From waste to performance – a novel hybrid composite for sustainable brake friction applications

The growing demand for ecofriendly brake friction materials has accelerated research into green alternatives to conventional hazardous components such as asbestos. This study examines novel hybrid composites with permanganate (KMnO 4 )-treated Alpinia galanga ( A. galanga ) stem fibers and Pseudoxytenanthera stocksii ( P. stocksii ) bamboo rhizomes as reinforcement, combined with Metapenaeus dobsoni ( M. dobsoni ) shrimp-shell powder as a functional filler. The treated natural fibers enhance structural integrity and thermal stability, while the shrimp-shell powder contributes to controlled abrasiveness and improved surface interaction, together tailoring the composite’s frictional and wear performance for brake applications. Three composite variants were evaluated, with AGSSC ( A. galanga-P. stocksii -Shrimp shell composite) exhibiting superior density (1.52 g/cm 3 ), lower void content (2.56%), higher hardness (89 HRL) (measured by Hardness Rockwell L-scale), coefficient of friction (0.39–0.38), and 26% lower wear rate. The study directly supports SDG 12: Responsible Consumption and Production by upcycling multiple waste resources, including M. dobsoni shrimp shells as bio-fillers, P . stocksii Bamboo rhizome residues, and discarded A. galanga stems from medicinal plant processing, into high-performance friction composites. This approach promotes circular resource use, reduces dependence on non-renewable and non-recyclable materials, and demonstrates a sustainable pathway for developing eco-friendly brake friction materials.