Eco-friendly surface modification to improve interfacial properties in natural fibre-reinforced epoxy composite

Abstract

Abstract Carbon nanostructures deposited on natural fibre surfaces can modify the fibre–matrix interface and influence load-transfer behaviour in polymer composites. In this study, carbon nanotubes were deposited onto jute fibre surfaces using a high-impulse electrophoretic deposition process. Epoxy-based composites with a fibre volume fraction of 45% were manufactured by vacuum-assisted resin transfer moulding using untreated jute fibre (JFEC) and carbon nanotube-coated jute fibre (CNT/JFEC). The interfacial behaviour of the composites was investigated using single yarn pull-out, short beam shear, transverse tensile, and dynamic mechanical analysis tests. The pull-out results revealed comparable interfacial shear strength values for treated and untreated fibres, indicating no statistically significant increase in IFSS. However, scanning electron microscopy showed a shift in the failure mechanism from fibre pull-out to increased fibre breakage in CNT-coated samples, suggesting a modification in the load-transfer behaviour at the fibre–matrix interface. Mechanical testing revealed a 17% increase in transverse tensile strength and a 10% increase in short beam shear strength for CNT/JFEC composites. In addition, dynamic mechanical analysis showed a notable increase in storage modulus in both the glassy and rubbery regions. These results indicate that the CNT coating alters the interfacial region and promotes more efficient stress transfer within the composite system.