Effect of mechanical, wear, thermal conductivity properties of biocarbon and biosilica particles in rubber composites
摘要
In this study, sustainable natural rubber (NR) composites reinforced with biocarbon and biosilica derived from Eleusine coracana straw waste were developed to explore eco-friendly alternatives to conventional petroleum-based fillers. Biocarbon and biosilica were incorporated individually and in hybrid form, and their effects on the mechanical, tribological, and thermal properties of NR were systematically evaluated. Hybrid biocarbon–biosilica composites exhibited a pronounced synergistic reinforcement effect compared to biosilica-only systems. The best formulation containing 10 phr biocarbon and 1.5 phr biosilica achieved superior performance, with a tensile strength of 40 MPa, tear strength of 56 N mm-1, hardness of 66 Shore A, and a controlled reduction in elongation at break. Tribological analysis revealed a significant improvement in wear resistance, with the specific wear rate reduced by ~ 55% and the coefficient of friction decreased to 0.56, attributed to enhanced filler–matrix adhesion and the formation of a stable carbon-rich tribo-layer. Thermal conductivity increased from 0.18 W m−1 K−1 for neat NR to 0.33 W m−1 K−1 for the hybrid composite due to the development of continuous heat-transfer pathways. Overall, the results demonstrate that biocarbon derived from agricultural waste is a viable and sustainable substitute for conventional carbon black, enabling the development of high-performance NR composites suitable for advanced industrial and automotive applications.