丙烯酸酯/双官能团共单体无皂乳液聚合的成粒机理

Study on Particle Formation Mechanism in the Emulsifier-Free Emulsion Polymerization of Acrylate/Comonomer with Double Functional Groups

研究了少量聚乙二醇马来酸单酯钠盐 (ZA- 6 )存在下 ,MMA/ BA无皂乳液聚合成粒过程 ,发现聚合初期产生的初级粒子消失后 ,2次周期性地产生小粒子 .经分析 ,是新的成核作用产生的 ,特称为周期成核现象 .表明在聚合的中晚期 ,成核过程并未真正结束 ,而是处于成核 -聚并的动态平衡之中 .

The particle formation mechanism of MMA/BA emulsifier free emulsion polymerization in the presence of small amount of ZA 6 comonomer (Sodium polyethylene glycol 600 maleate) was investigated with Coulter LS 230 laser particle size analyzer.After the primary particles of the early stage have vanished,new small particles were twice found periodically.It is believed to be formed by new nucleations by theoretical and data analyses. It is called periodic nucleation phenomenon. It is suggested that the nucleation processes do not end really at the middle and later stages of the polymerization,and it is in the dynamic equilibrium of nucleation and aggregation.