Blends of Polystyrene/Shoes Waste (SBRr): Influence of Mixture Sequence and Compatibilizer

The aim of this research is to analyze the influence of the mixture sequence and compatibilizer on the morphology and mechanical and thermomechanical properties of polystyrene (PS)/shoes waste (SBRr) blends. The blends are processed in a twin screw co-rotating extruder and then injection molded. They are analyzed by impact and tensile tests, Shore D hardness, heat deflection temperature (HDT), ductile-brittle transition temperature and transmission electron microscopy (TEM). The results showed that there is a significant increase in the impact strength, in the hardness and in the HDT of the blends when PS and styrene-butadiene-styrene (SBS) were mixed together in a first extrusion, prior to the incorporation of the SBRr into a second extrusion. However, the different mixing sequences studied apparently did not influence the results of tensile strength. The morphology showed by the mixing sequence (PS/SBS) + SBRr evidenced a better dispersion of the SBRr in the PS matrix, favoring better properties.