Effect of Recycling on Rheological and Mechanical Properties of High Impact Polystyrene

Abstract

High impact polystyrene (HIPS) was subjected to repeated thermal and shear stresses by different methods, using a high pressure capillary Rheometer, a laboratory extruder and a Brabender plasticorder. The results showed that the recycling of HIPS caused a decrease in the shear stresses and consequently in the viscosity at constant shear rate. The high pressure capillary Rheometer gave a greater decrease than with the Brabender plasticorder. Tensile strength values were progressively decreased with the laboratory extruder, but increased in the case of Brabender mixer; the elongation was decreased in both cases. This work was then applied in a local plant to compare experimental and actual results.