Utilizing in-situ construction of tailored block copolymer nanostructures to enhance CF/epoxy composites compressive properties

Abstract

The imbalance in the compressive strength to tensile strength ratio of carbon fiber reinforced polymer (CFRP) composites is a key factor that limits its lightweight application. Increasing the tenacity and strength of resin matrix has been evidenced as an effective method to address this problem. In this work, an interesting strategy that block copolymer nanostructures built in-situ in epoxy to simultaneously increase its tensile strength and fracture toughness, is provided. Benefitting from the nanostructures, the tensile strength and fracture toughness of epoxy matrix are increased by 19% and 236%, respectively, without lowering its Tg. Block copolymers’ impact on the morphologies and transformation of nanostructures, the relationship between nanostructures and epoxy properties, and the strengthening and toughening mechanism are systematically studied. Meanwhile, these epoxy resins with excellent tensile properties and toughness are selected for the verification of the CFRP composite performance. The compression properties and interfacial properties of CFRP composites were 34.5% and 17.8% improved, demonstrating that in-situ constructing nanostructures in resin matrix is an effective strategy to enhance the compressive and interfacial properties of composites. Our research is anticipated to offer some fresh suggestions for creating high-performance CFRP composites.