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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

    Maria Teresa Barros

    2010-04-01

    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.

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

    Li Jun Chen

    2012-01-01

    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%.

  3. Novel Unsaturated Sucrose Ethers and Their Application as Monomers

    Maria T. Barros

    2007-03-01

    Full Text Available Novel unsaturated ethers were synthesised in good yields starting from sucrose,using a two-step mild and efficient procedure based on the Gassman method, whichconsists in forming a vinyl group by the elimination of ethanol from mixed acetals withtrimethylsilyl trifluoromethanesulfonate in the presence of alkyl amines. Mixed acetals arereadily obtained from the corresponding alcohols and ethyl vinyl ether, using an acidiccatalyst. Conventional etherification involving a primary halide was also examined. Themonomers thus obtained were successfully polymerised by a free radical mechanism,yielding unbranched linear and soluble polymers with pending sucrose moieties, and someof their physical properties were determined.

  4. Delamination of layered double hydroxides in polar monomers: new LDH-acrylate nanocomposites.

    O'Leary, Shane; O'Hare, Dermot; Seeley, Gordon

    2002-07-21

    The layered double hydroxide Mg2Al(OH)6(C12H25SO4) was delaminated to give high levels of inclusion in acrylate monomers; subsequent polymerisation of the monomers containing the LDH dispersion gave polyacrylates with the inorganic component still in the delaminated form. PMID:12189866

  5. The effect of various frequencies of ultrasonic cleaner in reducing residual monomer in acrylic resin.

    Charasseangpaisarn, Taksid; Wiwatwarrapan, Chairat

    2015-12-01

    Monomer remaining in denture base acrylic can be a major problem because it may cause adverse effects on oral tissue and on the properties of the material. The purpose of this study was to compare the effect of various ultrasonic cleaner frequencies on the amount of residual monomer in acrylic resin after curing. Forty-two specimens each of Meliodent heat-polymerized acrylic resin (M) and Unifast Trad Ivory auto-polymerized acrylic resin (U) were prepared according to their manufacturer's instructions and randomly divided into seven groups: Negative control (NC); Positive control (PC); and five ultrasonic treatment groups: 28 kHz (F1), 40 kHz (F2), 60 kHz (F3) (M=10 min, U=5 min), and 28 kHz followed by 60 kHz (F4: M=5 min per frequency, U=2.5 min per frequency, and F5: M=10 min followed by 5 min per frequency, U=5 min followed by 2.5 min per frequency). Residual monomer was determined by HPLC following ISO 20795-1. The data were analyzed by One-way ANOVA and Tukey HSD. There was significantly less residual monomer in the auto-polymerized acrylic resin in all ultrasonic treatment groups and the PC group than that of the NC group (p0.05). The amount of residual monomer in heat-polymerized acrylic resin was significantly lower than that of auto-polymerized acrylic resin. In conclusion, ultrasonic treatment at low frequencies is recommended to reduce the residual monomer in auto-polymerized acrylic resin and this method is more practical in a clinical situation than previously recommended methods because of reduced chairside time. PMID:26190059

  6. [MORPHOLOGICAL FEATURES OF RAT MUCOUS MEMBRANE OF THE TONGUE EARLY AFFECTED BY ACRYLIC RESIN MONOMER].

    Davydenko, V; Nidzelskiy, M; Starchenko, I; Davydenko, A; Kuznetsov, V

    2016-03-01

    Base materials, made on the basis of various derivatives of acrylic and methacrylic acids, have been widely used in prosthetic dentistry. Free monomer, affecting the tissues of prosthetic bed and the whole body, is always found in dentures. Therefore, study of the effect of acrylic resins' monomer on mucous membrane of the tongue is crucial. Rat tongue is very similar to human tongue, and this fact has become the basis for selecting these animals to be involved into the experiment. The paper presents the findings related to the effect of "Ftoraks" base acrylic resin monomer on the state of rat mucous membrane of the tongue and its regeneration. The microscopy has found that the greatest changes in the mucous membrane of the tongue occur on day 3 and 7 day after applying the monomer and are of erosive and inflammatory nature. Regeneration of tongue epithelium slows down. PMID:27119844

  7. Syntheses of monomers in the reaction of hexamethylolmelamine with 2-hydroxyethyl acrylate and their photocuring

    A process has been developed for the syntheses of monomers from 2-hydroxyethyl acrylate and hexamethylolmelamine. Their structure were identified by IR and sub 1H-NMR. The photocuring characteristics of these compound and properties of the UV-cured films have been studied

  8. Enzyme-catalyzed synthesis of saccharide acrylate monomers from nonedible biomass.

    Kloosterman, Wouter M J; Brouwer, Sander G M; Loos, Katja

    2014-08-01

    Various cellulase preparations were found to catalyze the transglycosidation between cotton linters and 2-hydroxyethyl acrylate. The conversion and enzyme activity were found to be optimal in reaction mixtures that contained 5 vol % of the acrylate. The structures of the products were revealed by using TLC and (1) H and (13) C NMR spectroscopy. The enzyme-catalyzed reaction resulted in two products. The minor product originated from transglycosidation to hemicellulose and was found to be 2-(β-xylosyloxy)-ethyl acrylate. The major product was identified as 2-(β-glucosyloxy)-ethyl acrylate and the yield of the product was 5 wt % based on the amount of consumed cellulose. Glycosidation products with oligosaccharide moieties could not be detected in the reaction mixture. This result can be explained by the hydrolytic activities of the used cellulase preparation. Cellulase from Trichoderma reesei was found to possess, in addition to endoglucanase activity, cellobiosidase and β-glucosidase activities. Five other cellulase preparations from different origins were tested as well for catalysis of oligosaccharide acrylate synthesis. For most cellulase preparations the major transglycosidation product appeared to be 2-(β-glucosyloxy)-ethyl acrylate. Nevertheless, the endo-β-(1,4)-glucanase from Trichoderma longibrachiatum was found to catalyze the synthesis of 2-(β-cellobiosyloxy)-ethyl acrylate. Unlike the other cellulase preparations, endo-β-(1,4)-glucanase from T. longibrachiatum showed no detectable β-glucosidase activity and therefore oligosaccharide acrylate monomers were not further hydrolyzed into the monosaccharide acrylate 2-(β-glucosyloxy)-ethyl acrylate. PMID:24866837

  9. Effects of acrylic resin monomers on porcine coronary artery reactivity.

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

    2016-07-01

    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. PMID:27132475

  10. Study on grafting of different types of acrylic monomers onto natural rubber by {gamma}-rays

    Dafader, N.C. [Nuclear and Radiation Chemistry Division, Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission, P.O. Box 3787, Dhaka (Bangladesh)]. E-mail: nrcd@instaere.com; Haque, M.E. [Nuclear and Radiation Chemistry Division, Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission, P.O. Box 3787, Dhaka (Bangladesh)]. E-mail: nrcd@instaere.com; Akhtar, F. [Nuclear and Radiation Chemistry Division, Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission, P.O. Box 3787, Dhaka (Bangladesh)]. E-mail: nrcd@instaere.com; Ahmad, M.U. [Department of Chemistry, Jahangirnagar University, Savar, Dhaka (Bangladesh)]. E-mail: mesbah_ahmad@hotmail.com

    2006-01-15

    A comparative study of various acrylic monomers for grafting onto natural rubber was done. The stability of natural rubber latex (NRL) against coagulum with monomer, mechanical properties of grafted rubbers and percent of grafting were investigated. The NRL with monomers, methylacrylate (MA), ethylacrylate (EA) and n-butylacrylate (n-BA), is unstable but it is stable with methyl methacrylate (MMA), n-butyl methacrylate (BMA) and cyclohexyl methacrylate (CHMA). The mechanical properties and degree of grafting attained a maximum at a total radiation dose of 4 kGy. The values of tensile properties of MMA and CHMA grafted rubbers are almost similar, and higher than those of BMA grafted rubbers. On the other hand, the degree of grafting for CHMA is higher than those of MMA and BMA grafted rubbers. The infrared (IR) spectra of monomer grafted natural rubber were also studied.

  11. Influencing solvent miscibility and aqueous stability of aluminum nanoparticles through surface functionalization with acrylic monomers.

    Crouse, Christopher A; Pierce, Christian J; Spowart, Jonathan E

    2010-09-01

    With growing interest in the development of new composite systems for a variety of applications that require easily processable materials and adequate structural properties with high energy densities, we have pursued the chemical functionalization of oxide-passivated aluminum nanoparticles (nAl) using three acrylic monomers, 3-methacryloxypropyltrimethoxysilane (MPS), 2-carboxyethyl acrylate (CEA), and phosphonic acid 2-hydroxyethyl methacrylate ester (PAM), to provide chemical compatibility within various solvent and polymeric systems. Fourier transform infrared and X-ray photoelectron spectroscopy suggest that attachment of MPS and PAM monomers occurs through the formation of bonds directly to the passivated oxide surface upon reaction with surface hydroxyls, whereas CEA monomers interact through the formation of ionic carboxylate binding to aluminum atoms within the oxide. The coated particles demonstrate enhanced miscibility in common organic solvents and monomers; MPS and PAM coatings are additionally shown to inhibit oxidation of the aluminum particles when exposed to aqueous environments at room temperature, and PAM coatings are stable at even elevated temperatures. PMID:20795650

  12. Lattice Dynamics of Colloidal Crystals During Photopolymerization of Acrylic Monomer Matrix

    Sunkara, H. B,; Penn, B. G.; Frazier, D. O.; Ramachandran, N.

    1998-01-01

    The photoinitiated bulk polymerization process, which has been used recently in the manufacture of solid optical diffraction filters, is examined to understand the dynamics of both the crystalline colloidal arrays (CCA) and the host monomer species. Our analysis indicates that volume shrinkage of the monomer, changes in the dielectric properties of the monomer, and inhomogeneities of polymerization reaction rate across the dispersion during the polymerization process, are the major contributors for observed lattice compression and lattice disorder of the CCA of silica spheres in polymerized acrylic/methacrylic ester films. The effect of orientation of photocell with respect to the radiation source on Bragg diffraction of CCA indicated the presence of convective stirring in the thin fluid system during the photopolymerization that deleteriously affects the periodic array structures. To devise reproducible and more efficient optical filters, experimental methods to minimize or eliminate convective instabilities in monomeric dispersions during polymerization are suggested.

  13. Radiation Grafting of Acrylate Type Monomers onto Cellulose by Mutual and Preirradiation Techniques

    Radiation grafting is a frequently used technique to modify some properties of the widely used natural polymer cellulose (e.g. water absorption capacity, dyeability). In this work the properties of cotton fibres grafted with a wide variety of monomers were investigated as a function of the irradiation dose, grafting conditions and chemical structure of the monomers. The grafting was performed using both the preirradiation and mutual grafting methods. Before grafting we studied the effect of irradiation on the cotton-cellulose used in the experiments. Samples were irradiated in air, at room temperature by 60Co γ-rays up to 30 kGy dose. The degree of polymerization (DP) of the samples decreased from 1780 to 480 after 10 kGy irradiation. This change in DP did not result in a significant change in the tensile strength of the samples up to 30 kGy dose. No damage on the surface of the fibres was observed by using scanning electron microscopy even after 40 kGy irradiation. Preirradiation grafting: after irradiation the samples were immediately soaked in deoxygenated monomer solutions (water/methanol 80/20, in the case of 2-ethylhexyl acrylate pure methanol) at 40 degree for 1 hour with continuous stirring and nitrogen gas bubbling. The monomers used for grafting were acrylamide, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, N,N'-methylene bisacrylamide and 2-ethylhexyl acrylate. Mutual grafting: samples were soaked in deoxygenated monomer (N-vinyl pyrrolidone) or aqueous monomer solution (N-vinyl pyrrolidone or acrylamide) of different concentration containing also Mohr salt (to avoid homopolymerization) and irradieted in sealed glass ampulles at room temperature by 60Co gamma rays up to 40 kGy dose (dose rate 15 kGy/h). SEM pictures clearly showed the formation of a coating layer on the fibres. The grafting yield was measured by the percent increase in the mass of the samples and also by FTIR spectroscopy. Optimum grafting conditions were determined by varying

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

    Melinte, Violeta [Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Buruiana, Tinca, E-mail: tbur@icmpp.ro [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)

    2014-01-01

    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.

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

    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 (0.063–0.088 s−1) were lower than those determined in the monomer combinations (0.116–0.158 s−1) incorporating phosphate diacrylate (11 wt.%), BisGMA (33 wt.%), TEGDMA (10 wt.%), UDMA (10 wt.%) and HEMA (15 wt.%), the degree of conversion varying between 63.4 and 74.5%. The formed copolymers showed high values for water sorption (18.65–57.02 μg/mm3) and water solubility (3.51–13.38 μg/mm3), 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 20 s 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 (1 wt.%) 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. - Highlights: • Synthesis of photopolymerizable phosphate acrylate monomers is

  16. Hydration structure of poly(2-methoxyethyl acrylate): comparison with a 2-methoxyethyl acetate model monomer.

    Morita, Shigeaki; Tanaka, Masaru; Kitagawa, Kuniyuki; Ozaki, Yukihiro

    2010-01-01

    We have previously reported the hydration structure of a poly(2-methoxyethyl acrylate) (PMEA) antithrombogenic material. In the present study, the hydration structure of a 2-methoxyethyl acetate (MEAc) model monomer for PMEA was explored by means of attenuated total reflection infrared (ATR-IR) spectroscopy and differential scanning calorimetry (DSC). Water in MEAc does not show an evidence for cold crystallization by DSC, while it was found by ATR-IR spectroscopy that MEAc has a hydration structure similar to that of PMEA at a functional group level. Three different types of hydrated water, tightly bound water, loosely bound water and scarcely bound water, were identified in MEAc, as well as PMEA. It was suggested from the present study that the localized and concentrated water cluster having the three types of hydration structure on the surface of PMEA plays an important role in the biocompatibility. PMID:20566058

  17. Bioaccumulation study of acrylate monomers in algae (Chlorella Kessleri) by PY-GC and PY-GC/MS

    Acrylate monomers methylmethacrylate (MMA) and cyclohexylmethacrylate (CHMA) bioaccumulation has been determined in aquatic organism, algae (Chlorella kessleri). Algae were collected in amount of 0.4 mg and directly injected to the paralytic cell. In algae bodies accumulated monomers were analysed by pyrolysis gas chromatography (Py-GC) and pyrolysis gas chromatography coupled with mass spectrometry (Py-GC/MS). Traces of the accumulated monomers in algae body can be determined after 1-, 2 -, 3-weeks of incubation. Maximum content of MMA was determined after 3-week of experiment, contrariwise in the case of CHMA after 2-week exposition. Relationship with pyrolysis temperature has also been studied. (authors)

  18. Solid phase graft copolymerization of acrylic monomers onto thermoplastics and their use as blend compatibilizers

    Subramanian, Srinivas

    This research work is an extension of some of the earlier work done on the development of solid phase grafting technique to graft various monomers onto polymers as well as postulation of the usefulness of the graft copolymers thus synthesized. Polystyrene grafted with acrylic acid, previously developed in bench scale, was synthesized in pilot-plant scale batches. Process parameter studies on the grafting of acrylic acid onto polypropylene and developmental studies on the grafting of maleic anhydride onto polystyrene were also done. Polymers grafted with polar molecules such as maleic anhydride and acrylic acid have been used to compatibilize immiscible blends of polar and non-polar polymers. On the same note, the applicability of the solid phase graft copolymers as blend compatibilizers were investigated and their performance was compared to commercially available compatibilizers. Solid phase graft copolymerization process is a technique to synthesize graft copolymers. Some of its salient features are use of minimal solvent to conduct the reaction and easy equipment modification. It is a low pressure and low temperature process. This technique provides a viable alternative to the environmentally hazardous, and time consuming conventional process currently in use. Hence, development of this technique could be beneficial not only to the plastics industry, but also to mankind. Also, this technique provides a low-cost and extremely easy method to develop graft copolymers such as acrylic acid functionalized polymers that are rapidly gaining popularity as blend compatibilizers and polymer reinforcing agents. A study that proves the potential of these solid phase graft copolymers as good blend compatibilizers for industrially important immiscible polymers will develop interest in the industries about this grafting process. The free radical solid phase graft copolymerization process was carried in a modified Brabender-type mixer fitted with specially designed blades to

  19. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  20. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance

    Seo, Ji Yeon; Han, Mijeong

    2011-01-01

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  1. CROSS-REACTION PATTERNS IN GUINEA-PIGS SENSITIZED TO ACRYLIC-MONOMERS

    Clemmensen, S.

    1984-01-01

    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...... between hydroxyethyl and hydroxypropyl congeners. The importance of considering not only the functional group but also the core structure when assessing potential interactions was emphasized as butanedioldiglycidylether, hexamethylenediisocyanate and hexanedioldiacrylate - all with linear 6-atom cores...... and different functional groups - cross-reacted....

