Mechanical, thermal, dielectric, and flammability behavior of coir fiber/coir pith reinforced polyethylene composites

In recent decades, composite materials have gained worldwide attention in research due to their unique properties such as low weight, low density, high mechanical strength, biodegradability, and eco-friendliness. This study investigates the effect of coir fiber and coir pith loadings on the properties of polyethylene composites. The polyethylene composites were prepared with coir fiber at volume fractions of 20%, 50%, and 80%, while a hybrid composite was fabricated with 25% coir fiber and 25% coir pith. The results showed that the hybrid composite exhibited improved properties due to the combined action of coir fiber and pith. In contrast, the polyethylene composite reinforced with only coir fiber degraded more rapidly above 375 °C, indicating lower thermal stability compared to the hybrid composite. The study also explored the feasibility of processing hybrid polymer composite laminates using compression moulding. The findings revealed that the reinforcement volume fraction significantly influenced the mechanical properties. The hybrid composite demonstrated superior mechanical performance compared to the fiber-only composites, owing to the synergistic effect of fiber and pith. Additionally, the hybrid composite exhibited excellent electrical insulation behavior and was successfully fabricated into various types of strain insulators for electrical applications.