含聚氨酯型温度和pH双敏性水凝胶的合成及性能研究

合成了两种阴离子型的端烯基聚氨酯（UAA）预聚物，制备了pH值敏感的水凝胶，比较了它们的PH值响应性，将UAA预聚物与N－异丙基丙烯酰胺（NIPA）共聚，得到具有温度和PH值双重敏感性的水凝胶，研究发现聚氨酯侧链的引入对NIPA的相转变温度（LCST）几乎无影响，聚合温度和组成比对所合成的水凝胶性能有较大的影响。

STUDIES ON NOVEL POLYURETHANE-MODIFIED POLY(N-ISOPROPYLACRYLAMIDE) HYDROGELS

Urethane acrylate precursors (UAA) containing anionic groups were prepared. UAA Hydrogels were synthesized by free radical polymerization. Two kinds of N-isopropylacrylamide/urethane acrylate precursors (NIPA/UAA) copolymeric gels were prepared under various mass ratios of NIPA and UAA at different polymerization temperature. The influences of pH and temperature on the swelling ratios were investigated. High pH sensitivity was observed due to the carboxylic groups into the molecular backbone of UAA precursor. The result indicates that the incorporation of UAA precursor into the composite gel has little effect on the lower critical solution temperature (LCST) of PNIPA. The equilibrium swelling ratio is strongly influenced by the composition ratio of the composite gel and polymerization temperature.