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Mineto Uchiyama Prof. Dr. Kotaro Satoh Prof. Dr. Masami Kamigaito 《Angewandte Chemie (International ed. in English)》2015,54(6):1924-1928
A metal‐free, cationic, reversible addition–fragmentation chain‐transfer (RAFT) polymerization was proposed and realized. A series of thiocarbonylthio compounds were used in the presence of a small amount of triflic acid for isobutyl vinyl ether to give polymers with controlled molecular weight of up to 1×105 and narrow molecular‐weight distributions (Mw/Mn<1.1). This “living” or controlled cationic polymerization is applicable to various electron‐rich monomers including vinyl ethers, p‐methoxystyrene, and even p‐hydroxystyrene that possesses an unprotected phenol group. A transformation from cationic to radical RAFT polymerization enables the synthesis of block copolymers between cationically and radically polymerizable monomers, such as vinyl ether and vinyl acetate or methyl acrylate. 相似文献
3.
M. Tabata A. Lund P. O. Samskog S. Lunell M. B. Huang 《Journal of polymer science. Part A, Polymer chemistry》1988,26(10):2725-2736
The vinyl monomers methyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, and β-methylstyrene were dissolved in CF3CCl3, x-irradiated at 4 or 77 K, and investigated by ESR spectroscopy. The molecular cation of methyl acrylate has no resolved hyperfine structure, indicating that the unpaired electron is localized on the carbonyl oxygen. Evidence that a two-stage photoinduced reaction gives rise to a propagating radical was obtained. Propagating radicals were observed also with methyl methacrylate, acrylic acid, and methacrylic acid as solutes. The positive ion of β-methylstyrene has been prepared and characterized. The experimental data have been compared with molecular orbital calculations at different levels of approximation. 相似文献
4.
Living radical polymerization (LRP) of methyl acrylate (MA), acrylic acid (AA), and vinyl acetate (VAc) mediated by cobalt(II) porphyrin complexes ((TMP)CoII·, (TMPS)CoII·) are reported. The polymeric products with relatively low polydispersity and controlled number average molecular weight (Mn) based on one polymer chain per cobalt complex demonstrate the living characters of the polymerization process. The formation of block copolymers of poly(methyl acrylate)‐b‐poly(vinyl acetate) (PMA‐b‐PVAc) and poly(methyl acrylate)‐b‐poly(vinyl pyrrolidone) (PMA‐b‐PVP) demonstrate another important feature of LRP and extend the application of cobalt porphyrin mediated radical polymerization to a wider array of functionalized monomers. Kinetic studies using 1H NMR to follow the formation of orGano‐cobalt complexes reveal that two mechanisms, reversible termination (RT) and degenerative transfer (DT), occur during the polymerization process. MA and VAc polymerization mediated by cobalt porphyrin complexes are used to illustrate the properties of these two LRP pathways and evaluate the kinetic and thermodynamic properties for several of the central reactions. 相似文献
5.
Controlled free radical polymerization (CFRP) of vinyl chloride (VCM) and copolymerization with several comonomers have been studied in aqueous suspension. Therefore di-tert-butylnitroxide and three novel nitroxyl radicals were used as mediating agents. Copolymerization of VCM with styrene, partly combined with acrylonitrile, maleic acid anhydride and maleic acid imide as well as methyl methacrylate, n-butyl methacrylate, butyl acrylate and butadiene have been achieved, demonstrating an efficient route for novel vinyl chloride copolymer architecture. 相似文献
6.
Jaroslav Bartoň 《Macromolecular Symposia》2002,179(1):189-208
A new method for preparation of modified polymer particles in two steps was proposed. Free radical polymerization of an oil soluble vinyl monomer like butyl acrylate in inverse microemulsion containing polyacrylamide particles led to the formation of modified, partly hydrophobized, polyacrylamide particles. For the first step of the process (preparation of polyacrylamide particles in inverse microemulsion) is typical a very high polymerization rate while for the second step (polymerization of an oil soluble monomer (methyl acrylate, ethyl acrylate, butyl acrylate 2-ethylhexyl acrylate, methyl methacrylate, styrene) in the presence of polyacrylamide particles in inverse microemulsion, the reverse is true. The polymerization of an oil soluble monomer in some instances leads to the formation of 2-phase or even 3-phase disperse systems. The polymeric products obtained after precipitation of the polymer particles from the inverse microemulsions by ethanol were extracted by water and/or toluene and analyzed for acrylamide content. The separated polymer product contained high content of acrylamide, AAm/oil soluble monomer (butyl acrylate BA, or styrene, S) copolymer (85% of AAm/BA, ≈ 99% of AAm/S) besides relatively small amounts of homopolymers of oil soluble monomers (15% of BA, ≈ 1% of S homopolymers). 相似文献
7.
