Effect of electrospun polyamide 6 nanofibres on the mechanical properties of a glass fibre/epoxy composite

Recently, several types of nanoparticles are frequently incorporated in reinforced epoxy resin composites. A homogeneous dispersion of these nanoparticles is still a problem. Thermoplastic nanofibrous structures can tackle this dispersion issue. Therefore, this paper investigated the effect of electrospun polyamide 6 nanofibrous structures on the mechanical properties of a glass fibre/epoxy composite. The nanofibres were incorporated in the glass fibre/epoxy composite as stand-alone interlayered structures and directly spun on the glass fibre reinforcement. Both ways of nanofibre incorporation have no negative effect on the impregnation of the epoxy. Moreover, the nanofibres remain well dispersed within the matrix. Incorporation of nanofibres increases the stress at failure in the 0°-direction, the best results are obtained when the nanofibres are directly electrospun onto the glass fibres. Optical microscopic images also demonstrate that nanofibres prevent delamination when a 90° crack reaches a neighbouring 0° ply. Furthermore, mode I tests showed a small improvement when a thin nanofibrous structure is deposited directly onto the glass fibres. When the composites are loaded under 45°, it is proven that, for an identical stress, the glass fibre composite with deposited nanofibres has less cracks than when interlayered nanofibrous structures are incorporated. Generally, it can be concluded that the addition of polyamide 6 nanofibres improves some mechanical characteristics of a glass fibre/epoxy composite.