxic action in the SMART assay. The clinical significance of these observations has to be interpreted for data obtained in other bioassays.

  3. The Kinetics of Cellulose Grafting with Vinyl Acetate Monomer

    Directory of Open Access Journals (Sweden)

    Éva Borbély


    Full Text Available Cellulose is a natural raw material recurring in a great quantity. The demand touse it more and more widely is increasing. The production of cellulose derivates started asearly as the 19th century, however the modification of these materials meant the breakingup the fibrous structure, which made their use more difficult in paper industry. Themodified cellulose made by graft copolymerization, however, keeps its fibrous character,which provides a great advantage regarding its use. Grafting of industrial cellulose pulpwith vinyl-acetate allows for the production of grafted wood cellulose fibres that have athermoplastic layer on their surface. The binder fibre (fibrid produced in this way can beexcellently used for producing synthetic papers.In the first part of my experiments I dealt with choosing the parameters of graftcopolymerization which are best suited to various uses and after that I studied thedependence of graft reaction on the composition and properties of industrial celluloseapplied. The selection of the suitable reaction parameters was followed by the study ofreaction speed and activation energy. I have stated that the gross reaction of graftingindustrial cellulose with vinyl-acetate monomer is a second order reaction, which is provenby the fact that the invert of the momentary monomer concentration of the system plottedagainst time is a linear function. The rise of the curves, that is, the reaction speed increaseswhen the temperature in the range of 293–323 K is increasing, while the average activationenergy decreases.

  4. Stronger multilayer acrylic dielectric elastomer actuators with silicone gel coatings (United States)

    Lau, Gih-Keong; La, Thanh-Giang; Sheng-Wei Foong, Ervin; Shrestha, Milan


    Multilayer dielectric elastomer actuators (DEA) perform worst off than single-layer DEAs due to higher susceptibility to electro-thermal breakdown. This paper presents a hot-spot model to predict the electro-thermal breakdown field of DEAs and its dependence on thermal insulation. To inhibit the electrothermal breakdown, silicone gel coating was applied as barrier coating to multilayer acrylic DEA. The gel coating helps suppress the electro-thermally induced puncturing of DEA membrane at the hot spot. As a result, the gel-coated DEAs, in either a single layer or a multilayer stack, can produce 30% more isometric stress change as compared to those none-coated. These gel-coated acrylic DEAs show great potential to make stronger artificial muscles.

  5. Plant oil-based shape memory polymer using acrylic monolith

    Directory of Open Access Journals (Sweden)

    T. Tsujimoto


    Full Text Available This article deals with the synthesis of a plant oil-based material using acrylic monolith. An acrylic monolith bearing oxirane groups was prepared via simple technique that involved the dissolution of poly(glycidyl methacrylate-comethyl methacrylate (PGMA in ethanolic – aqueous solution by heating and subsequent cooling. The PGMA monolith had topologically porous structure, which was attributed to the phase separation of the polymer solution. The PGMA monolith was impregnated by epoxidized soybean oil (ESO containing thermally-latent catalyst, and the subsequent curing produced a crosslinked material with relatively good transparency. The Young’s modulus and the tensile strength of polyESO/PGMA increased compared with the ESO homopolymer. The strain at break of polyESO/PGMA was larger than that of the ESO homopolymer and crosslinked PGMA. Furthermore, polyESO/PGMA exhibited good shape memory-recovery behavior.

  6. Rheological behavior of acrylic paint blends based on polyaniline

    Directory of Open Access Journals (Sweden)

    Alex da Silva Sirqueira

    Full Text Available Abstract The rheological properties of acrylic paints and polyaniline (PAni blends, with different contents of PAni doped by dodecyl benzene sulphonic acid (DBSA and, dispersed by mechanical stirrer and ultrasonic, were investigated by controlled shear rate testing ramps. The results showed that the commercial acrylic paint had tended to deliver the required stability on the blends, in order to avoid sedimentation process. All samples exhibited non-Newtonian flow behavior (shear thinning, increasing PAni content the flow behavior index (n decreased (0.41 to 0.11 and power law model were used to fitted the experimental curves. The results showed that the addition of PAni-DBSA affects the viscoelastic behavior of the mixtures due to the interactions between the components in the mixture. The best properties were obtained for samples 90/10 wt % dispersed by ultrasonic, indicating the feasibility of the usage as a conducting paint.

