EFFECT OF SPECIFIC INTERACTIONS ON FILM CASTING OF HIGH-TEMPERATURE POLYMERS

Cast films were prepared from polybenzimidazole and a polyimide as wel l as from their blends over the whole composition range. The solvent w as N,N'-dimethyl acetamide (DMAc), which was removed by washing with w ater and drying. The amount of solvent retained by the films depended on sample preparation conditions and significantly influenced the stab ility of the polymer. Vapour absorption and FTIR studies have shown th at solvents enter into strong interaction with the polymers, especiall y with the polybenzimidazole component. The thorough removal of solven ts is an essential condition for the utilization of films prepared fro m these polymers.