Electrospun nanofibre toughened carbon/epoxy composites: Effects of polyetherketone cardo (PEK-C) nanofibre diameter and interlayer thickness

Polyetherketone cardo (PEK-C) nanofibres were produced by an electrospinning technique and directly deposited on carbon fabric to improve the interlaminar fracture toughness of carbon/epoxy composites. The influences of nanofibre diameter and interlayer thickness on the Mode I delamination fracture toughness, flexure property and thermal mechanical properties of the resultant composites were examined. Considerably enhanced interlaminar fracture toughness has been achieved by interleaving PEK-C nanofibres with the weight loading as low as 0.4% (based on weight of the composite). Finer nanofibres result in more stable crack propagation and better mechanical performance under flexure loading. Composites modified by finer nanofibres maintained the glass transition temperature (T_g) of the cured resin. Increasing nanofibre interlayer thickness improved the fracture toughness but compromised the flexure performance. The T_g of the cured resin deteriorated after the thickness increased to a certain extent.