摘要
应用大分子引发剂,以原子转移自由基聚合技术(ATRP)合成了聚对氯甲基苯乙烯接枝聚甲基丙烯酸N,N-二甲基氨基乙酯[(p-CMS)-g-DMAEMA]的两亲性环境敏感梳状高聚物.IR分析表明所得高聚物与设计结构基本一致;以特性黏数表征了高聚物的相对分子质量;粒度分析表明,高聚物具有明显的温度与pH值敏感性;在低临界溶解温度(LCST)下,水溶液中高聚物胶束数均粒径约30～50 nm在不同pH值环境中,通过调节亲水基团与疏水基团的比例,可在18～56℃范围内调节LCST,pH＜7.5时LCST消失.DSC分析表明梳状共聚物具有明显的微相分离结构.对非诺夫他林的控制释放实验表明高聚物具有较好地控制释放性能.
Through preparation of macromolecule initiator via atom transfer radical polymerization （ATRP）, comb-like environment-responsive copolymers were synthesized by using N,N- dimethylaminoethyl methacrylate as a functional monomer. The structure of macro-initiator and copolymers were characterized with infra-red spectroscopy, the molecular weight of copolymers were characterized by their intrinsic viscosity, and the copolymer＇s phase behavior was measured by diameter analysis. The result showed that the copolymer possessed distinct sensitivity towards temperature and pH. At the lower critical solution temperature （LCST）, the diameter of comblike polymer micelle was 30～50 nm. In different pH environments, by changing the proportion of the hydrophilic and hydrophobic segments on backbone and graft chain, LCST could be effectively adjusted between 18～56 ℃. Furthermore, LCST vanished when pH was lower than 7.5. The DSC measurement indicated that the comb-like copolymers presented micro-phase separation characteristic. The controlled drug release properties of the copolymers showed that the release rate for phenolphthalein depended on pH value.
出处
《化工进展》
EI
CAS
CSCD
北大核心
2005年第11期1273-1277,共5页
Chemical Industry and Engineering Progress
基金
国家自然科学基金资助项目(No.20374040)
关键词
两亲性高聚物
环境敏感
ATRP
控制释放
amphiphilic copolymer
environment-responsive
ATRP
controlled release
