Recyclable high-performance and fully biodegradable cassava starch composite hydrogels based on dynamic cross-linking

Hydrogels possess properties such as biocompatibility and flexibility, which render them promising multifunctional viscoelastic materials. Despite recent significant advancements in hydrogel technology, their applications remain constrained by factors such as inadequate mechanical performance, limited self-healing properties, and challenges related to recycling. This study presents a straightforward strategy utilizing dialdehyde cassava starch and gelatin to design a self-healing, recyclable hydrogel material with superior mechanical properties, achieved through dynamic molecular interactions, including Schiff base complexes and hydrogen bonds. These interactions are facilitated by the incorporation of dialdehyde cassava starch (DCS), prepared by oxidizing cassava starch (CS) with sodium periodate (NaIO₄), into the gelatin matrix. The addition of dialdehyde cassava starch endows the hydrogel material with remarkable properties, including outstanding tensile strength (133.22 kPa), exceptional compressive strength (1035.9 kPa), significant swelling stability, and self-healing capabilities. Notably, this gelatin/dialdehyde cassava starch hydrogel (GDCSH) demonstrates complete recyclability, thereby contributing to the reduction of environmental pollution. Overall, this study proposes a high-performance cassava starch composite hydrogel based on dynamic interactions, which may facilitate advancements in hydrogel materials research.