In situ formation of nanosized TiO2 domains within poly(amide–imide) by a sol–gel process

Abstract

Poly(amide–imide)/TiO2 (PAI/TiO2) composite films were prepared by an in situ sol–gel process. These composite films exhibited high optical transparency, having nanosized TiO2 rich domains well dispersed within the PAI matrix. The size of the domains increased from 5 to 50nm when the TiO2 content was increased from 3.7 to 17.9% by weight. Hydrogen bonding interactions between the amide groups in the PAI and the hydroxyl groups on the inorganic oxide were observed. In comparison to the pure PAI polymer, the PAI/TiO2 composite films exhibited higher glass transition temperature, an increase and flattening of the rubbery plateau modulus, and a decrease in crystallinity.