Grafting effects of polypropylene/polyethylene blends with maleic anhydride on the properties of the resulting wood–plastic composites

In the presented study, polypropylene (PP) and high density polyethylene (PE) were blended at the ratios of 80/20 and 20/80 to simulate recycled waste thermoplastic mixtures. The effects of in situ grafting of PP/PE blends with maleic anhydride through the extruder on the mechanical and rheological properties of resulting wood/plastic composites were investigated. Different ratios of PP and PE in the blends created distinct properties in the resulting composites. Grafting of PP and PE blends improved the tensile and flexure properties of the resulting composites. The composites exhibited a reduced water uptake and resultant dimensional swelling due to grafting with maleic anhydride. Grafting of the blends also considerably improved the interfacial bonding and enhanced the dispersion of wood in the matrix, as evidenced by rheological analysis and scanning electron microscopy.