  7. Electrical Properties of n-Butyl Acrylate-Grafted Polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.R.; Oh, W.J.; Suh, K.S. [Korea University (Korea, Republic of)


    The electrical properties of n-butyl acrylate-grafted polyethylene (PE-g-nBA) were investigated. In PE-g-nBA, hetero charge founded in LDPE slightly increased due to the nBA grafting. Conduction currents decreased with the increase of nBA graft ratio. AC breakdown strength increased and water treeing length decreased with the increase of graft ratio in PE-g-nBA. (author). 4 refs., 6 figs.

  8. Hemocompatibility of Chitosan/poly(acrylic acid) Grafted Polyurethane Tubing


    Lee, Hyun-Su; Tomczyk, Nancy; Kandel, Judith; Composto, Russell J.; Eckmann, David M.


    The activation and adhesion of platelets or whole blood exposed to chitosan (CH) grafted surfaces is used to evaluate the hemocompatibility of biomaterials. The biomaterial surfaces are polyurethane (PU) tubes grafted with an inner poly(acrylic acid) (PAA) and an outer CH or quaternary ammonium modified CH (CH-Q) brush. The CH, CH-Q and PAA grafted layers were characterized by ellipsometry and fluorescence microscopy. Material wear tests demonstrate that CH (CH-Q) is stably grafted onto PU tu...

  9. Late opacification of a hydrophilic acrylic intraocular lens

    Directory of Open Access Journals (Sweden)

    Al-Bdour Muawyah


    Full Text Available Cataract extraction and intraocular lens implantation is considered to be a safe procedure in most cases. However, the new advances in the surgical technique namely phacoemulsification and hence the increased use of foldable intraocular lenses have given rise to new complications including late opacification of intraocular lenses. In this case we report late opacification of a foldable hydrophilic acrylic intraocular lens and the surgical technique for its exchange.

  10. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision


    Ladan Espandar; Shameema Sikder; Majid Moshirfar


    Ladan Espandar1, Shameema Sikder2, Majid Moshirfar31Department of Ophthalmology, Tulane University, New Orleans, LA, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 3John A Moran Eye Center, University of Utah, Salt Lake City, UT, USAAbstract: Intraocular lens development is driven by higher patient expectations for ideal visual outcomes. The recently US Food and Drug Administration-approved Softec HD™ lens is an aspheric, hydrophilic acrylic intraocular le...

  11. Insights on the biodegradation of acrylic reline resins


    Neves, Maria Cristina Bettencourt, 1976-


    Tese de doutoramento, Medicina Dentária (Reabilitação Oral), Universidade de Lisboa, Faculdade de Medicina Dentária, 2012 Acrylic reline resins are extensively used in dentistry, since they readapt dentures to the continuous reabsorbed underlying tissues. Since present in the oral cavity for long periods of time, these materials are objective of the biodegradation phenomena, which represents the change on their chemical, physical and mechanical properties due to the oral environment condit...

  12. Nanocellulose Whiskers Grafted with Acrylic Monomers%丙烯酸单体接枝纳米纤维素晶须

    Institute of Scientific and Technical Information of China (English)

    周刘佳; 叶代勇


    以K2S2O8为引发剂,在纳米纤维素晶须(NCW)上接枝丙烯酸单体(AA),制备出丙烯酸接枝改性的纳米纤维素晶须.通过傅立叶变换红外光谱(FTIR)、透射电镜(TEM)、热重分析(TGA)等测试方法对接枝产物的性能进行了分析,并采用电导滴定的方法计算了接枝率以及表面取代基团含量.研究了反应条件对接枝率和接枝效率的影响.结果表明,在引发剂浓度为4 mmol/L,引发时间为5 min,纳米纤维素晶须与丙烯酸单体摩尔比为1: 1.5,反应时间为6 h的条件下,得到了接枝率为14.09%的丙烯酸接枝纳米纤维素晶须.实验证明,在NCW上可以接枝上丙烯酸,接枝率为14.09%的产物与NCW具有相似的表面形貌和热性能;TEM分析可知,接枝产物的分散性得到了提高;表面取代基团含量测试表明,接枝产物表面上的亲水性分散基团含量比NCW增加了5倍以上.

