Studies on new type of phenolic resin - Curing reaction of bisphenol-A-based benzoxazine with epoxy resin using latent curing agent and the properties of the cured resin

Curing reaction of bisphenol-A-based benzoxazine (Ba) with epoxy resin (Ep) using latent curing agent, and the properties of the cured resin were investigated. Consequently, by using latent curing agent, the ring opening reaction of benzoxazine ring occurred more rapidly, and then also the phenolic hydoroxyl group generated by the ring opening reaction of benzoxazine ring reacted with epoxy ring more rapidly. And it was found that the cure time of the molten resins from Ba and Ep with latent curing agent could be reduced and also the cure temperature could be lowered, compared with those from Ba and Ep without latent curing agent. The melt viscosity of the molten resins from Ba and Ep with. latent curing agent was kept about 50 [Pa s] at 100 degrees C even after 30 min, the molten resins from Ba and Ep with latent curing agent showed good thermal stability below 100 degrees C. However, above 170 degrees C the curing reaction of Ba with Ep with latent curing agent proceeded rapidly. The cured resin from Ba and Ep with latent curing agent showed good heat resistance, flame resistance, mechanical properties, and electrical insulation, compared with the cured resin from Ba and Ep without latent curing agent. (c) 2008 Wiley Periodicals, Inc.