Mechanical and Thermal Characterization of Styrenic Thermoplastic Elastomer Compounds with Recycled Content for Sustainable Automotive Applications

In the context of increasing environmental awareness and the transition toward a circular material economy, the development of sustainable polymeric materials has become a key focus of industrial research. Within this framework, thermoplastic elastomers (TPEs) represent a promising class of materials that combine the elasticity of rubbers with the processability and recyclability of thermoplastics. Their ability to incorporate recycled content further enhances their potential for reducing environmental impact in advanced automotive applications. This study investigates styrenic thermoplastic elastomers (TPS) based on a SEPS (Styrene–Ethylene–Propylene–Styrene) and polypropylene matrix containing over 50% recycled content, with the aim of evaluating the influence of recycled material on structure and performance. TGA, DSC, and ATR-FTIR analyses revealed comparable degradation behavior and similar chemical features between virgin and recycled compounds, while minor differences were possibly related to variations in the plasticizer fraction and polymer-oil interactions. These differences did not significantly compromise the mechanical integrity of the recycled materials under the conditions investigated. Mechanical tests (tensile, tear, hardness, compression set) confirmed that recycled TPS maintains mechanical performance comparable to virgin formulations, while accelerated weathering resulted in minimal color variation and excellent surface appearance retention. Overall, TPS with high recycled content exhibit stable thermal, chemical, and mechanical behavior, confirming their suitability as sustainable alternatives for automotive components.