Preparation and characterization of SiO2/polyimide composite films

The traditional silica/polyimide (SiO2/PI) hybrid films were prepared via a sol-gel process and the silica particles were obtained from hydrolyzing tetraethylorthosilicate (TEOS). In this article, a new SiO2/ N',N-dimethylacetamide (DMAc) solution was prepared and the nano-sized silica particles from silica sol dispersed very well in this organic solution. The novel SiO2/PI composite film was synthesized by reaction of 4,4'-Oxydianiline (ODA) and pyromellitic dianhydride (PMDA) in this new SiO2/DNLAC solution. The morphology of composites were characterized by SEM, the result indicated that silica particles homogeneously dispersed in polyimide films. TGA showed the decomposition temperature of the polyimide films had enhanced with the increase of silica content. Tensile tests on the films indicated an increase in the mechanical properties with the addition of silica particles.