Curing behaviors and properties of epoxy and self-catalyzed phthalonitrile with improved processability

The curing behaviors for high-performance resin system phthalonitrile-containing benzoxazine and epoxy (BA-Ph/EP), particularly the effect of the binary system composition and processing conditions on their processabilities were investigated and discussed in this article. Results indicated that all BA-Ph/EP prepolymers exhibited low initial processing viscosity (<0.3 Pa s) and have kept stable low viscosity until gel transition. The suitable molding temperature (ranged from 150 degrees C to 180 degrees C) and molding time (ranged from 20 min to 80 min) could be selected for practical applications of BA-Ph/EP systems. The studies of curing behaviors and gelatinization for BA-Ph/EP systems give further understanding of the curing kinetics and guidance for the fabrication of high-performance copolymers/polymers. The introduction of EP could significantly improve the cross-linking density of BA-Ph/EP polymers, and the appropriate content of EP is the key fact for the improvement. In addition, the effects of postcuring conditions on thermal properties and the adhesive property of BA-Ph/EP polymers were monitored. The thermal stabilities and adhesive property of various polymers also showed an obvious influence with the introduction of EP. The systematic study of BA-Ph/EP system could enable a broadened industrial application, especially in the areas that require high-temperature resistance.