Functionalized mesoporous silica/polyimide nanocomposite thin films with improved mechanical properties and low dielectric constant

A series of composite thin films composed of mesoporous silica (SBA-15) filled in polyimide were synthesized. The effect of SBA-15 modified with functional group of octyltrimethoxysilane (OTMS) or 3-aminopropyl trimethoxy silane (ATS) on the mechanical and dielectric properties as well as the thermal stability of thin films were investigated. The tensile strength and elongation of the composite films containing SBA-15 modified with ATS were higher than those with OTMS and pristine SBA-15. The dielectric constant was significantly reduced with increasing SBA-15 modified with ATS. The result indicates that the composite materials are potentially useful in radio-frequency/microwave substrate materials.