Flexural Properties of Chopped Kenaf and Carbon Fibre Reinforced Polymer Composites Embedded with Carbon Nanotubes

An experimental study was performed to investigate the flexural behaviour of chopped kenaf and carbon fibre reinforced polymer composites embedded with carbon nanotubes (CNT). The fibre content in the composites was 10 wt.% with three different CNT loadings, which were 0.5wt.%, 1.0wt.%, and 1.5wt.%. The CNT were dispersed in the epoxy resin using the mechanical stirrer and three-roll mill machine and mixed with the chopped fibres before being poured into the designated mould. Three-point bending tests were conducted with a specimen thickness and width of 4 mm and 10 mm, respectively, and a standard specimen length of 20% longer than the support span. The flexural test results showed that the chopped carbon fibre reinforced polymer (CFRP) with 0.5wt.% CNT exhibited the highest flexural strength and modulus (42 MPa and 2.9 GPa, respectively) compared to other composites with 1.0wt.% and 1.5wt.% CNT loading. The chopped kenaf fibre reinforced polymer (KFRP) composite with 0.5wt.% CNT loading showed the highest increase in the flexural strength and modulus, at 30 MPa and 2.8 GPa, respectively. Hence, it was concluded that the addition of CNT improved the flexural properties and 0.5 wt.% CNT was the ideal loading to enhance the flexural properties of chopped fibre-reinforced polymer composites.