Bio-Based Brake Pads: A Review of Natural Fillers and Their Performance Characteristics

The health and environmental hazards linked to asbestos-containing brake pads have precipitated a global initiative aimed at the development of sustainable alternatives derived from bio-based materials. This review article meticulously investigates the performance attributes of bio-based brake pads that incorporate natural fillers as viable substitutes for asbestos. The research emphasizes various agricultural byproducts, such as coconut shell powder, palm kernel shell, hemp fiber, sugarcane bagasse ash, and banana peel ash, assessing their mechanical, thermal, and tribological properties. The methodology encompasses an extensive analysis of the extant literature, elucidating the composition, processing methods, and performance indicators of these fillers within brake pad composites. Composites made from palm kernel shell demonstrated a compressive strength of up to 96.2 MPa, while materials based on coconut shell showcased exceptional hardness (up to 186.2 BHN) and wear resistance, with sugarcane bagasse ash and banana peel ash contributing to enhanced thermal stability attributable to their silica content. The conclusion accentuates the feasibility of these environmentally-friendly materials, which not only fulfill performance criteria but also alleviate the environmental and health concerns associated with asbestos. Recommendations entail the further optimization of filler compositions and surface treatments to enhance uniformity and adhesion within composite matrices, thereby facilitating sustainable applications in the automotive sector.