共查询到19条相似文献,搜索用时 62 毫秒
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乳液聚合的最新进展(上) 总被引:21,自引:0,他引:21
本文对近10多年中发展起来的与乳液聚合相关的聚合技术,如无皂乳液聚合、细乳液聚合、微乳液聚合、分散聚合等,也对其实施方法、理论研究结果和应用作了介绍;还针对近年来已经成为热点的核壳乳液、单分散聚合物微球及表面官能化的乳液微球的制备方法及应用进行了综述。 相似文献
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超声辐照引发MMA微乳液聚合 总被引:17,自引:0,他引:17
研究了超声波引发甲基丙烯酸甲酯(MMA)的微乳液聚合,辐照40min时单体转化率高达90%。透射电镜观察发现,PWWA微乳液平均粒径为36.5nm,粒径分布窄,表明超声波引发是制备PMMA微乳液的有效方法。采用分光光度计对微乳液聚合过程中乳胶粒的形成和大小进行了间接表征。研究了超声功率输出、乳化剂、助乳化剂、单体和引发剂对MMA微乳液聚合的影响。 相似文献
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超声辐照引发MMA微乳液聚合动力学研究 总被引:8,自引:0,他引:8
用自由基捕捉剂N,N-二苯基-2,4,6-三硝基苯肼基(DPPH)进行超声辐照引发甲基丙烯酸甲酯(MMA)微乳液聚合引发过程的动力学研究,结果表明,所得速率常数比超声辐照引发纯单体聚合的速率常数大一个数量级,说明超声辐照在微乳液聚合体系中的引发作用远远强于本体聚合;得到的表观活化能为正值,说明升温有利于超声辐照引发微乳液聚合,对聚合过程动力学的研究表明,引发剂用量决定聚合反应速率曲线恒速期的长短。 相似文献
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微乳液结构和丙烯酰胺反相微乳液聚合 总被引:41,自引:0,他引:41
本文对微乳液的结构及其特征作了概括性的论述,并着重总结了近年来在微乳液聚合方面的研究成果,特别是对丙烯酰胺,丙烯酸盐以及(2-甲基丙烯酰氧乙基)三甲基氯化铵等单位的反相微乳液聚合的研究工作进行了详尽论述。 相似文献
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过硫酸钾引发苯乙烯微乳液聚合 总被引:19,自引:1,他引:18
以具有Y型结构的乳化剂HOA制备苯乙烯微乳液,能有效提高体系中单体浓度和单体对乳化剂的比例,用过硫酸眼具有苯乙烯含量较高的微乳液聚合,记录聚合速率随转化率的变化,观测到了聚合恒速期的存在,恒速期随单体浓度减小,过硫酸钾浓度增加及乳化剂浓度增加而缩短,还研究了聚合动力学,探讨了微乳液聚合的机理。 相似文献
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过硫酸钾引发丙烯酰胺微乳液聚合 总被引:16,自引:0,他引:16
以山梨醇酐单月桂酸醋(Span20)和聚氧乙烯山梨醇酐单硬醋酸酯(Tween60)的混合物为乳化剂制备丙烯酰胺微乳液,研究了体系中Tween60浓度、水相丙烯酰胺浓度对微乳液电导行为的影响.用过硫酸钾引发微乳液聚合,发现聚合开始后,体系电导率迅速下降,在聚合进入恒速期后电导不再降低.聚合的动力学表达式为:Rp∝[AM]1.17[E]-1.26[I]0.5;Mv∝[AM]1.05[E]-0.94[I]-0.62.它与常规乳液聚合的动力学相差较大,却类似于悬浮聚合. 相似文献
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阳离子型微乳液聚合丙烯酰胺的表征 总被引:10,自引:0,他引:10
自从Hoar[1]和Schulman[2]利用乳化剂、水和油制得均一透明的微乳液以来,微乳液在许多领域中得到广泛应用.Candau[3,4]通过微乳液聚合得到分子量很高(105~106)的纳米级聚合物粒子,且聚合物分子链采取紧密缠绕的构象.Antonietti[5]在对苯乙烯微乳液聚合的研究报道中认为,聚合物分子链是以一种类似于网状交联结构的形态存在的,这些结果表明,通过微乳液聚合所得聚合物可能存在着一些特殊的性质.本文采用阳离子型乳化剂十六烷基三甲基溴化铵(CTAB)和脂肪族醇助乳化剂制备的油包水(W/O)型反相微乳液体系来聚合丙烯酰胺(Am),并与使用相同乳… 相似文献
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Peng Xu Haitao Wang Rong Tong Qiangguo Du Wei Zhong 《Colloid and polymer science》2006,284(7):755-762
Polymethylmethacrylate/SiO2 nanocomposite particles were prepared through microemulsion polymerization by using the silica particles coated with 3-(trimethoxysilyl) propyl methacrylate (MSMA) in both acidic and alkaline conditions. Core-shell and other interesting morphology nanocomposite particles were obtained depending on the pH of the microemulsion, the amount of silanol, and the coupling agent concentration employed. Then, by combining a modified microemulsion polymerization process, i.e., an additional monomer-adding process, the solid contents of the polymer/inorganic nanocomposite microemulsion could greatly increase. Thus, by adjusting these parameters and polymerization process, it was possible to control the morphology and size of the nanocomposites. 相似文献
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乳液聚合的最新进展(下) 总被引:3,自引:0,他引:3
乳液聚合的最新进展(下)王群,府寿宽,于同隐(复旦大学高分子科学系,上海,200433)2.5单分散聚合物微球的制备和应用自从50年代,Vanderhoff等人首次成功地制备单一尺寸的聚合物胶乳以来,对聚合物微球的兴趣日渐增长。乳液聚合是最早用于生产... 相似文献
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Kevin D. Hermanson Eric W. Kaler 《Journal of polymer science. Part A, Polymer chemistry》2004,42(20):5253-5261
Microemulsion and emulsion polymerization can have some similarities in starting conditions and polymerization mechanisms, but the resulting latices are unalike in particle size and molecular weight. Here we show that polymerizations can be formulated that display the characteristics often separately associated with microemulsion or emulsion polymerization. Kinetic modeling and particle size measurements show that emulsion polymerizations with initial concentrations close to the microemulsion–emulsion phase boundary demonstrate relatively fast consumption of monomer droplets and produce smaller particles. Because of their high surfactant concentrations, none of the emulsion polymerizations examined demonstrate the classical Smith–Ewart kinetics usually associated with emulsion polymerization. Instead these emulsion polymerizations have a long period of particle nucleation that subsides only after the disappearance of monomer droplets. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5253–5261, 2004 相似文献
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Emulsifier for microemulsion polymerization 总被引:3,自引:0,他引:3
By introducing an hydroxyl group and a lipophilic branch into the middle of lipophilic head of emulsifier 12-oxy-9-octadecenoic
acid, a new emulsifier was synthesized and applied in microemulsion polymerization. When the emulsifier content in the microemulsion
was kept to about 12%, the highest monomer content in microemulsion could achieve 35% for BA, 20% for St and MMA. The microemulsion
with high monomer content remained clear after polymerization, and the average diameters of polymer particles were 38.9 nm
for St microemulsion, 47.4 nm for BA, and 50.7 nm for MMA.
Received: 18 November 1997 Accepted: 16 January 1998 相似文献