  13. The relationship of acrylic ester monomers composition and their viscosity%丙烯酸酯单体组成与粘度的关系

    Institute of Scientific and Technical Information of China (English)

    王德海; 胡祥太; 蒋辉; 陈敏


    由单纯液体的粘度预测混合液体的粘度,具有流变学理论研究和工业应用价值.传统的预测方程利用各组分的粘度,分别从质量分数和摩尔分数的角度进行预测,实验发现传统方程在预测时误差较大.在前人方程的基础上,从分子结构的角度,引入溶度参数、范德华体积和活化能等参数修正摩尔分数,得到了一些新方程,并将各方程的计算值与实验值进行了比较.研究表明:用范德华体积和活化能共同修正所得的方程的计算值平均相对误差最小,仅为4.99%~7.60%,而且在预测有较复杂分子结构组分的混合物时体现了较大的优势,平均相对误差为1.12%.%It is significative to predict the viscosity of liquid mixture with the viscosity of the pure components in theoretical research of rheology and its industrial application. Traditional equations for predicting the blend viscosity use the viscosity of each component and their mass fraction or molar fraction. The experiment indicates that the traditional equations are not accurate enough. By introducing a set of parameters, to the formal equations, such as solubility, van der Waals' volume, activation energy, and then modifying the molar fractions in the view of molecular structure, we get some new equations. Comparing the experimental values to the calculated ones with the new equations, we find that the average relative error is small, only 4. 99%~7. 60%. In addition, the new equation has the advantage of being able to predict the viscosity of the mixture with complicated molecular structure components.

  14. Acrylic microspheres-based optosensor for visual detection of nitrite. (United States)

    Noor, Nur Syarmim Mohamed; Tan, Ling Ling; Heng, Lee Yook; Chong, Kwok Feng; Tajuddin, Saiful Nizam


    A new optosensor for visual quantitation of nitrite (NO2(-)) ion has been fabricated by physically immobilizing Safranine O (SO) reagent onto a self-adhesive poly(n-butyl acrylate) [poly(nBA)] microspheres matrix, which was synthesized via facile microemulsion UV lithography technique. Evaluation and optimization of the optical NO2(-) ion sensor was performed with a fiber optic reflectance spectrophotometer. Scanning electron micrograph showed well-shaped and smooth spherical morphology of the poly(nBA) microspheres with a narrow particles size distribution from 0.6 μm up to 1.8 μm. The uniform size distribution of the acrylic microspheres promoted homogeneity of the immobilized SO reagent molecules on the microspheres' surfaces, thereby enhanced the sensing response reproducibility (<5% RSD) with a linear range obtained from 10 to 100 ppm NO2(-) ion. The micro-sized acrylic immobilization matrix demonstrated no significant barrier for diffusion of reactant and product, and served as a good solid state ion transport medium for reflectometric nitrite determination in food samples.

  15. Acrylate Functionalized Tetraalkylammonium Salts with Ionic Liquid Properties

    Directory of Open Access Journals (Sweden)

    Silvia Janietz


    Full Text Available Acrylate functionalized ionic liquids based on tetraalkylammonium salts with terminal acrylates- and methylacrylates were synthesized. Melting points and ionic conductivity of twenty compounds in six groups were determined. Within one group the effect of three different counterions was investigated and discussed. The groups differ in cationic structure elements because of their functional groups such as acrylate and methacrylate, alkyl residues at the nitrogen and number of quaternary ammonium atoms within the organic cation. The effect of these cationic structure elements has been examined concerning the compiled parameters with a view to qualifying them as components for solid state electrolytes. The newly synthesized ionic liquids were characterized by NMR and FTIR analysis. The exchange of halide ions like bromide as counter ions to weakly coordinating [PF6], [OTf] or [TFSI] reduces the melting points significantly and leads to an ion conductivity of about 10−4 S/cm at room temperature. In the case of the dicationic ionic liquid, an ion conductivity of about 10−3 S/cm was observed.

  16. Synthesis and properties of acrylic copolymers for ocular implants (United States)

    Reboul, Adam C.

    There is a need for flexible polymers with higher refractive index and extended UV absorbing properties for improved intraocular lenses (IOLs). This research was devoted to the synthesis of new acrylic copolymers for foldable IOLs and to studies concerning IOL polymer properties. New polymers were synthesized from phenylated acrylates copolymerized with N-vinyl carbazole derivatives using bulk free radical addition methods. The copolymers had low Tg values, high refractive index, and were flexible. The N-vinyl carbazole derivatives were characterized by NMR and copolymers were characterized by DSC, UV-Vis, and refractometry. New phenothiazine based UV absorbers with high extinction coefficients were also synthesized for incorporation into ocular materials. Patent disclosures on UV absorbers and high refractive index polymers were prepared. A so called "glistening" phenomenon that occurs in all foldable intraocular lenses currently in clinical use is poorly understood and was studied. Research on this microvoid forming behavior included studies and development of methods to inhibit glistening in low Tg acrylic based copolymers. Glistenings were characterized using SEM and optical microscopy. A novel technique for inhibiting glistening was found and a patent disclosure was prepared.

