Effect of Ethylene-1-Butene as a Compatibilizer for the Optimization of Wood Flour and Ground Tyre Rubber in Polypropylene Composites

Abstract

The use of waste materials to make eco-friendly wood-polymer composites has been explored by many researchers for academic and industrial purposes due to the low cost, biodegradability, and availability of waste wood flour. Polypropylene (PP)/ground tyre rubber (GTR)/wood flour (WF) composites were prepared using an internal batch mixer at a temperature of 165 °C for 8 min, and the samples were injection-moulded at 190 °C with a pressure of 6 MPa. The design of the experimental approach was used to determine and optimize the proportions of each component in the composites. The morphology of the untreated composites showed more voids and the agglomeration of fillers, namely WF and GTR, in the PP matrix. Fewer voids, as well as improved distribution, were observed in the compatibilized composites. The incorporation of ethylene-1-butene as a compatibilizer improved the thermal stability and elongation at the break of the composites. The addition of WF increased the elongation at break and decreased the tensile strength of the composites. Overall, the use of statistically designed experiments has aided in attaining the optimum formulations of the wood flour–polymer composites.