  2. Preparation and reactivity of metal-containing monomers. Communication 3. Radiation graft polymerization of Co(II), Ni(II), and Cu(II) acrylates on polyethylene

    Graft polymerization of Co(II), Ni(II), and Cu(II) acrylates was carried out on polyethylene powder subjected to prior irradiation in the air and graft copolymers were obtained with up to 1.4 mass % metal content. The graft polymerization of metal acrylates on polyethylene proceeds 10 times more slowly than in the case of acrylic acid with virtually the complete absence of thermal homopolymerization. The graft rate is independent of the concentration of the metal-containing monomer in the range from 1 to 10 mass %. The graft polymerization of acrylates is initiated by radicals formed as a result of the decomposition of the hydroperoxide groups with subsequent predominantly bimolecular termination of the growing polymer chains in the case of Co(II) and Ni(II) acrylates and monomolecular termination in the case of Cu(II) acrylate. The effective activation energies for the graft polymerization reactions were determined

  3. Anionic polymerization of (meth)acrylate monomers with the ligated systems, metalloporphyrin and lanthanocene initiators

    Vlček, Petr

    New York: Nova Science Publishers, Inc, 2006 - (Jagur-Grodzinski, J.), s. 289-342 ISBN 1-59454-330-5 Institutional research plan: CEZ:AV0Z40500505 Keywords : anionic polymerization * copolymers * (meth)acrylates Subject RIV: CD - Macromolecular Chemistry

  4. Coating performance and characteristics for EB-curable aliphatic urethane acrylate coatings containing di functional monomer on wood surface

    Electron beam (EB) was used to cure coatings of aliphatic urethane diacrylate (AUA) diluted with tripropylene glycol diacrylate monomer (TPGDA). Cured coating films were characterized by Fourier transformed infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), gel fraction and swelling properties. The wood surfaces that cured at different irradiation doses were tested for their end use performance properties like gloss, pencil hardness, adhesion, chemical resistance, steam resistance and cigarette burn resistance. FTIR studies indicated that the density of acrylate functionality and degree of curing increased with increasing irradiation dose. This observation was supported by gel content and swelling investigation as well. The thermal stability, pencil hardness, adhesion and chemical resistance properties were improved by increasing the radiation doses. However, there was a significant decrease in gloss at higher radiation doses. The cured coating passed the steam and stain resistance test but not passed the cigarette burn resistance test

  5. Preparation of unsaturated acrylic prepolymer and electron beam curing of its mixture with vinyl monomers

    Electron beam curable prepolymers were prepared by the addition reaction of methyl methacrylate-glycidyl methacrylate copolymer with methacrylic acid, and electron beam curing was studied for the prepolymer and their mixtures of several kind of vinyl monomers. When the reaction was carried out in the presence of triethylbenzyl ammonium chloride in N,N-dimethyl formamide solution, the rate of addition reaction obeyed first-order kinetics. In the electron beam curing, the rate of gel formation of the prepolymer was slower than that of the mixtures of prepolymer and monomers. In the curing of mixtures of prepolymer with polyethyleneglycol dimethacrylates, the rate of gel formation increased with the increase in the degree of polymerization of polyethylene oxide fraction of polyethyleneglycol dimethacrylate, and decreased with the increase the polyethyleneglycol dimethacrylate content. The properties of cured coatings were also examined. (author)

  6. Permeability of different types of medical protective gloves to acrylic monomers.

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

    2003-10-01

    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. PMID:12974690

  7. Super water absorbent by radiation graft polymerization of acrylic monomers onto cassava starch

    Water superabsorbent gel has been applying in personal care, agriculture, medical supplies and water purification. In agricultural application, the gel will help to control soil erosion, limit loss of nutrients and slit for plants, decrease irrigation frequency, improve infiltration, and increase water retention in prolonged arid soil and droughts. The gel absorbs many times its weight in available water. The gel from poly(acrylamide) was developed in the 60's to grow plants in the deserts. The other gel from poly(acrylic acid) was used to absorb rapidly in baby diapers, sanitary napkins. These polymers are commonly produced from natural gas, which have recently been introduced as a soil conditioner with great success. Prior to these polymers, peat moss, agro-waste (sugar-cane waste, coffee-shell, etc.), activated kaolin were the alternative soil additives to hold water (20 times its weight), but poly(acrylamide) absorbs 400 times its weight and polyacrylate is capable of absorbing greater amounts of liquid than poly(acrylamide). In addition, starch and cellulose are biodegradable naturally occurring polymers, which are not capable of holding a great amount of water, but their modification by graft polymerization or crosslinking through radiation or chemical initiation techniques, they become the potential superabsorbent polymers. Radiation initiation of chemical reactions has been widely known for making novel materials because the degree of polymerization, grafting and crosslinking process can easily be controlled. Recently, it was shown that the starch and cellulose derivatives such as carboxymethyl starch, carboxymethyl starch can be synthesized by radiation-induced crosslinking at high concentrations. Their utilization in agriculture seems to be appropriately evaluated. In this article, the graft polymerization and crosslinking of acrylic acid onto cassava starch and field trial of its product (GAM-Sorb S) are reported. (author)

  8. Self-assembly of wires in acrylate monomer via nanoparticle dielectrophoresis

    This study investigates morphology and bulk growth rate of wires using dielectrophoresis in non-aqueous suspensions of carbon black nanoparticles dispersed in a diacrylate monomer. Growing anisotropic structures in adhesives to enhance thermal or electrical conductivity is highly desirable for many applications including semiconductor packing. As in aqueous suspensions, the wire growth threshold and growth rate depend on applied voltage and electrode separation. While assembly rate depends less on applied frequency than other field aspects, the morphology of assembled wires transitions from linear to fractal morphology with increasing frequency. Additionally, the wire growth rate in non-aqueous suspensions is temperature dependent and exhibits an upper threshold temperature for wire assembly.

  9. Self-assembly of wires in acrylate monomer via nanoparticle dielectrophoresis

    Slopek, Ryan P; Gilchrist, James F [Center for Advanced Materials and Nanotechnology, Department of Chemical Engineering, Lehigh University, Bethlehem, PA 18015 (United States)

    2010-02-03

    This study investigates morphology and bulk growth rate of wires using dielectrophoresis in non-aqueous suspensions of carbon black nanoparticles dispersed in a diacrylate monomer. Growing anisotropic structures in adhesives to enhance thermal or electrical conductivity is highly desirable for many applications including semiconductor packing. As in aqueous suspensions, the wire growth threshold and growth rate depend on applied voltage and electrode separation. While assembly rate depends less on applied frequency than other field aspects, the morphology of assembled wires transitions from linear to fractal morphology with increasing frequency. Additionally, the wire growth rate in non-aqueous suspensions is temperature dependent and exhibits an upper threshold temperature for wire assembly.

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

    Elif Aydogan Ayaz; Rukiye Durkan

    2013-01-01

    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.

  11. The effect of distribution of monomer moiety on the pH response and mechanical properties of poly(acrylonitrile-co-acrylic acid) copolymers

    The pH response and mechanical properties of copolymer-based hydrogels such as poly(acrylonitrile-co-acrylic acid) are usually attributed to their chemical composition. In this study, it has been shown that the architecture of the polymer chains, i.e. the distribution of comonomers in the macromolecules, also plays a major role in controlling these properties. A series of four poly(acrylonitrile-co-acrylic acids) with fixed composition (i.e. ∼30 mol% acrylic acid moieties) were synthesized, where the block lengths of both AN (acrylonitrile) and AAc (acrylic acid) moieties in the copolymers were varied by controlling the feeding pattern of the monomers during free radical copolymerization. These copolymers were then converted into fine fibers of the same dimensions. The monomer distribution in the four copolymers was estimated using quantitative carbon 13C nuclear magnetic resonance (NMR) and related to the mechanical and pH response properties of the resultant fibers. The pH response of the fibers with similar composition increased dramatically as the block length of the AAc moiety was increased, while the mechanical properties increased as a direct function of the block length of the AN moieties. The fiber's response at pH 10 in terms of the change in length increased by ∼four times while its response rate increased by ∼50 times with the increase in block length of the AAc moiety. On the other hand, the tensile properties and retractive stress increased by ∼four times with the increase in the block length of the AN moiety

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

    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-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 emitted to dose rate of 3.88 KGy

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

    Lima, Roberta B.; Rela, Paulo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Arthur, Valter, E-mail: arthur@cena.usp.br [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: claguiar@esalq.usp.br [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP, (Brazil). Dept. de Agroindustria, Alimentos e Nutricao

    2011-07-01

    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

  14. A study on the photopolymerization of acrylic monomers having fluorene moiety for the application of holographic data storage system.

    Jeon, Mina; Yoon, Sung Cheol; Lee, Jaemin; Han, Mijeong; Lee, Changjin

    2009-12-01

    We have prepared photopolymer compositions for holographic data storage system from aromatic diacrylate having fluorine moiety, a hybrid sol-gel, and photoinitiator. The fluorenyl diacrylate monomer was synthesized via nucleophilic substitution reaction of fluorene diphenol with an excess of 2-chloroethoxyethanol, followed by the reaction with acryloyl chloride. The physical and holographic properties of photopolymer were controlled by the ratio of precursor triethoxysilylpropyl polyethyleneglycol carbamate (TSPEG) in a hybrid sol-gel binder and the content of monomer. Also, we measured the photopolymerization rate and conversion of monomer by photo-differential scanning calorimeter (photo-DSC). Holographic recording was attempted by photopolymerization of the monomers in the photopolymer film using a 532 nm laser light in the presence of Irgacure 784 and holographic gratings were recorded into the photopolymer films by interfering two collimated plane wave beams. Contents of monomer and TSPEG were changed in the range of 0.25-1.0 equiv. and the composition were optimized in terms of diffraction efficiency. Finally, we obtained that efficient photopolymer films showed diffraction efficiency of 78% when 0.5 equiv. of TESPEG in sol-gel binder and 40% of compound 4 were added. PMID:19908697

  15. Synthesis of Hydrogel Based on Nata De Coco and Acrylic Acid as Co-Monomer Using Free Radical Polymerization Method

    Nata de Coco or known as bacterial cellulose is produced by Acetobacter xylinum where it is more stable than plant cellulose. Moreover, it also provides outstanding advantages to be developed as an environmental responsive hydrogels. In this study the bacterial cellulose-g-acrylic acid hydrogel was synthesized by using a free radical polymerization method. Ammonium persulfate (APS) was used to initiate the reaction, while N,N'-methylene bis acrylamide has been used as the crosslinking agent. In order to test the hydrogel respond, swelling tests were made at different pH. Furthermore, ATR-FTIR analysis was used to determine the interactions between bacterial cellulose and acrylic acid. Finally, the determination of glass transition (Tg) was made by using DSC. (author)

  16. Thickening effect of commercial associative thickeners on the latices of copolymers of acrylic monomers carrying hydrophilic reactive groups

    Quadrat, Otakar; Horský, Jiří; Šňupárek, J.

    2003-01-01

    Roč. 24, č. 2 (2003), s. 179-184. ISSN 0193-2691 R&D Projects: GA ČR GA104/99/0560 Institutional research plan: CEZ:AV0Z4050913; CEZ:MSM 253100001 Keywords : latices of acrylic copolymers containing 2-hydroxyethyl methacrylate groups * associative thickeners * thickening efficiency Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.656, year: 2003

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

    Zhang, Yuetao

    2013-11-27

    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

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

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

    2007-01-01

    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...

  19. Refractive index and dispersion of highly fluorinated acrylic monomers in the 1.5 µm telecom wavelength region measured with a spectroscopic Abbe refractometer

    Fluorinated polymers are very promising for integrated optics devices due to their high transparency in all three telecom wavelength regions around 0.85, 1.3 and 1.5 µm. Knowledge of the refractive index nλ and dispersion dnλ/dλ of these materials as a function of wavelength λ is necessary for fabricating polymer waveguides with a well-defined numerical aperture and group velocity dispersion in the above-mentioned spectral regions. We present a high resolution critical angle spectroscopic refractometer for measuring nλ and dnλ/dλ of liquid and solid samples in the 0.95–1.65 µm wavelength range. The device is based on extensions to a standard Abbe refractometer. The absolute accuracy of the spectroscopic refractometer in the near-IR equals ±2 × 10−4, the measurement range at 1.5 µm being nλ = 1.08–1.65. Finally, refractive index data in the 1.5 µm telecom wavelength region are given for a number of new highly fluorinated acrylic monomers, which have previously not been investigated to the best of our knowledge. (technical design note)

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

    Jiawei Chen

    2015-05-01

    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.

  1. Radiation induced copolymerization of binary monomers system(styrene/acrylic acid) and its application in removal of some heavy metals and dyes from aquatic solutions

    Radiation-induced coploymerization of binary monomer system styrene/acrylic acid (Sty/AAc) using direct radiation technique has been investigated. The appropriate reaction conditions such as solvent, commonomer concentration, commonomer composition and irradiation dose at which the coplymerization process was carried out successfully were selected. The effect of different parameters on the conversion percent of the commonmer into coplomer was studied by gravimetric method. It was found that, using methanol/distilled water as a cosolvent with composition 80/20 wt% enhanced the copolymerization process. The conversion (%) of the commonomer was increased with increasing radiation dose. Some properties of the coplymer such as wate uptake, thermal stability, surface topography were investigated. The improvement in such properties of the prepared coplymers was observed which makes possible uses in some practical applications such as in the removal of some heavy metals and dyes from wastewater. the prepared copolymer has good chemical and thermal stability where as the styrene content lead to increase the swelling behaviour. It was found that the maximum metal uptake by the coplymer is ordered in the sequence of Bp2+>Cu2+>Ni2+. The possibility of the removal of three classes of dyes from aqueous solutions; namely wegocet yellow 4GL (direct yellow 44), congo red (diect red 28). Remacryl blue 3G (basic blue3) and xylene blue *acid blue 7 was studied. It could be concluded that the Sty/AAc copolymer with composition 20/80 wt % can be used as a contrilled water retainer for carrying of some substance in aquatic fields involving environmental treatments. Also, it could be concluded that the most important parameter affecting the swelling behaviour and characteristic of the prepared copolymer are the type of conversion due to chemical treatment, the pH of the medium and coonstituents of the prepared copolymer

  2. 氟改性多层核壳结构丙烯酸乳液的制备%Preparation of multilayered core-shell styrene-acrylic fluorine monomer modified emulsion

    潘翠莲; 张恒; 胡振华; 殷树梅; 田民格

    2015-01-01

    The styrene-acrylate emulsion was prepared by the way of semi-continuous core-shelled emulsion polymerization combined with pre-emulsification process, choosing reactive emulsifiers sodium dodecyl sulfate and alkylphenol ethoxylates as composite emulsifier, butyl acrylate, methyl methacrylate as soft and hard monomer respectively, methacrylic acid and SR444 as functional monomer, the potassium persulfate as initiator, NaHCO3 as buffers. The multilayered core-shell styrene-acrylic fluorine monomer modified emulsion were prepared when the reaction temperature were 70, 85, 65 ℃ respectively. The results showed that the styrene-acrylate emulsion had a good ability of stain resistance and ultraviolet resistance, and also had self-cleaning function when used as latex paint. High performance emulsion could be obtained when the mass ratios of nuclear shell, transition layer and shell were 3:4:4; the dosage of crosslinking agent SR444 was 2% of the total monomer; fluorine monomer was 3%. The three glass-transition temperatures could testify that the polymer had three layers of core-shell structure.%采用半连续核壳乳液聚合方法,并结合预乳化工艺,选用乳化剂十二烷基硫酸钠与烷基酚聚氧乙烯醚进行复配,以丙烯酸丁酯、甲基丙烯酸甲酯分别作为软硬单体,甲基丙烯酸、季戊四醇三丙烯酸酯SR444为功能性单体,过硫酸钾为引发剂,NaHCO3为缓冲剂,在反应温度分别为70,85,65 ℃时,制备了氟改性多层核壳结构丙烯酸乳液.核层、过渡层、壳层质量比为3:4:4时,交联单体SR444用量为单体总用量的2%,氟单体用量为单体总用量的3%时,可得到性能优良的乳液.所得聚合物有3个玻璃化转变温度,证实该聚合物有3层核壳结构.

  3. 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

    Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of poly butyl 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.

  4. 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

    K. A. Shaffei

    2009-01-01

    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.

  5. Method of free radical polymerization of copolymerization of (meth)acrylic and vinyl monomers under control and (co)polymer produced thereby

    Lecomte, Philippe; Dubois, Philippe; Jérôme, Robert; Teyssié, Philippe; Senninger, Thierry

    1997-01-01

    PROBLEM TO BE SOLVED: To obtain a (co)polymer excellent in resistance to thermal decomposition by polymerizing or copolymerizing a monomer or monomers in the presence of an initiation system contg. a free-radical generator other than a bromoolefin and a catalyst comprising a Pd complex having an oxidation number of 0 and represented by a specific formula. SOLUTION: A Pd salt (e.g. Pd acetate), a ligand (e.g. triphenylphosphine), and a solvent (e.g. toluene) are charged into a reactor to form ...

  6. Study on the influence of monomers on the color characteristic of UV ink

    11 kinds of acrylate monomers were used for preparing UV four colors ink, these acrylate monomers were used frequently for preparing UV curing printing ink. The influence of acrylate monomers on color characteristic of UV curing printing ink was study on by means of comparing hue and saturation of various inks and comparing chromatic of different kinds of ink. The result showed that the type of monomers could affect the color of UV curing printing ink. (Author)

  7. Radiation curing applications of palm oil acrylates

    Various palm oil based urethan acrylate prepolymers (UP) were prepared from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following procedure derived from established methods. The products were compared with each other in term of their molecular weights (MW), viscosities, curing speed by UV irradiation, gel contents and film hardness. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers were tend to determine the molecular weights and hence viscosities of the final products of urethan acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the UV curing properties of the prepolymers. (author)

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

    Nagle, Susan

    2009-09-01

    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.

  9. SYNTHESIS OF BIOCOMPATIBLE ACRYLIC POLYMERS HAVING ASPIRIN-MOIETIES

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

    1983-01-01

    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.

  10. Occupational fingertip eczema from acrylates in a manicurist

    Denitza Zheleva; Razvigor Darlenski

    2015-01-01

    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 h...

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

    U. Akhmedov

    2012-09-01

    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.

  12. Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

    Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

  13. COMPLEX OXIDE CATALYSTS OF ACRYLIC ACID OBTAINING BY ALDOL CONDENSATION METHOD

    Nebesnyi, R.

    2015-01-01

    The present work is dedicated to solving the problem of diversification of the raw materials base for acrylate monomers obtaining,  first of all acrylic acid. Acrylic acid and its derivatives are bulk products of organic synthesis with a wide range of applications. The main industrial method of acrylic acid production is  propylene oxidation. But this method has instable economic indicators as propylene is petroleum origin raw material.It is possible to expand the resource base of acrylic aci...

  14. Transfer Reactions in Phenyl Carbamate Ethyl Acrylate Polymerizations

    Bennet, Francesca; Roelle, Thomas; Faecke, Thomas; Weiser, Marc-Stephan; Bruder, Friedrich-Karl; Barner-Kowollik, Christopher; Junkers, Thomas

    2013-01-01

    The transfer reactions occurring during polymerization of 2-(phenylcarbamoyloxy)ethyl acrylate (PhCEA) were studied by a detailed product mapping with electrospray ionization mass spectrometry (ESI-MS). Unlike postulated before, PhCEA exhibits the same characteristic transfer reactions as other acrylic monomers at elevated temperatures, resulting in vinyl-terminated and saturated products. Transfer to monomer via abstraction of a hydrogen atom from the ester side chain as suggested before is ...

  15. Palladium (II) catalyized polymerization of norbornene and acrylates

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2000-08-29

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: [(L)Pd(R)(X)].sub.2, where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  16. Palladium (Ii) Catalyzed Polymerization Of Norbornene And Acrylates

    Sen, Ayusman; Kacker, Smita; Hennis, April; Polley, Jennifer D.

    2001-10-09

    Homopolymers or copolymers of acrylates, homopolymers or copolymers of norbornenes, and copolymers of acrylates with norbornenes, may be prepared by contacting acrylate and/or norbornene monomer reactant under polymerization conditions and in the presence of a solvent with a catalyst system consisting essentially of a Pd(II) dimer component having the formula: where L is a monodentate phosphorus or nitrogen ligand, X is an anionic group, and R is an alkyl or aryl group.

