Preparation and performance of hydroxyethyl cellulose-enhanced self-healing hydrogel with improved mechanical properties

Hydrogels are excellent biomaterials widely used in medicine, industry and agriculture. Self-healing hydrogels have garnered significant interest, yet they typically exhibit poor mechanical strength. Research shows that the mechanical strength of hydrogels can be significantly enhanced by introducing a second-layer network structure. Based on this, a simple solution blending method was adopted in this study. Hydroxyethyl cellulose (HEC), serving as both a reinforcing component and a second network, was introduced into the dynamic cross-linking system composed of the main raw materials, polyvinyl alcohol (PVA) and borax, and a double-network hydrogel was successfully fabricated. The tensile and compressive strengths of the hydrogel with 1 wt% HEC reached 4.77 ± 0.29 and 4.94 ± 0.34 kPa, which were 4.04 and 2.77 times those of the pure hydrogel respectively. The hydrogel could achieve fracture healing after being left standing at room temperature for 30 s and its self-healing behaviour was supported by dynamic rheological cyclic tests. Quantitative tests revealed that the hydrogel achieved a self-healing efficiency η of 88.7% after healing at room temperature for 1 h. This research provides a practical and effective approach for constructing high-strength self-healing hydrogels based on cellulose reinforcement design, which is expected to lay a foundation for the expansion of the practical application of such materials.