Development and Evaluation of Nano‐ SiC , EPDM Reinforced Toughened Hemp Fiber/Polypropylene Composites With Improved Mechanical, Thermal and Environmental Properties

Plant fiber‐reinforced composites are widely preferred for both industrial and civil applications because of their good all‐round properties. However, fiber‐reinforced materials are brittle and poorly ductile, which limits their use in scenarios requiring high toughness. In this study, composites were prepared by melt blending and injection molding using alkali‐treated hemp fibers, polypropylene matrix, nano‐silicon carbide (0–4 wt%) as a reinforcing filler, and EPDM rubber (0–20 wt%) as a toughening agent. The results showed that 3 wt% of nano‐SiC increased the tensile strength by 6%, while 4 wt% of nano‐SiC increased the flexural strength and modulus by more than 10% compared to the hemp fiber/polypropylene composites. Nano‐SiC also improves crystallinity and thermal stability and reduces the coefficient of friction by up to 20.9% at low levels. The addition of EPDM significantly improves toughness. Impact strength and elongation at break increased by 167.3% and 429.1%, respectively, when the EPDM content was 20 wt%. Life Cycle Assessment (LCA) shows that electricity use is the largest source of carbon emissions (> 60%). Hemp fiber has a minimal environmental impact. In conclusion, the optimized HF/PP/nano‐SiC/EPDM composites achieve a balance between strength, toughness, and sustainability and show strong potential for use in automotive and structural applications.