PS-b-PEO为分散剂的苯乙烯悬浮聚合

摘要

The poly(styrene-b-ethylene oxide)(PS-b-PEO)block copolymer was synthesized via living anionic polymerization and was used as dispersing agent in styrene suspension polymerization. The relative molecular weight of PS block and the mass fraction of PEO block in PS-b-PEO were characterized respectively. The effect of the amount of PEO block in PS-b-PEO(the mass fraction of PEO block in styrene monomers), the mass fraction of PEO block in PS-b-PEO, and the agitation rate on the particle characteristics of PS polymerization were investigated. The results show that PS-b-PEO copolymers are synthesized successfully with PS blocks of molecular weight of5000 and PEO block in the mass fraction ranging from3.5% to27.3%. The particle size of PS gradually increases and the particle size distribution widens with the increase of the mass fraction of PEO block while the amount of PEO block is unchanged in styrene suspension polymerization. When PS-b-PEO copolymer in which the mass fraction of PEO block is5.0% is used as dispersant, the particle size of PS decreases and the particle size distribution narrows with the amount of PEO blocks rising from0.05% to1.20%. The particle size of PS declines when the agitation rate varies from220 r/min to570 r/min, and suspension polymerization proceeds steadily.%采用活性负离子聚合技术设计并合成了聚苯乙烯(PS)-聚环氧乙烷(PEO)嵌段共聚物(PS-b-PEO),并以此为分散剂进行苯乙烯悬浮聚合.分析了PS-b-PEO中PS嵌段的相对分子质量及PEO嵌段的质量分数,并考察了PS-b-PEO中PEO嵌段的质量分数、用量(PS-b-PEO中PEO嵌段占苯乙烯单体的质量分数)和搅拌速率对苯乙烯悬浮聚合颗粒特征的影响.结果表明:成功合成了PS嵌段相对分子质量为5000,PEO嵌段质量分数为3.5%~27.3%的PS-b-PEO;PEO嵌段用量相同时,随着PEO嵌段质量分数的增加,苯乙烯悬浮聚合得到的PS颗粒粒径逐渐增大且分布变宽;以PEO嵌段质量分数为5.0%的PS-b-PEO为分散剂时,PEO嵌段用量由0.05%增加到1.20%,PS颗粒粒径逐渐减小且分布变窄;搅拌速率由220 r/min增加到570 r/min,悬浮聚合仍能稳定进行且PS颗粒粒径减小.