Investigation of MXene-modified agar/polyurethane hydrogel elastomeric repair materials with tunable water absorption

Abstract The study of repairing materials is of paramount importance, considering that damage during usage can significantly impact performance and bring inconvenience during maintenance work. One highly sought-after material is water-swellable elastomers, known for their effect in sealing and repairing damaged materials. In this study, agar/polyurethane dual-network hydrogel elastomers were prepared, which were further modified by MXene. The material exhibits a uniform and flat surface, along with a rich pore-filled internal structure. It showcases excellent thermal stability, good tensile strength retention, and a controllable low swelling rate (SR) upon water absorption. The performance of the material can be regulated by the MXene content. In addition, the “water absorption–drying–water absorption” cycle effectively controls the reduction of the SR and gradually increases the tensile strength. All samples demonstrated exceptional photothermal conversion efficiency, stability, and durability, with the maximum conversion temperature increasing with the MXene content. The scratch repair experiments demonstrated the remarkable potential of these materials for photothermal conversion-assisted repair. These materials can be adapted as auxiliary restoration materials in water bodies and various application environments, making them ideal for repair and restoration purposes.