苯乙烯-甲基丙烯酸甲酯悬浮-乳液耦合聚合动力学

采用苯乙烯(St)悬浮聚合过程滴加甲基丙烯酸甲酯(MMA)乳液聚合组分，进行悬浮-乳液耦合聚合(SECP), 制备大粒径聚苯乙烯-聚甲基丙烯酸甲酯(PS-PMMA)复合粒子.采用¹H NMR分析方法，讨论了SECP动力学特征.St的SECP聚合速率和转化率与悬浮聚合一致;MMA聚合速率决定于乳胶粒子聚合速度和凝并在悬浮粒子表面的速度，聚合速率比常规乳液聚合速率低.由于凝并在悬浮粒子表面的PMMA乳胶粒子不再有乳液聚合特征，MMA在SECP中转化率低于同条件常规乳液聚合.分别得到乳化剂和引发剂浓度与SECP和普通乳液聚合恒速段聚合速率的关系.

Kinetics of styrene-methyl methacrylate suspension-emulsion combined polymerization

The kinetics of suspension-emulsion combined polymerization (SECP), in which methyl methacrylate (MMA) emulsion polymerization constitutes (EPC) were drop-wisely added to styrene (St) suspension polymerization system, was investigated.It was found that the addition of MMA EPC had no significant influence on the reaction rate of St suspension polymerization. The kinetics of MMA polymerization was quite different from that of MMA conventional emulsion polymerization, due to the aggregation of PMMA latex particles onto the surface of suspended particle of polystyrene. The conversion and polymerization rate of MMA in SECP were lower than that of MMA conventional emulsion polymerization in the same conditions. The polymerization rate of MMA in SECP increased with the increase of the emulsifier or initiator concentration. The influences of emulsifier concentration and initiator concentration on the steady stage polymerization rate of MMA in SECP and conventional emulsion polymerization were related.