Amino-Functionalized Poly(ether sulfone): A Novel Strategy for Enhancing the Mechanical Properties of Epoxy Resin and Carbon Fiber/Epoxy Composites

The mechanical properties of carbon fiber/epoxy (CF/EP) composites are often limited by the low mechanical performance of epoxy resin, leading to damage initiation and eventual failure of the composites. To enhance their mechanical performance, an amino-functionalized poly(ether sulfone) (APES) was synthesized and employed as a modifier for epoxy resin and used to fabricate CF/EP composites via hot-pressing. APES is capable of participating in the curing process and dispersing uniformly in the resin matrix. The results demonstrated that the introduction of APES improved the resin’s tensile strength by 23% and flexural strength by 19%. More importantly, compared with PES-modified CF/EP composites, APES-modified composites exhibited a more uniform matrix structure, significantly enhancing stress transfer between carbon fibers and resin. Therefore, the tensile and compressive strengths of APES-modified CF/EP composites increased by 24 and 26%, respectively, compared to those of unmodified composites, while PES-modified composites showed no significant improvement. These findings suggest that APES-modified epoxy resin effectively enhances the overall mechanical performance of CF/EP composites, offering new insights and potential applications for the development of high-performance composite materials.