Heat distortion temperatures, glass transition temperatures and extent of chemical cure of some amine-hardened epoxide resins

Abstract

The relationship between chemical cure and heat distortion temperature has been examined for some epoxides cured with aliphatic amines. The systems studied exhibit differences in the kinetic nature of the curing reaction and the amount of epoxide left after cure. On postcuring at higher temperatures, heat distortion temperatures are significantly increased, and reach steady values in some, but not all, cases. In some cases large increases in heat distortion temperature can occur without reaction of epoxide groups: this may be due to physical changes in the supermolecular structure of the epoxide. Heat distortion and glass transition temperatures have similar values. In consequence, heat distortion temperatures of components of an epoxide-isoprene copolymer have been examined in relation to theories of the glass transition.