Weathering of High-Density Polyethylene-Wood Plastic Composites

Due to the widespread use of wood-plastic composites (WPCs), high-density polyethylene-wood flour composites (HDPE/WF) were studied in order to determine their stability in different application conditions. UV degradation and periodic absorption/desorption of moisture cause damaging changes to material during WPCs' exterior application, so it is necessary to ensure WPCs' durability against atmospheric influences. Samples were characterized by FTIR spectroscopy and scanning electron microscopy (SEM) in order to study the degradation after simulated weathering. The degree of water absorption was also determined. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used for the determination of composites' thermal properties. Results show that the stability of the HDPE/WF composites to UV treatment highly depends on stabilizer content and its dispersion in the polymer matrix. Incompatibility of HDPE and wood particles is a major problem that should be solved to achieve good durability and satisfying properties in use.