酸敏性聚苯乙烯/聚丙烯酸水凝胶微球的研究

Study on Acid Sensitive Polystyrene/Polyacrylic Hydrogel Microspheres

酸敏性水凝胶具有p H值敏感性,其体积可随p H值的改变而相应的改变。酸敏性水凝胶在包括药物控制释放体系、分子分离体系、记忆元件开关、活性酶的包埋、传感器等方面具有一定的应用价值。本课题以制备一种具有核壳结构的酸敏性水凝胶微球为主要研究目的。首先利用无皂乳液聚合法制备了PS种子微球。SEM及激光粒度分布仪的测定表明,PS种子微球为亚微米级,呈现良好的单分散,无絮凝和凝结现象发生。以PS微球为种子,以AA为第二主要单体,利用种子乳液聚合法尝试制备了以PS为核,以PAA为壳的PS/PAA复合水凝胶微球。为了改善PS和PAA间的相容性,进行了种种实验。最终表明,以AA和少量的苯乙烯为第二单体,以AIBN为引发剂,在引发聚合之前进行第二单体向PS微球的充分渗入,可成功地制备PS/PAA复合微球。

Environmentally sensitive hydrogel can response to the external environment such as temperature, p H, solvents, electromagnetic field or chemical substances. As a result, it can be extensively used in the field of drug control system, memory components switches, sensors, molecular separation system, and so on. In this paper, in order to prepare acid-sensitive hydrogel microspheres with core-shell structure, PS seed microspheres were prepared by soap-free emulsion polymerization, then taking PS microspheres as seeds, and AA as the second main monomer, polystyrene（PS）/polyacrylic acid（PAA） polymer composite microspheres with core-shell structure were prepared by seed emulsion polymerization. In order to improve the compatibility between PS and PAA, various experiments were carried out. The results showed that, taking AA and small amount of styrene as the second main monomer, and AIBN as the initiator, the second main monomer was fully penetrated into PS microspheres before emulsion polymerization, at last polystyrene（PS）/polyacrylic acid（PAA） core-shell microspheres were successfully prepared.