Wouter Reyntjens Laura Jonckheere Eric Goethals Filip Du Prez 《Macromolecular Symposia》2001,164(1):293-300
Segmented polymer networks with LCST‐behavior have been prepared by free radical initiated copolymerization of α,ω‐bis‐methacrylate terminated poly(methyl vinyl ether) (PMVE) with 2‐hydroxy ethyl methacrylate (HEMA) or butyl acrylate (BA). The PMVE bis‐macromonomers have been obtained via a semi‐continuous process by end‐capping the living cationic polymerization of methyl vinyl ether (MVE) with HEMA. The phase separation temperature can be varied by changing the PMVE/comonomer ratio. Incorporation of PMVE‐grafts in the hydrogels increases the rate of deswelling and improves the mechanical properties. The application of the segmented networks for thermo‐controllable solid phase extraction has been demonstrated by their thermosensitive adsorption behavior of toluene from a water solution. 相似文献
8.
以丙烯酸、丙烯酸丁酯和甲基丙烯酸甲酯为单体,采用自由基聚合法制备了聚丙烯酸卷材涂料前驱成膜物,获得了适宜的制备工艺条件。研究表明,以三元共聚体系聚合产物为根本,以氨基树脂为交联剂,三乙胺为中和剂,可制备令人满意的水溶性聚丙烯酸卷材涂料前驱成膜物,为开发水溶性聚丙烯酸卷材涂料提供了基础数据。 相似文献
9.
The living cationic polymerization of vinyl ethers has been used to prepare a number of new polymers with special properties. Sequential polymerization of the hydrophilic methyl vinyl ether (MVE) and the hydrophobic octadecyl vinyl ether (ODVE) has lead to amphiphilic block-copolymers with emulsifying properties for water/decane mixtures. Poly(vinyl-ether) macromonomers were obtained by end-capping of living polymers with hydroxyethyl acrylate. Copolymerization of polyODVE-macromonomer with usual acrylates lead to highly branched hydrophobic polymers. When the end-capping was performed with bifunctionally living polymers, the corresponding “bis-macromonomers” were obtained. Copolymerization of such bis-macromonomers with styrene or butyl acrylate, leads to the formation of segmented polymer networks. In the case of polyODVE-poly(butyl acrylate), these networks showed a pronounced phase separation. Due to the crystallinity of the polyODVE domains, these materials showed shape memory properties. 相似文献
10.
含疏水链节的聚N-异丙基丙烯酰胺共聚物的温敏性 总被引:1,自引:0,他引:1
采用溶液聚合法合成了一系列N-异丙基丙烯酰胺(NIPAM)与甲基丙烯酸甲酯、丙烯酸乙酯、丙烯酸丁酯或甲基丙烯酸丁酯的无规共聚物,用浊度观测法和光散射法测定了不同共聚物水溶液的温敏相转变行为.结果表明:所得共聚物的低临界溶解温度(LCST)均低于均聚物PNIPAM的,酯类单体的结构和含量对共聚物的LCST有显著影响,其中酯基上的烷基对共聚物LCST的影响能力大于丙烯酸酯α位上的烷基,前者对增大共聚物的疏水性有更大贡献.通过NIPAM与特定丙烯酸酯单体进行无规共聚可以合成转变温度低于PNIPAM均聚物且具有预设LCST数值的水溶性温敏聚合物. 相似文献
11.
