分散剂对MMA悬浮聚合的影响

The effect of dispersant on MMA suspension polymerization

分别以碳酸镁、聚乙二醇(PEG2000)为分散剂,过氧化二苯甲酰为引发剂,采用悬浮聚合法合成聚甲基丙烯酸甲酯。研究了分散剂用量、反应温度、反应时间、引发剂用量、水与单体体积比对悬浮聚合的影响,结果表明,碳酸镁的稳定作用明显强于PEG2000,适宜的反应温度为80℃,反应时间为3h,引发剂用量为单体质量的3%,水与单体体积比为5:1~7:1。制得的聚合物颗粒大小均匀,碳酸镁为分散剂时,粒径为0.54~0.64mm,产率在90%以上,PEG2000为分散剂时,粒径在1mm以上,产率在90%以下。

Poly（ methyl methacrylate） was prepared by suspension polymerization,using benzoyl peroxide as initiator,magnesium carbonate and polyethylene glycol（ PEG2000） as dispersant,respectively.The effects of dispersant amount,reaction temperature,reaction time,initiator amount,volume ratio of water-monomers on the polymerization were investigated.The results indicated that the stable effect of magnesium carbonate was better than PEG2000. The optimum polymerization conditions were obtained as follows： reaction temperature of 80℃,reaction time of 3 h,initiator amount of 3%（ to monomer）,volume ratio of water-monomers of 5： 1 - 7：1. In these conditions,the particles were homogeneous,size of polymethyl methacrylate was 0. 54 - 0. 64 mm,and the yield was above90%（ magnesium carbonate as dispersant）,particle size was greater than 1 mm,and the yield was below 90%（ PEG2000 as dispersant）.