Improved Interlaminar Shear Behaviour of a New Hybrid Kevlar/Cocos Nucifera Sheath Composites with Graphene Nanoplatelets Modified Epoxy Matrix

This research investigated the effect of hybridizing Kevlar/cocos nucifera sheath and the effect of adding different wt.% of Graphene nanoplatelets (GNP) on the interlaminar shear behaviour of laminated composites. Initially, different wt.% (0, 0.25, 0.50, and 0.75) of GNP's were mixed with epoxy resin through Ultrasonic-sonication. Then the laminated composites were fabricated by hand lay-up method followed by hot pressing. The weight ratio of Kevlar (K) and cocous nucifera sheath (CS) are 100/0 (S1), 75/25(S2), 50/50 (S3), 25/75(S4), and 0/100(S5). Interlaminar shear strengths (ILSS) of different laminates were evaluated using a short beam shear test. The results revealed that hybrid composites S2 (75/25) possess higher ILSS than other laminates in the absence of GNP. Addition of GNP at 0.25 wt.% exhibited higher ILSS in all the laminates (S1 to S5) due to the improved interfacial properties. Further addition of GNP (0.50, and 0.75 wt.%) has declined the ILSS of the laminated composites due to aggregation and overlapping of GNP. XRD analysis reveals that at 0.25 wt.% of GNP, all the hybrid composites exhibited higher crystallinity index. Statistical analysis of the results has been performed using one way-ANOVA (Analysis of variance) and it shows that there is a statistically significant difference between the obtained interlaminar shear strength of the laminated composites.