RSM applied to PS/SBRr/SEBS Blends. Proper tool for maximized properties

Abstract

Reusing rubber waste from footwear industry emerges as great practise in order to reduce environmental damage on natural ecosystems. Based on this target, the present work aimed to apply the response surface methodology (RSM) to polystyrene/styrene-butadiene PS/SBRr blends compatibilized with styrene-ethylene-butylene-styrene (SEBS). A mixture planning was applied to PS/SBRr/SEBS blends in order to investigate mechanical and thermomechanical behaviors as response variables. Scanning electron microscopy (SEM) was used to evaluate the morphology of investigated blends, which were melt extruded in a corrotational twin screw extruder and specimens were injection moulded. High impact strength, toughness, elongation at break and thermal deflection temperature (HDT) were achieved at SEBS rich region (∼10%). At PS rich region, tensile strength, Shore D hardness and Vicat softening temperature (VST) were more expressive. Related to morphological character, blends with 10% SEBS presented the highest interfacial adhesion, with high level of plastic deformation. Gathered results show that depending on the composition, properties significantly change, being RSM a proper tool to preview trends on mechanical and thermomechanical properties. In general, PS/SBRr/SEBS blends may be properly used as packaging and building applications.