Mechanical properties of MWCNTs and graphene nanoparticles modified glass fibre-reinforced polymer nanocomposite

In the present study, the multi-walled carbon nanotubes (MWCNTs) and graphene nanoparticles were used as a reinforcement to fabricate glass fibre polymer composite at different orientations (unidirectional glass fibres 0 degrees and 90 degrees; woven glass fibres 0 degrees/90 degrees and 45 degrees/45 degrees). The composites were developed using hand lay-up-assisted vacuum bagging method at 1 torr pressure. The concentrations of nanoparticles (similar to diameter 5-20 nm) were varied in the range of 0.1-0.3 wt% in the matrix. The mechanical properties like impact strength, tensile strength and fatigue strength were carried out on Izod and Charpy machine, universal testing machine and computer-controlled machine under sinusoidal wave, respectively. It is observed that the glass fibre/epoxy composite blended with MWCNTs/graphene by 0.2 wt% has shown higher fatigue life by 56%, higher tensile strength by 36% and higher capability of energy absorption by 927.7% in notched type and lower capability of energy absorption by 155.43% in un-notched type, as compared to pure composite. The increment in properties is due to the better bonding between fillers and matrix. However, the increase of MWCNTs and graphene nanoparticles by wt% in composite laminates have shown lower fatigue strength because of the agglomeration of MWCNTs particles in matrix that caused the propagation of fatigue cracks under cyclic loading. Further, the damage behaviour of composite materials was analysed using scanning electron microscopy. It is found that a different damage behaviour in each composite is observed which is attributed to the matrix cracking, fibre rupture, fibre pullout, fibre split and fibre de-bonding.