Tensile Properties of Recycled Low-Density Polyethylene Composites with Sawdust and Natural Rubber

Abstract

The increasing generation of plastic and wood-processing wastes presents environmental and economic challenges, particularly in developing nations. This research explores how the addition of sawdust and natural rubber (NR) influences the tensile properties of composites made from recycled low-density polyethylene (rLDPE). Composite samples were prepared by varying sawdust content (0–50 wt %) and rLDPE content (50–100 wt %) with fixed NR proportions, while stearic acid, sulphur, and zinc oxide served as additives. The composites were processed via two-roll milling and compression moulding. Tensile properties were assessed according to ASTM D-638. Results showed that tensile strength improved in samples with moderate sawdust loading (Samples B and C), reaching a peak of 25.34 MPa in Sample C (20% sawdust, 80% rLDPE, 10% NR), outperforming both controls A (24.34 MPa) and G (20.60 MPa). As the percentage of sawdust was increased in Samples D to F, tensile strength reduced, though elongation was larger than Control A. The sample D having 70 g rLDPE, 30 g sawdust, and 10 g natural rubber exhibited the most favorable rigidity-flexibility balance. The research discloses that a properly calibrated blend of natural rubber and sawdust possesses the capability to enhance tensile performance and allow the fabrication of green composites for thermal insulation.