Characterisation of natural fibre reinforced epoxy hybrid composite using okra fibre, palmyra palm fibre, and date seeds powder for enhanced mechanical, thermal, and morphological properties

The primary objective of this study is to examine the mechanical, thermal, and morphological characteristics of a sustainable epoxy hybrid composite engineered from multiscale agricultural waste: date palm seed powder, palmyra palm fiber, and okra fiber. The work is ultimately intended to improve the composite’s strength, flexibility, and thermal stability by adding natural fibers and date palm seed powder to an epoxy matrix. Using a manual hand lay-up fabrication process, this study provides extensive insight into the interaction between natural fibers and agricultural by-products with respect to composite behaviour. This study compares two material formulations: a baseline binary composite comprising natural Okra ( Abelmoschus esculentus ) fibers and Palmyra Palm ( Borassus flabellifer ) fibers (Sample 1), and a ternary composite system enhanced with a 10 wt% particulate filler fraction of fine-ground Date Palm Seed Powder (Sample 2). To analyze material performance, morphological properties, and fiber-matrix interactions, the composites were subjected to standard tensile and three-point flexural bending tests, along with analytical characterization using SEM, TGA-DTA, XRD, and FTIR. The quantitative mechanical results demonstrate that the inclusion of the date palm seed powder acts as an effective load-bearing reinforcement; compared with the pure fiber baseline (Sample 1), the Sample 2 ternary composite exhibited a 24% increase in tensile strength, a 33% improvement in elongation at break, and a remarkable 179% surge in flexural strength. Morphological analysis via SEM confirmed enhanced fiber-matrix bonding, reduced microstructural voids, and lower crack propagation in the powder-filled system, while TGA indicated superior thermal stability through enhanced overall heat resistance. This research presents an efficient pathway for upcycling waste biomass into high-performance, cost-effective, and eco-friendly green materials. Due to their specific mechanical thresholds, these sustainable hybrid composites are well-suited for domestic, low-strength components and a range of industrial applications, including lightweight packaging frames, interior automotive trim panels, appliance casings, and indoor furniture paneling.