中文摘要：

通过大分子亲核取代反应合成了可生物降解、具有温度响应性的、具有乙氧羰苯氧基、甘氨酸乙酯和甲氧基乙氧基乙氧基侧链的聚膦腈,用31P NMR1、H NMR、IR、元素分析、DSC和GPC对其结构进行了确证.此聚膦腈的温度响应性能研究结果表明,在较高浓度的缓冲溶液中,其低临界溶液温度（LCST）不受浓度和pH值的影响;而在低浓度时,其LCST随浓度的减小而升高.亲脂性的乙氧羰苯氧基和甘氨酸乙酯侧链的引入,使此聚膦腈的LCST低于聚二（甲氧基乙氧基乙氧基）磷腈,而更接近于人体温度.对聚膦腈的水解降解性能研究结果表明,聚膦腈在碱性条件下的降解略快于在酸性条件下的降解,在中性条件下的降解最慢.这个新的聚膦腈在生物医用材料上具有潜在的应用价值.

英文摘要：

A biodegradable thermoresponsive polyphosphazene with propyl oxybenzoate,ethyl glycinate and methoxyethoxyethoxy side groups was synthesized via the macromolecular substitution reactions.Its structure was confirmed by 31P NMR,1H NMR,IR,elemental analysis and DSC.Its molecular weight was determined by GPC.The thermoresponsive properties and hydrolytic degradation of the polymer were studied as a function of pH.The LCST of the polymer was found to be almost independent on the pH change and its concentration at higher concentration.Due to the introduction of hydrophobic propyl oxybenzoate and ethyl glycinate side groups into the polymer,the LCST of the polymer was near body temperature and was lower than that of poly[bis（methoxyethoxyethoxy）phosphazene].The hydrolytic degradation of the polyphosphazene was pH-sensitive.The polymer was hydrolyzed faster in both acidic and basic buffer solution than in neutral buffer solution.On base of its thermoresponsiveness and biodegradability,the polyphosphazene may be promising for biomedical applications.