Synthesis of poly(acrylic acid)-Fe3+/gelatin/poly(vinyl alcohol) triple-network supramolecular hydrogels with high toughness, high strength and self-healing properties

摘要

Hydrogels with good mechanical and self-healing properties are of great importance for various applications. Poly(acrylic acid)-Fe3+/gelatin/poly(vinyl alcohol) (PAA-Fe3+/Gelatin/PVA) triple-network supramolecular hydrogels were synthesized by a simple one-pot method of copolymerization, cooling and freezing/thawing. The PAA-Fe3+/Gelatin/PVA triple-network hydrogels exhibit superior toughness, strength and recovery capacity compared to single- and double-network hydrogels. The mechanical properties of the synthesized hydrogels could be tailored by adjusting the compositions. The PAA-Fe3+/Gelatin/PVA triple-network hydrogel with 0.20 mmol Fe3+, 3% gelatin and 15% PVA could achieve good mechanical properties, the tensile strength and elongation at break being 239.6 kPa and 12.8 mm mm(-1), respectively, and the compression strength reaching 16.7 MPa under a deformation of about 91.5%. The synthesized PAA-Fe3+/Gelatin/PVA triple-network hydrogels have good self-healing properties owing to metal coordination between Fe3+ and carboxylic groups, hydrogen bonding between the gelatin chains and hydrogen bonding between the PVA chains. Healed PAA-Fe3+(0.20)/Gelatin3%/PVA15% triple-network hydrogels sustain a tensile strength of up to 231.4 kPa, which is around 96.6% of the tensile strength of the original samples. Therefore, the synthesized triple-network supramolecular hydrogels would provide a new strategy for gel research and expand the potential for their application. (c) 2019 Society of Chemical Industry