SEALANT LINER FOR SELF-SEALING PNEUMATIC SAFETY TIRES BASED ON DYNAMIC IMINE- AND HYDROGEN-BOND-CROSSLINKED INTERPENETRATING BUTYL RUBBER NETWORKS

ABSTRACT Autonomously repairing tire sealants are critical for vehicle safety; however, conventional self-healing formulations frequently fail under prolonged high-speed tire operation due to excessive flowability, resulting in compromised sealing performance and dynamic imbalance. We have designed a dual-crosslinked butyl rubber-based interpenetrating network (IPN) incorporating dynamic hydrogen bonds and imine bonds, which collectively ensure excellent self-healing capability, reprocessability, and high-temperature structural integrity. The fabricated IPNs exhibit an ultimate stress of 1.4–3.1 MPa and a breaking strain of 1450–2600%. The imine-crosslinked network ensures structural integrity at elevated temperatures, while the hydrogen-bonded network significantly enhances strength and toughness via reversible hydrogen bond breakage and reformation, facilitating efficient energy dissipation. Moreover, the designed IPNs achieve a high healing efficiency of ∼85% after 4 h at 80 °C. Such a healing efficiency stems from the synergistic interaction between imine-bond exchange reactions and hydrogen-bond dissociation/reformation dynamics. The IPN architecture harnesses the rapid reversibility of hydrogen bonds and the robust exchangeability of imine bonds, while the imine-bond-crosslinked network preserves the structural integrity of the material. This design effectively mitigates the flow behavior observed in conventional self-healing sealants during high-speed operation, providing a versatile platform for developing high-temperature-resistant, healable tire sealants with tunable mechanical properties.