Tribological behaviour of green wood-based unrecycled and recycled polypropylene compositesJan, Petra (Avtor) Matkovič, Sebastjan (Avtor) Bek, Marko (Avtor) Slemenik Perše, Lidija (Avtor) Kalin, Mitjan (Avtor) wearpolypropylenebio compositewood fillersrecyclingsustainabilityIn this study we evaluated the tribological performance of polypropylene composites with wood-flour fillers obtained as a by-product from the wood-processing industry, which were based on unrecycled and recycled polypropylene polymer matrices. The mechanical properties of polypropylene-wood composites with wood-filler loadings of 0–40 wt % were determined with tensile tests and their friction and wear behaviours were studied with dry reciprocating ball-on-disc sliding tests against 100Cr6 steel balls at room temperature. The addition of the wood fillers resulted in a significant improvement in the tribological performance compared to the neat, unrecycled, and recycled polypropylene materials: the friction coefficient decreased by up to 30%, while the wear resistance was improved by up to two orders of magnitude. While neat unrecycled polymers have better properties than recycled, addition of 40 wt % wood-filler content in both, recycled and unrecycled composites, resulted in almost the same level of coefficient of friction (∼0.25) and wear coefficient (2 × 10$^{−6}$ mm$^3$/(Nm) to 3 × 10$^{−6}$ mm$^3$/(Nm)). Even with the addition of as low as 5 wt % of wood fibres the wear resistance was improved for 63% and 43% for unrecycled and recycled composites, respectively, which indicates that the use of wood fillers could be a sustainable and cost-effective way to improve the polymer tribological performance, and could compensate for the normally poorer properties of recycled materials, making the recycled polypropylene-wood composites a suitable sustainable choice for tribological applications.20232023-04-25 13:51:45Članek v reviji145601sl