  17. Progress in the Synthesis Methods of Long Chain Alcohol Acrylate%长链醇丙烯酸酯合成方法的研究进展

    Institute of Scientific and Technical Information of China (English)

    毛文娟; 许孝良


    The long chain alcohol acrylate have gained enormous attention among material chemists over the years because of their three-dimensional effect and hydrophilic or hydrophobic macromolecule. They can be used as synthetic organic monomer of various polymers. In this paper, the synthesis methods of long chain alcohol acrylate were reviewed, which provided a fundamental base for the application in biological medicine, materials, surface active agent, etc.%长链醇丙烯酸酯是支链具有空间立体效应以及亲水性或疏水性的大分子,可以用作多种聚合化合物的有机合成单体。本文综述了长链丙烯酸酯的合成方法,为以后进一步研究其在生物医药、材料、表面活性剂等方面的应用提供依据。

  18. Preparation of Water-soluble Acrylic Lamination Coating%水溶性丙烯酸树脂硅钢片漆的研制

    Institute of Scientific and Technical Information of China (English)

    王鹏跃; 刘立柱; 翁凌; 李子帙; 魏景生; 金镇镐


    A water-soluble acrylic resin was prepared by solution polymerization using methyl methacrylate(MMA), acrylic acid(AA), styrene(SM) and butyl acrylate(BA) as monomer, butanoi as solvent and BPO as initiator. The optimum formula was determined by comparing the viscosity, gel time and water solubility of different formula of resin and the hardness, toughness and adhe sion of corresponding cured film. The effects of initiator, neutralizer and additive content on the properties of the lamination coating were investigated. The results show that the prepared film has smooth appearance, high hardness, excellent adhesion and toughness.%采用溶液聚合法,以甲基丙烯酸甲酯、丙烯酸、苯乙烯和丙烯酸丁酯为单体,正丁醇为溶剂,BPO为引发剂,制备了水性丙烯酸树脂.通过对比不同配方树脂对应漆液的粘度、凝胶化时间和水溶性,以及固化后漆膜的硬度、韧性和附着力等因素,确定了树脂的最佳配方.分析了引发剂、中和剂和助剂用量对硅钢片漆性能的影响.结果表明:制备的硅钢片漆漆膜外观光滑,硬度高,具有较好的附着力和韧性.

  19. [Free methyl-methacrylate content of some dental acrylates]. (United States)

    Szabó, G; Csekó, J; Szabó, I


    The authors have proved the presence of free monomer content in 0,26% with Superacryl Special, 0,29% with Superpont C-B, 0,8% with Kallocryl C and the Duracryl O from a metanol solution of samples taken by cutting. By means of soaking in water for three months the most dissolved free monomer was 0.002% from Superpont C-B and Kallocryl C, and 0.004% from Duracryl O. From Superacryl Special no MNA was dissolved in determinable quantity.


    Institute of Scientific and Technical Information of China (English)

    Kun Xu; Shu-xue Zhou; Li-min Wu


    Thermosetting acrylic coatings were prepared by using carboxyl acid group-containing acrylic oligomer and curing with titanium-oxo-clusters which were first pre-hydrolyzed from titanium n-butoxide. The curing ability of the titanium-oxo-cluster was examined using a microdielectric analytical (DEA) curing monitor, Fourier transformed infrared spectroscopy (FTIR), and Soxhlet extraction experiments, and the properties of the resulted coatings were investigated with pendulum hardness tester, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and ultraviolet-visible spectrometer. The effect of titania-oxo-cluster in leading acrylic oligomers to form thermosetting acrylic coatings was confirmed. An increasing pendulum hardness and modulus of acrylic coatings with increasing titania content was observed, which resulted from the increment of crosslinking degree rather than of the titania content. The thermosetting acrylic/titania coatings also showed better thermal stability and higher UV-blocking properties than those coatings using organic curing agent.

