苯乙烯-甲基丙烯酸甲酯的高温阴离子溶液共聚

Anionic Solution Polymerization of Polystyrene-b-Poly（methyl methacrylate） Copolymer at High Temperature

以正丁基锂（n-BuLi）为引发剂、四氢呋喃（THF）为极性调节剂,采用具有较大空间位阻和特定电荷环境的P配合物作为抑制剂,在80°C下实现了苯乙烯（St）与甲基丙烯酸甲酯（MMA）的阴离子嵌段共聚。采用GPC、FT-IR、1H-NMR等手段对共聚物的结构及分子量进行了分析。结果表明：共聚物中各链节的分子量与设计分子量接近,分子量分布系数小于1.1。添加P配合物可以有效抑制MMA中酯羰基的副反应,实现高温下St与MMA的阴离子嵌段共聚,P配合物与引发剂的适宜摩尔配比为1.5∶1。

Polystyrene-b-poly（methyl methacrylate） copolymer was synthesized by anionic polymerization at 80 °C using n-BuLi as the initiator,tetrahydrofuran as the regulator and complex compound P as the restraining agent owing to its steric hindrance and special charge environment.The copolymers were characterized by GPC、FT-IR and 1H-NMR.Results show that each block coincides with the design of molecular weight,and the molecular weight distribution is narrow（1.10）.The block copolymerization of styrene and methyl methacrylate can be carried out even at high temperature and the side reactions of anionic polymerization of methyl methacrylate are well retarded by adding complex compound P.The suitable molar ratio of complex compound P to initiator is 1.5∶1.