Development and comprehensive characterization of sustainable epoxy composites reinforced with Palmyra palm husk fiber and Aegle marmelos fruit peel powder

This study presents the development and comprehensive characterisation of sustainable epoxy composites reinforced with Palmyra palm husk fibre and Aegle marmelos fruit peel powder, utilising two abundant agricultural wastes as eco-friendly reinforcement materials. Composites were fabricated using the hand lay-up technique and characterised through tensile, flexural, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. The incorporation of 10 wt.% Aegle marmelos fruit peel powder showed an increased tensile response in the tested specimen; however, because only one specimen per formulation was evaluated, the observed improvement should be considered preliminary and requires validation through repeated testing, increasing the maximum load from approximately 12 MPa for the fibre-only composite to 14.1 MPa while improving ductility and energy absorption. The maximum apparent flexural stress was approximately 28.4 MPa for S1 and 26.3 MPa for S2. Although incorporating Aegle marmelos fruit peel powder did not increase peak flexural stress, the S2 composite showed a more gradual post-peak response, indicating improved damage tolerance under bending. The fracture-surface SEM micrographs reveal localised fibre pull-out, voids, cracks, and regions of relatively continuous matrix–fibre contact. These features provide qualitative evidence of fibre–matrix interaction and fracture mechanisms; however, we did not perform quantitative void-fraction and pull-out measurements. X-ray diffraction (XRD) analysis confirmed the retention of the lignocellulosic structure, with Segal crystallinity indices of 19.30% for S1 and 18.01% for S2, indicating a slight decrease in relative crystallinity after incorporation of the Aegle marmelos fruit peel powder with additional diffraction peaks at 26° and 38° (2θ), while FTIR spectra confirmed successful incorporation of the fruit peel powder through characteristic bands at 3400, 2900, 1580, 1210, and 800 cm -1 . These findings demonstrate that Aegle marmelos fruit peel powder is a promising sustainable bio-filler for developing lightweight, environmentally friendly epoxy composites with improved mechanical performance and structural integrity.