PAn-PEG-PAn三嵌段共聚物的合成和表征

在合成α,ω-双(对氨基苯基)聚乙二醇(BAPPEG)的基础上, 用化学氧化共聚法制备了PAn-PEG-PAn三嵌段共聚物. 研究了共聚时苯胺(An)与BAPPEG摩尔比(r)对共聚物的化学组成、UV-Vis谱图、热稳定性和在水溶液中的自组装特性的影响. 结果表明：随着r的增加, 共聚物中PAn链段的含量增大；其UV-Vis谱图中对应PAn链段的吸收峰出现红移, 且红移的程度增加； 热稳定性提高. 三嵌段共聚物在水中表现出自组装特性： 随着r的增加, 先形成粒径约为90 nm的PAn链段/PEG链段球型核壳胶束, 然后形成长为400～800 nm, 直径约为30 nm的棒状结构, 和棒状结构聚集形成的网状结构, 最后又变成球型胶束.

The Preparation and Characterization of PAn-PEG-PAn Rod-coil Triblock Copolymers

PAn-PEG-PAn rod-coil triblock copolymers were prepared by chemical oxidation copolymerization of aniline and α,ω-bis(p-aminophenyl) poly(ethylene glycol)( BAPPEG) and were characterized by IR, elemental analysis, UV-Vis absorption spectroscopy, thermogravimetric analysis and TEM. The results showed that with increasing the molar ratio of feed An to feed BAPPEG(r), the PAn segment length in the copolymer increased, which was indicated by the red shift of the UV-Vis characteristic absorption peak corresponding to the PAn segment, and the thermal stabilities were enhanced. The rod-coil-rod triblock copolymers in water self-assembled into such different nano-structures as coreshell micelles, rods or rods-based net structures, depending on the PAn segment length.