Comparative Analysis of Nano-CPH Reinforced Brake Pad Composites: Mechanical, Tribological, and Morphological Investigations

This study investigates the potential of nanostructured cocoa pod husks (nano-CPH) as an eco-friendly filler in automotive brake pad composites. Nano-CPH was incorporated into epoxy-based composites at varying concentrations (16–31 wt. %) along with other constituents such as silica, iron oxide, calcium carbonate, and graphite. The mechanical, tribological, and morphological properties of the composites were evaluated using standardized tests and scanning electron microscopy (SEM). The results showed that the optimal composition, which contained 21 wt. % nano-CPH exhibited significantly enhanced tensile strength (31.2 MPa), compressive strength (70.6 MPa), and Shore A hardness (88.83) compared with other filler loadings. Tribological testing revealed that the 21 wt. % nano-CPH composites exhibited the most stable and highest friction force (10.2–17.5 N) and low wear depth (15 µm), which can be attributed to the formation of a uniform, lubricating transfer film. SEM analysis confirmed the homogeneous dispersion of nano-CPH and strong matrix–filler interfacial bonding at this optimal loading. Comparative analysis highlighted the superior mechanical and tribological performance of the nano-CPH composite over other bio-based brake pad materials. These findings demonstrate the viability of nano-CPH as a sustainable, high-performance filler for eco-friendly brake pad applications, thereby promoting the valorization of agricultural waste in the automotive industry.