Some properties of composite films with thermally decomposed silicone resins.

Abstract

The raw materials of the present composite films were silicone resins, Al₂O₃, TiO₂, and talc. Upon heating, the hydrocarbon groups in side chains of silicone resins are gradually decomposed to form a solid residue involving siloxane bonds and decomposed hydrocarbon groups. Metal oxides in the solid residue appear on the surface. The present composite films heat-treated at 500°C show electronic conduction in dry air and act similarly to electrolytes in the presence of water vapor. Polymethylphenylsiloxane and polydimethylsiloxane were used as the silicone resins. The former is less decomposable than the latter at the same temperature. Therefore, the present composite films using polymethylphenylsiloxane heat-treated at 500°C had smaller specific surface areas and higher water repellency.