摘要
通过在聚酰胺酸中加入正硅酸乙酯(TEOS)和硅烷偶联剂(KH550),制备了不同SiO_2含量的PI/SiO_2杂化薄膜。采用FTIR、TMA、SEM以及TGA分析了PI/SiO_2杂化薄膜的性能和结构。结果表明,TEOS经水解缩合与聚酰亚胺(PI)形成了有机-无机杂化网络结构,SiO_2均匀分散在聚酰亚胺基体中;SiO_2和偶联剂的引入提高了杂化薄膜的热稳定性;随着SiO_2含量的增加,PI/SiO_2杂化薄膜的拉伸强度降低,但当SiO_2含量达到20%时,弹性模量增大到3.4GPa。
Polyimide-silica hybrid films of different silica content are prepared by the sol-gel reaction starting from tetraethyl orthosilicate（TEOS） and silane coupling agent（KH550） in the solution of polyamie acid. The chemical structure and properties are characterized by the methods of FT-IR,TMA, SEM and TGA. The results show that the TEOS forms organic-inorganic hybrid network structure with polyimide（PI） by hydrolysis and condensation, and SiO2 nanoclusters disperse in polyimide matrices homogeneously. The introduction of a certain amount of SiO2 and coupling agent helps to improve the thermal stability of nano-hybrid PI/SiO2 film. The tensile strength of the hybrid films decreases whereas the modulus increases to 3. 4GPa with the increase of SiO2 content to 20%.
