Effects of low concentration coupling agent addition on the physicomechanical behavior of wood fiber/HDPE composite

Abstract

In this study, a simple and efficient preparation method of wood-plastic composites (WPC) from maple wood flour (filler) and high-density polyethylene (HDPE) through extrusion was conducted, and the effects of low concentration (2% w/w) coupling agent addition (maleated polyethylene, MAPE) on their physical and mechanical properties were tested. Tensile test, dimensional stability (water absorption) test, melt flow rate test, and differential scanning calorimetry (DSC) analysis were utilized to assess the physicomechanical properties of the finished composite products. The tensile test quantified the ability of the materials to withstand pulling forces and resulting deformation prior to breakage. An improvement in terms of stiffness and resistance to breaking under stress was observed. There was a statistically significant difference between WPC and WPC+MAPE in terms of flexural strength and modulus (p < 0.05), but no statistically significant difference between the same samples in terms of strain at breakage (p > 0.05). There was also no observed difference in the melt flow rate and enthalpy functions of WPC and WPC+MAPE. The minimal addition of a coupling agent (MAPE) to WPC resulted in significantly improved dimensional stability, as evidenced by 13% lower thickness swelling and 3% lower mass gain through water absorption.