Hybrid epoxy polymer composites with bamboo fiber and crab shell particulates: mechanical and tribological behaviour

• Sustainable biodegradable composite was developed using marine waste crab shell (CS) and biofiller in epoxy+bamboo fiber composite • FTIR verifies epoxy ether linkages, hydrogen-bonding with bamboo fibers, and CaCO3 from CS particulates with effective interfacial interactions. • SEM shows void-filling/bridging by CS up to 6 wt.% with uniform dispersion; porosity and water absorption declines with gain in mechanical properties • Improved tribological behaviour attaining lower wear loss and improved CoF with wear track transitioning to mild abrasion. • Synergistic Orowan strengthening, crack deflection, and improved load transfer deliver peak performance at 6 wt.% CS; 9 wt.% causes agglomeration and property decline. The tribological, physical, and mechanical characteristics of epoxy polymer reinforced with crab shell (CS) particulates and bamboo fiber (BF) towards development of hybrid biocomposites (HBCs) was investigated in this study. Hand layup and compression moulding approaches were adopted for fabricating the sustainable HBCs. The BF content was maintained at 15 wt.%, with varying concentrations of CSs (0, 3, 6, and 9 wt.%) to formulate environmentally sustainable HBCs. The CS addition to epoxy-BF improved the stiffness, mechanical, water absorption, wear resilience, and load-bearing capability of HBCs. The HBC containing 6 wt.% CS established ideal performance, exhibiting greater impact (106.4 J/m), tensile (29.084 MPa), flexural (51.603 MPa), and compressive (26.88 MPa) strengths, with minimal porosity and wear depth (0.333% and 80.81 µm). CS biofillers amended interfacial connection across matrix and BFs enhanced better load distribution and fracture toughness. The CS particulates seal the voids by functioning as barriers thereby lowering porosity and limits water penetration thereby lowering water intake. The inherent surface hardness of CS suggestively improved the hardness and reduced wear. In comparison with epoxy+15%BF, the epoxy+15%BF+6%CS composite develops lower porosity, water absorption, % elongation and wear resilience and friction coefficient by 76.74, 64.89, 23.49, 52.59, and 18.09% with enhanced flexural, tensile, hardness, compression, and impact strengths by 13.09, 28.89, 6.49, 71.81, and 8.02%. The results emphasize the possibility of BF and CS-based HBCs as sustainable, reusable, and lightweight materials ideal for applications like automobile interior panels, seat cushions, non-structural marine interiors, ornamental boards, and advertising platforms.