Abstract
In the field of electrical equipments, unsaturated polyester resins and vinyl ester resins are widely used as adhesives and insulators. As a part of high-performing of thermosetting resins, we attempted thermostability improvement of them. In the case of thermosetting resins cured by radical polymerization, thermal decomposition occurs from vinyl groups derived from disproportionation reaction. It is known that the living radical polymerization inhibits the disproportionation reaction, thus we attempted to use living radical polymerization to improve thermostability of the resins. The thermal decomposition temperature of the resin cured by alkyl borane was higher than that cured by peroxide. Furthermore, the glass-transition temperature of the resin cured by the alkyl borane was higher than that cured by peroxide. From these results it was revealed that living radical initiator is a very effective reagent to improve thermostability of thermoset resins.
