Preparation and characterization of dual-network interpenetrating structure hydrogels with shape memory and self-healing properties

Abstract

Smart hydrogels that connect shape memory and self-healing properties through the same interaction are popular research projects. Based on supramolecular action and dynamic covalent bonds, a L-cysteine-Polyvinyl alcohol/hydroxyethyl cellulose(Cys-PVA/HEC) IPN hydrogel with shape memory and self-repair properties was prepared. Cys was grafted onto PVA by esterification reaction to form the copolymer Cys-PVA. Cys-PVA/HEC composite hydrogel was prepared by introduction of HEC into Cys-PVA, introduce the second network structure improved the mechanical properties of the hydrogel. The mechanical properties of Cys-PVA/HEC hydrogel were tested by dynamic mechanics (DMA), and the tensile strength is 65% higher than Cys-PVA. Cys-PVA/HEC hydrogel has been tested by thermal stimulation and redox stimulation experiments, showing significant shape memory performance. It is confirmed that Cys-PVA/HEC hydrogel has multi-response triple shape memory. Cys-PVA/HEC hydrogel showed good self-healing performance. The breaking tensile strength of the Cys-PVA/HEC hydrogel repaired after cutting can be restored to 87% by the DMA breaking tensile test. In addition, the morphology, pore size distribution, hygroscopic swelling performance and thermal stability of Cys-PVA/HEC hydrogel were investigated. The results show that Cys-PVA/HEC hydrogel is expected to become a potential candidate material in the field of intelligence.