Investigation on the Mechanical Properties of Rice Husk and Coconut Fibre Epoxy-Filled Composites for Automotive Application

Abstract

Sustainable materials are exploring natural fibres like coir fibres and rice husks as reinforcements in polymer composites due to their high tensile strength, durability, and resistance to corrosion. This research developed and characterized coir fibre and rice husk-reinforced epoxy composites, and evaluated their mechanical, thermal, and water absorption properties. Coir fibres and rice husks were extracted, washed, sun-dried, and treated with sodium hydroxide, forming composites using a hand layup process. The samples underwent rigorous testing for tensile, flexural, impact, and thermal stability using various techniques, providing a comprehensive understanding of natural fibre-reinforced epoxy composites. Treated RH composites exhibit increased water absorption at smaller particle sizes of 425 μm and 600 μm, while treated coir composites demonstrate enhanced water absorption at 1180 μm larger particle sizes. Coir/RH blend composites show consistent water absorption across all particle sizes. The results showed that untreated coir and RH composites exhibited higher flexural strength and impact energy, while 425 μm smaller particle sizes were more effective at reinforcing the composite. Treatment improved hardness in coir composites and thermal stability but reduced impact energy in RH composites. The optimal particle size for maximising impact energy was 425 μm for RH composites. Water absorption tests revealed that treatment increased water absorption in RH composites at smaller particle sizes, while treated coir composites showed the highest water
absorption at 1180 μm. Coir/RH blend composites absorb water consistently across all particle sizes. Coir and RH composites that have not been treated have higher flexural strength and impact energy. Treatment improves coir hardness but reduces RH impact energy. The study has significant implications for the development of advanced composites, especially in the automotive and construction sectors.