Enzymatic treatments of pine wood flour for high-density polyethylene composites: Impact on thermomechanical, aging, and wear behavior

The use of pine wood in wood-plastic composite WPC promotes sustainability by incorporating recycled or renewable materials, reducing the reliance on traditional wood sources, and minimizing environmental impact. This study focuses on treating pine wood flour (WF) with biological treatments (xylanase, pectinase, laccase, steam explosion) for use in WPC. The Scanning Electron Microscopy (SEM), Fourier Transform Infared spectroscopy (FTIR), biochemical analysis, and Thermo Gravimetric Analysis (TGA) were used to evaluate the effectiveness of the treatments in terms of the morphological, compositional, surface, and thermal stability of WF. The wear behavior of WPC was exanimate before and after hydrothermal aging. Morphological analysis of WF revealed that the enzymatic treatment produced a clean surface; it removed Xylan and led to a higher cellulose content (70%), and more porosity, and improved thermal stability and adhesion between WF and high density polyethylene (HDPE). Through analysis of wear and aging, we found the best wear resistance for laccase treatment among all WPC before and after aging, and it was lower than the HDPE. These findings highlight the positive impact of the enzymatic treatment on the adhesion between WF and HDPE, leading to reduced water absorption and increased wear resistance.