【摘要】 以氨基聚乙二醇单甲醚(MPEG-NH2)为大分子引发剂,采用开环聚合方法合成了聚L-丙氨酸-聚乙二醇嵌段共聚物(PAME),并对其结构进行了表征;用圆二色谱(CD)研究了嵌段共聚物在水溶液中的二级结构,用芘荧光探针技术研究了共聚物胶束的形成及其临界胶束浓度(CMC),利用动态光散射(DLS)和透射电镜(TEM)研究了胶束的粒径分布和形态.结果表明,在水溶液中共聚物链以α-螺旋构象形式存在,在一定条件下嵌段共聚物能够形成球形的稳定胶束,PAME-1形成胶束的CMC为1.99×10-5mol/L,CMC值受共聚物中聚L-丙氨酸(PLA)链段含量的影响.更多还原

【Abstract】 Block copolymers of poly(L-alanine)/poly(ethylene glycol)(PAME) were synthesized by ring opening polymerization and their structures were characterized.The secondary structure was investigated by circular dichroism(CD).The micellization and critical micelle concentrations(CMC) of PAME in water were monitored by fluorescent probe technique.The diameter and distribution of micelles were characterized by DLS and its shape was observed by TEM.The results show that the poly(amino acid) segment of block copolymer chains existed as α-helical conformation in aqueous solution.The block copolymers of PAME-1 and PAME-2 could form spherical micelles at room temperature,whose diameter was about several hundred nanometer.The CMC of PAME-1 micelle was 1.99×10~-5 mol/L,which depends on the PLA content of the copolymers.更多还原