Far-infrared emissive polypropylene/wood flour wood plastic composites: Manufacturing technique and property evaluations

Abstract

This study melt-blends polypropylene (PP), wood flour (WF), and far-infrared masterbatches into PP/WF wood plastic composites with far-infrared emissivity. During the process, maleic anhydride-grafted polypropylene (PP-g-MA) is added as the coupling agent between PP and WF. Mechanical property tests, scanning electron microscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), polarized light microscopy (PLM), and far-infrared emissivity are undertaken to evaluate various properties of the PP/WF wood plastic composites. The test results show that regardless of the WF content, mechanical properties of the composites remain at certain levels. The combination of 3 wt% PP-g-MA increases the interfacial adhesion between WF and PP, which in turn effectively increases the tensile strength by 20% and increases the flexural strength by 35%. The PP/WF wood plastic composites containing 4 phr (parts per hundreds of resin) of far-infrared masterbatches is 0.86 ɛ, which reaches the standard of good health care. The test results of XRD, DSC, and PLM show that the combination of both WF and far-infrared masterbatches helps the heterogeneous nucleating in PP, and increases the crystallization temperature of PP, but does not influence the crystalline structure of PP.