甲基丙烯酸羟乙酯的乳液聚合

Emulsion Polymerization of 2-Hydroxyethyl Methacrylate

研究了引发剂体系、乳化剂类型和用量、反应温度、电解质等对水溶性甲基丙烯酸羟乙酯(HEMA)在水相中进行自由基乳液聚合反应的单体转化率、凝聚率以及乳胶粒子粒径的影响。结果表明,使用油溶性引发剂偶氮二异丁腈(AIBN)可以提高单体转化率,降低凝聚率;乳化剂用量对转化率影响较小,但是可以明显降低凝聚物含量;反应温度增加,单体转化率先增加后减少,凝聚物含量增加,75℃是较理想的反应温度;使用AIBN时,中和剂NaHCO3对聚合有阻聚作用;乳胶粒子粒径分布较宽,呈现多峰分布。

The effects of initiator system, emulsifier type and amount, reaction temperature, and electrolyte on monomer conversion, coagulum content, particle size and distribution for the emulsion polymerization of the water-soluble 2-hydroxyethyl methacrylate（HEMA） were investigated. The results showed the oil-soluble initiator azoisobutyronitrile（AIBN） may increase the monomer conversion and decrease the coagulum; the amount of the emulsifier had little effect on the monomer conversion, but the coagulum greatly decreased with the increase of the amount of the emulsifier. As the reaction temperature increased from 65 ℃ to 85 ~C, the monomer conversion increased first and then decreased, and the coagulum increased continuously, and the ideal reaction temperature was 75 ℃. The presence of electrolyte, NaHCO3, decreased the monomer conversion; the particle distribution index was broader and multimodal distributions were observed.