电荷转移聚合法合成聚苯乙烯

Synthesis of polystyrene by charge-transfer polymerization

为了研究引发剂上的取代基对苯乙烯电荷转移聚合的影响,分别以对甲氧基苯胺/二苯甲酮、苯胺/二苯甲酮、对硝基苯胺/二苯甲酮络合物作为引发体系,苯乙烯(St)为单体,四氢呋喃(THF)为溶剂,在紫外光照射下,通过电荷转移聚合(CTP)法合成了聚苯乙烯(PS),并利用核磁共振仪(1H NMR)和凝胶渗透色谱仪(GPC)对其结构进行了表征。同时考察了反应时间和温度、溶剂极性、引发剂浓度以及取代基电子效应等对聚合反应的影响。结果表明,苯乙烯的电荷转移聚合反应符合常规自由基聚合机理;当苯胺的苯环上有硝基取代基时,单体转化率和聚合物分子量相对较低,而有甲氧基时,单体转化率和聚合物分子量相对较高。

In order to study the effect of substituent at initiator on the charge-transfer polymerization of styrene, polystyrene （PS） was synthesized via the charge-transfer polymerization （CTP） of sty- rene （St） under UV irradiation, using tetrahydrofuran （THF） as a solvent and aniline/benzophe- none, p-methoxyaniline/benzophenone and p-nitroaniline/ benzophenone complex as an initiator system, respectively. The structure of the resulting PS was characterized using nuclear magnetic res- onance （1H NMR） spectrometer and gel permeation chromatography （GPC）. The effects of reaction time, temperature, solvent polarity, initiator concentration and electronic effect of substituent on polymerization were investigated. The results showed that the CTP of St defers to the conventional free radical polymerization mechanism; when the substituent on the benzene ring of aniline is nitro group, the monomer conversion and the molecular weight of polymer are relatively low, while a me- thoxy group, the monomer conversion and the molecular weight of polymer are relatively high.