MMA/BA/双官能团单体无皂共聚乳液的稳定性

用马来酸酐和(聚)乙二醇合成了一系列双官能团共单体,将其用于MMA/BA无皂乳液共聚合.研究了共单体的空间效应、用量、加料方式对其无皂乳液稳定性的影响.用适当的共单体和半连续加料方式,可得到较稳定的乳液,粒径分布接近单分散.凝聚物的生成机理主要是失稳凝聚和架桥凝聚.

Stability of Emulsifier-free Emulsion Copolymerization of MMA/BA/Comonomer with Two Functional Groups

A series of functional comonomers with anionic and nonionic hydrophilic groups, sodium glycol maleate(SGM, or I 1) and sodium polyethylene glycol maleate (SPEGM, or I 2, I 4 and I 6) made from polyethylene glycol PEG200, PEG400 and PEG600, were synthesized and used in MMA/BA emulsifier free emulsion copolymerization. The effects of the spatial effect, concentration and feeding mode of comonomer on the stability of the emulsifier free latexes(EFL) were investigated. The stable and almost monodispersed EFL can be obtained with appropriate comonomer and semicontinuous feeding mode. Coagulum in the emulsifier free emulsion polymerization system was formed mainly by destabilizing coagulation mechanism owing to insufficient protecting groups on particles and by bridging coagulation mechanism caused by water soluble homopolymer of comonomers or copolymers enriched with such comonomers.