Nanolignin, a Coupling Bio-Agent for Wood-Plastic Composites

Abstract

The influence of nanolignin coupling bio-agent on some characteristics of polypropylene-wood flour composites was studied. Thus, nanolignin was prepared by the acidic method, and then different ratios of it (0, 1, 3 and 5 wt%) were added to a polypropylene-wood flour mixture. After mechanically mixing wood flour, nanolignin, and polypropylene, the mixture was injection molded. ASTM methods were used to measure the structural properties of nanolignin, and prepared composites’ water absorption, thickness swelling, bending modulus, and bending, tensile and impact strengths. Transforming the original lignin to nanolignin did not change the chemical bonds of the material. The addition of nanolignin yielded improved mechanical and physical properties of the composites prepared. Higher strength and dimensional stability are presented by nanolignin-containing composites when comparing them with those prepared with normal lignin. Nanolignin was shown by SEM (Scanning Electron Microscope) observation to be uniformly dispersed within the polymer matrix. Wood polymer composites (WPCs) with nanolignin exhibited comparable properties with the control samples prepared using maleic anhydride polypropylene (MAPP).