AC对St或MMA为壳层单体种子乳液聚合的影响

Effect of AC on seeding emulsion polymerization using St or MMA as shell monomer

在种子乳液聚合中加入发泡剂偶氮二甲酰胺(AC),制备了可发气核壳结构复合微球。探讨了AC用量对以聚苯乙烯(PSt)微凝胶为种子,St或甲基丙烯酸甲酯(MMA)为壳层单体的2种体系稳定性及转化率和反应速率的影响。结果表明,以MMA为壳层单体的聚合体系是较理想体系。当AC用量从1g增加到8g时,以St为壳层单体体系的最终转化率从96.2%下降到74.2%,以MMA为壳层单体体系的最终转化率基本不变,保持在96%左右。但AC的加入使以MMA为壳层单体体系的反应速度最大值的出现时间推后了10min,且其值仅为未加入AC体系的1/2左右。

In the presence of seed emulsion and AC(azodicarbamide),the foamable core-shell structured microparticles were prepared by seeding emulsion polymerization.Two kinds of foamable microparticles with the PSt microgel as the seed emulsion were prepared using St or MMA as the shell monomer respectively.The stability,conversion and reaction rate of the two systems was studied and compared.The results showed that the system with MMA as the shell monomer was better in the above aspects.When the amount of AC increased from 1 g to 8g, the final conversion of system with St as shell monomer decreased from 96.2%to 74.2%.The final conversion of system with MMA as shell monomer remained the same of about 96%.The introduction of AC into the system brought a 10 min delay in the appearance of maximum reaction rate,as well as the decrease of the reaction rate to the half of the original.