新型pH及温度敏感性水凝胶

水凝胶是由三维交联网络结构的高聚物和介质共同组成的多元体系 ,因其独特的刺激响应行为 ,已在药物释放体系、物料分离、化学机械、人工肌肉等领域显示了良好的应用前景1,2 ] .在人体体液这种复杂的环境中 ,水凝胶同时受到ｐＨ和温度等多重刺激作用 ,因此 ,研究多重响应性水凝胶具有重要意义 .聚氨酯作为一种广泛应用的高分子材料具有结构易调节、力学性能优异及生物相容性好等特点 ,在生物医学领域可将其用作假肢部件、外科用置入管、隐形眼睛等 .已有文献报道了ｐＨ敏感性聚氨酯水凝胶3～ 5] ,但对多重响应性聚氨酯基水凝胶的报道还很…

NOVEL pH AND TEMPERATURE-SENSITIVE HYDROGELS

New pH and temperature-sensitive hydrogels have been synthesized throug h copolymerization of anionic acrylate polyurethane prepolymer (P(U)) and N -isopropyl acrylamide (NIPAAm) under various feed ratios.Single glass transitio n t emperature was noticed from the DSC curves of the dried hydrogels,indicating of good miscibility between the two components.The pH sensitivity was much affecte d by the composition of the hydrogels and a lowest swelling degree was shown in hydrogel H4 with P(U)/NIPAAm feed ratio of 1/1.Hydrogel H4 also possessed low er critical solution temperature (LCST) of about 27℃ at both pH11 and pH7 sol utions.In the equilibrium hydrogel,most of the absorbed water was freezable wa ter with its content little affected by the hydrogel composition.Furthermore,t he gel strength was improved with incorporating more P(U) chains into the hydrog el.