Poly(2-vinyl pyridine) /silica and poly(4-vinyl pyridine)/silica nanocomposites were synthesized by casting of blend solutions of perhydropolysilazane and poly(2-vinyl pyridine-co-2-hydroxyethyl methacrylate) and poly(4-vinyl pyridine-co-2-hydroxyethyl methacrylate) random copolymers, respectively, and calcination of dried films at 100 degreesC under steam. The structures of the separated phases and the thermal properties of the composites were investigated by transmission electron microscopy (TEM), DSC, and TGA. (C) 2004 Wiley Periodicals, Inc.