PHYSICAL, THERMAL, AND BIODEGRADABILITY CHARACTERISATION OF SUGARCANE BAGASSE AND COCONUT SHELL REINFORCED EPOXY BIOCOMPOSITES FOR COMPOSTABLE PACKAGING APPLICATIONS

Natural fillers offer a sustainable alternative for reinforcing polymer matrix composites due to their adequate strength, low cost, biodegradability, and environmental compatibility. This study investigated the development of compostable hybrid biocomposites using a thermosetting epoxy resin matrix reinforced with 3-18 wt. % sugarcane bagasse and coconut shell particles. The biocomposites were fabricated via stir casting, and their microstructural, physical, thermal, and biodegradability properties were systematically evaluated. SEM analysis of the unreinforced epoxy resin revealed a dense, cross-linked structure characteristic of thermosetting polymers. The SEM image of the hybrid polymer-matrix biocomposite indicated good dispersion of bagasse and coconut shell particles within the matrix, signifying strong interfacial bonding. Among the formulations, the hybrid biocomposite containing 12 wt. % filler (6 wt. % sugarcane bagasse + 6 wt. % coconut shell) demonstrated optimal performance, exhibiting a density of 0.97 g/cm³, the lowest water absorption (0.15 %), and the highest thermal resistance, retaining 18 % of its mass at 700 °C. These results indicate enhanced char-formation and improved filler–matrix interaction. Biodegradability testing showed that this hybrid biocomposite demonstrated the highest degradation rate, with a weight loss of 18.5 %. The improved thermal resistance and reduced hydrophilicity confirmed the composite’s strong potential for compostable packaging applications, where both thermal durability and environmental degradability are essential.