Enhancing carbon fiber composites with fish scale biochar for superior strength and environmental sustainability

There is a pressing need to develop carbon fiber composites with sustainable fillers that enhance their strength without increasing costs or environmental impact. Such advancements would not only improve performance in high-stress applications but also align with global sustainability goals by utilizing eco-friendly materials and reducing waste. This study explores the use of biochar derived from fish scales as a sustainable filler material in carbon fiber epoxy composites. The biochar was produced through pyrolysis and incorporated into the composites at various weight percentages (0 %, 1 %, 3 %, 6 %, 9 %, 12 %, and 15 %). Mechanical properties, including tensile strength, flexural strength, impact strength, and interlaminar shear strength, were evaluated according to ASTM standards. The results demonstrated that the incorporation of biochar significantly improved the mechanical properties of the composites, with optimal performance observed at 9 % biochar content. At this concentration, the tensile strength increased by 60.02 %–674.21 MPa, the tensile modulus by 74.96 % to 46.05 GPa, the flexural modulus by 58.32 GPa, and the impact strength reached 102.32 kJ/m². It was found that achieving the optimal performance requires an optimal weight percentage of biochar. This study highlights the potential of fish scale-derived biochar as an effective and sustainable filler material for enhancing the performance of carbon fiber composites.