Effect of Treatment Processes on the Morphology and Mechanical Properties of Natural Fiber-Reinforced Epoxy Composites

The automotive industry is incorporating sustainable materials like rice husk into interiors for affordability, biodegradability, low density, and enhanced properties like durability and corrosion resistance.This research developed and characterized coir fibre and rice husk-reinforced epoxy composites, evaluating their mechanical, thermal, and water absorption properties. Coir fibres and rice husks were extracted, washed, sun-dried, and treated with sodium hydroxide, creating composites. The composites were tested for tensile strength impact resistance, water absorption, and thermal stability using Thermogravimetric analysis, Fourier Transform Infrared Spectrometry, Scanning Electron Microscope, and Izod impact testing for characterization.Rice husk (RH) composites exhibit increased water absorption at smaller particle sizes (425 μm and 600 μm), coir composites show enhanced absorption at larger sizes (1180 μm), and coir/RH blend composites maintain consistent water absorption.Untreated coir and RH composites showed higher impact energy at 425 μm, with smaller particle sizes being more effective for reinforcement, with 425 μm being the optimal size.The treatment improved water absorption in RH composites, particularly coir composites, with the highest absorption at 1180 μm, and also enhanced theirimpact resistance.The study reveals that treated coir fibre composites improve tensile strength, thermal stability, and impact resistance, while RH composites enhance impact resistance with varying particle sizes.Coir/RH blend composites, which balance water absorption and heat treatment, are highly beneficial in various industries such as automotive, aerospace, oil and gas, marine, and construction.