光敏性类交替共聚物自组装及其应用

Self-Assembly and Application of Photosensitive Alternating Copolymer

合成了光敏单体——对氯亚甲基苯乙烯与4-甲基-7-羟基香豆素的醚化产物(SC),并以SC为共聚单体与苯乙烯(St)和马来酸酐(MA)通过自由基共聚合成了双亲性类交替共聚物P(St/SC-alt-MA),再利用酸酐基元与2-氨基吡啶的胺解反应获得离子化的P(St/SC-alt-MA)(P(St/SC-alt-MAA))。用凝胶渗透色谱和核磁共振氢谱对P(St/SC-alt-MAA)的结构进行了表征;用激光粒度分析仪和透射电子显微镜表征了P(St/SC-alt-MAA)在选择性溶剂中自组装形成的胶束的结构;用紫外-可见分光光度计研究了不同辐照时间下P(St/SC-alt-MAA)胶束在特征紫外光波长处吸光度的变化。实验结果表明,P(St/SC-alt-MAA)胶束在365nm紫外光照射下发生光交联反应,在254nm紫外光照射下发生光解交联反应,说明P(St/SC-alt-MAA)胶束具备一定的光可逆特性。激光粒度分析仪和Zeta电位仪等测试结果显示,P(St/SC-alt-MAA)在选择性溶剂中形成了pH敏感的胶束,该胶束具有一定的乳化性能。

A photosensitive alternating copolymer P（St/SC-alt-MA） was synthesized from styrene （St）, photosensitive monomer styrene-containing coumarin （SC） and maleic anhydride （MA） by radical copolymerization. A new ionic amphiphilic photosensitive alternating copolymer P（ St/SC-alt- MAA） （P（St/SC-alt-MAA） ） was further obtained by functional amidolysis of anhydride unit of P（St/SC-alt-MA） with 2-aminopyridine, which was characterized by means of GPC and ^1H NMR. P（St/SC-alt-MAA） could self-assemble into micelles in selective solvent. The diameters and morphologies of micelles were examined by means of DLS and TEM. The photo-responsive properties of P （St/SC-alt-MAA） were studied by means of UV-Vis. It was found that the polymer micelles could be photocross-linked under 365 nm UV light and its reversible photocleavage could take place under UV light of 254 nm. At selective solvent and by means of DLS and Zeta potential, it was found out that the micelle particles were pH-responsive and possessed efficient emulsibility.