Fracture behaviour of carbon fibre/epoxy composites interleaved by MWCNT- and graphene nanoplatelet-doped thermoplastic veils

Abstract

Polyphenylene-sulfide (PPS) veils doped with MWCNTs and graphene nanoplatelets (GNPs) were used as interleaves of a carbon fibre/epoxy composite, aiming to study its effects on the fracture performance. Interlaying original PPS veils significantly improved the mode-I and mode-II fracture toughness of the laminates due to a PPS fibre bridging mechanism. The addition of MWCNTs on the veils improved the PPS fibre/epoxy adhesion by introducing additional interactions, i.e. MWCNT pull-out and breakage, between the PPS fibres and the epoxy during the fracture process. This further improved the fracture toughness of the laminates at a relatively low content of MWCNTs. In contrast, the incorporation of GNPs on the veils decreased the PPS fibre/epoxy adhesion, resulting in detrimental effects on the fracture performance.