Polystyrene/Recycled Sbr Powder Compounds Produced in An Internal Batch Mixer

Abstract

The properties of recycled styrene-butadiene rubber (SBR) powder with polystyrene (PS) have been studied as a function of compounding conditions in an internal batch mixer. In particular, the effect of temperature (160–220°C), rotor speed (30–120 rpm), homogenization time (3–9 min), components introduction order, surface treatment of SBR powder with a PS/tetrahydrofuran (THF) solution, and addition of a coupling agent (styrene-ethylene-butylene-styrene, SEBS) were studied. The compounds were then compression moulded and samples were prepared to measure their hardness, tensile properties (modulus, strength and elongation at break) and impact strength. Morphological analysis via scanning electronic microscopy (SEM) on selected samples was also performed to determine the interfacial state between the components. From all the results obtained, an optimisation procedure is proposed allowing the best compound to be determined as a function of final application.