Biocomposites Reinforced with Cellulose-Rich Snake Plant and Sesbania aculeata Lignocellulosic Fibers: Fabrication, Property Optimization and Structure-Performance Relationships

The increasing demand for sustainable, bio-derived materials has intensified interest in lignocellulosic fibers as reinforcements in polymer biocomposites. This study develops epoxy biocomposites reinforced with cellulose-rich lignocellulosic fibers extracted from snake plant ( Sansevieria trifasciata ) and Sesbania aculeata . Hybrid composites were fabricated using five fiber ratios (100/0, 75/25, 50/50, 25/75, 0/100 SP/SA) to systematically evaluate the influence of fiber composition on physical, mechanical, and fracture behaviors. The results show that increasing Sesbania aculeata content enhances stiffness, hardness, and dimensional stability due to its higher density and lignin content, whereas higher snake plant loading significantly improves tensile, flexural, and impact strengths, resulting from better fiber-matrix adhesion and greater cellulose contribution to load transfer. Among the hybrids, the 75SP/25SA composite exhibits the highest tensile (38.6 MPa) and impact strength (28.19 kJ/m²), while the 50SP/50SA composite achieves the greatest flexural strength (137 MPa). SEM analysis confirms that failure mechanisms vary with fiber composition, transitioning from ductile fiber rupture in SP-rich composites to brittle debonding and fiber pull-out in SA-rich systems. The findings demonstrate that tailored hybridization of cellulose-rich lignocellulosic fibers enables tunable strength-stiffness synergy and improved sustainability, providing pathways for their use in structural, automotive, and consumer applications.