Self-Healing Elastomers: A sustainable solution for automotive applications

Among the most fruitful material-industry relationships is that of rubber and the automotive industry. Tires, seals, gaskets, hoses, tubes, soft, and damping parts are common applications in an industry that consumes more than 75 % of world rubber production. However, this relationship faces significant challenges. The difficulty of reprocessing rubbers due to their irreversible crosslinked network that ensures thermal stability, mechanical robustness and chemical resistance, makes them incompatible with the Circular Economy model. Numerous efforts are coordinated daily to overcome the Linear Economy model and achieve more environmentally friendly rubbers. Strategies like devulcanization, recycling, and self-healing are already being considered by several researchers and industries. Thanks to self-healing, a tire will be able to seal damage due to punctures or cracks. Thanks to self-healing, materials will be able to live longer and thus have an extended lifetime. This review delves into the key concepts of self-healing in the most commonly used elastomeric matrices in the automotive industry. While a more application-oriented approach is still necessary, the first steps have been taken towards future scalability in the sector. By analyzing the state-of-the-art taking into consideration the nature of the elastomeric matrix (natural or synthetic), as well as the different healing mechanisms (extrinsic, intrinsic and combinations), the chemistry behind them, and the mechanical performance, this review highlights the potential transformative impact of these concepts to revolutionize the industry and pave the way for a more sustainable future.