Effect of treatment on mechanical and thermal properties of date palm fibers/polyvinyl chloride composites

This study investigates the incorporation of date palm fibers, an abundant agricultural waste, into polyvinyl chloride (PVC) composites at a 25% fiber weight ratio. Alkali treatment, potassium permanganate oxidation, and silane coupling were applied to enhance fiber-matrix adhesion. The composites were fabricated using a hot pressing method. The results revealed significant improvements in mechanical, thermal, and moisture resistance properties for treated fibers compared to untreated ones. Potassium permanganate treatment achieved the highest tensile strength 9.57 MPa, while alkali treatment provided the highest Young's modulus about 304.5 MPa and thermal stability. Silane-treated composites exhibited the lowest water absorption. X-ray diffraction analysis showed that chemical treatments improved the crystallinity index (CI) of date palm fibers, with alkali treatment increasing CI from 28.6% to 40.5%, and potassium permanganate and silane treatments raising it to 37.5% and 41.8%, respectively. These findings highlight the potential of treated date palm fiber composites as sustainable alternatives for industrial applications such as construction and automotive, aligning with both economic and environmental objectives. Highlights: Enhanced PVC composites using date palm fibers. Alkali, permanganate, and silane treatments improve mechanical properties. Permanganate treatment achieves the highest tensile strength. Reduced water absorption and improved thermal stability in treated composites. Sustainable application of agricultural waste in industrial materials.