Poly(2,6-dimethyl-1,4-phenylene ether) PPO®) capping and its significance in the preparation of PPO®/epoxy laminate

The thermal expansion property at 288°C of poly(2,6-dimethyl-1,4-phenylene ether) (PPO®)/epoxy laminate was found to be affected by the PPO/epoxy copolymer content in the laminate. Capping of redistributed PPO with epoxide-containing reagents such as Araldite® EPN 1138 and an “upstaged” resin was readily accomplished with tetraethylammonium hydroxide or N, N-dimethylaminopyridine as the catalyst during the varnish preparation step. The resulting PPO/epoxy laminate maintained the nonlofting property despite the presence of phenolic hardener (curing accelerator) and antimony pentoxide (flame retardant) in the formulation.