  1. High sucrose consumption promotes obesity whereas its low consumption induces oxidative stress in Drosophila melanogaster. (United States)

    Rovenko, Bohdana M; Kubrak, Olga I; Gospodaryov, Dmytro V; Perkhulyn, Natalia V; Yurkevych, Ihor S; Sanz, Alberto; Lushchak, Oleh V; Lushchak, Volodymyr I


    The effects of sucrose in varied concentrations (0.25-20%) with constant amount of yeasts in larval diet on development and metabolic parameters of adult fruit fly Drosophila melanogaster were studied. Larvae consumed more food at low sucrose diet, overeating with yeast. On high sucrose diet, larvae ingested more carbohydrates, despite consuming less food and obtaining less protein derived from yeast. High sucrose diet slowed down pupation and increased pupa mortality, enhanced levels of lipids and glycogen, increased dry body mass, decreased water content, i.e. resulted in obese phenotype. Furthermore, it suppressed reactive oxygen species-induced oxidation of lipids and proteins as well as the activity of superoxide dismutase. The activity of catalase was gender-related. In males, at all sucrose concentrations used catalase activity was higher than at its concentration of 0.25%, whereas in females sucrose concentration virtually did not influence the activity. High sucrose diet increased content of protein thiols and the activity of glucose-6-phosphate dehydrogenase. The increase in sucrose concentration also enhanced uric acid level in females, but caused opposite effects in males. Development on high sucrose diets was accompanied by elevated steady-state insulin-like peptide 3 mRNA level. Finally, carbohydrate starvation at yeast overfeeding on low sucrose diets resulted in oxidative stress reflected by higher levels of oxidized lipids and proteins accompanied by increased superoxide dismutase activity. Potential mechanisms involved in regulation of redox processes by carbohydrates are discussed.

  2. Expression profiling of sucrose metabolizing genes in Saccharum, Sorghum and their hybrids. (United States)

    Ramalashmi, K; Prathima, P T; Mohanraj, K; Nair, N V


    Sucrose phosphate synthase (SPS; EC, sucrose synthase (SuSy; EC and soluble acid invertase (SAI; EC are key enzymes that regulate sucrose fluxes in sink tissues for sucrose accumulation in sugarcane and sorghum. In this study, the expression profiling of sucrose-related genes, i.e. SPS, SuSy and SAI in two sets of hybrids viz., one from a Sorghum × Saccharum cross and the other from a Saccharum × Sorghum cross, high- and low-sucrose varieties, sweet and grain sorghum lines was carried out using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) at monthly intervals. The results indicated differential expression of the three genes in high- and low-sucrose forms. Expression of SPS and SuSy genes was high in high-sucrose varieties, Saccharum × Sorghum hybrids and sweet sorghum and lower in low-sucrose varieties, Sorghum × Saccharum hybrids and grain sorghum. SAI showed a lower expression in high-sucrose varieties, Saccharum × Sorghum hybrids and sweet sorghum and higher expression in low-sucrose varieties, Sorghum × Saccharum hybrids and the grain sorghum. This study describes the positive association of SPS and SuSy and negative association of SAI on sucrose accumulation. This is the first report of differential expression profiling of SPS, SuSy and SAI in intergeneric hybrids involving sugarcane and sorghum, which opens the possibility for production of novel hybrids with improved sucrose content and with early maturity.

  3. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

    Energy Technology Data Exchange (ETDEWEB)

    Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik [Radiation Processing Technology Division, Malaysian Nuclear Agency (Nuclear Malaysia), Bangi, 43000 Kajang, Selangor (Malaysia); Ibrahim, Mohammad Izzat [Faculty of Science, University of Malaya (UM), 50603 Kuala Lumpur (Malaysia); Yunus, Nurulhuda Mohd [Faculty of Science and Technology, National University Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)


    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  4. Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application (United States)

    Tajau, Rida; Ibrahim, Mohammad Izzat; Yunus, Nurulhuda Mohd; Mahmood, Mohd Hilmi; Salleh, Mek Zah; Salleh, Nik Ghazali Nik


    The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-based compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.

  5. Effect of Atmospheric Pressure Glow Discharge Treatment on Polymerization of Acrylic Fabric and Its Printing Behavior

    Directory of Open Access Journals (Sweden)

    D M El-Zeer


    Full Text Available Acrylic fibers have been treated by atmospheric pressure glow discharge (APGD plasma in open air to enhance surface antistatic properties. The treated surfaces are investigated by scanning electron microscopy (SEM, Fourier-Transition Infrared Spectroscopy (FTIR and Atomic Force Microscope (AFM. Plasma treatment of acrylic fabric has been found to increase the surface roughness, modify the nature and density of surface functionalities, and drastically improve the wettability and antistatic ability of acrylic fibers.

