Mechanical recycling of expanded polystyrene and tire rubber waste as compatibilized and toughened blends

Packaging represents a significant source of all polymer waste produced in the world. Thus, improving recycling methods is essential to achieve an environmentally sustainable condition since the volume of produced polymer and of related waste has grown. Expanded polystyrene (EPS) foam is a thermoplastic with important performance of properties such as thermal isolation and absorption of mechanical energy that allow large application in packaging and other segments. However, the EPS recycling is a challenger due to its low density and poor properties. The rubber incorporation to the recycled EPS is an alternative for the toughening of the polymer matrix as well as improving its mechanical properties. In present study, EPS waste from electric and electronic products packaging was treated by three distinct methods for polymer densification and after it was thermo-mechanically processed by extrusion with variable content of ground tire rubber (GTR) and compatibilizer agent styrene-butadiene-styrene (SBS) copolymer to produce compatibilized and toughened PS/rubber blends. Mechanical, thermal and rheological properties of materials were evaluated by different analyses. The incorporation of rubber to the recycled EPS has significantly improved the mechanical properties of the material and the presence of the SBS agent was effective to compatibilize the PS/rubber blends. Therefore, the preparation of compatibilized PS/rubber blends showed to be a way to the mechanical recycling of EPS and rubber tires waste.