溶胶-凝胶法制备氧化硅-氧化铝共掺杂聚酰亚胺薄膜及其性能

The Fabrication and Properties of Polyimide/Silica-Alumina Hybrid Film

采用溶胶-凝胶法制备纳米二氧化硅及氧化铝溶胶,将溶胶混合后掺入正在反应的聚酰胺酸中,制得聚酰亚胺/二氧化硅-氧化铝杂化薄膜。利用扫描电子显微镜对杂化薄膜的微观形貌进行了表征,并测试了无机组分含量不同的杂化薄膜的力学性能、热稳定性及介电性能。试验结果表明,杂化薄膜材料中无机相呈现纤维结构和颗粒结构,有效地提高了薄膜的力学性能。杂化薄膜与纯膜相比,热分解温度有较大提高,且随着无机组分含量增大,热分解温度呈现先上升后下降的趋势。介电性能分析表明,杂化薄膜的介电常数和介电损耗与频率的关系符合德拜松弛极化机理。

As an engineering material, polyimides （PI） have been extensively applied in many areas such as microelectrics, electric industries and aerospace etc. In this paper, some polyimide/sailica-alumina hybrid films were fabricated using silicon and aluminum sols obtained by sol-gel method. The. microstructure, mechanical properties, thermal stability and dielectric properties of hybrid film were investigated. Results indicate that the mechanical properties of PI hybrid film are improved by the addition of SiO2 and A1203 due to the formation of fibre structure of inorganic phases. Compared with the plain polyimide, the hybrid films have a higher thermal stability. Relation of dielectric constant and dielectric loss angle with frequency in the hybrid films accordes with Debye relaxation polarization mechanism.