EFFECT OF HOT WATER ON THE PHYSICO-MECHANICAL PROPERTIES OF DELEB WOOD (BORASSUS AETHIOPUM) REINFORCED RECYCLED POLYPROPYLENE COMPOSITES

Abstract

This study investigates the use of hot-water-treated Deleb wood (Borassus Aethiopum) as a filler in recycled polypropylene (rPP) for wood–plastic composite (WPC) production. The wood was treated at 140 °C and 2.5 bar, then processed into particle sizes of 75, 150, and 300 µm, with filler loadings ranging from 10–50%. Maleic anhydride grafted polypropylene was used as a compatibilizer, and composites were produced via extrusion and compression molding. Mechanical properties, including tensile strength, modulus, flexural strength, impact energy, elongation at break, and hardness, were evaluated. Results showed that treated wood composites exhibited superior mechanical performance compared to untreated ones, with optimal tensile strength observed at 20% filler loading. Treated samples showed an average improvement of about 29% in tensile strength across particle sizes. However, elongation at break decreased with increasing filler content and was higher in untreated composites. Water absorption increased with filler loading, reaching a maximum at 50% and a minimum at 10%. Overall, hot water treatment improved both mechanical properties and moisture resistance. The method is eco-friendly, cost-effective, and suitable for enhancing WPC performance for outdoor applications without chemical modification.