Thermal and Mechanical Properties of Recycled Polystyrene ^†

Plastic waste is increasing, and a strategy to reduce it is needed to minimize the integration of virgin raw material in the production of parts. Motivated by legislation and environmental awareness, companies are looking for new materials or recycled ones. The main purpose of this work was to study the changes in performance of recycled polystyrene (PS). The thermal and mechanical properties of the injected samples were evaluated, namely tensile, 3-point bending, Shore D hardness, Differential Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA). The results obtained showed interesting correlations comparing virgin (after the first cycle of injection molding) and recycled raw materials. For instance, the tensile strength of the polystyrene decreased by about 15% after the first reuse of the virgin material (second cycle of injection molding) when compared to the virgin one, and this value was maintained in the second and third material reutilizations.