端环氧基聚苯乙烯低聚物的合成与机理

Synthesis and Reaction Mechanism of Epoxy-Terminated Polystyrene Oligomer

在常压、惰性气体保护下,以正丁基锂引发苯乙烯进行阴离子聚合,并用少量甲基丙烯酸缩水甘油酯(GMA)在适中温度下进行终端共聚,制得了末端带环氧基团的窄分布聚苯乙烯低聚物。用GPC、FT-IR1、H-NMR及盐酸-二氧六环银量法对低聚物的分子量及其结构进行了分析,考察了GMA用量、终端共聚的反应温度以及反应时间对环氧端基含量(即环氧端基与低聚物的摩尔比)的影响。结果表明:在GMA与聚苯乙烯阴离子反应的过程中,GMA在活性种的终端发生了聚合,所得产物中环氧端基与聚合产物的摩尔比可根据需要进行调节。终端共聚反应温度及反应时间分别以10℃和2.0 h为宜。

The living poly（styryl）lithium was formed by anionic polymerization with the protection of argon under normal pressure, where styrene, cyclohexane, tetrahydrofuran and n-butyllithium were used as monomer, solvent, polar reagent and initiator respectively. Epoxy-terminated polystyrene oligomer with narrow molecular weight distribution was synthesized by end capping copolymerization of the poly （styryl）lithium with glycidyl methacrylate（GMA） at the moderate temperature. Oligomer was characterized by GPC, FT-IR, ^1 H-NMR and hydrochloric acid-dioxane argentimetric method. Effects of GMA dosage, end capping copolymerization time and temperature to the content of epoxy end group （the molar ratio of epoxy function and oligomer） were also studied. Results indicate interestingly that the double bond of GMA polymerized with polystyryl carbanion and the molar ratio of epoxy end group and polystyrene oligomer can be adjusted. The best copolymerization temperature and time are 10 ℃ and 2 h, respectively.