  6. Color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for non metal clasp denture


    Jang, Dae-Eun; Lee, Ji-Young; Jang, Hyun-Seon; Lee, Jang-Jae; Son, Mee-Kyoung


    PURPOSE The aim of this study was to compare the color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for the non-metal clasp dentures to those of thermoplastic polyamide and conventional heat-polymerized denture base resins. MATERIALS AND METHODS Three types of denture base resin, which are conventional heat-polymerized acrylic resin (Paladent 20), thermoplastic polyamide resin (Bio Tone), thermoplastic acrylic resin (Acrytone) were used as materials for this study...

  7. Studies on the hydrolysis of biocompatible acrylic polymers having aspirin-moieties. (United States)

    Gu, Z W; Li, F M; Feng, X D; Voong, S T


    Both the homogeneous and heterogeneous hydrolysis of five new acrylic polymers having aspirin-moieties, i.e. polymers of beta-(acetylsalicylyloxy)ethyl methacrylate, beta-(acetylsalicylyloxy) propyl methacrylate,beta-(acetylsalicylyloxy) ethyl acrylate, beta-hydroxy-gamma-(acetylsalicylyloxy) propyl methacrylate, beta-hydroxy-gamma-(acetylsalicylyloxy) propyl acrylate were investigated in acidic or alkaline medium at 30 degrees C or 60 degrees C, respectively. It was observed that the chief hydrolyzed product is always aspirin with minor amount of salicylic acid.

  8. Preparation of Poly(acrylic acid) Hydrogel by Radiation Crosslinking and Its Application for Mucoadhesives


    Young-Chang Nho; Jong-Seok Park; Youn-Mook Lim


    A mucoadhesive drug delivery system can improve the effectiveness of a drug by maintaining the drug concentration and allowing targeting and localization of the drug at a specific site. Acrylic-based hydrogels have been used extensively as a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, poly(acrylic acid) was selected to prepare the bioadhesive hydrogel adhering to mucosal surfaces using a radiation process. Poly(acrylic acid) was dissolved in ...

  9. Production and monomer composition of exopolysaccharides by yogurt starter cultures. (United States)

    Frengova, G I; Simova, E D; Beshkova, D M; Simov, Z I


    As components of starter cultures for Bulgarian yogurt, Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus revealed extensive exopolysaccharide (EPS) production activity when cultivated in whole cow's milk. The polymer-forming activity of thermophilic streptococci was lower (230-270 mg EPS/L) than that of the lactobacilli (400-540 mg EPS/L). Mixed cultures stimulated EPS production in yogurt manufacture, and a maximum concentration of 720-860 mg EPS/L was recorded after full coagulation of milk. The monomer structure of the exopolysaccharides formed by the yogurt starter cultures principally consists of galactose and glucose (1:1), with small amounts of xylose, arabinose, and/or mannose.

  10. Biosynthesis of monomers for plastics from renewable oils. (United States)

    Lu, Wenhua; Ness, Jon E; Xie, Wenchun; Zhang, Xiaoyan; Minshull, Jeremy; Gross, Richard A


    Omega-hydroxyfatty acids are excellent monomers for synthesizing a unique family of polyethylene-like biobased plastics. However, ω-hydroxyfatty acids are difficult and expensive to prepare by traditional organic synthesis, precluding their use in commodity materials. Here we report the engineering of a strain of the diploid yeast Candida tropicalis to produce commercially viable yields of ω-hydroxyfatty acids. To develop the strain we identified and eliminated 16 genes encoding 6 cytochrome P450s, 4 fatty alcohol oxidases, and 6 alcohol dehydrogenases from the C. tropicalis genome. We also show that fatty acids with different chain lengths and degrees of unsaturation can be more efficiently oxidized by expressing different P450s within this strain background. Biocatalysis using engineered C. tropicalis is thus a potentially attractive biocatalytic platform for producing commodity chemicals from renewable resources.

  11. Star polymers by ATRP of styrene and acrylates employing multifunctional initiators

    DEFF Research Database (Denmark)

    Jankova, Katja Atanassova; Bednarek, Melania; Hvilsted, Søren


    scission of the ester linkages and the second step corresponds to the normal PS degradation. Star poly(methyl acrylates) with various cores are likewise prepared in a controlled manner by ATRP of methyl acrylate in bulk and in solution at 6080 degrees C with the 1,1,4,7,7-pentamethyldiethylene triamine...... ligand. Under these conditions, higher conversions were possible still maintaining low PDI signaling controlled star growth. Multiarm stars of poly(n-butyl acrylate) and poly(n-hexyl acrylate) with controlled characteristics have also been prepared....

