Sugarcane bagasse for sustainable development of thermoset biocomposites

Abstract

Lignocellulosic natural fibers are increasingly utilized as reinforcements in thermoset matrix composites, driven by economic and environmental demands. Sugarcane bagasse, a byproduct of the sugar industry, is a particularly promising source of these fibers. This study thus explores the development of sustainable composites by incorporating sugarcane bagasse fibers into bio-epoxy and unsaturated polyester resin matrices. Chemical treatments, including alkali, silane and oxalic acid, were applied to enhance fiber-matrix adhesion and improve mechanical, thermal and physical properties. The physical measurements revealed that chemical modifications of the bagasse have a significant impact on the density, water absorption and wettability of both thermosetting matrices. Additionally, SEM analysis revealed variations in composite morphology, such as brittle matrix failure, fiber breakage, fiber pullouts and voids, with the alkali-treated fibers exhibiting the best fiber-matrix interface for both types of resins. The mechanical testing of the composites reinforced with untreated and chemically treated sugarcane bagasse particulates revealed distinct variations in tensile strength and modulus, flexural strength and modulus, impact strength and hardness cross the different treatments. Superior mechanical performance was observed for the alkali treated specimen. Similarly, from the degradation temperatures and activation energies from the thermal analysis, the alkali treated fibers provided better thermal stability. These findings highlight the potential of sugarcane bagasse in eco-friendly composite design, though further research is needed to optimize treatments for better performance.