无规甲基化β-环糊精对甲基丙烯酸甲酯无皂乳液聚合影响的研究

Study on effect of RAMEB on soap-free emulsion polymerization of MMA

摘要:

采用溶液法制备了无规甲基化β-环糊精(RAMEB)/甲基丙烯酸甲酯(MMA)包合物。利用紫外-可见光谱、热重-差热分析等检测手段研究了RAMEB与MMA的包合作用。摩尔比法表明RAMEB与MMA可以形成化学计量比为1:1的包合物。TG -DSC分析表明RAMEB能与MMA形成较为稳定的包合物，从而使MMA的热稳定性大大提高。以MMA为单体，过硫酸钾为引发剂。研究了RAMEB对无皂乳液聚合反应的影响。结果表明，当RAMEB的加入量为0.5g时，体系在75℃反应30min时单体转化率达到89.21%，比同一时间下没有加入RAMEB的空白样的单体转化率提高了30.6%。当RAMEB的加入量为1g时，聚合反应速率比空白样低，单体的最终转化率与空白样差不多。同时，RAMEB的引入可以使得PMMA微球粒径变大，随着RAMEB加入量的增加，聚合物微球的大小越来越均匀。

Abstract:

The inclusion complex of methyl methacrylate（MMA） with randomly methylated β-cyclodextrin (RAMEB) was synthesized by solvent method and characterized by TG-DSC, UV．Molar ratio method shows that the 1∶1 inclusion compound has formed between RAMEB and MMA. TG –DSC analysis shows that RAMEB and MMA have formed steady inclusion and the stability of MMA has increased remarkably. Using MMA as monomer, K2S2O8 as initiator, we investigated the influence of RAMEB on the sope-free emulsion polymerization of MMA. It is found that when the addition of RAMEB is 0.5g, the conversion of MMA reached 89.21% in 30min at 75℃. Compared to no addition of RAMEB, the conversion increased 30.6%. When the addition of RAMEB is 1g, the polymerization speed decelerated and monomer conversion was almost the same compared to no addition of RAMEB. The addition of RAMEB increased particle size of PMMA. With the increase of RAMEB, PMMA particles are getting more and more uniform.