二乙烯苯为支化单体的支化聚苯乙烯合成反应

Synthesis of Branched Polystyrene Using Divinylbenzene as the Branch Agent

以α-溴代异丁酸叔丁酯(t-BBiB)为引发剂,二乙烯苯(DVB)为支化单体,在90℃的条件下经原子转移自由基聚合(ATRP)合成支化聚苯乙烯。用气相色谱(GC)、核磁共振(1H-NMR)和三检测体积排除色谱(TD-SEC)对聚合反应过程和聚合物进行了分析表征。结果表明,在聚合体系中少量带有贫电子双键的共聚单体甲基丙烯酸丁酯(BMA)存在下,能提高引发剂效率,可以在高单体转化率下(>95%)保证聚合反应体系不交联,合成得到高分子量的支化聚苯乙烯,而且分子量分布相对较窄。

The branching copolymerization of styrene with divinylbenzene （DVB） as the branching agent was carried out using atom transfer radical polymerization （ATRP） in anisole at 90 ℃. Gas chromatography （G C）, proton nuclear magnetic resonance spectroscopy （^1H-NMR） and triple detection size exclusion chromatography （TDSEC） were used to analyze and characterize the polymerization and the resulting polymers. It shows the polymerization suffers from crosslinking reaction with DVB as the branch agent due to decreased initiator efficiency. Moreover, the decreased initiator efficiency comes from the absence of monomer of poor electron vinyl group. Adding butyl methacrylate（BMA）, a typical monomer with poor electron vinyl group, can restrain the gelation effectively, and branched polystyrene with some narrow molecular weight distribution has been prepared at high monomer conversion （ 〉 95 % ）.