  17. 两性聚羧酸类高聚物阳离子丙烯酸酯单体 DAC 的制备及其性能%Preparation and performance of cationic acrylate monomer (DAC) for amphoteric carboxylic acid polymer

    陈宝璠

    2015-01-01

    以丙烯酸甲酯(MA)与2氯乙醇(CE)为反应原料,通过酯交换反应制备了丙烯酸氯乙醇酯(CA)中间体,再将 CA 与三甲胺(TMA)水溶液反应,合成了一种用于制备两性聚羧酸类高聚物的阳离子丙烯酸酯单体(丙烯酰氧乙基三甲基氯化铵,DAC).采用 FTIR 和1 HNMR 对 DAC 结构进行了表征,并考察了 n(TMA)/n (CA)、催化剂用量、阻聚剂用量、反应温度和反应时间对 CA 转化率和 DAC 质量分数的影响.结果显示:最佳制备工艺条件为 n(TMA)/n(CA)=1.2,催化剂用量为 CA 中间体质量的4.5%,阻聚剂用量为 CA 中间体质量的0.6%,反应温度为50℃,反应时间为3 h.以 DAC 为阳离子单体,与丙烯酸(AA)、聚乙二醇单甲醚丙烯酸酯(MPEGAA)通过反相乳液共聚合制得两性聚羧酸类高聚物,该高聚物具有优异的保坍性和较高的早期抗压强度.%A cationic acrylate monomer,[2-(acryloyloxy)ethyl]trimethyl ammonium chloride,DAC),used for synthetizing amphoteric carboxylic acid polymer was prepared by reaction of 2-chloroethyl acrylate (CA)inter-mediate and trimethylamine (TMA)aqueous solution.The 2-chloroethyl acrylate (CA)intermediate was pre-pared by transesterification of methyl acrylate and 2-chloroethanol.The DAC structure was identified by means of FTIR and 1 HNMR.The influences of n (TMA)/n (CA),dosages of catalyst and polymerization inhibitor,reaction temperature and reaction time were investigated with the conversion rate of CA and mass fraction of DAC.The results show that the optimal technological conditions for the preparation includes:n(TMA)/n(CA)is 1.2,the dosage of catalyst is 4.5% and the dosage of polymerization inhibitor is 0.6%according to the mass of CA,the reaction temperature is 50 ℃ and the reaction time is 3 h.And the amphoter-ic carboxylic acid polymer was prepared by means of inverse emulsion copolymerization of DAC,acrylic

  18. Thermal Polymerization of N-Butyl Acrylate

    Ingham, J. D.

    1982-01-01

    Simple new polymerization method enables production of n-butyl acrylate polymer of desired high molecular weight, without disadvantages that usually attend more conventional methods. Process, which is hybrid of thermal, solution, and emulsion polymerization methods, involves controlled thermal polymerization of monomer at moderate temperatures without use of catalysts or additives.

  19. Polymerization of organized monomers

    Stoiljković Dragoslav M.

    2004-01-01

    Full Text Available The current explanations of olefin and vinyl monomer polymerization propose that monomer molecules are successively added one by one to the growing polymer chain. This may be true if the monomer molecules exist as individual species in a polymerizing system, e.g. in dilute solutions of monomer. There are cases, however, in which monomer molecules are organized: bulk liquid monomer, solid monomer, a monomer monolayer adsorbed on a support, etc. Various supra-molecular species and particles of monomer exist in such cases. In the 1960-ties, Semenov, Kargin and Kabanov proposed a theory of organized monomer polymerization. In the last 25 years, our research group has further developed and applied that theory to various polymerizing systems: the radical polymerization of compressed ethene gas, the radical polymerization of liquid methyl methacrylate, olefin polymerization by transition metals and by Al-based catalysts. An outline of the main achievements are presented in this article.

  20. Novel azo-peresters radical initiators used for the synthesis of acrylic pressure-sensitive adhesives

    2008-04-01

    Full Text Available Acrylic pressure-sensitive adhesives (PSA based on two monomers: 2-ethylhexyl acrylate and acrylic acid were synthesized in organic solvent ethyl acetate using AIBN (2, 2'-azo-diisobutyronitrile and new synthesized azo-peresters as radical initiators. After polymerization the viscosity, molecular weight and polydispersity of synthesized acrylic PSA were evaluated. The novel synthesized radical azo-perester initiators were synthesized, isolated and compared with industrial predominant usable azo-initiator AIBN.

  1. Radiation sensitive acrylate composition

    This application relates to radiation-sensitive compositions and more particularly to such compositions comprising acrylated esters. As used in this specification, the term acrylated esters refers to either acrylic or methacrylic acid resins. 3 tabs

  2. Photopolymerization kinetics of acrylate monomer initiated with diphenyl(4-phenylthio)phenylsufonium hexafluorophosphate%DPPH引发丙烯酸酯单体光聚合动力学研究

    徐娟; 蒋姗; 王克敏; 俞强; 马贵平; 聂俊

    2011-01-01

    A cationic photoinitiator diphenyl (4-phenylthio)phenylsu fonium hexafluorophosphate ( DPPH )has been synthesized.The structure of DPPH was identified by FTIR and 1H NMR spectrum,and UV spectrum showed that the maximum absorption wavelength was 302 nm.The photopolymerization kinetics was studied by real-time infrared spectroscopy ( RT-IR ).The results showed that the maximum polymerization rate largely depended on the initiator concentration, while the polymerization rate increased with the increase of light intensity.The increase of monomer functionality led to decrease of the polymerization rate and the double bond conversion,as well as prolonged the time toward to the maximum polymerization rate.%采用傅立叶红外光谱仪、核磁共振仪对阳离子光引发剂4-(苯硫基)苯基二苯基硫鎓六氟磷酸盐(DPPH)结构进行了表征.紫外光谱分析表明该引发刺在302 nm处有最大紫外吸收.通过实时红外(RT-IR)对DPPH引发丙烯酸酯单体光聚合动力学过程进行了研究.考查了引发剂浓度、光强及不同官能度单体对双键转化率及聚合速率的影响.随引发剂浓度增加,最大转化速率先增大后减小.而光强增加,最大转化速率增加.单体官能度越高,双键转化率与最大转化速率越低.达最大转化速率的时间越长.

  3. Performance comparison of acrylic and thiol-acrylic resins in two-photon polymerization.

    Jiang, Lijia; Xiong, Wei; Zhou, Yushen; Liu, Ying; Huang, Xi; Li, Dawei; Baldacchini, Tommaso; Jiang, Lan; Lu, Yongfeng

    2016-06-13

    Microfabrication by two-photon polymerization is investigated using resins based on thiol-ene chemistry. In particular, resins containing different amounts of a tetrafunctional acrylic monomer and a tetrafunctional thiol molecule are used to create complex microstructures. We observe the enhancement of several characteristics of two-photon polymerization when using thiol-acrylic resins. Specifically, microfabrication is carried out using higher writing velocities and it produces stronger polymeric microstructures. Furthermore, the amount of shrinkage typically observed in the production of three-dimensional microstructures is reduced also. By means of microspectrometry, we confirm that the thiol-acrylate mixture in TPP resins promote monomer conversion inducing a higher degree of cross-linked network formation. PMID:27410383

  4. PREPARATION AND PROPERTIES OF SILICONE-ACRYLATE COPOLYMER LATEX

    Mu-jie Yang; Wei Zhang

    2004-01-01

    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.

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

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

    2008-01-01

    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.

  6. Synthesis of highly carboxylate acrylic resins for leather impregnation

    Ollé Otero, Lluís; Solé, M.M.; Shendrik, Alexander; Labastida, L.; Bacardit Dalmases, Anna

    2012-01-01

    This work describes the synthesis of new leather finishing acrylic resins. Four resins ware synthesized varying the concentration of ethyl acrylate, and metracrylic acid. Sodium lauryl sulphate was used as emulsifying system. By means of an experimental design, an optimal resin for leather impregnation was defined. The results obtained indicated that the variation of the monomer concentration influences the resin properties, the hardness of the film, and the penetration into the leather. Most...

  7. Development of radiation curable surface coating based on soybean oil. part I. preparation and characterization of acrylated oil

    An epoxy acrylate was synthesized from epoxidized soybean oil (ESOL) by using acrylic acid monomer. Triethyl amine (TEA) and hydroquinone were used as catalyst and inhibitor respectively. The epoxidized soybean oil acrylate (ESOLA) is done by introducing acrylic acid into oxirane groups of the epoxidized oil (ESOL). This reaction was confirmed by analytical data in terms of oxirane oxygen content, acid value, viscosity and spectroscopically analysis

  8. The study of synthesis and photocuring behaviors of organic silicon modified methylacrylate and acrylate

    Wang, Si-yuan; Zou, Ying-quan

    2012-03-01

    Ten different silicon-containing methyl acrylate and acrylate monomers were synthesized by the substitution reaction of chlorosilanes or chlorosiloxanes with 2-Hydroxyethyl methacrylate or 2-Hydroxyethyl acrylate. Using triethylamine as the catalytic agent, tetrahydrofuran as the solvent, pure products can be obtained with one-step reaction after reduced pressure distillation or column chromatography via controlling raw ratio and reaction time. In this study, one to four silicon contained methyl acrylate and acrylate monomers were synthesized with simple methd and high yield. Monomers' properties were characterized through IR, 1H-NMR, 13C-NMR and their viscosity and thermostability were also characterized. The polymers' have good performance on UV-curing and low surface energy.

  9. Acrylic Bone Cements Modified with Starch

    Krilova, V; Vītiņš, V

    2010-01-01

    The successful result of restorative and replacement surgical operation depends significantly on properties of used bone cement. Acrylic bone cements are usually based on methylmethacrylate polymer, while monomer polymerization begins after mixing of components in mixing device and terminates in living tissue. Polymerization of methylmethacrylate is exothermic process, and temperature increase might cause tissue necrosis with concomitant implant aseptic loosening. Developed non-ionogenic and ...

  10. Advances in acrylic-alkyd hybrid synthesis and characterization

    Dziczkowski, Jamie

    2008-10-01

    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

  11. Rapid Solid-State Photopolymerization of Cyclic Acetal-Containing Acrylates

    Berchtold, Kathryn A.; Hacioğlu, Bilge; Nie, Jun; Cramer, Neil B.; Stansbury, Jeffrey W.; Bowman, Christopher N.

    2009-01-01

    A cyclic acetal-functionalized urethane acrylate monomer is synthesized here and polymerized in a crystalline state without the polymerization kinetics being deleteriously affected by the solid state. Depending on the processing conditions, the cyclic acetal urethane acrylate monomer exists in either a metastable liquid state or a crystalline state at ambient conditions. Due to mobility restrictions, extremely poor polymerization kinetics and functional group conversions are typically achieve...

  12. Pulse radiolysis of aqueous lignin solutions with acryl monomers

    Radiation-induced polymerization in aqueous solutions of methylmethacrylate and methylacrylate with and without lignin added was studied by pulse radiolysis method. Optical spectra of intermediates taking part in the chain evolution were obtained. The rate constant of the chain polymerization termination diminished when lignin added from 1.2 x 109 up to 2 x 108 mol-1 s-1. A reaction scheme of radiation-induced polymerization was proposed which included the lignin entering in chain propagation reactions. (author)

  13. Synthesis of acrylic prepolymer

    An acrylic prepolymer was synthesized from glycidyl methacrylate (GMA), butyl methacrylate (BMA), methyl methacrylate (MMA) and acrylic acid (AA). Butyl acetate (BAc), benzoyl peroxide (BzO), 4-methoxyphenol (MPh) and triethylamine (TEA) were used as solvent, initiator, inhibitor and catalyst respectively. Observations of the synthesis leading to the formation of acrylic prepolymer are described. (author)

  14. Effect of Nanoclay on Thermal Conductivity and Flexural Strength of Polymethyl Methacrylate Acrylic Resin

    Tahereh Ghaffari; Ali Barzegar; Fahimeh Hamedi Rad; Elnaz Moslehifard

    2016-01-01

    Statement of the Problem: The mechanical and thermal properties of polymethyl methacrylate (PMMA) acrylic resin should be improved to counterweigh its structural deficiencies. Purpose: The aim of this study was to compare the flexural strength and thermal conductivity of conventional acrylic resin and acrylic resin loaded with nanoclay. Materials and Method: The methacrylate monomer containing the 0.5, 1 and 2 wt% of nanoclay was placed in an ultrasonic probe and mixed with the PMMA p...

  15. Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

    Petrov, P; Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S.; J M Irache; Müller, A.H.E. (Axel H.E.)

    2013-01-01

    The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

  16. Performance behavior of modified cellulosic fabrics using polyurethane acrylate copolymer.

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

    2014-06-01

    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. PMID:24661889

  17. Silicone/Acrylate Copolymers

    Dennis, W. E.

    1982-01-01

    Two-step process forms silicone/acrylate copolymers. Resulting acrylate functional fluid is reacted with other ingredients to produce copolymer. Films of polymer were formed by simply pouring or spraying mixture and allowing solvent to evaporate. Films showed good weatherability. Durable, clear polymer films protect photovoltaic cells.

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

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

    2014-01-01

    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

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

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

    2015-01-01

    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 ...

  20. Sucrose Metabolism in Plastids

    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.

    2001-01-01

    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

  1. Epoxy-acrylic core-shell particles by seeded emulsion polymerization.

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

    2016-07-01

    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. PMID:27078740

  2. METHACRYLATE AND ACRYLATE ALLERGY IN DENTAL STUDENTS.

    Maya Lyapina

    2013-09-01

    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

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

    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 facto...... of fifty. This paper is concerned with the apparent crosslinking produced by the radiation grafting of two monomers to polyethylene: acrylic acid and acrylonitrile....

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

    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....

  5. Oligosaccharides Derived from Sucrose

    Monsan, Pierre F.; Ouarné, Francois

    Sucrose is a non-reducing disaccharide, consisting of an α-D-glucopyranosyl residue and a β-D-fructofuranosyl residue linked covalently by their respective anomeric carbons (α-D-glucopyranosyl-1,2-β-D-fructofuranoside). It is not just a simple disaccharide, among others: in fact, the energy of its glycosidic bond is higher than that of a usual glycosidic bond. It is equal to 27.6 kJ/mol, which is similar to the energy of a nucleotide-sugar bond as in UDP-glucose or ADP-glucose. This means that sucrose is a protected and activated form of D-glucose (as well as of D-fructose), which plays a key role in the metabolism of plants, for a wide variety of synthesis reactions.

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

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

    2009-01-01

    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.

  7. Radiation-induced polymerization of acrylated systems

    Complete text of publication follows. It has been generally accepted that ionizing radiation induces free radical polymerization in acrylate compounds. It is also reported that, following primary ionization events, acrylates and methacrylates scavenge thermalized electrons to give rise to radical anions and radical cations, which undergo reactions producing the corresponding free radicals. Acrylates have received the most attention in radiation curable pressure sensitive adhesives (PSAs). 2-EHA is well known for its unique pressure-sensitive adhesive properties. An understanding of its primary mechanism of polymerization is of industrial as well as fundamental interest. High entanglement and high molecular weight between crosslinks are crucial for the high shear and peel strength, required of PSAs. Such polymers may be formed using thermal and UV-initiation in solvent or emulsion. Electron beam can also provide these properties when the monomer is polymerized at moderate dose rates and at low temperature. Pulsed electron beam provides a special advantage under conditions where the dose per pulse is below the threshold for overlap (ca. 40 Gy/pulse) and the pulse rate is high enough (>1 kHz) to maintain a quasi-heterogeneous mode at high doses rates. Maintaining low temperature in the early stages of polymerization is important in achieving good properties

  8. Ligand switch in photoinduced copper-mediated polymerization: synthesis of methacrylate-acrylate block copolymers

    CHUANG, Ya-Mi; Wenn, Benjamin; Gielen, Sam; Ethirajan, Anitha; Junkers, Thomas

    2015-01-01

    The use of photo-induced copper-mediated radical polymerization (photoCMP) to synthesize mixed acrylate/methacrylate (methyl acrylate, MA and methyl methacrylate, MMA) block copolymers is investigated. Reactions in which only one type of ligand (Me6TREN) is used lead to unsuccessful outcomes of polymerization due to a mismatch in reactivity of the two monomers. A ligand exchange to PMDETA for methacrylate is required to obtain good block structures. Due to insufficient re-initiation of polyac...

  9. Synthesis and characterization of acrylated epoxidized soybean oil for UV cured coatings

    Habib, Firdous; Bajpai, Madhu

    2011-01-01

    This paper investigates the curing of biodegradable polymer films which were synthesized from soybean oil through the ultraviolet radiation and their stability against thermal degradation. In this study the epoxidation of soybean oil has been carried out via peracetic method. Further, an epoxy acrylate resin was synthesized from the epoxidized soybean oil (ESO) by using acrylic acid monomer. Triethylamine (TEA) and hydroquinone were used as a catalyst and inhibitor respectively. The acrylatio...

  10. Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends

    Ying Nie; Min-Feng Tang; Xiao-Dong Fan; Xiang Liu

    2008-01-01

    Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) and glycidyl methacrylate (GMA) as monomers and ammonium p...

  11. In situ polymerization of vinyl monomers in polyester yarns

    The effects of a pretreatment of polyester (PET) yarns with a strongly interacting solvent such as dimethylformamide (DMF) on vinyl monomer incorporation were investigated. When the DMF pretreatment is carried out at high temperatures (above 1200C), the swollen PET structure is stabilized by solvent-induced secondary crystallization. This substrate is highly suitable for the incorporation of vinyl monomers. In situ polymerization of vinyl monomers in DMF-treated PET was investigated using chemical and γ-irradiation polymerization techniques, both in the presence and in the absence of excess monomer outside the PET fibers. When polymerization was carried out in a system in which a constant supply of free radicals was available from the outside of the PET fibers, lower initiator concentrations and smaller γ-irradiation doses were necessary. These results are attributed to a low efficiency of the initiator inside the PET fiber due to mobility restrictions. Water uptake and moisture regain of PET yarns containing poly(hydroxyethyl methacrylate) and poly(acrylic acid) were also investigated. When most of the vinyl polymer was inside the PET fiber, water absorption was limited. The changes in mechanical properties of the PET yarns resulting from the DMF pretreatment were partially reversed by in situ polymerization of vinyl monomers

  12. Textile dyestuff adsorption by polysaccharide-g-acrylic acid

    Aimed of this study to determine the ability of polysacharide of banana peel as an adsorbent of textile dyes (Maxilon Yellow) before and after the grafting process. The grafting copolymerization process was done by using acrylic acid as monomer, then irradiated by gamma rays as initiator. Parameters observed were adsorption ability of dye, soaking time with KOH, acrylic acid concentration, irradiation dose and resistance to acids. The results showed the optimum absorption obtained at the time of KOH immersion for 3 hours, the concentration of acrylic acid by 20% and the irradiation dose of 30 kGy. Adsorption percentage of polysacharide to Maxilon Yellow after grafting increased by 18,48% compared to before grafting. Resistance to the acid test increased significantly. The results of this study are expected to overcome the problems of waste dyes in the textile industry. (author)

  13. Acrylic vessel cleaning tests

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

  14. Graft-copolymerization of hydrophilic monomers onto irradiated polypropylene fibers

    A method of graft-copolymerization of hydrophilic monomers such as 1-vinyl-2 pyrolidone, acrylonitrile, acrylic acid and acrylamide onto irradiated polypropylene fibers has been studied. Gamma ray as well as electron beam were employed for the irradiation processes. Graft copolymerization kinetics and the properties of grafted fibers have been investigated. Moisture regain, dyes absorption and the melting point of the grafted fibers increased with the increase of the degree of grafting. Polypropilen 1-vinyl-2 pyrrolidone grafted fibers showed excellent dyes absorption of almost all kinds of dyes such as direct, basic, acid, reactive, dispers, and naphtol. However for polypropylene acrylic acid grafted fibers, the colour fastness to washing was found to be unsatisfactory. The colourfastness to washing for polypropylene grafted fibers was found to be fairly good for certain dyes such as v and naphtol dyes

  15. Acrylic purification and coatings

    ,

    2012-01-01

    Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different surface treatment and cleaning techniques have been employed in the past to remove this type of contamination. A new method of dealing with the problem has been proposed and used for a prototype acrylic DEAP-1 detector. Inner surfaces of the detector were coated with a layer of ultra pure acrylic, meant to shield the active volume from alphas and recoiling nuclei. An acrylic purification technique and two coating techniques are described: a solvent-borne (tested on DEAP-1) and solvent-less (being developed for the full scale DEAP-3600 detector).

