The Effect of Amine and Phenolic Curing Agents on Curing Temperature of High Temperature Phthalonitrile Resin for Preparation of High Performance Carbon/ Phthalonitrile Composite

In this work, Phthalonitrile resin based on bisphenol A was synthesized with a yield of 93% and a purity of 98.91%, and its structure was identified using various techniques. To investigate the effect of curing agent type on curing temperature and thermal property of resin, the synthesized resin was cured with two different curing agents including bisphenole A and methylene dianiline. It was observed that the amine curing agent, despite its lower weight percentage, has a more significant effect on accelerating the curing process. Finally, a composite of the synthesized phthalonitrile resin and carbon fibers was prepared with two resin contents, 32% and 41%, and its mechanical and thermal properties were evaluated. The results indicated that the composite with 32% resin content exhibited superior properties, with an interlaminar shear strength (ILSS) of 36.4 MPa and a modulus of 14.56 GPa. The thermal resistance of both resin and composite was assessed using the TGA technique, revealing that the pure resin has a char yield of 72%, while the composite with 32% resin content has a char yield of 87% at 800°C under a nitrogen atmosphere. Moreover, the TGA results demonstrated that the phthalonitrile / carbon fiber composites has approximately the same thermal stability at air and argon atomosphere, domenstrating excellent ability of this resin as a thermal barrier.