Graphene oxide induced fast curing of amino novolac phthalonitrile

Graphene oxide (GO) possessing hydroxyl and epoxy groups was synthesized by a modified Hummer's process and was found to conform to the empirical formula C-0.801[epoxy](0.190)[OH](0.009). GO was examined as a curative for amino novolac phthalonitrile (APN). It was found to facilitate the crosslinking reaction by acting as a reactant for the amino group. Additionally, epoxy and OH groups in GO react with the nitrile groups of APN providing another pathway for facilitating the curing of APN. Epoxy groups in GO react with the nitrile groups of APN in the presence of OH groups (generated by the epoxy-amine reaction), facilitating the crosslinking at a lower curing temperature. Blending with GO decreases the overall curing temperature of APN. The co-reaction of the two systems led to a single phase matrix whose failure mode changed from brittle to ductile with no penalty in the thermal stability.