过渡金属催化原子转移自由基聚合反应合成窄分散性聚苯乙烯

Synthesis of Polystyrene with Narrow Molecular Weight Distribution by UsingTransition Metal Catalyzed Atom Transfer Free Radical Polymerization

以２－氯代丙酸乙酯（２－〔ＥＰＮ〕Ｃｌ），２２’－联吡啶（ＢＰＹ）和氯化亚铜组成过渡金属催化络合引发体系。对其引发苯乙烯进行原子转移自由基聚合反应（ＡＴＦＲＰ）进行了初步研究，考察了引发剂组成对聚合反应及聚合产物分子量和分子量分布的影响，采用核磁共振仪和凝胶渗透色谱仪对聚合物结构和聚合物分子量及聚合物分子量分布进行了表征分析。实验结果表明：在常规自由基聚合反应条件下，采用适当的引发剂配比，聚合反应表现出较好的活性聚合反应行为，聚合物分子量与单体转化率之间存在较好的线性关系，而且与理论计算值比较接近，聚合物分子量分布指数可达１２左右。初步研究结果表明：过渡金属催化原子转移自由基聚合反应是一种有效的可控自由基聚合反应。

Ethyl 2-chloropropionate〔2-(EPN)Cl〕,22-dipyridyl(BPY) and cuprous chloride(CuCl) were used as the initiator of transition metal catalyzed atom transfer free radical polymerization of styrene.The end groups,molecular weight and molecular weight distribution (MWD) of the obtained polystyrene were characterized by using 1 H-NMR and gel permeation chromatography(GPC).The preliminary results show that atom transfer free radical polymerization proceeds in a living fashion:molecular weight increases linearly with monomer conversion and molecular weight distribution index is as low as 12.From these studies,it can be concluded that well defined polymer will be prepared from transition metal catalyzed atom transfer free radical polymerization under a relatively simple polymerization condition.