中文摘要：

以正硅酸乙酯（TEOS）前驱体,采用溶胶-凝胶法向部分缩醛的聚乙烯醇（APVA）水溶液中引入二氧化硅（SiO2）粒子,再通过冷冻/解冻法制备了温敏性聚乙烯醇缩乙醛（APVA）/二氧化硅（SiO2）复合凝胶。用扫描电镜、红外光谱和力学性能分析仪对产物的结构、微观形貌和力学性能进行了表征,并对其温敏性的影响因素进行了研究。结果发现,低临界溶解温度（LCST）随着缩醛度增加而降低;SiO2粒子的存在可增大凝胶的溶胀比和拉伸强度,对凝胶的LCST影响很小;当SiO2含量为15%、粒径200nm左右时,拉伸断裂强度达到最大值2.04MPa。

英文摘要：

NanoSiO2 was obtained from tetraethyl orthosilicate（TEOS） via a sol-gel process in partially acetalyzed poly（vinyl alcohol）（APVA） solution.Then APVA/SiO2 composite hydrogels were prepared using the method of freeze/thawing.The structure,morphology and tensile strength of the products were characterized by FT-IR spectrograph,scanning electron microscopy and mechanical property test machine.The thermo-sensitive mechanism was discussed and the effect of the degree of acetalysis on the lower critical solution temperature（LCST） was investigated.The results showed that the APVA/SiO2 hydrogels with higher degree of acetalysis showed the lower LCST and the addition of SiO2 improved the tensile strength and the swelling ratio but had little influence on the LCST of the hydrogels.When the SiO2 content was 15% and the particle size was about 300nm,the tensile strength of the products got the maximum 2.04MPa.