Super Tough, Ultrastretchable, and Thermoresponsive Hydrogels with Functionalized Triblock Copolymer Micelles as Macro-Cross-Linkers

Vinyl-functionalized thermosensitive Pluronic F127 micelles have been used as multifunctional cross-links for the synthesis of super tough, highly resilient and thermoresponsive nanomicelle (NM) hydrogels. Pluronic F127 diacrylate (F127DA) with vinyl groups on both ends self-assembled in aqueous solution into micelles. Such micelles served as multifunctional macro-cross-links to copolymerize with acrylamide (AAm) monomers, generating novel NM hydrogels with extraordinary tensile and compressive properties, without using any chemical cross-linkers. Uniaxial tensile tests demonstrated a fracture strain above 2265%, an ultimate stress of 276 kPa, and a fracture energy of 2.34 MJ/m³. Under compression tests, these hydrogels did not fracture up to 98% strain and 62 MPa stress. Cyclic compressive loading–unloading tests at 90% strain showed no decay of the hyseteresis energy, indicating an unprecedented fatigue resistance.