摘要
用膨胀计法研究了50℃时甲基丙烯酸甲酯和45℃时丙烯酸-2-乙基己酯的种子乳液聚合反应第Ⅱ阶段的动力学过程。求得smith-Ewart递推方程的解析解;再辅以计算机数据模拟,得到了与聚合反应相关的动力学参数。体系中每个乳胶粒子内的平均自由基数目大于1,自由基进入乳胶粒子的速率常数随引发剂浓度的增加而增大。乳胶粒子内自由基双基终止速率常数比本体聚合低转化率时的双基终止速率常数低四个数量级。
The kinetics for the second stage of the seeded emulsion polymerization of me-thylmethacrylate at 50℃ and 2-ethylhexylaerylate at 45℃ have been studied dilate-metrically. The correspondent kinetic parameters of the polymerization are obtained,solving analytically the generalized Smith-Ewart equation followed by using data-fitting techniques. The average number of free radicals per particle, ■, is foundbigger than 1. The rate coefficient of free radicals entering into the emulsion par-ticles increases with the concentration of the initiator. The bimolecular terminationrate coefficient in the emulsion polymerization is smaller than the typical value fora bulk polymerization at low conversion by a magnitude order of 4.
出处
《复旦学报（自然科学版）》
CAS
CSCD
北大核心
1991年第1期8-18,共11页
Journal of Fudan University：Natural Science
基金
国家自然科学基金资助课题
关键词
MMA
2-EHA
反应动力学
聚合
乳液
emulsion polymerization, kinetics, methylmethacrylate
2-ethylhexyl-acrylate, kinetic parameters.
