Eco-Friendly and Cost-Effective High-Density Polyethylene-Based Composites: Optimizing Wood-Plastic Composites for...

Petroleum-based products have been linked to global warming. In this context, wood-plastic composites (WPCs) emerge as an economically and ecologically attractive alternative. Therefore, for the first time, this study aims to produce, optimize, and characterize high-density polyethylene (HDPE)-based WPC loaded with sawdust (St) and fiberglass (FG) without compatibilizers. The amounts of St (0-40%, w/w) and FG (0-40% w/w) were optimized for compressive strength using a Simplex Lattice mixture design. The WPCs were extensively characterized. The composites demonstrated densities ranging from 780 to 987 kg/m³, low moisture retention (0.83-2.45%), and mechanical properties of 0.97-10.89 kN. Scanning electron microscopy (SEM) micrographs showed homogeneous materials in mixtures containing St. The random distribution of Si on the material surfaces was identified by energy dispersive spectroscopy (EDS). Furthermore, the optimization indicated that the WPC loaded with 40% St (40 St) leads to the most compression-resistant (11.034 kN) composite. The results suggest a 17.3% greater strength than that of the control (8.93 kN). On the other hand, a simple calculation indicates a 37% reduction in the production cost for the optimized 40 St (US$ 0.53/kg) amount compared to pure HDPE (US$ 0.84/kg). Additionally, substituting HDPE with St (amount of 40 St) could reduce equivalent carbon emissions. Thus, the results suggest that 40 St WPC has potential market applications. The new technology could contribute to environmental sustainability, lowering production costs.