Study on the inter-laminar shear properties of carbon fiber reinforced epoxy composite materials with different interface structures

To explore relationship between the inter-laminar shear properties and the interfacial structure of carbon fiber (CF) reinforced epoxy resin (EP) composite materials (CFRPs), four CFRPs with different interfacial structures were prepared through introducing polar groups on the surface of the CF and then combining the modified CF with the EP, including CF/EP (where no polar group was introduced), CF-COOH-EP (where carboxyl group -COOH was chemically introduced), CF-COOH/MXene /EP (where -COOH was chemically introduced while MXene was physically introduced and the MXene was non-covalently bonded to CF and to EP), and CF-CONH-MXene-EP (where both of -COOH and MXene were chemically introduced and the MXene was covalently bonded to CF and to EP). Results of inter-laminar shear strength (ILSS) of the materials and morphology of transverse and longitudinal cross-sections of the damaged materials show that with enhancing the interfacial interaction between CF and EP, the ILSS increases and the interlayer shear failure gradually changes from a single interface debonding (for CF/EP) to a combination of interface debonding and matrix fragmentation. The interfacial structure of CF-COONH-MXene-EP with higher interfacial interaction could bear more interlayer shear forces, being beneficial for improving the service life of CFRPs. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The study reveals that enhancing the interfacial interaction between CF and EP can increase the inter-laminar shear strength of CFRPs, transitioning the interlayer shear failure from single interface debonding to a combination of interface debonding and matrix fragmentation.CF-COOH-MXene-EP with higher interfacial interaction can withstand more interlayer shear forces, contributing to improving the service life of CFRPs.