  12. The effects of sympathectomy and dexamethasone in rats ingesting sucrose

    Directory of Open Access Journals (Sweden)


    Full Text Available Both high-sucrose diet and dexamethasone (D treatment increase plasma insulin and glucose levels and induce insulin resistance. We showed in a previous work (Franco-Colin, et al. Metabolism 2000; 49:1289-1294 that combining both protocols for 7 weeks induced less body weight gain in treated rats without affecting mean daily food intake. Since such an effect may be explained by an increase in caloric expenditure, possibly due to activation of the sympathetic nervous system by sucrose ingestion, in this work, and using 10% sucrose in the drinking water, male Wistar rats were divided into 4 groups. Two groups were sympathectomized using guanethidine (Gu treatment for 3 weeks. One of these groups of rats received D in the drinking water. Of the 2 groups not receiving Gu, one was the control (C and the other received D. After 8 weeks a glucose tolerance test was done. The rats were sacrificed and liver triglyceride (TG, perifemoral muscle lipid, and norepinephrine (NE levels in the liver spleen, pancreas, and heart were determined. Gu-treated rats (Gu and Gu+D groups showed less than 10% NE concentration compared to C and D rats, less daily caloric intake and body-weight gain, more sucrose intake, and better glucose tolerance. The area under the curve after glucose administration correlated significantly with the mean body weight gain of the rats, except for D group. Groups D (D and Gu+D also showed less caloric intake and body-weight gain but higher liver weight and TG concentration and lower peripheral muscle mass. The combination of Gu+D treatments showed some peculiar results: negative body weight gain, a fatty liver, and low muscle mass. Though the glucose tolerance test had the worst results for the D group, it showed the best results in the Gu+D group. There were significant interactions for Guan X Dex by two-way ANOVA test for the area under the curve in the glucose tolerance test, muscle mass, and muscle lipids. The results suggest that

  13. Exposing Differences in Monomer Exchange Rates of Multicomponent Supramolecular Polymers in Water. (United States)

    Baker, Matthew B; Gosens, Ronald P J; Albertazzi, Lorenzo; Matsumoto, Nicholas M; Palmans, Anja R A; Meijer, E W


    The formation of multicomponent and bioactive supramolecular polymers is a promising strategy for the formation of biomaterials that match the dynamic and responsive nature of biological systems. In order to fully realize the potential of this strategy, knowledge of the location and behavior of bioactive components within the system is crucial. By employing synthetic strategies to create multifunctional monomers, coupled with FRET and STORM techniques, we have investigated the formation and behavior of a bioactive and multicomponent supramolecular polymer. By creating a peptide-dye-monomer conjugate, we were able to measure high degrees of monomer incorporation and to visualize the equal distribution of monomers within the supramolecular polymer. Furthermore, by tracking the movement of monomers, we uncovered small differences in the dynamics of the bioactive monomers.

  14. Use of Monomer Fraction Data in the Parametrization of Association Theories

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios; Tsivintzelis, Ioannis; von Solms, Nicolas;


    “improved” model parameters can be obtained if monomer fraction data are included in the parameter estimation together with vapor pressures and liquid densities. The expression “improved” implies parameters which can represent several pure compound properties as well as monomer fraction data for pure......, liquid densities and monomer fractions of water and alcohols. The 4C scheme is the best choice for water, while for methanol there is small difference between the 2B and 3B association schemes....

  15. Enzymatic Specific Production and Chemical Functionalization of Phenylpropanone Platform Monomers from Lignin


    Ohta, Yukari; Hasegawa, Ryoichi; Kurosawa, Kanako; Maeda, Allyn H.; Koizumi, Toshio; Nishimura,Hiroshi; Okada, Hitomi; Qu, Chen; Saito, Kaori; Watanabe, Takashi; Hatada, Yuji


    Abstract Enzymatic catalysis is an ecofriendly strategy for the production of high‐value low‐molecular‐weight aromatic compounds from lignin. Although well‐definable aromatic monomers have been obtained from synthetic lignin‐model dimers, enzymatic‐selective synthesis of platform monomers from natural lignin has not been accomplished. In this study, we successfully achieved highly specific synthesis of aromatic monomers with a phenylpropane structure directly from natural lignin using a casca...

  16. Tonoplast Sugar Transporters (SbTSTs) putatively control sucrose accumulation in sweet sorghum stems. (United States)

    Bihmidine, Saadia; Julius, Benjamin T; Dweikat, Ismail; Braun, David M


    Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed.

