High-Strength, Rapid-Recovery, Solvent-Resistant, and Recyclable Fluorinated Acrylic Polyurethane with Supramolecular and Covalently Dual-Cross-linked Networks

High-performance polymer elastomers with high strength, rapid recovery, solvent resistance, and recyclability are desired in engineering fields. The incorporation of supramolecular interactions as sacrificial bonds for energy dissipation is an effective strategy to enhance the mechanical performance of polymers. However, this approach can result in a loss of resilience due to excessive energy consumption. In this study, we developed a kind of noncovalently supramolecular and covalently dual-cross-linked fluorinated acrylic polyurethane (PU-PFOMA) by incorporating adipic acid dihydrazide and acrylate-modified cyclodextrins into the polyurethane main chains and polymerizing perfluorooctyl methacrylate (PFOMA) in the polyacrylate side chains. The resulting PU-PFOMA demonstrated superior mechanical properties (54.36 MPa), elongation at break (1150%), and toughness (248.05 MJ/m3) due to the multiple H-bonds formed by adipic acid dihydrazide and the stable covalently cross-linked structure achieved through radical copolymerization. Furthermore, PU-PFOMA exhibited excellent resilience, attributed to the stable interchain cross-linking and the driving force generated by the poly(oxytetramethylene) glycol (PTMG) and PFOMA segments to reform their respective aggregates, owing to their thermodynamically incompatible nature. PU-PFOMA also demonstrated exceptional low-temperature resistance, including high strength (265.62 MPa), high toughness (648.44 MJ/m3) at −70 °C, and excellent resilience at −60 °C. More importantly, the PU-PFOMA elastomer has good solvent resistance that compared with PU because of the introduction of fluoroalkyl chains and could be reprocessed by hot pressing (130 °C, 10 MPa) and recover more than 70% of its toughness after reprocessing procedure. This study highlights the prospective uses of PU-PFOMA in fields necessitating robust mechanical characteristics and resistance to low temperatures.