Title
Mechanical performance of epoxy adhesive composites reinforced with waste tire rubber and coconut shell biochar
Authors
MADASAMY SERMARAJ, KALIMUTHU RAMANATHAN and K. J. NAGARAJAN

Received January 4, 2026
Published Volume 60 Issue 3-4 March-April
Keywords waste tire rubber, coconut shell biochar, tensile strength, impact strength, fracture toughness

Abstract
The disposal of waste tires and coconut shells poses significant environmental challenges, as both materials are often discarded in landfills, contributing to pollution, habitat destruction, and health hazards. This study investigates the incorporation of waste tire particles and coconut shell biochar into epoxy resin–based hybrid polymer composites using the compression molding technique. Pyrolysis was employed to produce coconut shell biochar at temperatures of 400 °C and 800 °C in order to analyze variations in material characteristics. The composites were prepared with different weight proportions of tire rubber and biochar, and properties such as tensile strength, impact strength, and fracture toughness were evaluated. The addition of particles at all concentrations led to significant reduction in impact strength and fracture toughness of the composites compared to the neat resin sample; however, the addition of biochar, particularly at lower to moderate loadings, substantially enhanced tensile strength, with a maximum improvement of 66.1% observed for composites containing biochar produced at 400 °C. The distribution and interfacial adhesion of particles within the resin matrix along the fractured surfaces were examined using scanning electron microscopy, and the nature of failure was identified through morphological analysis. By utilizing waste tire particles and coconut shell biochar, this study aimed to develop materials that are not only mechanically robust, but also contribute to a cleaner and more sustainable future.