Christy D. Petruczok Richard F. Barlow Devon A. Shipp 《Journal of polymer science. Part A, Polymer chemistry》2008,46(21):7200-7206
The synthesis of poly(tert‐butyl acrylate‐block‐vinyl acetate) copolymers using a combination of two living radical polymerization techniques, atom transfer radical polymerization (ATRP) and reversible addition‐fragmentation chain transfer (RAFT) polymerization, is reported. The use of two methods is due to the disparity in reactivity of the two monomers, viz. vinyl acetate is difficult to polymerize via ATRP, and a suitable RAFT agent that can control the polymerization of vinyl acetate is typically unable to control the polymerization of tert‐butyl acrylate. Thus, ATRP was performed to make poly(tert‐butyl acrylate) containing a bromine end group. This end group was subsequently substituted with a xanthate moiety. Various spectroscopic methods were used to confirm the substitution. The poly(tert‐butyl acrylate) macro‐RAFT agent was then used to produce (tert‐butyl acrylate‐block‐vinyl acetate). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7200–7206, 2008 相似文献
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Grigoriy A. Mun Zauresh S. Nurkeeva Gulnara T. Akhmetkalieva Sergey N. Shmakov Vitaliy V. Khutoryanskiy Sang Cheon Lee Kinam Park 《Journal of Polymer Science.Polymer Physics》2006,44(1):195-204
Novel water‐soluble amphiphilic copolymers have been synthesized by free radical copolymerization of 2‐hydroxyethylacrylate with vinyl butyl ether. In water these copolymers exhibit lower critical solution temperature, which depends on the content of hydrophobic vinyl butyl ether units. The interaction between these copolymers and poly(acrylic acid) or poly(methacrylic acid) in aqueous solutions results in formation of interpolymer complexes stabilized by hydrogen bonds and hydrophobic interactions. An increase in hydrophobicity of the copolymers leads to the enhancement of their complex formation ability with respect to poly(acrylic acid) and poly(methacrylic acid). Poly(methacrylic acid) forms stronger complexes with the copolymers when compared with poly(acrylic acid). The complexes exhibit dual sensitivity to pH‐ and temperature and this property may be easily adjusted regulating the strength of interaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 195–204, 2006 相似文献
13.
The thermal degradation of copolymers based on butyl acrylate-methyl acrylate-acrylic acid used as acrylic pressure-sensitive
adhesives, especially for bonding of plasticizer containing materials, has been investigated using thermogravimetry and pyrolysis-gas
chromatography at 250°C. It was observed that during the pyrolysis of butyl acrylate-methyl acrylate-acrylic acid copolymers
unsaturated monomers as methyl acrylate, methyl methacrylate, butyl acrylate and butyl methacrylate were formed. During the
side-chain butyl acrylate-methyl-acrylate-acrylic acid-copolymer degradation the presence of methyl alcohol and butyl alcohol
was observed. 相似文献
14.
Harald Braun 《European Polymer Journal》2002,38(1):151-156
Butyl vinyl ether (BVE) and methyl methacrylate (MMA) mixtures were polymerized by using free radical initiators in conjunction with a cationic initiator such as diphenyl iodonium salt. Polymerization mechanism involves free radical polymerization of MMA which is switched to cationic polymerization of BVE by addition of growing poly(MMA) radicals to BVE and subsequent oxidation of electron donating polymeric radicals to the corresponding cations by iodonium ions. Two representative bifunctional monomers, ethylene glycol divinyl ether (EGDVE) and ethylene glycol dimethacrylate (EGDMA) were also used together with MMA and BVE, respectively, in photo and thermal crosslinking polymerizations. Vinyl ether and methacrylate type monomers can successfully be copolymerized by this double-mode polymerization under photochemical conditions. 相似文献
15.
Duygu Avci Lon J. Mathias 《Journal of polymer science. Part A, Polymer chemistry》2002,40(19):3221-3231
Novel phosphorus‐containing acrylate monomers were synthesized by two different routes. The first involved the reaction of ethyl α‐chloromethyl acrylate and t‐butyl α‐bromomethyl acrylate with diethylphosphonoacetic acid. The monomers were bulk‐ and solution‐polymerized at 56–64 °C with 2,2′‐azobisisobutyronitrile. The ethyl ester monomer showed a high crosslinking tendency under these conditions. The selective hydrolysis of the ethyl ester phosphonic ester compound was carried out with trimethylsilyl bromide, producing a phosphonic acid monomer. In the second route, ethyl α‐hydroxymethyl acrylate and t‐butyl α‐hydroxymethyl acrylate were reacted with diethylchlorophosphate. The bulk homopolymerization and copolymerization of these monomers with methyl methacrylate and 2,2′‐azobisisobutyronitrile gave soluble polymers. The attempted hydrolysis of the monomers was unsuccessful because of the loss of the diethylphosphate group. The relative reactivities of the monomers in the photopolymerizations were also compared. The ethyl α‐hydroxymethyl acrylate/diethylphosphonic acid monomer showed higher reactivity than the other monomers, which may explain the crosslinking during the polymerization of this monomer. The reactivities of other derivatives were similar, but the rates of polymerization were slow in comparison with those of methyl methacrylate. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3221–3231, 2002 相似文献
16.
