Room-Temperature Self-Healing Ablative Composites\nvia Dynamic Covalent Bonds for High-Performance Applications

Abstract

High-performance\nablative composites demonstrate promising applications\nin the field of aerospace for thermal protection. In this study, the\npreparation of flexible thermal ablative composites with fast room-temperature\nself-healing properties was reported. First, a facile route to synthesize\ntransparent and self-healing PDMS-polyurethane (PU) elastomers was\nproposed. Results showed that the room-temperature self-healing efficiency\nof PDMS-PU elastomers can reach as high as 92.9% for 3 h. Low-field\nNMR analysis indicated that the mobility of molecular chains plays\na critical role in determining the self-healing efficiency of PDMS-PU\nelastomers. Afterward, polymeric thermal protection composites which\ncan be self-healed at room temperature within 24 h were prepared.\nResults indicated that the self-healed composites can withstand flame\nerosion at nearly 1300 °C. This work provides insights into expanding\nthe application of self-healing materials in the aerospace industry,\nwhere heat ablation and the intactness of thermal protection systems\nare both primary concerns.