An Underwater Self-Healing Polysulfide Elastomer with In-Situ Curing and Adhesion

As oceanic activities expand, the strategic importance of designing multifunctional materials suitable for underwater applications becomes increasingly apparent. Underwater self-healing materials offer significant advantages by autonomously repairing damage in-situ during operations, thereby minimizing resource waste and enhancing environmental sustainability. However, most self-healing materials do not have sufficient stability in aquatic environments due to the presence of water-sensitive weak cross-linking bonds. Herein, polysulfide elastomers capable of underwater self-healing have been developed through a straightforward, one-step thiol–ene click reaction strategy. This reaction can occur in-situ underwater due to its water insensitivity. The abundance of disulfide bonds in the elastomer enables the formation of coordination bonds with metals, endowing the material with outstanding underwater metal adhesion properties. The optimal elastomer LPTM-55 shows extraordinary toughness of 1.49 MJ/m3, underwater self-healing efficiency of 90% within 7 h and adhesion strength up to 1.2 MPa. This innovative material, characterized by its underwater curing, adhesion and self-healing capabilities, demonstrates significant potential for applications in underwater sealing and repair.