Mechanical performance and morphological behaviour of hybrid kenaf and empty fruit bunch fibres reinforced poly(lactic acid) biocomposites

The development of high-performance biodegradable biocomposites is essential to address plastic waste and resource sustainability challenges. However, biocomposites often exhibit limited mechanical performance and moisture sensitivity due to the hydrophilic nature of lignocellulosic fibres. This study investigates hybrid biocomposites based on poly(lactic acid) (PLA) reinforced with kenaf and empty fruit bunch fibres (EFB) to enhance structural and degradation performance. Hybrid biocomposites were fabricated via internal mixing followed by compression moulding. Hybridisation significantly improved mechanical properties of biocomposites. The incorporation of empty fruit bunch fibres into kenaf reinforced PLA increased tensile strength by approximately 47% and tensile modulus by 32% compared with non-hybrid biocomposites. The hybrid biocomposites also exhibited enhanced density and the highest biodegradation rate, with about 0.33% weight loss after ten days of soil burial. Fourier transform infrared analysis confirmed reduced hydroxyl and ester groups after fibre treatment, indicating improved interfacial compatibility. Scanning electron microscopy revealed stronger fibre–matrix adhesion, contributing to increased stiffness and strength. These findings demonstrate that kenaf and empty fruit bunch fibre hybridisation effectively enhances mechanical performance while maintaining biodegradability, supporting sustainable biocomposites development. Hybrid biocomposites were fabricated using PLA reinforced with kenaf and EFB fibres. Hybridisation improved tensile strength (~ 47%) and modulus (~ 32%). Alkali treatment enhanced fibre–matrix adhesion, confirmed by Fourier transform infrared spectroscopy and SEM. Fibre incorporation increased density and accelerated biodegradation. The developed hybrid biocomposites support SDG 9, SDG 12, and SDG 13.