Thermo-mechanical recycling of polypropylene for the facile and scalable fabrication of highly loaded wood plastic composites

摘要

In this study, polypropylene (PP) was reprocessed at various cycles to simulate recycling to be used as a matrix for highly loaded wood plastic composites (WPC). The neat and composite samples were produced using a batch mixer and injection molder. The extent of PP recycling was analyzed using chromatography, rheology, microscopy, and other physical/mechanical properties. While successive thermo-mechanical processing caused considerable chain scission of the PP, shown by the reduction in melt viscosity and the average molecular weight. While, other properties like tensile strength and modulus did not change significantly. The repeated reprocessing allowed for the incorporate of high 70 wt% wood flour (WF) to produce highly filled WPC. Overall, the WPCs displayed appealing physical properties through the increase in hardness and stiff characteristics while reducing the composites elongation by -17%. This indicates that the recycling of PP could be of great importance to reduce waste accumulation by producing WPCs for construction and other applications.