支化聚苯乙烯-丙烯酸叔丁酯的合成及表征

Synthesis and Characterization of Branched Poly(St-co-t-BA)

以α-溴代异丁酸叔丁酯(t-BBiB)为引发剂,溴化亚铜CuBr/五甲基二乙基三胺(PMDETA)为催化体系,二乙烯苯(DVB)为支化单体,采用原子转移自由基聚合(ATRP)合成支化聚苯乙烯和丙烯酸叔丁酯共聚物。采用核磁(1H NMR)、凝胶渗透色谱(GPC)、多角度激光散射(MALLS)对聚合过程及产物进行表征分析,结果表明:单体转化率小于70%时,主要生成带有悬垂双键的初级链;随反应进行,悬垂双键参与反应形成支化大分子,分子质量快速增加。

The branching copolymer of styrene and tert-butyl acrylate was synthesized by atom transfer radical polymerization（ATRP）.Divinylbenzene（DVB）,tert-butyl-2-bromoisobutyrate（t-BBiB） and the complex of CuBr/Pentamethyldiethylenetriamine（PMDETA） were used as branching agent,initiator and catalyst respectively.The formation of branched copolymer was confirmed by proton nuclear magnetic resonance（1H NMR）,gel permeation chromatography（GPC） and multi angle laser light scattering（MALLS）.The results show that highly branched polymers mainly form at the late stage and linear chain propagation dominates at the early stage of polymerization（70% conversion）.