Abstract: A new method for preparation of polystyrene nanoparticles by using a method of RAFT living polymerization was studied.Firstly,small molecular reversible addition⁃fragmentation chain transfer agent,three thiocarbonate (DBTTC),was synthesized for active polymerization.Then the emulsifier free emulsion polymerization method was used to prepare styrene polystyrene latex with narrow particle size distribution using itaconic acid as the monomer and ammonium persulfate as initiator.Effects of the molar ratio of St/IA,molar ratio of acetone/water,reaction temperature and amount of DBTTC on the latex particle size were studied respectively.The latices were characterized by Malvern nanosizer,TEM,GPC,surface tension and conductometric titration.The results show that when the temperature is 78 ℃,the molar ratio of St/IA is 10,and the molar ratio of DBTTC/St is 0.064,the molar ratio of acetone/water is 4∶6,the polystyrene nanometer latex particles with average particle size of 98 nm can be obtained.

Key words: Soap?free emulsion polymerization, Itaconic acid, Living polymerization, Polystyrene, RAFT

摘要： 采用一种RAFT活性聚合的新方法制备衣康酸改性聚苯乙烯纳米粒子。首先合成用于活性聚合的小分子可逆加成⁃断裂链转移剂三硫代碳酸酯（DBTTC）。然后采用无皂乳液聚合的方法，以生物质原料衣康酸为共聚单体，过硫酸铵为引发剂，在丙酮/水溶液中进行苯乙烯共聚反应，合成了粒径分布窄的聚苯乙烯乳液。分别研究了苯乙烯（St）/衣康酸(IA)单体配比、丙酮/水配比、反应温度以及DBTTC用量等对乳液粒径的影响。用激光粒度分布仪、透射电子显微镜（TEM）、凝胶渗透色谱（GPC）、表面张力仪和电导率仪对乳液进行表征。结果表明，当温度为78 ℃，n(St)/n(IA)为10，n(DBTTC)/n(St)为0.064，n(丙酮)/n(水)为4∶6,可获得平均粒径为98 nm的聚苯乙烯纳米乳胶粒。

关键词: 无皂乳液聚合, 衣康酸, 活性聚合, 聚苯乙烯, 可逆加成?断裂链转移