Multiscale Reinforcement of Epoxy Composites with Glass Fibre and Carbon Nanotube

Abstract

This paper presents an investigation on the modification of macro-scale fibre reinforcement with nano-scale filler to produce multiscale glass fibre reinforced polymer (GFRP) composites. Glass fibres were spray-coated with multi-walled carbon nanotube (MWCNT) aqueous suspension and were stacked together with epoxy binder to produce composite laminates by using hand lay-up method, followed by vacuum bagging. The stability of MWCNT aqueous suspension was analysed using zeta potential and UV-Vis and the distribution of MWCNT on the glass fibre was examined using scanning electron microscope. To evaluate the mechanical performance, flexural test and short beam test were performed. Improvement by 53.6% and 74.8% was observed in flexural strength of the 5-ply glass fibre (5GF) composites incorporated with 0.1 and 0.5 wt% of MWCNT, respectively. Meanwhile, flexural modulus of the same composites showed more than 20% improvement at both MWCNT concentrations. For interlaminar shear strength (ILSS), the highest improvement was found to be at 0.5 wt% of MWCNT which increased ILSS of the multiscale composite by 43.8% compared to the control sample (5GF). It is also interesting to note that 6-ply glass fibre (6GF) composite had lower flexural properties and ILSS in comparison to 4-ply glass fibre (4GF) and 5GF multiscale composites incorporated with MWCNT, indicating that we successfully reduced the weight of the GFRP composites by reducing the glass fibre ply but significantly enhanced their mechanical performance.