Performance Enhancement of Natural Fiber Hybrid Biocomposites Using Coupling Agents

Abstract

Natural fiber-reinforced hybrid biocomposites have emerged as sustainable alternatives to conventional polymer composites due to their low density, biodegradability, and cost-effectiveness. However, their mechanical performance is often limited by weak interfacial adhesion between hydrophilic natural fibers and hydrophobic polymer matrices. This study investigates the effect of coupling agents on the performance enhancement of hybrid biocomposites reinforced with multiple natural fibers. Epoxy-based composites were fabricated using varying combinations of jute, sisal, and kenaf fibers, with and without silane-based coupling agents. Mechanical characterization, including tensile, flexural, and impact testing, was conducted to evaluate the improvements in strength, stiffness, and energy absorption. Scanning electron microscopy (SEM) was employed to analyze fiber-matrix interfacial bonding and fracture mechanisms. Results indicate that the use of coupling agents significantly enhances interfacial adhesion, leading to improved load transfer, reduced fiber pull-out, and increased overall mechanical performance. The study demonstrates that appropriate fiber hybridization combined with coupling agents provides a practical route to optimize the mechanical properties of sustainable biocomposites, enabling their wider adoption in structural, automotive, and consumer applications.