Effect of nanographene addition on dielectric, mechanical and flame retardation properties of snake grass fiber/kevlar epoxy composites

Abstract

This research intends to explore the impact of nanographene on the dielectric, mechanical, and flame retardation behaviour of fiber composites made of snake grass fiber (SF) and Kevlar. The nanographene was evenly dispersed in the epoxy through sonication. The SF/Kevlar hybrid composites with added graphene were fabricated using compression moulding. Mechanical tests were analyzed, comprising impact, flexural, tensile, and interlaminar shear strength. The mechanical test results showed that the hybrid composites containing 3% nanographene showed an improvement of 40.66%, 46.12%, 37.33%, and 26.58%, respectively. The cracked surfaces after the tensile test were subjected to a micrographic analysis. The micrograph images revealed a strong interaction between the SF/Kevlar fiber and the epoxy, with the addition of nanographene. The dielectric test revealed that adding nanographene enhanced the dielectric loss and dielectric constant. The composite containing 5wt.% nanographene showed a 52% increase in dielectric loss compared to the reference sample. The inclusion of nanographene in SF/Kevlar hybrid epoxy composites reduces the flame propagation speed. The sample with 5 wt.% nanographene showed better performance in flammability studies. The presence of nanographene enhances the thermal resistance of the composite, delaying the ignition and reducing the overall flame spread rate.