ATRP法制备两亲嵌段共聚物及其在不同介质中的自组装研究

Preparation of amphiphilic block copolymer by ATRP and its self-assembly in different media

采用原子转移自由基聚合法(ATRP)合成了一种新型的pH敏感和热敏性两亲性嵌段共聚物聚(甲基丙烯酸甲酯)-嵌段-聚(N-异丙基丙烯酰胺)-嵌段-聚[N,N-(二甲基氨基)甲基丙烯酸乙酯](PMMA-b-PNIPAM-b-PDMAEMA)。首先制备了预期分子量的AB型两亲共聚物(PMMA-b-PNIPAM)和ABC型两亲三嵌段共聚物(PMMA-b-PNIPAM-b-PDMAEMA)。用凝胶渗透色谱(GPC)、核查氢谱和红外光谱对其进行表征。结果表明:在甲苯(TL)、四氢呋喃(THF)和N,N-二甲基甲酰胺(DMF)中AB型两亲嵌段共聚物的温度响应能力以及自组装胶束形态均有所不同。胶束溶液的透射率随温度的升高而变化,这些变化反映了嵌段共聚物的pH敏感和热敏性。通过透射电子显微镜和动态光散射系统地研究了胶束行为和形态。

A new pH-sensitive and heat-sensitive amphiphilic block copolymer poly(methyl methacrylate)-block-poly(N-isopropylacrylamide)-block-poly[N,N-(Dimethylamino)ethyl methacrylate](PMMA-b-PNIPAM-b-PDMAEMA)was synthesized by atomic transfer radical polymerization(ATRP)method.AB type amphiphilic copolymer(PMMA-b-PNIPAM)and ABC type amphiphilic triblock copolymer(PMMA-b-PNIPAM-b-PDMAEMA)with expected molecular weight were first prepared.It was characterized by GPC,1 H-NMR and FT-IR spectroscopy.In TL(toluene),THF and DMF,the temperature response ability and self-assembled micelle morphology of AB type amphiphilic block copolymers were different.In addition,the transmittance of the micellar solution changes with the increase of temperature,and these changes reflected the pH sensitivity and heat sensitivity of the block copolymer.The behavior and morphology of micelles were studied by transmission electron microscopy(TEM)and dynamic light scattering(DLS)systems.