Synthesis and characterization of some polyimide-epoxy composites

Abstract

Composites from some novel polyimide and commercial epoxy were prepared aiming to improve the thermal behavior of epoxy resins. Two diamines namely 4-4'-diamino-4''-hydroxytriphenyl methane (DHTM) and 4-4'-diaminotriphenyl methane (DTM) were synthesized by reacting aniline and aldehydes according to a reported method. The synthesized diamines were blended with commercially available epoxy 1, 4-butanedioldiglycidylether (BDDE) to synthesize model epoxy amine networks which were compared with polyimide-epoxy composites. The polyimides were synthesized by reaction of these diamines with aromatic anhydride namely 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride (BTDA). These synthesized polyimides were dispersed in epoxy diamine networks to prepare composites. All the monomers and composites were characterized by making use of various analytical techniques including FTIR, NMR, TGA, DSC and XRD. Presence of hydroxyl group in the diamine helped in better dispersion of polyimide leading to high Tg and high char yield at 600 °C.