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Przemysaw Kubisa - One of the best experts on this subject based on the ideXlab platform.
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atom transfer radical polymerization of Acrylates in an ionic liquid
Macromolecular Rapid Communications, 2001Co-Authors: Tadeusz Biedron, Przemysaw KubisaAbstract:The atom-transfer radical polymerization (ATRP) of Acrylates in 1-butyl-3-methylimidazolium hexafluorophosphate was investigated. The solubility of the Acrylates in the ionic liquid depends on the substituent. The homogeneous polymerization of methyl Acrylate gives polymers with Mn close to the calculated value and relatively narrow polydispersity. In heterogeneous polymerizations of higher Acrylates, with the catalyst present in the ionic liquid phase, deviations from ideal behavior are observed although the polymerization of butyl Acrylate approaches the conditions of a controlled polymerization.
Virgil Percec - One of the best experts on this subject based on the ideXlab platform.
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set lrp of semifluorinated Acrylates and methAcrylates
Polymer Chemistry, 2014Co-Authors: Shampa R Samanta, Ruilong Cai, Virgil PercecAbstract:Single electron transfer-living radical polymerization (SET-LRP) of 1H,1H,2H,2H-perfluorooctyl Acrylate, 2,2,3,3,4,4,4-heptafluorobutyl Acrylate, and 1H,1H,5H-octafluoropentyl methAcrylate up to [M]0/[I]0 = 30 and 1H,1H,5H-octafluoropentyl Acrylate up to 93% monomer conversion targeting [M]0/[I]0 = 260 with excellent control of molecular weight and molecular weight distribution was accomplished in 2,2,2-trifluoroethanol (TFE) at 25 °C for the Acrylates and 50 °C for the methAcrylate. These experiments demonstrated that TFE serves as a very good solvent for SET-LRP of semifluorinated monomers using hydrazine activated Cu(0) wire as a catalyst, bis(2-bromopropionyl)ethane and p-toluene sulfonyl chloride as initiators, and Me6-TREN as a ligand. Analysis of the kinetics of polymerization and of the polymer chain ends by a combination of 1H-NMR, GPC, MALDI-TOF and chain-end functionalization by “thio-bromo” click reaction demonstrated the synthesis of perfect or near-perfect chain-end functional semifluorinated homopolymers.
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copper ii tertiary amine synergy in photoinduced living radical polymerization accelerated synthesis of ω functional and α ω heterofunctional poly Acrylates
Journal of the American Chemical Society, 2014Co-Authors: Athina Anastasaki, Shampa R Samanta, Vasiliki Nikolaou, Qiang Zhang, James A Burns, Christopher Waldron, Alice J Haddleton, Ronan Mchale, Virgil PercecAbstract:Photoinduced living radical polymerization of Acrylates, in the absence of conventional photoinitiators or dye sensitizers, has been realized in “daylight’”and is enhanced upon irradiation with UV radiation (λmax ≈ 360 nm). In the presence of low concentrations of copper(II) bromide and an aliphatic tertiary amine ligand (Me6-Tren; Tren = tris(2-aminoethyl)amine), near-quantitative monomer conversion (>95%) is obtained within 80 min, yielding poly(Acrylates) with dispersities as low as 1.05 and excellent end group fidelity (>99%). The versatility of the technique is demonstrated by polymerization of methyl Acrylate to a range of chain lengths (DPn = 25–800) and a number of (meth)Acrylate monomers, including macromonomer poly(ethylene glycol) methyl ether Acrylate (PEGA480), tert-butyl Acrylate, and methyl methAcrylate, as well as styrene. Moreover, hydroxyl- and vic-diol-functional initiators are compatible with the polymerization conditions, forming α,ω-heterofunctional poly(Acrylates) with unparalleled ...
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set lrp of hydrophobic and hydrophilic Acrylates in trifluoroethanol
Polymer Chemistry, 2013Co-Authors: Shampa R Samanta, Martin E Levere, Virgil PercecAbstract:Efficient disproportionation of CuBr–Me6-TREN in 2,2,2-trifluoroethanol (TFE) to produce “nascent” Cu(0) and CuBr2–Me6-TREN indicates that this semifluorinated alcohol has the potential to be an excellent solvent for Cu(0) mediated single electron transfer-living radical polymerization (SET-LRP). Herein, we report the SET-LRP of a range of hydrophobic and hydrophilic Acrylates, including methyl Acrylate (MA), n-butyl Acrylate (nBA), tert-butyl Acrylate (tBA), 2-ethylhexyl Acrylate (EHA) and 2-hydroxyethyl Acrylate (HEA) using 2-bromopropionate (MBP) and 2-ethylbromoisopropionate (EBiB) as initiators, and Me6-TREN as ligand in TFE. Analysis of the kinetics of polymerization and of the polymer chain ends by a combination of 1H NMR, GPC, MALDI-TOF and chain-end functionalization by “thio-bromo” click reaction demonstrated the synthesis of perfect or near-perfect chain-end functional polyAcrylates by SET-LRP in TFE.
