Oxo-Metal-Polyimide Nanocomposites. 2. Enhancement of Thermal, Mechanical, and Chemical Properties in Soluble Hexafluoroisopropylidine-Based Polyimides via the in Situ Formation of Oxo-Lanthanide(III)-Polyimide Nanocomposites

Tris(2,4-pentanedionato)lanthanide(III) polyhydrates were added as inorganic sol−gel precursors to DMAc solutions of the polyimides formed from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and 1,3-bis-(aminophenoxy)benzene, 6FDA/1,3(3)-APB and 6FDA/2,2-bis[4-(4-aminophenoxy]hexafluoropropane, 6FDA/4-BDAF. Thermal treatment of doped-resin films gave composite oxo-metal(III) nanocomposite membranes which were visually clear with lower linear coefficients of thermal expansion, increased moduli, and reduced solvent sensitivity. Glass transition temperatures and 10% weight loss temperatures in nitrogen were close to those of the parent polymers. Films were characterized by thermal, mechanical, X-ray, and transmission electron micrographic techniques.