Improving Mechanical and Physical Properties of Wood-Plastic Composites Using Natural Rubber Latex Sludge Waste

Abstract

The disposal of synthetic materials and industrial by-products hasbecome a pressing environmental issue, particularly in the wood and polymersectors. This study investigated the feasibility of utilising natural rubber latexsludge waste as a reinforcing filler in wood-plastic composites (WPCs). Theinfluence of latex sludge content (20-40 wt%) and particle size (≤149 μm, 149-400 μm, and 400-707 μm) on the mechanical, thermal and physical propertiesof WPCs were examined. The WPC panels were fabricated via twin-screwextrusion followed by hot compression moulding. The morphological analysisrevealed that finer sludge particles enhanced interfacial adhesion andhomogeneity. The thermal analysis demonstrated that the addition of latexsludge marginally improved the thermal stability of WPCs, with optimalperformance observed at intermediate particle size. Higher sludge contentincreased the modulus of rupture but reduced the stiffness and hardness,attributed to the elastic nature of the sludge. Using finer latex sludge particlessignificantly improved WPC flexural strength and hardness, while reducingwater absorption due to better matrix packing and decreased hydrophilicity.These findings highlighted the potential of latex sludge as a value-added fillerin WPCs, offering an innovative approach to waste valorisation and materialenhancement for sustainable industrial applications.