Improving interfacial and mechanical properties of epoxy resin composites by chemical grafting modification of poly‐ether‐ether‐ketone microparticles with carbon nanotubes

Abstract

AbstractThe research on epoxy resin toughening is of great significance for its application in aerospace, automotive industries, marine vessels, and other fields. Poly‐ether‐ether‐ketone (PEEK) and carbon nanotubes (CNTs) are ideal candidates for epoxy reinforcement in thermoplastic materials and nanomaterials, respectively. In this study, CNTs were first chemically grafted onto PEEK microparticles using an amidation reaction. These modified hybrid materials were then utilized as fillers in epoxy composites to enhance their strength and toughness. The changes in sample structure, composition, thermal properties, and wettability during the chemical grafting process between CNTs and PEEK were systematically studied. In comparison to pure PEEK, the surface energy of CNTs‐PEEK hybrid materials increased by 11.58% due to CNTs grafting, resulting in improved wettability and enhanced interface bonding between PEEK and the epoxy matrix. Concurrently, the CNTs‐PEEK/epoxy composites exhibited significant enhancements, with the highest tensile strength, tensile elongation at break, flexural strength, and flexural modulus increased by 31.00%, 30.84%, 121.43%, and 23.22%, respectively. The positive reinforcement effect of modified CNTs‐PEEK fillers in epoxy composites and the exploration of CNTs grafting onto PEEK extend the potential applications of epoxy composites.Highlights CNTs were bonded to PEEK via an amidation reaction by the chemical grafting method. CNTs‐PEEK have an 11.58% increase in surface energy compared to pure PEEK. CNTs‐PEEK/epoxy composites showed improved mechanical properties. The enhancement mechanisms of CNTs‐PEEK/epoxy composites were analyzed.