  17. Effect of sucrose starvation on sycamore (Acer pseudoplatanus) cell carbohydrate and Pi status. (United States)

    Rébeillé, F; Bligny, R; Martin, J B; Douce, R


    The mobilization of stored carbohydrates during sucrose starvation was studied with sycamore (Acer pseudoplatanus) cells. When sucrose was omitted from the nutrient medium, the intracellular sucrose pool decreased rapidly during the first hours of the experiment, whereas the starch content remained practically unchanged. After 10h of sucrose starvation, starch hydrolysis replaced sucrose breakdown. From this moment, the phosphate-ester pool and respiration rate decreased with time. Conversely, the intracellular Pi concentration increased. 31P n.m.r. of intact sycamore cells indicated that, under these conditions, most of the Pi accumulated in the vacuole. These results strongly suggest that starch breakdown, in contrast with sucrose hydrolysis, is not rapid enough to maintain a high cellular metabolism.

  18. Effect of sucrose on physical properties of spray-dried whole milk powder. (United States)

    Ma, U V Lay; Ziegler, G R; Floros, J D


    Spray-dried whole milk powders were prepared from whole condensed milk with various sucrose concentrations (0%, 2.5%, 5%, 7.5%, and 10% w/w), and their glass transition temperature and some physical properties of importance in chocolate manufacture were evaluated. In milk powder samples, the glass transition temperature and free-fat content decreased in a nonlinear manner with sucrose addition. Moreover, increasing sucrose concentration reduced the formation of dents on the particle surface. Addition of sucrose in whole condensed milk increased linearly the apparent particle density and in a nonlinear manner the particle size of spray-dried milk powders. The particle size volume distribution of milk powders with the highest sucrose concentration differed from the log-normal distribution of the other samples due to the formation of large agglomerates. Neither vacuole volume, nor the amorphous state of milk powders was affected by sucrose addition.

  19. Mechanisms of Sucrose and Non-Nutritive Sucking in Procedural Pain Management in Infants

    Directory of Open Access Journals (Sweden)

    Sharyn Gibbins


    Full Text Available The administration of sucrose with and without non-nutritive sucking (NNS has been examined for relieving procedural pain in newborn infants. The calming and pain-relieving effects of sucrose are thought to be mediated by endogenous opioid pathways activated by sweet taste. The orogustatory effects of sucrose have been demonstrated in animal newborns, and in preterm and full term human infants during painful procedures. In contrast to sucrose, the analgesic effects of NNS are hypothesized to be activated through nonopioid pathways by stimulation of orotactile and mechanoreceptor mechanisms. Although there is uncertainty as to whether the effects of sucrose and NNS are synergistic or additive, there is sufficient evidence to support the efficacy of combining the two interventions for procedural pain relief in infants. In this review article, the underlying mechanisms of sucrose and NNS, separately and in combination for relieving procedural pain in preterm and full term infants, are examined. Clinical and research implications are addressed.

  20. Rapid "one-pot" preparation of polymeric monolith via photo-initiated thiol-acrylate polymerization for capillary liquid chromatography. (United States)

    Bai, Jingyao; Wang, Hongwei; Ou, Junjie; Liu, Zhongshan; Shen, Yehua; Zou, Hanfa


    A facile approach was exploited for fast preparation of polymer-based monoliths in UV-transparent fused-silica capillaries via "one-pot" photo-initiated thiol-acrylate polymerization reaction of dipentaerythritolpenta-/hexaacrylate (DPEPA) and 1-octadecanethiol (ODT) in the presence of porogenic solvents (1-butanol and ethylene glycol). Due to relative insensitivity of oxygen inhibition in thiol-ene free-radical polymerization, the polymerization could be performed within 5 min. The effects of composition of prepolymerization solution on the morphology and permeability of poly(ODT-co-DPEPA) monoliths were investigated in detail by adjusting the content of monomer and binary porogen ratio. The physical properties of poly(ODT-co-DPEPA) monoliths were characterized by Fourier transform infrared spectroscopy (FT-IR), mercury intrusion porosimetry (MIP) and nitrogen adsorption/desorption measurement. The evaluation of chromatographic performance was carried out by capillary liquid chromatography (cLC). The results indicated that the poly(ODT-co-DPEPA) monolith was homogeneous and permeable, and also possessed a typical reversed-phase retention mechanism in cLC with high efficiency (∼75,000 N m(-1)) for separation of alkylbenzenes. Eventually, the further separation of tryptic digest of proteins by cLC tandem mass spectrometry (cLC-MS/MS) demonstrated its potential in the analysis of biological samples.