Double dynamic bonds tough hydrogel with high self-healing properties based on acylhydrazone bonds and borate bonds

Hydrogels with excellent self-healing properties have specific applications in smart polymer materials, but they often do not have excellent mechanical properties, or the preparation process of hydrogels is too complicated. Here, we prepared a multi-functional intelligent hydrogel using a simple water bath one-pot method through the synergistic effect of dual dynamic cross-linked agents, including acylhydrazone bonds (the first cross-linked agent) and borate ester bonds (the second cross-linked agent), at the same time hydrogen bonds provided physical interaction. The hydrogel exhibited excellent self-healing ability (up to 91%) and extraordinary mechanical strength (tensile stress 173.1405 kPa and hysteresis energy of 1.8659 MJ m(-3)). The research used chemical cross-linked (acylhydrazone bonds and borate ester bonds) and physical cross-linked (hydrogen bonds). The prepared hydrogel had the dual advantages of excellent self-healing performance and high mechanical strength. The hydrogel can be used in smart materials, such as working pressure tissues and sensing materials that require a certain degree of mechanical strength and self-healing properties, and also provides a design strategy for preparing hydrogels with high mechanical strength and excellent self-healing properties.