Thixotropic interparticle interaction between silica and nonionic polymer particles prepared by static dispersion polymerization
Thixotropic interparticle interaction between silica and nonionic polymer particles prepared by static dispersion polymerization
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DOI：
10.1016/j.polymer.2011.01.056
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发表时间：
2011-03
期刊：
影响因子：
4.6
通讯作者：
Shintaro Kawano;Asumi Sei;M. Kunitake
中科院分区：
文献类型：
--
作者：
Shintaro Kawano;Asumi Sei;M. Kunitake
研究了苯乙烯、甲基丙烯酸甲酯、甲基丙烯酸乙酯、甲基丙烯酸丁酯和甲基丙烯酸苄酯在含有未改性二氧化硅粒子的水分散体系中的静态分散聚合。苯乙烯的聚合得到了二氧化硅和单分散聚苯乙烯（PS）颗粒的混合分散体，与二氧化硅颗粒的水分散体相比，它是非常稳定的。增强的分散稳定性是由于基于二氧化硅和PS颗粒在水性分散体中的弱吸引力的颗粒间相互作用的触变效应。形成其中二氧化硅颗粒被较小PS颗粒包围的聚集体，并抑制二氧化硅颗粒的絮凝，从而提供增强的分散稳定性。与甲基丙烯酸酯类似物的类似静态聚合反应的结果表明，苯环和二氧化硅表面上的羟基之间的氢键，而不是来自引发剂残基的静电相互作用，是弱相互作用的触变聚集的起源。
Static dispersion polymerization of styrene, methyl methacrylate, ethyl methacrylate, butyl methacrylate and benzyl methacrylate, initiated by a lipophilic initiator in an aqueous dispersion with unmodified silica particles was investigated. Polymerization of styrene gave a mixed dispersion of silica and monodisperse polystyrene (PS) particles, which was extremely stable compared with the aqueous dispersion of silica particles. The enhanced dispersion stability is due to a thixotropic effect based on weak attractive interparticle interactions between silica and PS particles in aqueous dispersion. An aggregate in which silica particles are surrounded by the smaller PS particles is formed and inhibits flocculation of silica particles, thus giving enhanced dispersion stability. The results of similar static polymerization reactions with methacrylate analogs indicate that hydrogen bonds between benzene ring and hydroxy groups on the silica surface, and not electrostatic interaction derived from initiator residues, are the origin of weak interaction for thixotropic aggregation.