Fabrication of Bioinspired Fluorine-Free Anti-Icing/Deicing Films Based on Waterborne Polyurethane via Dynamic Noncovalent Interactions

Anti-icing and deicing films are severely restricted in practical applications due to complex preparation processes, high costs, and poor mechanical stability. Inspired by the adsorption-inhibition effect of antifreeze proteins (AFPs) from Arctic fish, this study proposes a strategy to mimic the antifreeze mechanism of AFPs by regulating the arrangement of hydrophobic groups and charged functional groups. Sulfobetaine methacrylate (SMBA) and glycerol monostearate (GMS) were introduced into polyurethane chain segments to prepare alkylated dynamic ionic copolymers (ANSPG). The –SO3– and –N+(CH3)3 groups in SMBA hinder the ordered deposition of water molecules into the ice crystal lattice through electrostatic adsorption, thereby inhibiting ice crystal growth. Meanwhile, the hydrophobic alkyl chains of SMBA and the hydrophobic segments of GMS form a dense hydrophobic layer via hydrophobic interactions, which enhances the adsorption stability on the ice crystal surface and mimics the interaction between the hydrophobic sites of antifreeze proteins (AFPs) and ice crystals. Subsequently, a network-structured waterborne polyurethane anti-icing and deicing film (ANSPG-PT-x) was prepared by combining with a biomimetic adhesive (PT) and successfully applied to fabrics. The research results show that the presence of SMBA can not only disrupt the ordered arrangement of water molecules, but also induce phase separation with GMS. This effect promotes the enrichment of hydrophobic groups on polyurethane macromolecular chains to form a dense hydrophobic layer, thereby endowing the film with excellent anti-icing and deicing properties. Fabrics finished with ANSPG-PT-1.4 exhibit outstanding comprehensive performance, including a static contact angle of 138.2°, a hydrostatic pressure of 87.6 kPa, an ice nucleation inhibition time of ΔT = 1408 S at −20 °C, a rapid deicing capability within 221 S, an ice adhesion strength of 28.16 kPa, a thermal stability of 258.5 °C, excellent resistance to more than 50 washing cycles, and an air permeability of 144.3 mm/s.