Dispersion of surface-modified silica nanoparticles in polyamide-imide (PAI) films for enhanced mechanical and thermal properties

Abstract

Silica nanoparticles modified with aminophenyl group were fabricated through two-step sol-gel process under the weak acidic condition due to fast hydrolysis and condensation rate of 3-aminophenyl trimethoxysilane. The aromatic groups on the surface of silica nanoparticles enhanced their dispersion stability in PAI film, and the amine groups were chemically bound with PAI by opening the cyclic imide through nucleophilic attack on carbonyl groups. The thermal stability and mechanical properties of the silica/PAI nanocomposite films have been improved by increasing the amount of modified silica nanoparticles up to 12 wt.%. Specially elongation showed a significant increase by 42.37%.