Sugarcane bagasse reinforced polymer based environmentally sustainable composites: influence of fiber content and matrix selection

Environmentally sustainable composites reinforced with sugarcane bagasse fiber (SBF), a natural fiber derived from the residual biomass of sugarcane processing, were developed using four polymer matrices: unsaturated polyester resin (UPR), bio-epoxy (BE), polylactic acid (PLA) and high-density polyethylene (HDPE). SBF content was varied at 3 wt%, 6 wt% and 9 wt%. Thermosetting composites were prepared using the open casting method, while thermoplastic composites were fabricated through compression molding. The study assessed physical and mechanical responses to elucidate the influence of matrix type and fiber loading. Composite density and properties like tensile modulus, flexural modulus, hardness and toughness improved with increasing fiber content, while tensile strength, elongation at break, flexural strength and flexural strain declined. Moisture susceptibility rose with higher fiber content, highlighting a trade-off between reinforcement and durability. Notably, 3 wt% BE composites exhibited superior tensile strength, 6 wt% BE had the highest tensile modulus and impact strength, 3 wt% PLA achieved peak flexural strength, 9 wt% PLA showed the greatest flexural modulus and 6 wt% PLA displayed the highest shore D hardness. These findings provide critical insights for optimizing polymer-fiber systems in sustainable composite design.