Poly(amide-imide)/TiO2 (PAVTiO(2)) composite films were prepared by an in s
itu sol-gel process. These composite films exhibited high optical transpare
ncy, having nanosized TiO2 rich domains well dispersed within the PAI matri
x. The size of the domains increased from 5 to 50 nm when the TiO2 content
was increased from 3.7 to 17.9% by weight. Hydrogen bonding interactions be
tween 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 co
mposite films exhibited higher glass transition temperature, an increase an
d flattening of the rubbery plateau modulus, and a decrease in crystallinit
y. (C) 1999 Elsevier Science Ltd. All rights reserved.