Highly stretchable, self‐adhesive, and self‐healable double network hydrogel based on alginate/polyacrylamide with tunable mechanical properties

Abstract A number of synthetic hydrogels suffer from low mechanical strength. Despite of the recent advances in the fabrication of tough hydrogels, it is still a great challenge to simultaneously construct high stretchability, and self‐adhesive and self‐healing capability in a hydrogel. Herein, a new type of double network hydrogel was prepared based on irreversible cross‐linking of polyacrylamide chains and Schiff‐base reversible cross‐linking between glycidyl methacrylate‐grafted ethylenediamine and oxidized sodium alginate (OSA). The combination of both cross‐linkings and their synergistic effect provided a novel hydrogel with high strength, stretchable, rapid self‐healing, and self‐adhesiveness to different material. Besides, the hydrogels with diverse OSA content could maintain their original shapes after loading–unloading tensile test. The resulting hydrogel has a great potential in various fields for supporting and load‐bearing substance.