氯化聚乙烯对甲基丙烯酸甲酯／苯乙烯共聚动力学的影响

THE EFFECTS OF CHLORINATED POLYETHYLENE ON THE KINETICS OF METHYL MATHACRYLATE/STYRENE COPOLYMERIZATION

将甲基丙烯酸甲酯（ＭＭＡ）／苯乙烯（Ｓ）在氯化聚乙烯（ＣＰＥ）存在下进行悬浮溶胀接枝共聚，考察了ＣＰＥ对ＭＭＡ／Ｓ共聚动力学行为的影响．ＣＰＥ提高了聚合体系的粘度，使自动加速提前，扩散因素增加，对共聚有阻滞作用．ＣＰＥ是链转移剂，使ＭＭＡ／Ｓ共聚物分子量降低．ＣＰＥ对ＭＭＡ的吸附渗透优于对Ｓ的吸附，造成接技部分与非接技部分组成的差异．ＣＰＥ含量、溶胀时间、转化率、硫酸用量对共聚组成均有影响。

The effects of chlorinated polyethylene(CPE) on the kinetic behaviors of suspension-swelling graft copolymerization of methyl mathacrylate(MMA)/styrene(S) in the synthesis of MCS resin were studied. The presence of CPE increases the viscosity of polymeric system and diffusion effect, makes the gel effect much earlier and decreases the maximum rate of copolymerization. CPE gives retardation and chain t'ransfer effects on the MMA/S copolymerization. The former will lower the rate, while the latter lower the molecular weight. In comparison with S, CPE will preferably adsorb MMA and swell with more MMA in a shorter time owing to their similar solubility parameters and specific interaction. It causes the different composition of MMA/S random and graft copolyrners. The CPE content, swelling time, conversion and the amount of mercaptan will affect the copolymer composition.