双亲嵌段共聚物PSt-b-P(St-alt-MA)-b-PAA的自组装行为

以三硫代碳酸二(α, α'-二甲基-α-乙酸)酯(BDATC)为链转移剂, 以苯乙烯、马来酸酐、丙烯酸为原料, 通过可逆加成-断裂链转移(RAFT)合成了双亲嵌段共聚物PSt-b-P(St-alt-MA)-b-PAA。通过选择性溶剂N, N-二甲基甲酰胺(DMF)诱导聚合物进行自组装, 利用紫外-可见光光度仪、纳米激光粒度仪详细研究了共聚物中亲疏水嵌段长度、初始浓度、体系pH值对聚合物自组装行为的影响。通过化学交联的方法制备得到了聚合物交联胶束, 利用透射电镜表征了形貌与尺寸, 研究明确了其形状和尺寸的稳定性。结果表明, 上述因素均会影响共聚物的自组装行为和自组装胶束的形态, 经乙二胺交联得到的交联自组装胶束平均粒径为145.4nm, 并具有良好的形状和尺寸稳定性。

Self-assembly behavior of amphiphilic block copolymer PSt-b-P(St-alt-MA)-b-PAA

Amphiphilic block copolymer PSt-b-P(St-alt-MA)-b-PAA was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using S, S'-bis(R, R'-dimethyl-α"-acetic acid)-trithiocarbonate as RAFT agent and styrene, maleic anhydride, acrylic acid as monomers. The self-assembled micelles of PSt-b-P(St-alt-MA)-b-PAA were induced by selective solvent dimethylfomamide. The effects of block length, initial concentration and pH on the self-assembled micelles were investigated through ultra-violet and visible spectrophotometer and laser particle size analyzer. The crosslinked micelles fabricated by chemical crosslinking had stable morphology and diameter as characterized with transmission electron microscope. Block length, initial concentration and pH would affect self-assembly behavior of copolymer and morphology of self-assembled micelle. The micelles crosslinked by ethylenediamine with average particle diameter of 145.5nm had stable morphology and size.