  16. Di(hydroxyphenyl)- benzimidazole monomers

    Connell, John W. (Inventor); Hergenrother, Paul M. (Inventor); Smith, Joseph G. (Inventor)

    1993-01-01

    Di(hydroxyphenyl)benzimidazole monomers were prepared from phenyl-hydroxybenzoate and aromatic bis(o-diamine)s. These monomers were used in the synthesis of soluble polybenzimidazoles. The reaction involved the aromatic nucleophilic displacement of various di(hydroxyphenyl)benzimidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds in the presence of an alkali metal base. These polymers exhibited lower glass transition temperatures, improved solubility, and better compression moldability over their commercial counterparts.

  17. Sucrose translocation in Pseudomonas saccharophila

    Unlike many microorganisms, P. saccharophila is capable of growth on sucrose but not on glucose or fructose without prior mutation. For the wild-type sucrose uptake into cells requires induction by substrate and this is accompanied by the appearance of a membrane-bound protein with an apparent MW of ∼ 84kDa. A constitutive, overproducer of this protein has been isolated and as expected this mutant transports sucrose in an amplified manner. Scatchard analysis of 3H-sucrose binding to cytoplasmic membranes reveals an apparent K/sub D/ of about 1.0μM for both mutant and wild-type. In contrast mutant membranes contain 5-6 times more binding sites than the wild-type membranes. 6'-deoxy-6'-(2-hydroxy-4-azido)benzamido-sucrose (6'-HABS), a sucrose analogue, has been used to identify the protein responsible for sucrose binding. When cytoplasmic membranes are irradiated in the presence of 125I-6'-HABS, a significant portion of the radioactivity is found covalently associated with the 84kDa band in SDS-PAGE. Importantly, labeling of this band is largely prevented when unlabeled sucrose is present during photolysis. The authors believe that the 84kDa protein may be a sucrose permease and efforts are underway to reconstitute it in a functional form

  18. Synthesis of insecticidal sucrose esters

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

    2006-01-01

    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. Sucrose accumulation in mature sweet melon fruits

    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 14C-fructose + UDP-glu synthesized 14C-sucrose and efflux kinetics indicated that the 14C-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

  20. Radiation grafting of monomers on plastics and fibers

    The various methods for grafting monomers to a variety of backbone polymers utilizing ionizing radiation are briefly reviewed with emphasis on the most commonly used technique, namely, simultaneous grafting. The variables influencing the optimization of grafting are discussed. These include role of solvent, effects of temperature, radiation dose and dose rate, and homopolymer formation. Recent developments involving the use of novel additives in these reactions are also summarized. Additive effects discussed include the role of mineral acids, polyfunctional monomers, multifunctional acrylates, and inorganic salts. Mechanisms to explain effects of these additives are proposed. Applications of radiation grafting including potential commercial utilization are summarized. The significance of concurrent grafting in curing reactions, particularly with electron beam irradiation, is discussed, including the possible role of ionic intermediates in these reactions. Future trends in grafting are delineated. (orig.)

  1. Hyperbranched urethane-acrylates

    Tasić Srba

    2004-01-01

    Full Text Available The synthesis, characterization and UV-curing of hyperbranched urethaneacrylates (HB-UA were investigated in this study. They were evaluated as oli-gomers in model UV curable coatings. HB-UAs were synthesized by reaction of an aliphatic hyperbranched polyester of the second generation (HBRG2 and an isocyanate adduct, obtained by the reaction of isophoronediisocyana-te and different hydroxy alkyl acrylates. Their thermal properties and viscosities depend on the degree of modification of HBRG2 and the type of hydroxy alkyl acrylate used. The introduction of a flexible alkoxylated spacer between the HBP core and acrylate end groups reduces steric hindrance by moving the cross linkable acrylate groups away from the HBP core and increase its reactivity. Due to the presence of abstractable H-atoms in the α-position to the ether links, HB-UAs based on poly(ethylene oxide monoacrylate are very reactive and do not show oxygen inhibition. The obtained coatings combine a high cross linking density with flexible segments between the cross links, which results in a good compromise between hardness and flexibility and have the potential to be used in different UV-curing applications.

  2. Microemulsion polymerization of butyl acrylate irradiated by γ-ray

    Radiation polymerization of butyl acrylate was carried out in microemulsion with high monomer and low emulsifier content. The rate of polymerization shows three intervals--the increasing period, the plateau period and the decreasing period for most cases. The length of nucleation period is independent of monomer content and temperature, and becomes longer with the increase of dose rate and the decrease of emulsifier content. The length of Rp plateau region increases with the increase of monomer and emulsifier content and with the decrease of dose rate. By studying the kinetics, the following formula were derived: Rp ∝ [M]0.93D1.27 [E]-1.07; Mn ∝ [M]0.65D0.28 [E]-1.66. (author)

  3. Polymerisation by acrylamide and acrylic acid inverse suspension

    Sergio Alejandro LLoreda Blanco

    2010-04-01

    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.

  4. Radiation hardening of epoxide-acrylate compositions

    Radiation setting of epoxy oligomers modified with vinyl monomers was studied. The setting was accomplished under the effect of γ-radiation of 60Co at the dose rate of 1750 Mrad/s. The content of the gel fraction in the radiation set epoxy-acrylate-styrene compositions increases by 20%, and the phase transition temperature is higher than for compositions set under normal conditions. In all compositions investigated the maximum content of the gel fraction is observed at 8-9 Mrad dose and is 60-70%, on the average. An increase in degree of setting up to 92-98% can be achieved by additional heat treatment of the compositions

  5. Propenyl ether monomers for photopolymerization

    Crivello, James V.

    1996-01-01

    Propenyl ether monomers of formula V A(OCH.dbd.CHCH.sub.3).sub.n wherein n is an integer from one to six and A is selected from cyclic ethers, polyether and alkanes are disclosed. The monomers are readily polymerized in the presence of cationic photoinitiators, when exposed to actinic radiation, to form poly(propenyl ethers) that are useful for coatings, sealants, varnishes and adhesives. Compositions for preparing polymeric coatings comprising the compounds of formula V together with particular cationic photoinitiators are also disclosed, as are processes for making the monomers from allyl halides and readily available alcohols. The process involves rearranging the resulting allyl ethers to propenyl ethers.

  6. Effects of preirradiation graft polymerization of acrylic acid onto polyethylene film

    With the aid of preirradiation method of grafting onto low-density polyethylene film, a systematic investigation was made of grafting of aqueous acrylic acid under conditions such as monomer concentrations, irradiation dose, dose rate, reaction time, the effect of concentrations of Mohr's salt and sulphuric acid on the graft reaction. (author)

  7. Copolymers Formation by Photopolymerization of (Meth)acrylates Containing Dissolved Polyheteroarylenes

    Dmitriy A. Sapozhnikov; Tat'yana V. Volkova; Sakharova, Antonina A.; Gasanov, Rashid G.; Vanda Yu. Voytekunas; Abadie, Marc J. M.; Jean-Yves Sanchez; Vygodskii, Yakov S.

    2009-01-01

    Radical photopolymerization of (meth)acrylates in the presence of dissolved polyheteroarylenes has been investigated. The kinetics of radical polymerization of unsaturated monomers in the presence of polyheteroarylenes and model compounds has been studied by Differential Scanning Photocalorimetry and Infrared Spectroscopy. From the results of investigations into the kinetics and the polymer structures (Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance, Size-exclusion Chromat...

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

    Bojanić Vaso

    2010-01-01

    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

  9. Ionic Liquid Epoxy Resin Monomers

    Paley, Mark S. (Inventor)

    2013-01-01

    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.

  10. Technology and the use of acrylics for provisional dentine protection.

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue. PMID:24566021

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

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

    2008-01-01

    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.

  12. Synergistic effect of additives including multifunctional acrylates in wood plastic composites

    Wood Plastic Composite (WPC) was prepared with simul (soft wood, density = 0.4g/cc) and butylmethacrylate (BMA) monomer using 10% methanol as the swelling agent. Effect of additives including multifunctional acrylates such as tripropylene glycol diacrylate (TPGDA), trimethylol propane triacrylate (TMPTA), oligomer acrylates like the urethane (UA), epoxy (EA) and polyester (PEA) acrylates and N-vinyl pyrrolidone (NVP) was investigated using 1 to 3 Mrad dose at 0.8 Mrad/h. Synergistic increases in polymer loading yields was achieved in presence of the additives, particularly with the trifunctional acrylate (TMPTA). In addition, acid as well as urea were also used as co-additives and synergistic enhancement in yields of polymer loading were obtained. The synergistic polymer loading by acid addition causes substantial decrease in tensile strength of the composite; but other additives and co-additives increase both the polymer loading and the tensile strength in these systems. (author)

  13. Surface coating of jeungjing wood (Paraserianthes Falcataria (L) NIELSEN) with acrylate resins by using radiation technique

    An experiment on surface coating with acrylate resins has been done by using radiation technique to improve the quality and added value of jeunjing wood (Paraserianthes Falcataria (L) NIELSEN). Doses used in Electron Beam (BE) radiation were 20, 40, and 60 kGy. Epoxy acrylate and ester acrylate resins were used as coating materials after added with tripropylene glycol diacylate (TPGDA) monomer, 2,2-dimethyl-2hidroxy acetophenone (Darocur 1173) photoinitiator and talc as base coat. Top coat consists of este acrylate Setacure AM 548, after added with titanium dioxide OK 412 as additive respectively. Titanium dioxides in the mixture were varied at the concentration level of 0, 2, 4 and 6 % by weight. Conventional coating as comparison was carried out by using varnish as coating material. The results showed that the properties of film on jeunjing wood by EB curing are better than that of conventional one. (authors)

  14. [Acrylic resin removable partial dentures

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

    2011-01-01

    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

  15. Monomer Migration and Annihilation Processes

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

    2005-01-01

    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.

  16. Sucrose release from polysaccharide gels.

    Nishinari, Katsuyoshi; Fang, Yapeng

    2016-05-18

    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. PMID:26952168

  17. Acrylic Acid and Esters Will Be Oversupply

    Zheng Chengwang

    2007-01-01

    @@ 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.

  18. Effect of Additives on UV-Activated Urethane Acrylate Polymerization Composite Coatings

    Zane GRIGALE-SOROCINA; Martins KALNINS; Jana SIMANOVSKA; Elīna VINDEDZE; Ingmars BIRKS; Evita BRAZDAUSKA

    2016-01-01

    An increased demand for new and improved coating systems, for environmental & health & safety and performance reasons, have appeared during the recent decades. Currently, there is new interest in preparation of thin UV curable urethane acrylate (UA) composite coatings with short-term properties. Cellulose based additives: nitrocellulose, cellulose acetate butyrate, sucrose benzoate and silica were evaluated to determine their influence on unreacted composite characteristics (viscosity, pigmen...

  19. A study on antithrombogenic polymeric dialytic membrane. Irradiation grafting acrylic acid and styrene into polyethylene films

    A new type of antithrombogenic polymeric dialytic membrane with a hydrophilic-hydrophobic microphase structure was prepared by grafting acrylic acid and styrene into polyethylene films, using peroxidation pre-irradiation technique. Various ratios of monomers influencing on properties of the grafted films were examined. Experimental results showed that the grafted films have superior mechanic strength, and their antithrombogenicity and permeability were 30 and 10 times higher than that of the ungrafted films respectively on condition of the volume ratio 1:1 (styrene vs acrylic acid)

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

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

    2004-01-01

    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.

  1. Sucrose compared with artificial sweeteners

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

    2014-01-01

    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 a...

  2. Sucrose ingestion causes opioid analgesia

    Segato F.N.

    1997-01-01

    Full Text Available The intake of saccharin solutions for relatively long periods of time causes analgesia in rats, as measured in the hot-plate test, an experimental procedure involving supraspinal components. In order to investigate the effects of sweet substance intake on pain modulation using a different model, male albino Wistar rats weighing 180-200 g received either tap water or sucrose solutions (250 g/l for 1 day or 14 days as their only source of liquid. Each rat consumed an average of 15.6 g sucrose/day. Their tail withdrawal latencies in the tail-flick test (probably a spinal reflex were measured immediately before and after this treatment. An analgesia index was calculated from the withdrawal latencies before and after treatment. The indexes (mean ± SEM, N = 12 for the groups receiving tap water for 1 day or 14 days, and sucrose solution for 1 day or 14 days were 0.09 ± 0.04, 0.10 ± 0.05, 0.15 ± 0.08 and 0.49 ± 0.07, respectively. One-way ANOVA indicated a significant difference (F(3,47 = 9.521, P<0.001 and the Tukey multiple comparison test (P<0.05 showed that the analgesia index of the 14-day sucrose-treated animals differed from all other groups. Naloxone-treated rats (N = 7 receiving sucrose exhibited an analgesia index of 0.20 ± 0.10 while rats receiving only sucrose (N = 7 had an index of 0.68 ± 0.11 (t = 0.254, 10 degrees of freedom, P<0.03. This result indicates that the analgesic effect of sucrose depends on the time during which the solution is consumed and extends the analgesic effects of sweet substance intake, such as saccharin, to a model other than the hot-plate test, with similar results. Endogenous opioids may be involved in the central regulation of the sweet substance-produced analgesia.

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

    2008-10-01

    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.

  4. Structural, thermal and morphological characterization of UV-graft polymerization of acrylated-epoxidized soybean oil onto goat leather

    Urena-Nunez, Fernando; Vigueras-Santiago, Enrique; Hernandez-Lopez, Susana; Linares-Hernandez, Karla; Linares-Hernandez, Isabel

    2008-01-01

    Graft of acrylated-epoxidized soybean oil onto goat leather was achieved using UV-radiation. Graft percentage, structural, morphological and thermal characterizations are discussed in terms of: morphology of the leather grafted face and the UV-radiation dosage. The obtained results are of importance since an environmental friendly monomer could be used to change or improve some properties of leather articles.

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

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

    2013-01-01

    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...

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

    Javakhishvili, Irakli; Kasama, Takeshi; Jankova, Katja; Hvilsted, Søren

    2013-05-25

    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 via Cu(I)-mediated "click" reaction. PMID:23588100

  7. 21 CFR 184.1854 - Sucrose.

    2010-04-01

    ... 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 crystallization from sugar cane or sugar beet juice that has been extracted by pressing or diffusion,...

  8. Effects of Sugar (Sucrose) on Children's Behavior.

    Rosen, Lee A.; And Others

    1988-01-01

    Examined effects of sugar on behavior of 45 preschool and elementary school children. Provided all children with basic breakfast that included drink containing either 50 g of sucrose, a comparably sweet placebo, or very little sucrose. Found some small behavior changes in high-sucrose group. All effects were small in magnitude and not considered…

  9. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

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

    2016-06-01

    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.

  10. Biocompatibility of alendronate-loaded acrylic cement for vertebroplasty

    T Calvo-Fernández

    2010-10-01

    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.

  11. Effect of structure and molecular weight on properties of pressure sensitive adhesives (PSA) formulated from palm oil based urethane acrylate (POBUA)

    Various palm oil (RBD Palm Olein) based urethane acrylate prepolymers (UPs) having different structures and molecular weight were synthesized from palm oil based polyols, diisocyanate compounds and hydroxyl terminated acrylate monomers by following established synthesis procedures described elsewhere. The products (UPs) were compared with each other in term of their molecular weight (MW), viscosities and UV curing performances of pressure sensitive adhesives (PSA) UP based formulations. The molecular structure of diisocyanate compounds and hydroxyl acrylate monomers tend to determine the molecular weight and hence viscosities of the final products of urethane acrylate prepolymers (UP), whereas, the MW of the UP has no direct effects on the coatings and adhesive properties of UV curable UP based PSA. (Author)

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

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

    2009-02-15

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

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

    Wang, Hua; Wang, Mozhen; Ge, Xuewu

    2009-02-01

    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 °C in order to obtain PU dispersions. Consecutively, an in-situ graft copolymerization of the vinyl monomers with the synthesized PU was initiated by γ-ray radiation at room temperature. The grafting efficiency of PU with vinyl monomer ( GPU/monomer) was calculated from 1H 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. GPU/monomer varied as GPU/styrene(37%)> GPU/butyl acrylate (BA)(21%)> GPU/methyl methacrylate (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.

  14. Magnetostructural study of iron sucrose

    Magnetic and structural analyses have been performed on an iron sucrose complex used as a haematinic agent. The system contains two-line ferrihydrite particles of about 5 nm that are superparamagnetic above approximately 50 K. The observed low-temperature magnetic dynamics of this compound is closer to simple models than in the case of other iron-containing drugs for intravenous use like iron dextran

  15. Effect of molecular weights and structures on properties of epoxidized palm oil acrylate (EPOLA) based radiation curable pressure sensitive adhesives (PSA)

    Three different types of EPOLAs were synthesised using epoxidized palm oil product (EPOP) and three different acid functional acrylate monomers (AFAMs) following the established acrylation procedures. The results were EPOLAs with three different MWs and structures. These EPOLAs were then formulated into PSA and the results were compared with each other. Higher MW and more branched AFAM produced higher MW EPOLA and consequently higher adhesive properties as compared to that of lower MW and more linear AFAM. (Author)

  16. Preparation and characteristics of acrylic acid/styrene composite plasma polymerized membranes

    Plasma polymerization has gained increasing interest for the deposition of functional plasma-polymerized membranes suitable for a wide range of applications on account of its advantageous features. In this work, acrylic acid/styrene composite plasma polymerized membranes were synthesized by plasma polymerization of a mixture of acrylic acid and styrene monomers in a low-frequency after-glow capacitively coupled plasma (CCP) discharge process. The structure and composition of the plasma polymerized membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the partial pressure ratio between acrylic acid (AA) and styrene (St), applied discharge power and the energy of the extracted particles have considerable effects on the structure and the content of functional groups of the deposited membranes.

