The Influence of Mechanical and Mechanochemical Activation of Hardwood Wood Waste on Biocomposite Properties

Abstract

As the demand for sustainable environment friendly materials increases, the biocomposites such as wood-polymer composite (WPC) have gained more attention in past years. Wood wastes and by-products like sawdust, chips, bark and wood residues as well as recycled polymers can serve as raw materials for production of WPC. However, there are still many issues obtaining WPCs, mainly a poor compatibility between a hydrophobic polymer matrix and a hydrophilic wood filler. In the present study, mechanical and mechanochemical activation of aspen wood waste were performed to increase their compatibility with recycled polypropylene matrix in the WPC, and the impact of both methods on the biocomposite properties were studied. It was found, that mechanochemical activation (MCA) of aspen wood particles leads to increased hydrophobicity of the obtained WPC compared to the WPC with mechanically activated (MA) particles. Work of adhesion with water was remarkably lower for the WPC modified by MCA which also correlates with moisture sorption results. Surface free energy of the WPC modified by MCA was lower compared to the WPC modified by MA, mostly due to decreased the polar component of surface free energy. The modulus of elasticity (MOE) were competitive for both the WPC formulations, however, MCA led to increased flexural strength of WPC compared to MA.