Decorating wood flour/HDPE composites with wood veneers

Abstract

The low surface free energy makes wood plastic composites difficult to bond with traditional adhesives, such as urea formaldehyde resin (UF). This study investigates the decoration of wood flour/high‐density‐polyethylene composite (WF/HDPE) board with poplar wood veneers. High‐density polyethylene (HDPE) or maleic anhydride grafted polyethylene (MAPE) film was introduced between the veneer and the WF/HDPE composite board as an intermediate component to strengthen the bond. Surface bonding strength, hot water resistance, and bending performance of the composites were then evaluated. Contact angle, Attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) spectroscopy, and scanning electron microscopy (SEM) were used to analyze the interface of the wood veneer and the WF/HDPE composites. The addition of MAPE film enhanced the polar characteristic of the WF/HDPE composite surface and increased the number of functional groups reacting with the –OH groups present in the wood veneer. A MAPE intermediate film increased the surface bonding strength of the wood veneer to WF/HDPE composite surface, and also endured boiling water without delimitation failure. After being covered with the wood veneer, the flexural strength and modulus of WF/HDPE composite panels increased four times comparing to that of the uncovered composites. POLYM. COMPOS., 39:1144–1151, 2018. © 2016 Society of Plastics Engineers