Post-Industrial Recycled Polypropylene for Automotive Application: Mechanical Properties After Thermal Ageing

The transport sector's impact on climate change and energy-related greenhouse gas (GHG) emissions has raised significant concerns, prompting the automotive industry to transition towards greener solutions. This includes producing lighter vehicles with sustainable materials, like recycled plastics. Understanding the behavior of these new recycled compounds is crucial, especially regarding their response to ageing and stress conditions throughout a vehicle's lifecycle. This study aims to investigate the mechanical property variations of virgin and recycled talc-filled polypropylene (PP) compounds used in the automotive industry, emphasizing the effects of thermal ageing after recycling. Polypropylene samples with different talc concentrations and post-industrial recycled content percentages are examined. Thermal (TGA and DSC) and spectral (FT-IR) analysis reveal structural changes due to recycling-induced thermo-mechanical degradation. A multi-axial impact test shows varied ductile and brittle behaviors between virgin and recycled PP, influenced by filler content. Impact strength, tensile, and flexural properties are assessed, highlighting differences between virgin and recycled PP, but maintaining properties over ageing time. Despite thermo-oxidative degradation from recycling and thermal ageing, the mechanical performance of recycled polypropylene materials remains unaffected, making them a viable sustainable alternative for the automotive industry.