  17. Catalytic routes towards acrylic acid, adipic acid and epsilon-caprolactam starting from biorenewables

    Beerthuis, R.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    The majority of bulk chemicals are derived from crude oil, but the move to biorenewable resources is gaining both societal and commercial interest. Reviewing this transition, we first summarise the types of today's biomass sources and their economical relevance. Then, we assess the biobased productions of three important bulk chemicals: acrylic acid, adipic acid and epsilon-caprolactam. These are the key monomers for high-end polymers (polyacrylates, nylon 6.6 and nylon 6, respectively) and a...

  18. Modification of polyethersulfone films by grafting hydrophilic monomers with 60Co γ-rays

    Polyethersulfone (PES), with its high strength, high temperature resistance, corrosion- resistance, oxidation resistance and applicability under wide pH range, is used extensively as ultrafiltration and nanofiltration membrane. However, PES membranes foul easily in such an application because of hydrophobic nature of PES raw materials. Improving the hydrophilicity of PES by grafting hydrophilic monomers onto it is of potential to solve the problem. At present, common approaches to improve hydrophilicity of PES membranes are UV grafting modification, plasma modification, and chemical modification, whereas grafting and modifying PES films by 60Co γ-rays has rarely been reported. Studies have been carried out in our laboratory to graft hydrophilic monomers onto PES membranes directly or PES powders via simultaneous radiation grafting with the rays. Acrylic acid, methyl acrylic acid or acrylamide was used to study effects of the monomer concentration, irradiation dose and dose rate, solvent, inhibitor and pH of the grafting solution on the degree of grafting. The results showed that hydrophilicity of all the PES membranes could be improved, with the extent of improvement being dependent on the grafting conditions. (authors)

  19. 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

    Intan Nirwana

    2006-03-01

    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.

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

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

    2014-01-01

    , polymerizations of lauryl or stearyl acrylate were performed, resulting in two novel polymer modifications on the MWCNT (poly(lauryl acrylate) or poly(stearyl acrylate)). The method was found to give time dependent loading of polymers as a function of time (up to 38 wt% for both acrylates), and showed a plateau...... were found to be substantially improved, where poly(lauryl acrylate) was found to be the superior surface modification, resulting in a conductive composite....

  1. Sucrose synthesis in gamma irradiated sweet potato

    Effect of α-irradiation carbohydrate metabolism was examined to elucidate mechanism of sucrose accumulation in sweet potato (SP). Enzymes examined were: β-amylase, phosphorylase, phosphoglucomutase, phosphoglucose isomerase, sucrose phosphate synthetase and sucrose synthetase. Irradiated SP (Red Jewell) sucrose was synthesized to yield 10.7% after 4 d PI. Activities of sugar synthesizing enzymes in irradiated SP were enhanced to different degrees using 100-200 Krad and 3 d PI at 240C. Phosphorylase and phosphoglucomutases specific activities reached 2.4 and 1.8 folds, respectively compared to control SP. β-amylase, phosphoglucose isomerase, sucrose synthetase and sucrose phosphate synthetase were also affected to yield 1.2, 1.3, 1.3 and 1.2 folds, respectively compared to controls. It is believed that amylase hydrolyzed starch to glucose which is converted to fructose by phosphoglucose isomerase. Sucrose is then formed by sucrose phosphate synthetase and/or sucrose synthetase leading to its accumulation. The irradiated SP was used for alcohol fermentation leading to 500 gal. of 200 proof ethanol/acre (from 500-600 bushels tuber/acre)

  2. Production of 16% ethanol from 35% sucrose

    A strain of Saccharomyces cerevisiae, which showed marked fermentation activity, ethanol and temperature tolerance and good flocculation ability, was selected for ethanol production. A stuck fermentation occurred at sucrose concentration of 25%. Increasing the yeast inoculum volume from 3% to 6% showed positive effects on fermentation from 25% sucrose. The ratio of added nitrogen to sucrose, which gave the best results (for the selected yeast strain), was determined. It was concluded that this ratio (nitrogen as ammonium sulphate at a rate of 5 mg g-1 of consumed sucrose) is constant at various sugar concentrations. Addition of nitrogen at this ratio produced 11.55% ethanol with complete consumption of 25% sucrose after 48 h of fermentation. However fermentation of 30% sucrose at the above optimum conditions was not complete. Addition of yeast extract at a level of 6 g l-1 together with thiamine at a level of 0.2 g l-1 led to complete utilization of 30% sucrose with resultant 14% ethanol production. However the selected yeast strain was not able to ferment 35% sucrose at the same optimum conditions. Addition of air at a rate of 150 dm3 min-1 m3 of reactor volume during the first 12 h of fermentation led to complete consumption of 35% sucrose and 16% ethanol was produced. This was approximately the theoretical maximum for ethanol production.

  3. Monomer-dimer problem on some networks

    Wu, Ruijuan; Yan, Weigen

    2016-09-01

    Zhang et al. (2012) obtained the exact formula for the number of all possible monomer-dimer arrangements and the asymptotic growth constant on a scale-free small-world network. In this note, we generalize this result and obtain the exact solution on the monomer-dimer model on many networks. Particularly, we prove that these networks have the same asymptotic growth constant of the number of monomer-dimer arrangements.

  4. Graft Polymerization of Acrylic Acid on a Polytetrafluoroethylene Panel by an Inductively Coupled Plasma

    Lan, Yan; You, Qingliang; Cheng, Cheng; Zhang, Suzhen; Ni, Guohua; Nagatsu, M.; Meng, Yuedong

    2011-02-01

    Surface modification on a polytetrafluoroethylene (PTFE) panel was performed with sequential nitrogen plasma treatments and surface-initiated polymerization. By introducing COO- groups to the surface of the PTFE panel through grafting polymerization of acrylic acid (AA), a transparent poly (acrylic acid) (PAA) membrane was achieved from acrylic acid solution. Grafting polymerization initiating from the active groups was achieved on the PTFE panel surface after the nitrogen plasma treatment. Utilizing the acrylic acid as monomers, with COO- groups as cross link sites to form reticulation structure, a transparent poly (acrylic acid) membrane with arborescent macromolecular structure was formed on the PTFE panel surface. Analysis methods, such as fourier transform infrared spectroscopy (FTIR), microscopy and X-ray photoelectron spectroscopy (XPS), were utilized to characterize the structures of the macromolecule membrane on the PTFE panel surface. A contact angle measurement was performed to characterize the modified PTFE panels. The surface hydrophilicities of modified PTFE panels were significantly enhanced after the plasma treatment. It was shown that the grafting rate is related to the treating time and the power of plasma.

  5. The electrospinning of the copolymer of styrene and butyl acrylate for its application as oil absorbent.

    Xu, Naiku; Cao, Jipeng; Lu, Yuyao

    2016-01-01

    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. PMID:27610302

  6. Radiation modification of water absorption of cassava starch by acrylic acid/acrylamide

    Graft co polymerizations of acrylamide and/or acrylic acid onto cassava starch by a simultaneous irradiation technique using gamma-rays as the initiator were studied with regard to various parameters of importance: the monomer-to-cassava starch ratio, total dose (kGy), dose rate (kGy h-1), acrylamide-to-acrylic acid ratio, and the addition of nitric acid and maleic acid as the additives. Grafting parameters were determined in relation to the water absorption of the saponified graft copolymer. The water absorption of the saponified graft copolymer in salt and buffer solutions of different ionic strengths was also measured, from which the super absorbent properties are found to be P H sensitive. The starch graft copolymers of acrylamide and acrylic acid give higher water absorption than the starch graft copolymers of either acrylamide or acrylic acid alone. The porosity of the saponified starch graft copolymers prepared by the acrylamide/acrylic acid ratios of 70:30 and 50:50 was much higher than the porosity of copolymers in terms of fine networks. Ionic strength and multi-oxidation states of the saline and buffer solutions markedly decreased the water absorption of the saponified cassava starch grafted super absorbent polymers.

  7. SYNTHESIS OF SOAP-FREE ACRYLIC HYDROSOLS

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

    2002-01-01

    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.

  8. Photo-triggered surface grafting of acrylic monomers by SET-LRP

    Vorobii, Mariia; Laun, J.; de los Santos Pereira, Andres; Pop-Georgievski, Ognen; Kostina, Nina Yu.; Barner-Kowollik, C.; Rodriguez-Emmenegger, Cesar; Junkers, T.

    Prague : Institute of Macromolecular Chemistry AS CR, 2015. s. 78. ISBN 978-80-85009-82-8. [Functional Polymers at Bio -Material Interfaces - 79th Prague Meeting on Macromolecules. 28.06.2015-02.07.2015, Prague] Institutional support: RVO:61389013 Keywords : polymer brushes * surface characterization Subject RIV: CD - Macromolecular Chemistry

  9. Development of radiation curable surface coating based on soybean oil. part II: Evaluation of the prepared acrylated resin as surface coatings by using EB or UV sources for radiation curing applications

    In recent years, there has been a growing trend in using vegetable oils as raw materials in acylation production that can be cured by UV/EB systems. The acrylated resin formulates by using individually different functional acrylate monomers were prepared and cured by EB or UV sources. The characterization properties of the cured films were investigated in terms of pendulum hardness, bending, impact, gloss, adhesion and chemical tests. Other formulations were prepared by mixing a constant ratio of different functional acrylate monomers and exposed to UV or EB irradiation. The results showed that the hardness of cured films were increased by increasing the functionality of monomers with excellent adhesion for all formulations but at expense of other properties involving bending and impact tests. Therefore, it can be deduce that the hardness of the curing surface coating by using EB was found to be nearly twice the hardness of the curing surface coating by using UV irradiation. Also, the best formulations which have given good chemical and mechanical properties are (mono-di) functional acrylate monomer resin under EB and (mono-tri) functional acrylate monomer resin under UV irradiation

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

    Schaffer, A.A.; Aloni, B.

    1987-04-01

    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.

  11. Immobilization of yeast cells with copolymer by radiation polymerization of hydrophilic and hydrophobic monomers

    The immobilization of yeast cells was carried out by using the copolymer produced by radiation polymerization of hydroxyethyl acrylate (HEA) and glyciolyl methacrylate (GMA) monomer at -78 degree C low temperature. The immobilized cells with the copolymer, poly (HEA-GMA) had higher ethanol productivity than free cells. However, the ethanol productivity of immobilized cells varied with the composition of copolymer, in which the ethanol productivity of immobilized yeast cells with the copolymer from 17% HEA and 6% GMA was the highest, 29 mg/ml · h, increasing by 3 times in comparison with that of free cells. And it was obvious that the activity of immobilized yeast cells was higher when the concentration of monomer was 20-30%. The relation between the properties of copolymer and the ethanol productivity of immobilized yeast cells was also investigated

  12. Graft copolymers of polypropylene films. 1. radiation induced grafting of mixed monomers. Vol. 3

    Radiation graft copolymerization of co monomer mixtures of acrylic acid (AAC), and styrene (S) onto polypropylene (PP) film by mutual method has been investigated. The effects of different factors that may affect the grafting yield such as inhibitor concentration (Mohr's salt), solvent composition (MeOH and H2 O), radiation dose and dose rate were considered. It was found that the role of Mohr's salt is very effective when the ratio of AAC in the co monomer mixtures was at lower values. However, the addition of 1.25 Wt% of Mohr's salt reduced the homo polymer formation and enhances the grafting process. Graft copolymerization in presence of solvent mixture composed of methanol and water was found to afford higher grafting than in pure methanol regardless of the composition of the co monomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20% H2 O:80%MeOH and a co monomer mixture of 20%AAC:80%sty. An attempt was made to determine each PAAC and PS fractions in the total graft yield obtained. Two methods of analysis based on using the reactivity ratios reported in literature, elemental analysis and IR spectroscopy. The determination of poly (acrylic acid) and polystyrene fractions by elemental analysis is believed more accurate than these by reactivity ratio. The precise results obtained by elemental analysis with respect to the chemical structure of known polymer prepared under identical conditions. The results obtained by IR measurements go well with that obtained with the reactivity ratio methods. 5 figs., 3 tabs

  13. Study on preirradiation grafting of acrylic acid to cotton cellulose

    Grafting copolymerization of acrylic acid to cotton cellulose by using pre-irradiating method was investigated. At lower concentration of monomer (10%) the relationship between grafting yield and total dose, dose rate, reaction time and reaction temperature was measured. It was found that in the temperature range of 294 K to 323 K the grafting yield decreased with increasing of grafting reaction temperature. The grafting yields as a function of above reaction conditions were given by the expression Gr% = 5.9 x 10-10De20.27/RT(1-e-0.313te-6.87/RT), where R 8.314 x 10-3kj·K-1·mol-1, D = irradiation dose, T = reaction temperature, and t = reaction time

  14. Radiation curing silicone acrylate systems

    Radiation curing silicone systems by either ultra violet light (UV) or electron beam (EB) is introduced. The cure is based on the polymerization of the acrylic C = C double bond via a radical chain reaction. In the EB curing process a sufficient number of radicals for spontaneous polymerization is produced due to the high radiation energy whereas with UV light the energy is not as intensive thus a photo-initiator is required for a UV process. The required high local radical concentration provided by its decay. The radical generation immediate chain-growing leads to rapid and efficient crosslinking even at room temperature. It is for this reason that silicone acrylates cure immediately. All coater capable of handling 100% thermally curing silicones are suitable for the use with Goldschmidt's RC systems

  15. Cytoskeleton mimetic reinforcement of a self-assembled N,N'-dialkylimidazolium ionic liquid monomer by copolymerization.

    Grubjesic, S.; Seifert, S.; Firestone, M. A.; Materials Science Division

    2009-08-11

    Preparation and photopolymerization of a decylmethylimidazolium ionic liquid (IL) that possesses an acrylate counteranion are described. This IL monomer self-assembles upon addition of water and can be copolymerized with poly(ethylene glycol) diacrylate (PEGDA) in the presence of a photoinitiator, forming a mechanically durable material that adopts a lamellar structure with in-plane hexagonally ordered pores, as evidenced by small-angle X-ray scattering (SAXS). Thermogravimetric analysis, the extent of polymerization, and solubility-swelling studies indicate the formation of a network copolymer of the IL monomer and the PEGDA. Additional evidence for the formation of a nanostructured copolymer is provided by evaluating the product formed by replacement of the IL monomer with the nonpolymerizable analogue, decylmethylimidazolium chloride. The results demonstrate the possibility of designing a self-assembled amiphiphilic bilayer architecture that is reinforced by polymerization and cross-linking.

  16. Graft copolymerization of vinyl monomers onto nylon 6 fibers by simultaneous γ-ray irradiation

    Vinyl monomers, such as styrene, methyl methacrylate, methyl acrylate, vinyl acetate, acrylonitrile, and acrylamide, were grafted onto nylon 6 fibers by a simultaneous γ-ray irradiation technique. The effects of various additives on the apparent percent graft as well as on the molecular weight and mole number of grafted vinyl polymer branches were investigated. The molecular weight of the grafted vinyl polymer branch was determined by the limiting viscosity number of the branch polymer obtained by selective hydrolysis of the backbone nylon 6. The apparent percent graft of the grafted polystyrene increased by adding methanol, ethanol, acetic acid, or propionic acid to styrene monomer. The maximum amount of the apparent graft was obtained at the 1:1 mixture of styrene and methanol. The additive which behaved as a good swelling agent to nylon 6 and, at the same time, as a precipitant to polystyrene gave higher apparent percent graft. The apparent percent graft of vinyl monomers except vinyl acetate was increased by adding methanol or ethanol to the monomers. (author)

  17. Development of ionic gels using thiol-based monomers in ionic liquid

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

    2016-04-01

    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.

  18. Property Research of Instant Polymerization Acrylate Size Mixture%瞬时聚合丙烯酸酯浆料的性能研究

    吴长春; 武海良; 沈艳琴; 杨微

    2011-01-01

    探讨在采用瞬时聚合法直接合成固体丙烯酸酯浆料的过程中,疏水性单体丙烯酸丁酯用量对所生成丙烯酸酯浆料性能的影响.测试了不同丙烯酸丁酯用量下反应生成物的水溶性、水溶液黏度及对涤棉粗纱黏附性,并对合成的固体丙烯酸浆料进行红外表征.结果表明:在丙烯酸的中和度为50%、氧化还原引发体系中引发剂为单体量的6%时,丙烯酸丁酯为单体量的25%时合成的浆料性能最好,所生产的浆料为丙烯酸-丙烯酸钠盐-丙烯酸丁酯共聚物.%Effect of hydrophobic monomer butyl acrylate amount on acrylate size mixture property in the process of compounding solid acrylate size mixture directly by instant polymerization was discussed. Water-soluble, solution viscosity and adhesion to polyester cotton roving of polymer were tested in condition of different butyl acrylate amount. Infrared spectroscopy was done on solid acrylate size mixture. The result shows that property of the acrylate size mixture is the best,the size mixture is acrylate,acrylic acid,butyl acrylate copolymer when acrylic acid neutralization degree is 50% ,initiator content in redox initiation system is 6% ,butyl acrylate is 25%.

  19. Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin.

    Gong, Shi-Qiang; Epasinghe, D Jeevanie; Zhou, Bin; Niu, Li-Na; Kimmerling, Kirk A; Rueggeberg, Frederick A; Yiu, Cynthia K Y; Mao, Jing; Pashley, David H; Tay, Franklin R

    2013-06-01

    Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol-gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly(methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances. PMID:23485857

  20. Effect of Additives on UV-activated Urethane Acrylate Polymerization Composite Coatings

    Zane GRIGALE-SOROCINA

    2016-05-01

    Full Text Available An increased demand for new and improved coating systems, for environmental & health & safety and performance reasons, have appeared during the recent decades. Currently, there is new interest in preparation of thin UV curable urethane acrylate (UA composite coatings with short-term properties. Cellulose based additives: nitrocellulose, cellulose acetate butyrate, sucrose benzoate and silica were evaluated to determine their influence on unreacted composite characteristics (viscosity, pigment suspension stability and characteristics of cured film (ultimate tensile strength, elongation at break, surface gloss, surface scratch resistance and film adhesion loss time. The most suitable additive content was found to provide required viscosity. All additives increase surface scratch resistance, but cellulose based additives increase surface gloss values and decrease the time of adhesion loss. Silica has great effect on the interaction between linear and hyperbranched urethane acrylates, which has crucial influence on the stability of uncured pigmented mixture samples.

