This article deals with experimental investigation of composites based on recycled high-density polyethylene (RHDPE) and poplar fibers (Populus deltoids) formed by air-forming and hot-pressing. The effects of the fiber content (55, 70, and 85 wt%) and compatibilizing agent (0, 2, and 4wt%) concentration on the mechanical properties and water absorption were evaluated. The use of polyethylene-grafted maleic anhydride (PE-g-MA) improved the compatibility between the fiber and RHDPE. Adding PE-g-MA at 2 and 4wt% in the composite formulation significantly improved both the stability and mechanical properties.
The tensile strength of the composites containing PE-g-MA was superior to those of the composites without compatibilizing agent. As expected, the flexural of the composites increased with the wood content. Low internal bond strength was observed for the panels with different fiber loading and compatibilizing agent content in our study.