James A. Harris Oscar Hinojosa Jett C. Arthur 《Journal of polymer science. Part A, Polymer chemistry》1974,12(3):679-688
Ferric chloride-photosensitized free-radical initiation was used to generate propagating radicals in polymerization of acrylic acid (AA), methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), acrylamide (A), and diacetone acrylamide (DAA) in rigid glasses of methanol, ethanol, n-propanol, isopropanol, or acetone at near liquid nitrogen temperatures. When the temperatures of the glasses were increased, primary radicals derived from the solvents reacted with the monomers to yield propagating radicals. Formation and conformational changes of the propagating radicals at different temperatures were studied by electron spin resonance (ESR) spectroscopy. It was concluded that one type of propagating radical was formed in all cases. However, when the temperature of the rigid glass was increased, the structural conformation of the radical that initially allowed the near-equivalent interaction of the α-hydrogen and one of the β-hydrogens with the unpaired electron generated a three-line spectrum. 相似文献
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Delphine Chan‐Seng David A. Rider Gérald Guérin Michael K. Georges 《Journal of polymer science. Part A, Polymer chemistry》2008,46(2):625-635
Living‐radical polymerization of acrylates were performed under emulsion atom transfer radical polymerization (ATRP) conditions using latexes prepared by a nanoprecipitation technique previously employed and optimized for the polymerization of styrene. A macroinitiator of poly(n‐butyl acrylate) prepared under bulk ATRP was dissolved in acetone and precipitated in an aqueous solution of Brij 98 to preform latex particles, which were then swollen with monomer and heated. Various monomers (i.e. n‐butyl acrylate, styrene, and tert‐butyl acrylate) were used to swell the particles to prepare homo‐ and block copolymers from the poly(n‐butyl acrylate) macroinitiator. Under these conditions latexes with a relatively good colloidal stability were obtained. Furthermore, amphiphilic block copolymers were prepared by hydrolysis of the tert‐butyl groups and the resulting block copolymers were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The bulk morphologies of the polystyrene‐b‐poly(n‐butyl acrylate) and poly(n‐butyl acrylate)‐b‐poly(acrylic acid) copolymers were investigated by atomic force microscopy (AFM) and small angle X‐ray scattering (SAXS). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 625–635, 2008 相似文献
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Richard A. Wolf John M. Warakomski Thomas L. Staples Michael J. Fazio 《Journal of polymer science. Part A, Polymer chemistry》2001,39(9):1391-1402
A series of hydrazones were prepared and tested for their ability to act as free‐radical initiators for vinyl monomers. The most active initiators were the tertiary butyl hydrazones of aromatic, aliphatic ketones. The most reactive vinyl monomers were acrylate‐type monomers, with methacrylate‐type monomers being somewhat less reactive. When the most reactive hydrazone initiators, such as compound 1 , were added to ambient‐temperature solutions of acrylate monomers, such as aqueous sodium acrylate or aqueous acrylamide, polymerizations to hard gels occured within 1 min. In some cases of vinyl polymerizations, these hydrazone initiators can act as low‐temperature alternatives to redox initiators. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1391–1402, 2001 相似文献
19.
Kudyshkin V. O. Vokhidova N. R. Bozorov N. I. Sidorenko O. E. Ruban I. N. Voropaeva N. L. Rashidova S. Sh. 《Russian Journal of Applied Chemistry》2004,77(6):994-997
The performance of allylbenzene and allyl phenyl ether as chain-transfer agents in radical polymerization of styrene, methyl acrylate, butyl methacrylate, vinylpyrrolidone, and vinylcaprolactam was evaluated. 相似文献
20.
Md. Ibrahim H. Mondal Yasumitsu Uraki Makoto Ubukata Koki Itoyama 《Cellulose (London, England)》2008,15(4):581-592
The influence of treating cotton fibres with several amines on the mechanical properties, moisture sorption ability before
and after graft polymerization, and on graft yields for various water-soluble and water-insoluble vinyl monomers were analysed.
As compared to water, the treatment with amines, ethylenediamine (EDA) in particular, resulted in a decrease in the crystallinity
and tensile strength of the cotton fibres, and an increase in the moisture sorption. The graft yields of amine-treated cotton
fibres using water-soluble monomers, acrylic acid (AA), methacrylic acid (MAA) and acrylamide (AM) were greater than those
observed for water-treated cotton fibres, whereas the graft yields using water-insoluble monomers, methyl acrylate (MA), methyl
methacrylate (MMA) and vinyl acetate (VA) were lower. The moisture sorption ability was improved by the graft polymerization
with water-soluble monomers. The improvement was enhanced for MA and MAA by treatment with sodium hydroxide to form the corresponding
sodium carboxylate derivatives. The tensile strength of EDA-treated cotton was slightly reduced by grafting, while that of
the water-activated cotton yarn was barely changed. These results suggest that the graft polymerization of amine-treated cotton
fibres with certain vinyl monomers increased the moisture sorption ability without resulting in increased fibre rigidity. 相似文献