论文部分内容阅读
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。
Silica (SiO 2) particles were introduced into aqueous solution of partially acetal polyvinyl alcohol (APVA) by sol-gel method using tetraethoxysilane (TEOS) as precursors. Polyvinyl acetal (APVA) / silica (SiO2) composite gel. The structure, microstructure and mechanical properties of the product were characterized by scanning electron microscopy, infrared spectroscopy and mechanical properties analyzer, and the influencing factors of temperature sensitivity were also studied. The results showed that the low critical solution temperature (LCST) decreased with the increase of the degree of acetalization. The presence of SiO2 particles increased the swelling ratio and the tensile strength of the gel, and had little effect on the LCST of the gel. When the SiO2 content was 15 %, Particle size of 200nm or so, the tensile strength at break to reach the maximum 2.04MPa.