Studies on preparation and characterization of modified polyimide-silica hybrid film by sol-gel process

Anhydride terminated poly(amic acid) were prepared by the reaction of oxydianiline and excess pyromellitic dianhydride and then propylmethyldiethoxysilane endcapped poly(amic acid) that crosslinkable silanol group in chain end of the poly(amic acid), were synthesized by adding of 3-aminopropyl diethoxysilane to the poly(amic acid). Subsequently novel polyimide-silica hybrid film were prepared by adding tetraethoxysilane and distilled water to the silane endcapped poly(amic acid) via the sol-gel reaction. The hybrid film had high 10% weight loss temperature in the range of 595 similar to 602 degrees C. From the evidence of scanning electron microscope (SEM), the hybrid films were transparent up to 40 wt % of their silica content.