  1. The influence of monomer molar ratio on the properties of copolymers based on methyl methacrylate and methacrylic acid

    Ristić Ivan S.

    2009-01-01

    Full Text Available The application of polymers for controlled drug delivery is influenced by no toxicity and solubility in different pH mediums. There already are existing pharmaceutical medicaments based on aqueous dispersion of an anionic copolymer methyl acrylate, methyl methacrylate and methacrylic acid. The aim of this work was to synthesise copolymers of methyl methacrylate and methacrylic acid and to estimate the effects of monomers ratio (1:1 and 1:2 on the molecular mass, polydispersity index, and solubility of obtained polymers. Acetone was used as a solvent because both monomers and the initiator azobisisobutyronitrile are soluble in it. FTIR method was used for functional group characterization, the gel permeation chromatography method for average molecular weights and the distribution of molecular weights determinations. High pressure liquid chromatography (HPLC was applied for the estimation of residual monomers in obtained copolymers. The titration with ethanol solution of NaOH was used for assessing of monomer units in copolymers. The copolymer with the molar ratio of monomers 1:1 was soluble in water bufer with pH values higher then 6, while the copolymer with the molar ratio of monomers 1:2 was soluble in bufer with pH higher then 9.

  2. 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

    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: aloir@iq.ufrgs.br [University of Hull, Hull (United Kingdom). Dept. of Chemistry

    2012-07-01

    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)

  3. [Sucrose reward promotes rats' motivation for cocaine].

    Li, Yan-Qing; LE, Qiu-Min; Yu, Xiang-Chen; Ma, Lan; Wang, Fei-Fei

    2016-06-25

    Caloric diet, such as fat and sugar intake, has rewarding effects, and has been indicated to affect the responses to addictive substances in animal experiments. However, the possible association between sucrose reward and the motivation for addictive drugs remains to be elucidated. Thus, we carried out behavioral tests after sucrose self-administration training to determine the effects of sucrose experience on rats' motivation for cocaine, locomotor sensitivity to cocaine, basal locomotor activity, anxiety level, and associative learning ability. The sucrose-experienced (sucrose) group exhibited higher lever press, cocaine infusion and break point, as well as upshift of cocaine dose-response curve in cocaine self-administration test, as compared with the control (chow) group. Additionally, despite similar locomotor activity in open field test and comparable score in cocaine-induced conditioned place preference, the sucrose group showed higher cocaine-induced locomotor sensitivity as compared with the chow group. The anxiety level and the performance in vocal-cue induced fear memory were similar between these two groups in elevated plus maze and fear conditioning tests, respectively. Taken together, our work indicates that sucrose experience promotes the rats' motivation for cocaine. PMID:27350195

  4. Functional Analysis of Arabidopsis Sucrose Transporters

    John M. Ward

    2009-03-31

    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.

  5. Superhydrophocity via gas-phase monomers grafting onto carbon nanotubes

    Zha, Jinlong; Batisse, Nicolas; Claves, Daniel; Dubois, Marc; Frezet, Lawrence; Kharitonov, Alexander P.; Alekseiko, Leonid N.

    2016-05-01

    Superhydrophobic films were prepared using dispersions of fluorinated multi-walled carbon nanotubes (MWCNTs) or nanofibers (CNFs) in toluene. The grafting of polystyrene allowed stable dispersions to be obtained. The grafting of polystyrene (PS), polyacrylic acid (PAA) and polyaniline (PANI) onto nanofibers and MWCNTs was first evidenced by solid state NMR and Infrared Spectroscopy. The graft polymerization of styrene, acrylic acid and aniline monomers was initiated by radicals (dangling bonds) formed due to the initial fluorination. The process appeared as highly versatile and efficient for different polymers. The consumption of those radicals in the course of grafting was evidenced by EPR, through decrease of the spin density. The hydrophobic/hydrophilic character was tuned according to the grafted polymer nature, i.e. hydrophobic with PS or hydrophilic with PAA. Finally, in order to reach superhydrophobicity, films were prepared from CNFs or MWCNTs, irrespective of their average diameter, that allowed adequate structuring of the surface. The presence of fluorine atoms on their surface also favors superhydrophobicity. Water contact angles of 155 ± 2° and 159 ± 2° were measured for the films casted from fluorinated CNFs or MWCNTs with grafted polystyrene, respectively.

  6. Direct initiation of the photopolymerization of acrylates by 222 nm excimer UV radiation

    Complete text of publication follows. Usually, the photopolymerisation of functionalised monomers and oligomers requires the addition of one or several photoinitiators to the formulation. The light of typically used mercury lamps (1>250 nm) is mainly absorbed by the photoinitiator leading to initiating species (radicals) with a high quantum yield. The introduction of excimer lamps as monochromatic UV sources with an intense short-wavelength emission opens up new possibilities for a photoinitiator-free initiation of the acrylate polymerisation. Like most other organic compounds, acrylates strongly absorb light with a wavelength shorter than about 220 to 240 nm, and they can therefore be directly excited by the 222 nm excimer radiation from a KrCl* lamp. Real-time FTIR-ATR spectroscopy was used to study the reactivity of various neat acrylates. Depending on the absorption coefficient, aliphatic acrylates can be cured up to a thickness of several microns whereas for highly absorbing aromatic acrylates, the depth of cure reaches only some hundred nanometres. Since the radical yield is low, photopolymerisation without photoinitiator has to be performed in an inert atmosphere. Laser photolysis experiments were carried out with a KrCl* excimer laser (pulse width 20 ns, up to 5 mJ per pulse) to investigate the primary processes of the direct initiation. Additionally, quantum chemical calculations were performed to assist the interpretation of the photolysis data. For all acrylates studied, direct excitation at 222 nm first leads to the formation of a triplet state which is highly localized at the vinyl double bond (and not at the carbonyl group). This triplet state may undergo different reactions like inter- and intramolecular hydrogen transfer and biradical formation as well as the addition to a ground state molecule (chain start). Our current interpretation of the experimental results and the quantum chemical calculations will be presented and discussed

  7. Radiation grafting of acrylic acid onto polypropylene films

    A study has been made for the preparation of membranes by the direct radiation grafting of acrylic acid (AAc) onto polypropylene (PP) films. The appropriate reaction conditions were selected under which the graft polymerization was carried out successfully. The effect of different solvents such as benzene, methanol/water mixture, isopropanol/water mixture, dimethyl formamide and distilled water on the swelling and grafting process of AAc onto PP films was investigated. In this grafting system ammonium ferrous sulphate (Mohr's salt) and ferric chloride were used as inhibitors to minimize the homopolymerisation of AAc and the suitable concentration of the inhibitor was found to be 1.0 and 1.5 wt% for Mohr's salt and ferric chloride, respectively. Also, the effect of monomer concentration on the rate of grafting was investigated. The dependence of the grafting rate on monomer concentration was found to be 1.1 order. This grafting system proceeded by diffusion controlled process. Some selected properties of the grafted films such as swelling behaviour, gel determination, mechanical and electrical properties were also investigated. It was found that the grafted membranes possess good hydrophilic properties which may make them promising in some practical applications. (author)

  8. Radiation induced emulsion polymerization of 2-ethylhexyl acrylate

    The effects of radiation dose rate concentration of emulsifier and monomer content on reaction rate of radiation induced 2-ethylhexyl acrylate (EHA) emulsion polymerization have been studied. Nonionic surfactants, polyoxyethylene alkyl ether peregolo 0 with HLB about 15 and polyoxyethylene nonylphenolether (emulsifier OP) with HLB 15, are used as the emulsifiers in this work. It has been found that the dependence of RP on I (RP proportional to In) is changed with the index n from 0.29 for M/W = 2/8 (monomer/water in volume) to 0.91 for 5/5, where [E] of peregolo 0 is 4%. It has also been found that RP proportional to [E]0.58 for peregolo 0 and RP proportional to [E]0.51 for emulsifier OP. In order to interpret the results sufficiently, both micellar nucleation and micro-droplet nucleation have been taken into account for the emulsion polymerization of the present system irradiated without agitation, especially for the case with a higher M/W value the later may be the main nucleation process

  9. Corrosion Inhibitive Evaluation of an Environmentally Friendly Water-Base Acrylic Terpolymer on Mild Steel in Hydrochloric Acid Media

    Azghandi, Mojtaba Vakili; Davoodi, Ali; Farzi, Gholam Ali; Kosari, Ali

    2013-12-01

    The corrosion inhibitive performance of an environmentally friendly water-base acrylic terpolymer [methyl methacrylate/Butyl Acrylate/Acrylic acid (ATP)] on mild steel in 1 M HCl was investigated by alternating current and direct current electrochemical techniques and the quantum chemical method. An efficiency of more than 97 pct was obtained with 0.8 mmol/L ATP. The increase in inhibitor concentration and immersion time has a positive effect, while the temperature influence is negligible on the inhibitor efficiency. The present terpolymer obeys the Langmuir isotherm, and thermodynamic calculation reveals a chemisorption type on the surface. Density functional calculations showed that the lone pairs of electrons of oxygen in the structure of three monomers are suitable sites to adsorb onto the metal surface. Finally, in the presence of ATP, a decrease in surface roughness and corrosion attacks was demonstrated by atomic force microscopy and optical microscopy examinations, respectively.

  10. Radiation-curing of acrylate composites including carbon fibres: A customized surface modification for improving mechanical performances

    Martin, Arnaud; Pietras-Ozga, Dorota; Ponsaud, Philippe; Kowandy, Christelle; Barczak, Mariusz; Defoort, Brigitte; Coqueret, Xavier

    2014-12-01

    The lower transverse mechanical properties of radiation-cured acrylate-based composites reinforced with carbon-fibre with respect to the thermosettable analogues was investigated from the viewpoint of chemical interactions at the interface between the matrix and the carbon material. XPS analysis of representative commercial carbon fibres revealed the presence of a significant amount of chemical functions potentially exerting an adverse effect on the initiation and propagation of the free radical polymerization initiated under high energy radiation. The EB-induced polymerization of n-butyl acrylate as a simple model monomer was conducted in the presence of various aromatic additives exhibiting a strong inhibiting effect, whereas thiols efficiently sensitize the initiation mechanism and undergo transfer reactions. A method based on the surface modification of sized fibres by thiomalic acid is proposed for overcoming the localized inhibition phenomenon and for improving the mechanical properties of the resulting acrylate-based composites.

  11. Use of acrylic acid in the synthesis of molecularly imprinted polymers for the analysis of cyproheptadine

    The synthesis and comparative characterization of molecularly imprinted polymers (MIPs) with cyproheptadine (CYP), using two different monomers, acrylic acid (AA) and methacrylic acid (MAA), are described. Polyacids (PA) [poly(methacrylic acid) (PMAA) and poly(acrylic acid) (PAA)] were obtained by the radical polymerization of MAA and AA, respectively, in dichloromethane as the porogen solvent-imprinted medium. The non-covalent imprinting process was performed via thermal decomposition of an azo-initiator at 60 deg. C, using ethylene glycol dimethacrylate as the cross-linker and 2,2'-azobis(2-methylpropionitrile) as the initiator. The selectivities of MIPs and NIPs particles were evaluated in binding experiments of the four synthesized polymeric materials (MIPaa, MIPmaa, NIPmaa and NIPaa) with CYP. The effects of monomers on: a) the surface morphology, b) the binding capacity and c) the swelling properties of imprinted and non-imprinted polymers were studied and are presented here. Polymer material morphology was assessed with scanning electron microscopy (SEM). This revealed differences in monomer function, depending on which one was employed, as well as differences in function when polymerization occurred in the presence of template or without it. Non-specific retention of the template to NIPs was higher for NIPs-PAA polymers than for NIPs-PMAA materials. In terms of specific binding (ΔQ = QMIP - QNIP), MIPmaa showed the greatest value (53.47%) in comparison with MIPaa (50.07%)

  12. Effect of ionizing radiation on properties of acrylic pressure sensitive adhesives

    Pressure-sensitive adhesives for technical application are widely produced. The biological properties of adhesives depend on the type of monomers used. The available literature data as experience of the authors of this study in the area of pressure-sensitive acrylic adhesive, polymers used in medicine, polymerisation in aqueous media, radiation sterilization, permit to make an assumption that it is possible to elaborate the technology of production of pressure-sensitive adhesives in aqueous emulsion for medical applications. Identification of phenomena influencing the adhesive properties, especially its adhesion, cohesion, tack and durability is of great importance. The control of polymer structure is performed by means of adequate selection of conditions of synthesis and parameters of radiation processing. The authors investigate the influence on the final products of such factors as the type and amount of monomers used, their mutual ratio, as well as the ratio monomers and the dose of ionising radiation. There is no available literature information concerning the investigation of resistance of acrylic emulsion adhesive to sterilisation by electron beam. It is known from unpublished research that some adhesives are resistant to radiation, while others undergo destruction. It probably depends on the composition of emulsion, specifically on the additives which modify adhesives. Simultaneous achievement of good cohesion and adhesion in the case of such types of pressure sensitive adhesives is very difficult pressure sensitive adhesives is very difficult

  13. Structural development of sucrose-sweetened and sucrose-free sponge cakes during baking.

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

    2003-06-01

    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. PMID:12866615

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

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

    2006-01-01

    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.

  15. Effect of Nanoclay on Thermal Conductivity and Flexural Strength of Polymethyl Methacrylate Acrylic Resin

    Tahereh Ghaffari

    2016-06-01

    Full Text Available Statement of the Problem: The mechanical and thermal properties of polymethyl methacrylate (PMMA acrylic resin should be improved to counterweigh its structural deficiencies. Purpose: The aim of this study was to compare the flexural strength and thermal conductivity of conventional acrylic resin and acrylic resin loaded with nanoclay. Materials and Method: The methacrylate monomer containing the 0.5, 1 and 2 wt% of nanoclay was placed in an ultrasonic probe and mixed with the PMMA powder. Scanning electron microscopy was used to verify homogeneous distribution of particles. Twenty-four 20×20×200-mm cubic samples were prepared for flexural strength test; 18 samples containing nanoclay and 6 samples for the control group. Another 24 cylindrical samples of 38×25 mm were prepared for thermal conductivity test. One-way ANOVA was used for statistical analysis, followed by multiple-comparison test (Scheffé’s test. Statistical significance was set at p< 0.05. Results: Increasing the concentration of nanoclay incorporated into the acrylic resin samples increased thermal conductivity but decreased flexural strength (p< 0.05. Conclusion: Based on the results of this study, adding nanoclay particles to PMMA improved its thermal conductivity, while it had a negative effect on the flexural strength.

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

    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

  17. Preparation of nanoparticles from acrylated palm oil microemulsion using radiation technique

    The use of microemulsion in the development of nanoparticle based on acrylated palm oil product is demonstrated. Acrylated palm oil microemulsions were prepared using ionic surfactant. Combination methods of emulsion polymerization and radiation crosslinking were applied to the microemulsion system for synthesizing nanoparticle. The ionizing radiation technique was introduced to generate a crosslinking reaction in the development of nanoparticle. The nanoparticle was evaluated in terms of particle diameter, surface charge, pH and conductance. Their image was captured using Transmission electron microscopy (TEM). Results show that the size, charge and shape of the particles are influenced by concentration of surfactants, monomer concentration, radiation dose and time of storage. The study showed a promising method to produced nanoparticle. This nano-sized product has the potential to be utilized as controlled-drug-release-carrier. (Author)

  18. Copolymerization of Indene with Acrylic Acid, Itaconic Acid and Acrylonitrile: Characterization and Reactivity Ratios

    Random copolymers of indene (In) with acrylic acid (AA), itaconic acid (IA) and acrylonitrile (AN) were synthesized by free radical polymerization in dioxane in the presence of azobisisobutyronitrile as an initiator at 60 degree C. The homopolymer of indene and acrylonitrile was prepared using K2MnO4 and sulphuric acid as an initiator, while acrylic acid and itaconic acid were prepared using K2S2O8 solution. The reactivity ratios of the monomers were calculated by different methods. X-ray diffraction as well as thermal analyses were studied. The latter was studied via thermogravimetric analysis and differential thermal analysis. The complexation with metal ions such as Cu+2 and Fe+2 was investigated. The copolymerization and the complexation processes were confirmed by FTIR spectroscopy. Also the activation energy of the prepared copolymers was determined

  19. Preparation of poly (acrylic acid)-modified chitosan amphiphilic gels by γ-rays irradiation

    Poly (acrylic acid)-modified chitosan amphiphilic gels were prepared via O-maleoyl-N-phthaloyl- chitosan as an intermediate by grafting with poly (acrylic acid). The reaction was carried out in a homogeneous sys- tem by γ-ray irradiation. Evidence of grafting was obtained from FTIR spectroscopy. The effects for grafting reaction were investigated systematically. Results show that the grafting degree depends on monomer concentration and ab- sorbed dose. The swelling behavior of chitosan samples with different grafting degree was studied in different buffers as a function of pH. It can be found that all the samples swollen slightly at low pH but very well at high pH. More- over, the swelling behavior of chitosan samples in DMF has been evaluated. (authors)

  20. Properties of radiation curable hyperbranched polyurethane acrylate from palm oil oleic acid

    Radiation curable hyperbranched urethane acrylate (HBPUA) from oleic acid of palm oil was synthesized aided by p-toluene sulfonic acid as a catalyst. This mixture was then used as the core (HBP-1) and reacted with palm oil oleic acid to form the hyperbranched polyol (HBP-2). HBPUA was prepared by reacting HBP-2 resin with diisocyanate and hydroxyl-containing acrylate monomer with the presence of 0.1-2 wt% dibutyltin dilaurate as a catalyst. The reaction was confirmed by several analytical data i.e. hydroxyl value (OHV), Fourier Transform infrared (FT IR) spectroscopy gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analyses. The HBPUA was easily curable when subjected to electron beam (EB) or ultraviolet (UV) radiation. (authors)

  1. Super absorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch

    Full text: Super absorbent was synthesized by radiation-induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage and germination energy were determined in order to evaluate the possibility of super absorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by FTIR. Results indicated that the sand mixed with 0.1%wt super absorbent can absorb more water than the sand without super absorbent. The germination energy of corn seeds mixed with 0.5% super absorbent was obviously higher than those without super absorbent. These experimental results showed that the super absorbent has considerable effect on seed germination and the growth of young plants. Keywords: Super absorbent, Radiation, Acrylic acid, Cassava starch

  2. Kinetics characterization of a novel photopolymerizable siloxane-modified acrylic resin

    An experimental study was carried out for the development and characterization of innovative photopolymerizable siloxane-modified acrylic formulations for possible use as protective coatings. The kinetics of the radical photopolymerization mechanism induced by UV and visible radiations in presence of suitable photoinitiators was studied by a calorimetric analysis by varying the testing conditions (temperature, light power emission, atmosphere). The reactivity, expressed in terms of both heat developed and rate of reaction, was generally found to decrease when the photopolymerization was carried out in air, due the inhibiting action of the oxygen towards the free-radical polymerization. The addition of both a silane coupling agent or a high molecular weight polysiloxane monomer to the acrylic resin was found to reduce the heat of reaction. Experimental data were fitted to a kinetic model to quantify the effects of light intensity and temperature on reaction rates and extent of reaction. A good agreement between the experimental data and the theoretical model was generally found.