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ultrafast single electron transfer degenerative chain transfer mediated living radical polymerization of Acrylates initiated with iodoform in water at room temperature and catalyzed by sodium dithionite
Journal of Polymer Science Part A, 2005Co-Authors: Virgil Percec, Ernesto Ramirezcastillo, Anatoliy V Popov, Luis A Hinojosafalcon, Tamaz GuliashviliAbstract:Sodium dithionite in the presence of NaHCO3 in water acts as a single- electron-transfer agent and facilitates the single-electron-transfer/degenerative-chain- transfer mediated living radical polymerization (SET-DTLRP) of Acrylates initiated with iodoform at room temperature. The resulting ,-di(iodo)polyAcrylates can be used as macroinitiators for the SET-DTLRP of other Acrylates. Ultrahigh-molar-mass poly- (tert-butyl Acrylate) can be synthesized via the SET-DTLRP of tert-butyl Acrylate and has a very low weight-average molecular weight/number-average molecular weight ratio of 1.15. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2178 -2184, 2005
Tadeusz Biedron - One of the best experts on this subject based on the ideXlab platform.
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atom transfer radical polymerization of Acrylates in an ionic liquid
Macromolecular Rapid Communications, 2001Co-Authors: Tadeusz Biedron, Przemysaw KubisaAbstract:The atom-transfer radical polymerization (ATRP) of Acrylates in 1-butyl-3-methylimidazolium hexafluorophosphate was investigated. The solubility of the Acrylates in the ionic liquid depends on the substituent. The homogeneous polymerization of methyl Acrylate gives polymers with Mn close to the calculated value and relatively narrow polydispersity. In heterogeneous polymerizations of higher Acrylates, with the catalyst present in the ionic liquid phase, deviations from ideal behavior are observed although the polymerization of butyl Acrylate approaches the conditions of a controlled polymerization.
Richard P Wool - One of the best experts on this subject based on the ideXlab platform.
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fundamental thermo mechanical property modeling of triglyceride based thermosetting resins
Journal of Applied Polymer Science, 2013Co-Authors: John J La Scala, Richard P WoolAbstract:The glass transition temperature (Tg) of Acrylated triglycerides was clearly a function of the level of acrylation of triglyceride-based polymers and was modeled using simple empirical relationships. We began by calculating the distribution of unsaturation sites in plant oils. We assumed a binomial distribution of chemical functionality that was added to these unsaturation sites to calculate the distribution of epoxides, Acrylates, and reacted Acrylates to predict the crosslink density, thermal softening, and dynamic mechanical behavior. The glass transition temperatures of n-Acrylated triglycerides were used as the relaxation temperatures of Acrylated oils with a broad distribution of functionality for prediction of the modulus as a function of temperature. Essentially, the percent drop in the elastic modulus is equal to the percentage of n-Acrylated triglycerides in the Acrylated oil with Tg less than that of the ambient temperature. The tan (δ) was also accurately predicted based on the percentage change of n-functional triglycerides as the temperature changes from one relaxation temperature to the next. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
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property analysis of triglyceride based thermosets
Polymer, 2005Co-Authors: John J La Scala, Richard P WoolAbstract:Abstract Triglycerides with Acrylate functionality were prepared from various oils and model triglycerides. The triglyceride-Acrylates were homopolymerized and copolymerized with styrene. The cross-link densities of the resulting polymer networks were predicted utilizing the Flory–Stockmayer theory. Although the model predictions overestimated the cross-link density, the trends in the cross-link density predictions matched the experimental results. In both cases, the cross-link density was found to increase gradually at low levels of acrylation and then linearly at higher levels of acrylation. The deviation in the experimental results and model predictions were the result of intramolecular cross-linking. Approximately 0.5 and 0.8 Acrylates per triglyceride were lost to intramolecular cyclization for homopolymerized triglyceride-Acrylates and triglycerides copolymerized with styrene, respectively. The glass transition temperature ( T g ) increased approximately linearly with the cross-link density from as low as −50 °C to as high as 92 °C. Simple models accurately predicted the effect of cross-link density on T g . The tensile strength and modulus of triglyceride-based polymers increased exponentially at low levels of Acrylate functionality, but increased linearly at higher levels of Acrylate functionality, as predicted by vector percolation theory.
