摘要
研究了CuBr/N,N,N′,N″,N″-五甲基二乙烯基三胺催化的2-(2-溴代异丁酰氧基)乙基甲基丙烯酸酯(BIEM)与大量甲基丙烯酸-N,N-二甲氨基乙酯(DMAEMA)的自缩合原子转移自由基共聚合。分别利用气相色谱、三检测凝胶渗透色谱测定了聚合反应过程中单体转化率、所得聚合物的分子量与分子量分布及特性黏数等随反应时间的变化。结果表明,支化结构在反应早期就已经形成,但是由于具有支化结构的聚合物链相对于共聚单体浓度太低,因此在转化率不大的情况下,支化结构的聚合物链之间无法互相缩合,只能以向DMAEMA的链增长为主,从而导致在聚合物分子量增长同时支化度反而下降。
CuBr/ N,N,N＇,N″,N″-Pentamethyldiethylenetriamine-catalyzed self-condensing atom transfer radical polymerization （SCATRP） of 2-（2-bromoisobutyryloxy）ethyl methacrylate （BIEM） with a large excess of （N,N-dimethylamino）ethyl methacrylate （DMAEMA） was carried out,in which the conversion,molecular weight and its distribution and specific viscosity of the PDMAEMA at different time intervals were investigated by gas chromatography,gel-permeation chromatography,multi-angle laser light scattering and online visometry.The results suggest that the branched PDMAEMA primary chains form even from the early stage,and,due to the very low concentration,they only further polymerize with DMAEMA; as a result,the molecular weight increases while the degree of branching decreases steadily with the reaction time.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2010年第11期67-70,共4页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(20674033)
江苏省自然科学基金资助项目(BK2008142)
教育部留学回国人员科研启动基金
