A Novel Interface Structure for Preparing Compatible Wood/Polyvinyl Chloride Composites

In this work, wood plastic composites (WPCs) were prepared from polyvinyl chloride (PVC), wood flour (WD) and poly-1,4-butylene glycol adipate diol (PBA) based polyurethane prepolymer (PUP). It was found that during melt mixing, a multifunctional polyurethane layer between PVC and wood was in situ formed; the inner layer consisted of urethane linkages which increased the compatibility between wood filler and polyurethane, the outer layer was a PBA soft segment which was compatible with PVC continuous phase because PBA was a plasticizer for PVC. The novel interface structure improved compatibility of the composites, and the mechanical properties of the composites obviously improved compared to WD/PVC composites. With the increasing wood content, the mechanical properties and hydrophobicity of composites were decreased while the thermal stability increased. Polyurethane as a rubber component also could improve the impact property of composites. Therefore, the novel interface structure improved the compatibility and the properties of the composites.