  3. Kinetics characterization of a novel photopolymerizable siloxane-modified acrylic resin

    Corcione, C. Esposito, E-mail: carola.corcione@unile.it [Dipartimento di Ingegneria dell' Innovazione, Universita del Salento, via per Monteroni, 73100 Lecce (Italy); Previderio, A.; Frigione, M. [Dipartimento di Ingegneria dell' Innovazione, Universita del Salento, via per Monteroni, 73100 Lecce (Italy)

    2010-09-20

    An experimental study was carried out for the development and characterization of innovative photopolymerizable siloxane-modified acrylic formulations for possible use as protective coatings. The kinetics of the radical photopolymerization mechanism induced by UV and visible radiations in presence of suitable photoinitiators was studied by a calorimetric analysis by varying the testing conditions (temperature, light power emission, atmosphere). The reactivity, expressed in terms of both heat developed and rate of reaction, was generally found to decrease when the photopolymerization was carried out in air, due the inhibiting action of the oxygen towards the free-radical polymerization. The addition of both a silane coupling agent or a high molecular weight polysiloxane monomer to the acrylic resin was found to reduce the heat of reaction. Experimental data were fitted to a kinetic model to quantify the effects of light intensity and temperature on reaction rates and extent of reaction. A good agreement between the experimental data and the theoretical model was generally found.

  4. Acrylates and methacrylates of formal-glycerine

    Present article is devoted acrylates and methacrylates of formal-glycerine. The formal-glycerine was obtained in the form of mixture of isomers 1.2 and 1.3 from glycerine and paraform with hydrochloric acid. The structure of obtained acrylates and methacrylates is studied by means of molecular refraction, element analysis and infrared spectroscopy.

  5. Effects of monomer functionality on performances of scaffolding morphologic transmission gratings recorded in polymer dispersed liquid crystals

    The effects of monomer functionality on performances of holographic polymer dispersed liquid crystal (HPDLC) transmission gratings are systematically investigated. Acrylate monomers with an average functionality ranging from 2.0 to 5.0 are used to prepare these samples. We find scaffolding morphologic transmission gratings (characterized by a high phase separation degree, a well alignment of LCs and low scattering loss) can be obtained irrespective of the monomer functionality, although the exact optimal curing intensity varies. The temporal evolution of the grating formation is studied and the onset time of the LC phase separation decreases significantly with the increase in average monomer functionality. It is also shown that the gratings prepared from low average functionality monomers require a comparatively low switch-off electric field (∼8 V μm−1) whilst suffering from mechanical fragility and long-term instability. Our results not only provide a complete understanding of scaffolding morphologic gratings in terms of the material composition effect, but also provide insight into the formation mechanisms of non-droplet morphologic HPDLC gratings. (paper)

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

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

    2008-01-01

    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.

  7. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Liu, Fangfang; Conghui DU; Linya ZHANG

    2015-01-01

    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 (NH4)2S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that...

  8. THE PROBABLE HAZARDS OF SUCROSE IN MAN

    H. Mohammadiha

    1974-08-01

    Full Text Available The effect of dietary sucrose on DNA formation in rat liver and kidney compared with that of starch was studied. Male, weanling rats were fed for 6 and 14 days on diets containing 68% 'sucrose or 68% starch, and liver and kidneys were examined for 1ilie amount and rate of formation of DNA; and also for content of fat, protein, and moisture. Food intake and weight gain were estimated. Sucrose fed animals had heavier liver and kidneys than starch fed animals. Food intake and weight gain were similar on both diets. The enlargement of the liver after six days was mainly due to increase in1cell number calculated from DNA content. Whereas, after 14 days, the enlargement was mostly due to incensement of cell size. The proportion of protein and moisture in the liver of sucrose fed animals was less than in the starch fed ones, whereas fat content was 25'% higher. Sucrose feeding had no effect in six days on weight of kidneys, but after 14 days heavier kidneys were produced. Exemption of cortex showed no difference in cell number or cell size. Twenty-four hours before killing the animals were injected intraperitoneally with H3 thymidine. Radioactive count was too low, the results too variable for any conclusions to be drawn.

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

    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.

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

    Marcelo Aparecido Chinelatto

    2014-01-01

    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.

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

    Ritter, Helmut; Tabatabai, Monir; Herrmann, Markus

    2016-01-01

    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. PMID:26977183

  12. Degradable thiol-acrylate hydrogels as tunable matrices for three-dimensional hepatic culture.

    Hao, Yiting; Lin, Chien-Chi

    2014-11-01

    A degradable poly(ethylene glycol)-diacrylate (PEGDA) hydrogel system was developed using simple macromer formulations and visible light initiated thiol-acrylate photopolymerization. In addition to PEGDA, other components in this gelation system include eosin-Y as a photo-sensitizer, bi-functional thiol (dithiothreitol, DTT) as a dual-purpose co-initiator and cross-linker, and N-vinylpyrrolidone (NVP) as a co-monomer. Gelation was achieved through a mixed-mode step-chain growth polymerization mechanism under bright visible light exposure. Increasing photo-sensitizer or NVP concentrations accelerated photo-crosslinking and increased final gel stiffness. Increasing bi-functional thiol content in the prepolymer solution only increased gel stiffness to some degree. As the concentration of thiol surpassed certain range, thiol-mediated chain-transfer events caused thiol-acrylate gels to form with lower degree of cross-linking. Pendant peptide, such as integrin ligand RGDS, was more effectively immobilized in the network via a thiol-acrylate reaction (using thiol-bearing peptide Ac-CRGDS. Underline indicates cross-linkable motif) than through homo-polymerization of acrylated peptide (e.g., acryl-RGDS). The incorporation of pendant peptide comes with the expense of a lower degree of gel cross-linking, which was rectified by increasing co-monomer NVP content. Without the use of any readily degradable macromer, these visible light initiated mixed-mode cross-linked hydrogels degraded hydrolytically due to the formation of thiol-ether-ester bonds following thiol-acrylate reactions. An exponential growth relationship was identified between the hydrolytic degradation rate and bifunctional thiol content in the prepolymer solution. Finally, we evaluated the cytocompatibility of these mixed-mode cross-linked degradable hydrogels using in situ encapsulation of hepatocellular carcinoma Huh7 cells. Encapsulated Huh7 cells remained alive and proliferated as time to form cell clusters

  13. Cationically polymerizable monomers derived from renewable sources

    Crivello, J.V.

    1991-10-01

    The objective of this project is to make use of products obtained from renewable plant sources as monomers for the direct production of polymers which can be used for a wide range of plastic applications. In this report is described progress in the synthesis and polymerization of cationically polymerizable monomers and oligomers derived from botanical oils, terpenes, natural rubber, and lignin. Nine different botanical oils were obtained from various sources, characterized and then epoxidized. Their photopolymerization was carried out using cationic photoinitiators and the mechanical properties of the resulting polymers characterized. Preliminary biodegradation studies are being conducted on the photopolymerized films from several of these oils. Limonene was cationically polymerized to give dimers and the dimers epoxidized to yield highly reactive monomers suitable for coatings, inks and adhesives. The direct phase transfer epoxidation of squalene and natural rubber was carried out. The modified rubbers undergo facile photocrosslinking in the presence of onium salts to give crosslinked elastomers. 12 refs., 3 figs., 10 tabs.

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

    Ahmad Arabi Shamsabadi

    2016-04-01

    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.

  15. Grafting of acrylic acid on etched latent tracks induced by swift heavy ions on polypropylene films

    In order to continue with a systematic study that include different polymers and monomers, the residual active sites produced by heavy ion beams, that remain after the etching process, were used to start the grafting process. To produce tracks, foils of polypropylene (PP) were irradiated with 208Pb of 25.62 MeV/n. Then, these were etched and grafted with acrylic acid (AA) monomers. Experimental curves of grafting yield as a function of grafting time with the etching time as a parameter were measured. Also, the grating yield as a function of the fluence and etching time was obtained. In addition, the permeation of solutions, with different pH, through PP grafted foils was measured

  16. Radiopurity measurement of acrylic for DEAP-3600

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from 238U and 232Th. Another background of particular concern is diffusion of 222Rn during manufacturing, leading to 210Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of 238U and 232Th equivalent, and 10−8 ppt 210Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented

  17. Radiopurity measurement of acrylic for DEAP-3600

    Nantais, C. M.; Boulay, M. G. [Department of Physics, Engineering Physics, and Astronomy, Queen' s University, Kingston, Ontario K7L 3N6 (Canada); Cleveland, B. T. [SNOLAB, Lively, Ontario P3Y 1N2 Canada and Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)

    2013-08-08

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from {sup 238}U and {sup 232}Th. Another background of particular concern is diffusion of {sup 222}Rn during manufacturing, leading to {sup 210}Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of {sup 238}U and {sup 232}Th equivalent, and 10{sup −8} ppt {sup 210}Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented.

  18. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin... acrylamide with partial hydrolysis, or by copolymerization of acrylamide and acrylic acid with the...

  19. Isotachophoresis of proteins in sucrose density gradients.

    Acevedo, F

    1993-10-01

    The separation of proteins from human serum by isotachophoresis in sucrose density gradients, with mixtures of discrete amphoteric substances as spacers, is described. Open columns and columns with a dialysis membrane to hold the sucrose gradients were used. A simple algorithm based on the Kohlrausch function was used to calculate the amount of each spacer. The pH gradients generated in open columns were found to be in agreement with the calculations. The load was up to two gram proteins. The analysis of the fractions obtained after the separation showed a distribution of components similar to as analytical isotachophoresis. It is concluded that sucrose density gradients are suitable as supporting media for the preparative separation of proteins by isotachophoresis. The high resolution attained and the possibility of scaling-up the separation systems are major advantages of this system. In addition, the sample is easily and completely recoverable. PMID:8125049

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

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

    2007-01-01

    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.

  1. Occupational respiratory disease caused by acrylates.

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

    1993-05-01

    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. PMID:8334539

  2. Adsorption of uranium ions by crosslinked polyester resin functionalized with acrylic acid from aqueous solutions

    In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer (Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl ketone peroxide (MEKp, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI) concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated. The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. The adsorption capacity and free energy change were determined by using D-R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the thermodynamic parameters of enthalpy (ΔHo), entropy (ΔSo) and free energy change (ΔGo) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich, Elovich, pseudo-first order and pseudo-second-order kinetic models. (author)

  3. The use of epoxidised palm oil products (EPOP) for the synthesis of radiation curable resins. II. Ultraviolet (UV) curing of epoxidised RBD palm oil acrylate (EPOLA)

    Epoxidised RBD palm olein acrylate (EPOLA) and polyurethane acrylate (PUA) prepared at UTN laboratory were used as base polymers or oligomers in the formulations of ultraviolet (UV) curable resins. Mono-, di- and trifunctional monomers were utilized both as crosslinkers as well as for diluents. Curing was done by means of 20 cm wide IST UV machine with the conditions of 8A current and 4m/min conveyor speed. The properties of the cured films were investigated by using pencil hardness tester and gel content analysis

  4. Study on synthesis of high content acrylic resin%高含量丙烯酸树脂的合成研究

    高凯; 孙继昌

    2013-01-01

    Emulsion polymerization of acrylic resin is introduced. The high solid content, transparent and multipurpose acrylic resin was obtained through adjusting monomer ratio, kinds and amounts of initiators and emulsifier by emulsion polymerization.%  介绍了一种乳液聚合方法,通过乳液聚合,调整单体比例,控制引发剂和乳化剂的品种及数量,合成高含固量、透明、多用途的丙烯酸树脂。

  5. Plant Sucrose Transporters from a Biophysical Point of View

    Dietmar Geiger

    2011-01-01

    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.

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

    Wang, Shu; Robertson, Megan L

    2015-06-10

    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

  7. BD monomer and elastomer production processes.

    Lynch, J

    2001-06-01

    The monomer 1,3 butadiene (BD) is a product of the petrochemical industry. It is used to make several elastomers including the very high volume styrene butadiene rubber (SBR) that comprises the bulk of automobile tires. It is also used to make polybutadiene rubber that is used in parts of tires, coatings, composites and other products. The monomer can be converted to chlorobutadiene (chloroprene) and used to make polychloroprene (neoprene). BD is one of the several olefins created by cracking hydrocarbons in the presence of steam. A mixed C4 stream from the steam cracker is then sent to a BD monomer extraction unit. Modern units typically use dimethyl formamide as the extraction solvent. SBR is commonly made by the copolymerization of BD and styrene, along with various additives to control the reaction, in a water emulsion. The reaction proceeds in a continuous chain of reactors until it is 'shortstopped' by a strong reducing agent. After removing unreacted monomers from the stabilized latex, it is blended, coagulated and dewatered. The resulting dry rubber crumb is bailed, film wrapped and stored in crates. The polymerization of BD to make polybutadiene rubber can be conducted as a water suspension type polymerization similar to SBR or in a solvent system followed by solvent recovery and transfer into water suspension. PMID:11397387

  8. Softening and elution of monomers in ethanol

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

    2009-01-01

    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...

  9. Nonfouling hydrogels formed from charged monomer subunits.

    Dobbins, Sean C; McGrath, Daniel E; Bernards, Matthew T

    2012-12-13

    A critical challenge in the field of biomaterials is the often undesirable, but immediate, coating of implants with nonspecifically adsorbed proteins upon contact with bodily fluids. Prior research has shown that overall neutral materials containing a homologous arrangement of mixed charges exhibit nonfouling properties. This has been widely demonstrated for zwitterionic materials and more recently for coatings containing an equimolar mixture of positively and negatively charged monomer subunits. In this investigation it is demonstrated that nonfouling hydrogels can be formed through this approach, and the physical properties of the resulting materials are thoroughly characterized. In particular, hydrogels were formed from mixtures of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (TM) and 3-sulfopropyl methacrylate potassium salt (SA) monomers with varying concentrations of a triethylene glycol dimethacrylate (TEGDMA) cross-linker. The swelling, weight percentage water, surface zeta potential, and compressional properties of the gels were characterized, and the nonfouling properties were demonstrated using enzyme-linked immunosorbant assays for both negatively charged fibrinogen and positively charged lysozyme. The results confirm that the TM:SA hydrogel systems have nonfouling properties that are equivalent to established nonfouling controls. Additionally, even though the gels were resistant to nonspecific protein adsorption, a composition analysis suggests that there is room to further improve the nonfouling performance because there is a slight enrichment of the SA monomer relative to the TM monomer. PMID:23189949

  10. Characterization of electron beam cured epoxy acrylate

    Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM)

  11. Gel time of calcium acrylate grouting material.

    Han, Tong-Chun

    2004-08-01

    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. PMID:15236477

  12. Resistance of acrylic vessel to gamma irradiation

    Carneiro, Andre Cavalcanti; Menezes, Maria Angela de B.C.; Pereira, Marcio Tadeu; Rocha, Nirlando Antonio; Vilela, Jefferson Jose, E-mail: andreccarneiro@gmail.com, E-mail: menezes@cdtn.br, E-mail: mtp@cdtn.br, E-mail: nar@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Braga, Mario Roberto Martins S.S., E-mail: mariomartins@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2013-07-01

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the {sup 222}Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  13. Resistance of acrylic vessel to gamma irradiation

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the 222Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  14. Rapid Output Growth of Special Acrylic Esters

    Wang Lianzhi

    2007-01-01

    @@ 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.

  15. 21 CFR 172.869 - Sucrose oligoesters.

    2010-04-01

    ... the Food Chemicals Codex, 4th ed. (1996), p. 820. National Academy Press, 2101 Constitution Ave. NW... Ignition, Appendix IIC, Method I, in the Food Chemicals Codex, 4th ed. (1996), pp. 751-752, (using a 1-gram... for “Sucrose Fatty Acid Esters” in the First Supplement to the 4th ed. of the Food Chemicals...

  16. A novel fluorescent assay for sucrose transporters

    Gora Peter J

    2012-04-01

    Full Text Available Abstract Background We have developed a novel assay based on the ability of type I sucrose uptake transporters (SUTs to transport the fluorescent coumarin β-glucoside, esculin. Budding yeast (Saccharomyces cerevisiae is routinely used for the heterologous expression of SUTs and does not take up esculin. Results When type I sucrose transporters StSUT1 from potato or AtSUC2 from Arabidopsis were expressed in yeast, the cells were able to take up esculin and became brightly fluorescent. We tested a variety of incubation times, esculin concentrations, and buffer pH values and found that for these transporters, a 1 hr incubation at 0.1 to 1 mM esculin at pH 4.0 produced fluorescent cells that were easily distinguished from vector controls. Esculin uptake was assayed by several methods including fluorescence microscopy, spectrofluorometry and fluorescence-activiated cell sorting (FACS. Expression of the type II sucrose transporter OsSUT1 from rice did not result in increased esculin uptake under any conditions tested. Results were reproduced successfully in two distinct yeast strains, SEY6210 (an invertase mutant and BY4742. Conclusions The esculin uptake assay is rapid and sensitive and should be generally useful for preliminary tests of sucrose transporter function by heterologous expression in yeast. This assay is also suitable for selection of yeast showing esculin uptake activity using FACS.

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

    Oyola, Yatsandra; Dai, Sheng

    2016-06-01

    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). PMID:27145863

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

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

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

    Musa Ahmad

    2002-08-01

    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.

  20. Acrylic coatings exhibiting improved hardness, solvent resistance and glossiness by using silica nano-composites

    Dashtizadeh, Ahmad; Abdouss, Majid; Mahdavi, Hossein; Khorassani, Manuchehr

    2011-01-01

    To prepare nano-composite emulsion acrylic resins with improved surface hardness and solvent resistance, nano-silica particles were treated with surfactants. The monomers of methyl methacrylate/butylacrylate were co-polymerized on the surface of dispersed silica particles. Several emulsions with different silica contents and copolymer mole fractions were prepared. Finally the emulsions were modified to water-based acrylic coatings and improved properties such as surface hardness, solvent resistance and glossiness were determined. The study of coatings was directed to find the improved resin by optimum surface properties. Size distribution and morphology of latexes were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy and scanning electron microscopy. The glass transition temperature of nano-composites was measured and discussed its relation with silica contents, monomer mole fractions and improved properties of coatings. The optimum pendulum hardness of coatings was on 0.46 methyl methacrylate mole fraction and 120 g silica content. An increase in pendulum hardness of nano-composites with the addition of modified silica was observed. DLS and TEM studies indicate that silica particles were dispersed homogenously through the polymer matrix.

