Improvement of mode-II interlaminar fracture toughness of carbon textile composites with modified matrix of thermoplastic and thermoset epoxy-addition of glass fibers

Abstract

Interlaminar fracture toughness of a material with a layered structure such as CFRP is poor and cracks between the layers easily lead to fatal result. Interlaminar fracture toughness still plays an important role in damage propagation of CFRP. In this study, mode II inter-lamina fracture toughness of CFRP was investigated by ENF test for clarifying effect on weight-average molecular weight of matrix and matrix modification with glass fiber. Micro glass fibers whose diameter was 0.5 μm with 0.3wt% of weight content were added into thermoplastic epoxy resin and thermoset epoxy resin, respectively, for the matrix of the textile carbon fiber composite prepared by our laboratory. State of the fracture surface was also changed accompanying with the change of the weight-average molecular weight of the matrix. In these results, Mode II interlaminar fracture toughness of the composite was improved by preventing the crack propagation with fiber bridging of added glass fibers on the interface regardless of the types of matrix of thermoplastic and thermoset epoxy resin.