Preparation and properties of a double-crosslinked, high-strength polyvinyl alcohol/acylhydrazone self-healing hydrogel

In this paper, PVA/BDA/ADH gels with good mechanical properties and self-healing properties were prepared using polyvinyl alcohol (PVA), 4,4-biphenyldicarboxaldehyde (BDA), and adipic dihydrazide (ADH) as raw materials. The hydrogel network achieves chemical-physical double cross-linking through acylhydrazone bonds and hydrogen bonds. The as-prepared PVA/BDA/ADH gels have good mechanical properties (the tensile stress of PVA/BDA/ADH gels is about 2 times that of pure PVA hydrogel) due to chemical and physical double cross-linking. It also has good self-healing properties under external conditions. Compared with pure PVA hydrogel, PVA/BDA/ADH gels have more stable self-healing properties.