  1. Surface reliefs on diacrylate monomer films by spatially controlled UV photopolymerization

    The non-uniform ultraviolet (UV) photopolymerization of acrylic films allows the formation of surface reliefs through a self-developing process. The parameters that influence the growth of the reliefs for polymer films made of bis-phenol-A-diglycidil-ether diacrylate (BGEDA), an aliphatic polyurethane diacrylate and an aromatic polyurethane diacrylate, mixed with tri-propylen-glycol diacrylate as promoter, have been investigated. The results show that the time of photopolymerization, the after-curing self-developing time, the mixture composition and the polymer film thickness influence the relief development in a complex way. The behaviours of the different monomers were explained on the basis of two main factors: the properties of the polymeric network and the diffusion phenomena which take place in the polymer bulk

  2. Synthesis, characterization, swelling and dye adsorption properties of starch incorporated acrylic gels.

    Mandal, Bidyadhar; Ray, Samit Kumar

    2015-11-01

    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. PMID:26318665

  3. Inverse opal pH sensors with various protic monomers copolymerized with polyhydroxyethylmethacrylate hydrogel

    Highlights: ► We polymerized four different inverse opal pH sensors by using vinyl monomers containing acidic or basic substituents. ► Stepwise swelling response from polyprotic acid sensor was investigated. ► Opposite color changing responses were obtained for acidic and basic sensors. ► Composite pH sensor with wide pH sensing range was fabricated by mixing different monomers. ► Both acid and base sensors show the response time as fast as ∼10 s. - Abstract: pH sensitive inverse opal sensors were synthesized using various vinyl monomers containing acidic or basic substituents. Acrylic acid (AA), vinylphosphonic acid (VPA), vinylimidazole (VI), and dimethylaminoethylmethacrylic acid (DMAEMA) were respectively copolymerized with hydroxyethylmethacrylate (HEMA), the building block monomer of the hydrogel via UV-initiated photopolymerization. Opal templating and subsequent template removal enabled the fabrication of four inverse opal (IO) hydrogel colorimetric sensors, which responded to pH in different fashions. pH-dependent swelling of the IO hydrogel induced the red-shift of the diffracted color. The sensors containing AA or VPA, the proton donating monomers showed the color shifts from green to red with pH increase due to the increased concentration of carboxylate anions bound to the hydrogel. Diprotic VPA sensor exhibited two-step increases of diffracted wavelengths at its pKa1 and pKa2 respectively. The sensors containing proton acceptors, VI and DMAEMA showed the pH-dependent color changes in an opposite way to the AA sensor and the VPA sensor since their ionizations take place by lowering pH due to the protonation at the amino groups. The shapes of pH response curves of VI and DMAEMA sensors were similar but pKbs were different from each other. Optical diffraction responses of four sensors were compared with the calculated concentration ratios of the ionized species to the total monomer with pH variation, and a deswelling effect in the vicinities

  4. Inverse opal pH sensors with various protic monomers copolymerized with polyhydroxyethylmethacrylate hydrogel

    Shin, Jinsub; Han, Sung Gu [Department of Chemistry, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Lee, Wonmok, E-mail: wonmoklee@sejong.ac.kr [Department of Chemistry, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of)

    2012-11-08

    Highlights: Black-Right-Pointing-Pointer We polymerized four different inverse opal pH sensors by using vinyl monomers containing acidic or basic substituents. Black-Right-Pointing-Pointer Stepwise swelling response from polyprotic acid sensor was investigated. Black-Right-Pointing-Pointer Opposite color changing responses were obtained for acidic and basic sensors. Black-Right-Pointing-Pointer Composite pH sensor with wide pH sensing range was fabricated by mixing different monomers. Black-Right-Pointing-Pointer Both acid and base sensors show the response time as fast as {approx}10 s. - Abstract: pH sensitive inverse opal sensors were synthesized using various vinyl monomers containing acidic or basic substituents. Acrylic acid (AA), vinylphosphonic acid (VPA), vinylimidazole (VI), and dimethylaminoethylmethacrylic acid (DMAEMA) were respectively copolymerized with hydroxyethylmethacrylate (HEMA), the building block monomer of the hydrogel via UV-initiated photopolymerization. Opal templating and subsequent template removal enabled the fabrication of four inverse opal (IO) hydrogel colorimetric sensors, which responded to pH in different fashions. pH-dependent swelling of the IO hydrogel induced the red-shift of the diffracted color. The sensors containing AA or VPA, the proton donating monomers showed the color shifts from green to red with pH increase due to the increased concentration of carboxylate anions bound to the hydrogel. Diprotic VPA sensor exhibited two-step increases of diffracted wavelengths at its pK{sub a1} and pK{sub a2} respectively. The sensors containing proton acceptors, VI and DMAEMA showed the pH-dependent color changes in an opposite way to the AA sensor and the VPA sensor since their ionizations take place by lowering pH due to the protonation at the amino groups. The shapes of pH response curves of VI and DMAEMA sensors were similar but pK{sub b}s were different from each other. Optical diffraction responses of four sensors were compared

  5. Emulsion Polymerization of Etyl Acrylate: The Effect of Surfactant, Initiator Concentration and PolymerizationTechnique on Particle Size Distribution

    Nitri Arinda

    2009-04-01

    Full Text Available Emulsion polymerization was conducted using ethyl acrylate monomer. Theeffect of sodium lauryl sulfate concentration, ammonium persulfate concentration, the various of polymerizationtechniques and feeding time to the conversion, particle size and its distribution were observed. The purpose of thisresearch is to obtain the optimum condition of ethyl acrylate homopolymer with particle size around 100 nm, to get theparticle size distribution monodisperse and to get solid content value of the experiment closed to its theoretical value.The optimum condition then could be applied in shell polymerization of core-shell polymers. The results of the researchshowed that semicontinuous technique obtained optimum sodium lauryl sulfate concentration at 20 CMC (criticalmicelle concentration and ammonium persulfate concentration is 3%. By using batch technique that the biggestparticle size is 123 nm with conversion 95.8% and monodisperse. The shorter of feeding time the more monomer ofethyl acrylate being polymerized, it is showed by the higher conversion up to 94.4% and the bigger particle size is107.9 nm.

  6. Aspects of sucrose transport in stem parenchyma of sweet sorghum

    Sweet sorghum [Sorghum bicolor (L.) Moench] is a sucrose-storing crop with a storage tissue anatomically similar to that of sugarcane (Saccharum spp.). However, recent evidence suggests that sweet sorghum may be biochemically different from sugarcane. 14C-sucrose uptake was studied in excised tissue discs from fully-elongated internodes of Rio sweet sorghum. Washout studies gave results consistent with a 3 compartment system. After 3 hours of uptake, most of the 14C was found in the vacuole compartment, and was determined by HPLC to be sucrose. Total sucrose uptake consisted of a PCMBS-sensitive (active) and a PCMBS-insensitive (passive) component. Active sucrose uptake had a pH optimum of 4.5. Total sucrose uptake was negatively correlated with the internal sucrose content of the tissue. Fructosyl-labelled 14C-sucrose was not randomized during uptake, suggesting that sucrose cleavage is not a requirement for sucrose uptake in sweet sorghum. This data suggests that in sweet sorghum, sucrose is transported intact by a specific carrier, as opposed to the sucrose-cleavage-and-resynthesis transport system that apparently operates in sugarcane

  7. Metabolism of sucrose during storage in intact sorghum stalk

    Grasses of the Andropogoneae, such as sorghum (Sorghum bicolor [L.] Moench) and sugarcane (Saccharum spp.), accumulate large amounts of harvestable sucrose in the stalk. Sucrose is translocated from the leaves, yet the metabolic fate of sucrose up to and during storage in the stalk is uncertain. This study determined whether sucrose is necessarily routed through inversion and hexose-phosphate isomerization for storage in cells of the intact stalk. Sorghum stalks were dual-infused with [U-14C]sucrose and [fructose-1-3H(N)]sucrose during stages of sucrose accumulation. Unperturbed tissue was used for subsequent sugar analyses. Solutes in cell extracts were separated sequentially through enzymatic conversion and ion-exchange removal of the reaction products. The hexose moieties of sucrose were analyzed separately. A mean of 95% of recovered 14C was in sucrose. In sucrose, 46% of 14C and 77% of 3H were recovered in the fructose moiety. The significant retention of asymmetry in tritium labeling of sucrose indicates that a cycle of cleavage and resynthesis did not dominate sucrose accumulation in cells of the sorghum stalk. (author)

  8. Functionalization of nanodiamond with epoxy monomer

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

    2011-01-01

    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. Modification of Poly(Ethylene Terephthalate) Fiber by Grafting of Acrylic Acid/Acrylamide for Removal of Pb+2 from Aqueous Solutions

    A new fibrous adsorbent was prepared by grafting Acrylic Acid /Acryl Amide co-monomers onto Poly(Ethylene Terephthalate) fibers. The resulting sorbent has been characterized by Fourier Transform Infrared spectroscopy, Thermo Gravimetric Analysis, Scanning Electron Microscopy and elemental analysis and studied for the preconcentration and determination of trace Pb+2 ion from water sample. The effects of reaction conditions such as monomer mixture ratio, grafting yield, polymerization. The time and temperature on grafting were investigated. Batch adsorption method was used for the pre concentration studies. Recovery of Pb+2 was 100.2% at optimum conditions. The adsorption capacity of the adsorbent was found 44.1 mg/g for Pb+2.

  10. Elution of Monomers from Provisional Composite Materials

    Simon Daniel Schulz

    2015-01-01

    Full Text Available The aim of this study was to evaluate the elution of substances from different materials used for the manufacturing of temporary indirect restorations, after storage in saliva and ethanol 75%. 10 samples of three chemically cured materials (Protemp 3 Garant, Systemp.c&b, and Trim and one light-cured material (Clip F were stored in saliva and ethanol 75% for 24 h, 7, and days 28 days. From the storage media at each time period, samples were prepared and analysed by LC-MS/MS, in order to access the elution of monomers. The results differed among the materials (P ≤ 0.05. No monomers were detected in the samples of Protemp 3 Garant and Clip F. Substances were detected only in ethanol samples of Systemp.c&b and Trim. The amount of BisGMA, TEGDMA, and UDMA 2 released from Systemp.c&b was higher compared to Trim. Storage time affected the release of substances (P ≤ 0.05. The highest release was observed within the first 24 h. It can be concluded that provisional resin composite materials do not show high release of monomers and this release is material dependent. However, the detection of additional peaks during the analysis, suggesting the formation of by-products of the eluted substances, may not be in favour of these materials with respect to their toxicity.

  11. 21 CFR 888.4220 - Cement monomer vapor evacuator.

    2010-04-01

    ... (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...

  12. Sucrose Inversion An Experiment on Heterogeneous Catalysis

    Adélio Mendes; Magalhães, Fernão D.; Luis M. Madeira

    2003-01-01

    llustration of heterogeneous catalysis concepts in laboratory courses is not usually simple or economical. For our undergraduate senior lab course we have developed an environmentally friendly experiment dealing with several aspects of heterogeneous catalysis, having in mind the use of readily available and relatively inexpensive equipment, and chemicals on a compact setup, which students can safely operate. The experiment deals with the acid-catalyzed sucrose inversion, performed in packed b...

  13. A Facile Strategy for Catalyst Separation and Recycling Suitable for ATRP of Hydrophilic Monomers Using a Macroligand.

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

    2016-01-01

    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. PMID:26506506

  14. Use of acrylic acid in the synthesis of molecularly imprinted polymers for the analysis of cyproheptadine

    Feas, Xesus [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain); Fente, Cristina A. [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain)], E-mail: cfente@lugo.usc.es; Hosseini, S. Vali [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain); Seijas, Julio A. [Organic Chemistry, Campus Lugo, University of Santiago de Compostela. Aptdo 280, E-27080, Lugo (Spain); Vazquez, Beatriz I.; Franco, Carlos M.; Cepeda, Alberto [Analytical Chemistry, Nutrition and Bromatology, Campus Lugo, University of Santiago de Compostela. E-27002, Lugo, Galiza (Spain)

    2009-03-01

    The synthesis and comparative characterization of molecularly imprinted polymers (MIP{sub s}) with cyproheptadine (CYP), using two different monomers, acrylic acid (AA) and methacrylic acid (MAA), are described. Polyacids (PA) [poly(methacrylic acid) (PMAA) and poly(acrylic acid) (PAA)] were obtained by the radical polymerization of MAA and AA, respectively, in dichloromethane as the porogen solvent-imprinted medium. The non-covalent imprinting process was performed via thermal decomposition of an azo-initiator at 60 deg. C, using ethylene glycol dimethacrylate as the cross-linker and 2,2'-azobis(2-methylpropionitrile) as the initiator. The selectivities of MIP{sub s} and NIP{sub s} particles were evaluated in binding experiments of the four synthesized polymeric materials (MIP{sub aa}, MIP{sub maa}, NIP{sub maa} and NIP{sub aa}) with CYP. The effects of monomers on: a) the surface morphology, b) the binding capacity and c) the swelling properties of imprinted and non-imprinted polymers were studied and are presented here. Polymer material morphology was assessed with scanning electron microscopy (SEM). This revealed differences in monomer function, depending on which one was employed, as well as differences in function when polymerization occurred in the presence of template or without it. Non-specific retention of the template to NIP{sub s} was higher for NIP{sub s}-PAA polymers than for NIP{sub s}-PMAA materials. In terms of specific binding ({delta}Q = Q{sub MIP} - Q{sub NIP}), MIP{sub maa} showed the greatest value (53.47%) in comparison with MIP{sub aa} (50.07%)

  15. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Lyndon Jones

    2012-01-01

    Full Text Available Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

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

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

    2015-01-01

    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. PMID:25594340

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

    Ayman M. Atta

    2015-01-01

    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.

  18. Crystallization inhibition of an amorphous sucrose system using raffinose

    LEINEN K.M.; LABUZA T.P.

    2006-01-01

    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.

  19. STUDY ON THE SYNTHESIS AND PHYSICOCHEMICAL PROPERTIES OF SUCROSE POLYESTER

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

    2006-01-01

    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.

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

    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: s_yuhua@163.com [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)

    2013-11-15

    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.

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

    Yoshinori Kadoma

    2012-05-01

    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.

  2. Photochemistry of Acrylates at 222 nm

    Excimer lamps as monochromatic UV sources with an intense short wavelength mission (specially Kr Cl, 222 nm) allow a photo initiator-free initiation of the acrylate polymerisation. Laser photolysis (Kr Cl excimer laser, pulse width 20 ns, up to 5 ml per pulse) gives rise to similar transient spectra (max << 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, a-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 un relaxed triplet state, but not from the relaxed triplet state that is observed spectroscopically. A reaction scheme accounting for the observed products is presented

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

    WANG Zhiyu; LIU Zuoxin

    2006-01-01

    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).

  4. In vitro evaluation of chemically cross-linked shape-memory acrylate-methacrylate copolymer networks as ocular implants.

    Song, Li; Hu, Wang; Zhang, Hongbin; Wang, Guojie; Yang, Huai; Zhu, Siquan

    2010-06-01

    Acrylates have been used in ophthalmic practice as a paradigmatic implant material for decades, especially as intraocular lens for their excellent transparency. A novel polymeric shape memory system of chemically cross-linked acrylate-methacrylate copolymer networks was developed and characterized in this study. The thermomechanical properties, shape memory properties, transparency, and surface wettability as well as cytotoxicity were systematically evaluated to mimic the in vivo situation by differential scanning calorimetry (DSC), tensile tests, spectrophotometer, Abbe refractometer, contact angle measurements, and MTT assay. It was found that the chemically cross-linked copolymer network behaves as an elastomer capable of arbitrary shaping above the glass-transition temperature. Transition temperatures of the networks were tunable through the change of the composition of monomers. PMID:20462221

  5. Radiation curing of surface coating of coconut wood (Cocos nucifera L) parquet using epoxy acrylate and unsaturated polyester

    Experiment on surface coating of coconut wood (Cocos nucifera L) parquet has been done using ultra violet (UV) light radiation. Unsaturated polyester with trade name Polylite P-8009 and epoxy acrylate with the trade name Laromer EA-81, were used as coating materials after being added with tripropylene glycol di acrylate monomer and additive. Irradiation was conducted at the conveyor speed of 3 m/minute. Coating materials were added with 2-hydroxy-2-methyl-1-phenyl propanone as fotoinisiator. Experimental result showed that increasing concentration of fotoinisiator and matting agent increased hardness and abration resistance of the film. Most of the films have good resistance against household chemicals, solvent, and stain except 10% sodium hydroxide. The optimum concentration of the fotoinisiator was 2% and the matting agent concentration was 5%. (authors)

  6. Concepts for stereoselective acrylate insertion

    Neuwald, Boris

    2013-01-23

    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.

  7. Static and dynamical critical behavior of the monomer-monomer reaction model with desorption

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

    2016-06-01

    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.

  8. Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction.

    Saed, Mohand O; Torbati, Amir H; Nair, Devatha P; Yakacki, Christopher M

    2016-01-01

    This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline elastomers (LCEs) with facile control over network structure and programming of an aligned monodomain. Tailored LCE networks were synthesized using routine mixing of commercially available starting materials and pouring monomer solutions into molds to cure. An initial polydomain LCE network is formed via a self-limiting thiol-acrylate Michael-addition reaction. Strain-to-failure and glass transition behavior were investigated as a function of crosslinking monomer, pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). An example non-stoichiometric system of 15 mol% PETMP thiol groups and an excess of 15 mol% acrylate groups was used to demonstrate the robust nature of the material. The LCE formed an aligned and transparent monodomain when stretched, with a maximum failure strain over 600%. Stretched LCE samples were able to demonstrate both stress-driven thermal actuation when held under a constant bias stress or the shape-memory effect when stretched and unloaded. A permanently programmed monodomain was achieved via a second-stage photopolymerization reaction of the excess acrylate groups when the sample was in the stretched state. LCE samples were photo-cured and programmed at 100%, 200%, 300%, and 400% strain, with all samples demonstrating over 90% shape fixity when unloaded. The magnitude of total stress-free actuation increased from 35% to 115% with increased programming strain. Overall, the two-stage TAMAP methodology is presented as a powerful tool to prepare main-chain LCE systems and explore structure-property-performance relationships in these fascinating stimuli-sensitive materials. PMID:26862925

  9. 40 CFR 721.5325 - Nickel acrylate complex.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting...

  10. 21 CFR 175.210 - Acrylate ester copolymer coating.

    2010-04-01

    ... 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...