Development and characterization of composites produced from recycled polyethylene terephthalate and waste marble dust

Abstract

The current paper presents the results of a study on the processing and characterization of waste marble powder-reinforced recycled polyethylene terephthalate (rPET) composites. Samples with up to 20 wt% marble dust (MD) content were produced with twin-screw extrusion followed by injection molding. Subsequently, the morphological and mechanical features and the wear resistance of the developed composites were studied. In terms of mechanical properties, the incorporation of MD steadily improved both the tensile and flexural modulus of rPET, while the strength values showed an optimum at 2.5–5.0 wt%, depending on the mode of loading. Above the optimal MD concentration, the strength values deteriorated, however, even at maximum (20 wt%) marble content they were still similar to that of neat rPET, which proves the potential of utilizing waste MD in this specific polymer as filler material. The surface hardness of the fabricated samples also gradually improved with higher marble content, yet it came at the cost of impact toughness. The analysis of wear performance revealed an increasing resistance against wear up to 5.0 wt% filler loading, above which the dust particles got easily peeled off from the matrix, decreasing its efficiency.