Tuula Estlander - One of the best experts on this subject based on the ideXlab platform.
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Occupational respiratory hypersensitivity caused by preparations containing Acrylates in dental personnel
Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology, 1998Co-Authors: Päivi Piirilä, Tuula Estlander, Helena Keskinen, Lasse Kanerva, M. Hytönen, M. Tuppurainen, Henrik NordmanAbstract:Background Allergic contact dermatitis caused by Acrylate compounds is common in dental personnel; they also often complain of work-related respiratory or conjunctival symptoms. Objective The aim of the present study was to report the cases of Acrylates induced respiratory hypersensitivity in dental personnel diagnosed in Finland during the last 6 years. Methods Occupational asthma, rhinitis, laryngitis and pharyngitis cases were diagnosed according to patient history, PEF monitoring, and a work-simulating provocation test. Results Twelve cases of respiratory hypersensitivity caused by Acrylates diagnosed in dental personnel (six dentists and six dental nurses) in 1992–97 are reported. During this period one case of conjunctivitis and one of laryngitis have been published separately. Nine cases of occupational asthma, two rhinitis cases, and one laryngitis case were verified according to the challenge tests with dental Acrylate compounds (Acrylates, methAcrylates and epoxy Acrylates). Only three patients had positive skin-prick test reactions to common environmental allergens, and none reacted to Acrylates in the skin-prick tests. Five patients had an elevated total IgE (>110 kU/L). PEF follow-up showed an occupational effect in all examined eight patients with diagnosed asthma. The mean duration of exposure to Acrylates was 22 years, and the duration of respiratory symptoms 8 years. Conclusions The results indicate that Acrylates constitute an important hazard for dental workers. The mechanism of respiratory hypersensitivity is still unknown, and it is probably not IgE-mediated.
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occupational allergic contact dermatitis from 2 hydroxyethyl methAcrylate and ethylene glycol dimethAcrylate in a modified acrylic structural adhesive
Contact Dermatitis, 1995Co-Authors: Lasse Kanerva, Timo Leino, Tuula EstlanderAbstract:Acrylates have a broad area of application in various products including glues, sealants and adhesives. Whereas anaerobic acrylic sealants arc well-known sensitizers, Acrylate glues that cure in air have only seldom been reported as allergens. Here a patient sensitized to such a glue, and developing hand dermatitis that spread to the lower arms, chest, neck and face, is presented. Her glue was analyzed by gas chroma tography/mass spectrometry (GC/MS) and contained 24,6% 2-hydroxyethyl methAcrylate (2-HEMA) and 0.4% ethylene glyol dimethAcrylate (EGDMA). These 2 Acrylate compounds, as well as her glue, provoked an allergic patch test reaction. Also many other Acrylate compounds, e.g., tetrahydrofurfuryl methAcrylate, gave an allergic reaction indicating cross-allergy. The patient could not continue in her previous workplace because of severely-relapsing skin symptoms.
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occupational allergic contact dermatitis caused by epoxy diAcrylate in ultraviolet light cured paint and bisphenol a in dental composite resin
Contact Dermatitis, 1995Co-Authors: Riitta Jolanki, Lasse Kanerva, Tuula EstlanderAbstract:Allergic contact dermatitis (ACD) caused by epoxy di(meth)Acrylates or bisphenol A is rare. Here 2 such cases are reported. A dental assistant had allergic contact dermatitis (ACD) caused by bisphenol A contained in dental composite resin (DCR) products based on epoxy dimethAcrylate. The contact allergy was verified by allergic patch test reactions to bisphenol A and 2 DCRs. The DCRs giving allergic reactions were analyzed, and 0.014-0.015% of bisphenol A was detected. Occupational ACD caused by bisphenol A in dental composite resins has not been described before. The other patient was a male process worker in a paint factory. He was sensitized by an epoxy diAcrylate, 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (BIS-GA), and other Acrylate compounds contained in raw materials of ultraviolet-light-curable paint. The epoxy diAcrylate gave an allergic patch test reaction down to 0.016% in pet. He also had an allergic patch test reaction to several other Acrylate compounds, 2-hydroxyethyl Acrylate, 2-hydroxypropyl Acrylate, 1,4-butanediol diAcrylate, 1,6-hexanediol diAcrylate, diethyleneglycol diAcrylate, triethylene glycol diAcrylate, and tripropylene glycol diAcrylate, indicating cross and/or concomitant sensitization.
