磷酰胆碱基pH敏感性ABA型嵌段共聚物的合成与胶束化

摘要

采用氯化亚铜/2,2＇-联二吡啶催化体系,2,5-二溴己二酸二乙酯为引发剂,甲醇为溶剂运用希莱克技术,利用原子转移自由基聚合（ATRP）方法合成了ABA型三嵌段共聚物PDEAEMA-b-PMPC-b-PDEAEMA.1H NMR和GPC（凝胶渗透色谱）对聚合物组成、结构及分子量进行了表征,利用透光率、粘度测定研究了嵌段共聚物溶液的pH敏感性,利用表面张力测定、荧光探针和透射电镜研究了嵌段共聚物胶束化作用,确定了共聚物水溶液的临界胶束浓度（CMC）.结果表明所合成的ABA型三嵌段共聚物水溶液具有pH敏感性,其临界相变pH 7～7.5.调节溶液pH值可实现嵌段共聚物胶束化形成＂花状＂胶束,并测定了其临界胶束浓度.%ABA triblock copolymer [A=2-（diethylamino）ethylmethacrylate],DEAEMA;B=2-methacryloyloxyethyl phosphorylcholine,MPC]（PDEAEMA-b-PMPC-b-PDEAEMA） was synthesized via atom transfer radical polymerization（ATRP） in methanol using CuBr/2,2＇-bipyridyl as the catalyst system and diethyl-meso-2,5-dibromoadipate as the initiator.PDEAEMA-b-PMPC-b-PDEAEMA was characterized by 1H NMR and GPC.The pH sensitivity of the triblock copolymer aqueous solutions was investigated by transmittance and viscosity measurements.The micellization of the triblock copolymer aqueous solutions was investigated by surface tension measurements,fluorescence probe and transmission electron microscope.The results show that the resultant block copolymer has pH sensitivity,the critical phase change pH was 7～7.5,＂flower micelle＂ can be formed through adjusting solution pH,and the critical micelle concentration（CMC） of the triblock copolymer aqueous solution was measured.