Morphology, mechanical properties, and dimensional stability of wood particle/high density polyethylene composites: Effect of removal of wood cell wall composition

• Removal of hemicellulose reduced water absorption and thickness swelling.
• Removal of lignin caused the highest tensile modulus and storage modulus.
• WPCs with αC had the highest tensile strength, elongation at break, and toughness.

Variation in the chemical composition of wood cell walls has a significant influence on the properties of wood plastic composites (WPCs). This study investigated the effect of removal of hemicellulose and/or lignin on the mechanical properties and dimensional stability of WPCs. Four types of wood particles with various compositions including native wood flour (WF), hemicellulose-removed particle (HR), holocellulose (HC), and α-cellulose (αC) were prepared and compounded with high density polyethylene (HDPE) in an extruder, both with and without maleated polyethylene. Injection molding was used to make test specimens. The HR-based composites exhibited the best water resistance. The HC-based composites obtained a greater tensile modulus but a lower water resistance. The highest values for tensile strength, elongation at brake, toughness, and impact strength were achieved by the composites filled with αC.