氧化-还原引发剂引发苯乙烯超浓乳液聚合的研究

Concentrated Emulsion Polymerization of the Styrene Initiated by Redox Initiator System at Lower Temperature

以过氧化羟基二异丙苯 ( CHPO)和四乙烯五胺 ( TEPA)为氧化 -还原引发剂 ,以十二烷基硫酸钠 ( SDS)为乳化剂 ,十六醇 ( CA)为共乳化剂 ,通过超浓乳液聚合方法制备了聚苯乙烯乳胶粒子 .探讨了乳化剂浓度及配比、分散相体积分数、引发剂种类、引发剂浓度及配比和温度等各因素对乳液稳定性、聚合速率、乳胶粒子大小、形态及分布的影响 .用透射电子显微镜 ( TEM)观察了乳胶粒子的形态 ,用粘度法测定了聚苯乙烯的粘均分子量 .考察了苯乙烯进行超浓乳液聚合的反应动力学 ,求得在 3 0℃时聚合速率方程为 Rp=K[M]0 .36 [I]0 .4 9[E]0 .72 ,表观活化能为 1 9.72 k J/mol.所得乳胶粒子的直径在 0 .1～ 0 .3 μm之间 ,粘均分子量在 2× 1 0 6～ 4× 1 0 6之间 .

Polystyrene latex particles were prepared by concentrated emulsion polymerization by using \{CHPO\} TEPA as the redox initiator system and SDS CA as the surfactants. The effects of polymerization condition on the polymerization process were investigated. The effects of surfactant, initiator, temperature and monomers volume fraction on the stability of emulsion, the kinetic process of polymerization and the average size of PS latex particles were discussed. The morphology and size of PS particles were obtained by TEM. The kinetic equation R p= K 0.36 0.72 0.49 and apparent activation energy E a=19.72 kJ/mol at 30 ℃. The molecular weight was measured by viscosity method in the range of 2×10 6-4×10 6.