两亲性嵌段共聚物PAA-b-PS的合成及胶束形态

Synthesis and Micellar Morphology of PAA-b-PS Amphiphilic Block Copolymers

通过丙烯酸叔丁酯的自由基调聚和苯乙烯的原子转移自由基聚合(ATRP)法合成了聚丙烯酸叔丁酯-聚苯乙烯(PtBA-b-PS)嵌段共聚物,然后在三氟乙酸作用下进行选择性水解得到了两亲性聚丙烯酸-聚苯乙烯(PAA-b-PS)嵌段共聚物。利用1H-NMR、FT-IR和GPC对产物的结构进行了表征。采用透析法制备了PAA-b-PS胶束,并利用激光纳米粒度仪和TEM观测了胶束的形态和大小,考察了PS嵌段的分子量对胶束大小的影响。结果表明:嵌段共聚物PAA-b-PS在水中自组装形成球状胶束,胶束平均粒径为140～190 nm,并随PS嵌段分子量的增加而增大,且粒径分布较窄。

Poly（tert-butyl acrylate-b-styrene）（PtBA-b-PS） block copolymer was synthesized by radical telomerization of tert-butyl acrylate（tBA） and atom transfer radical polymerization of styrene.Poly（acrylic acid-b-styrene）（PAA-b-PS） amphiphilic block copolymers were obtained by selective hydrolysis in the presence of trifluoroacetic acid,which were characterized by 1H-NMR,FT-IR and GPC.The amphiphilic block copolymeric micelles were prepared by dialysis against water.Laser particle size analyzer and transmission electron micrograph（TEM） measurements were used to examine the morphology and the size of the micelles.The effect of the molecular weight of PS block on the size of the micelles was investigated.Results showed that PAA-b-PS amphiphilic block copolymers formed spherical micelles with average size of 140-190 nm,and the size distribution was narrow.The average size of micelles increased with the molecular weight of PS block.