Synergistic Reinforcement of Hydrophobic and Deicing Performance Using Chain-Suspended Polysulfothioamide-Grafted Acrylate Polymers and MWCNTs–OH

Abstract

Photothermal hydrophobic surfaces are among the most promising anti-icing materials, but their deicing efficiency is limited by the low content of low-surface-energy substances in the coating. Here, we propose a solution that synergistically enhances hydrophobic deicing performance by combining a pendant-chain polysulfothiourea-grafted acrylate polymer with hydroxylated multiwalled carbon nanotubes (MWCNTs–OH). Hydroxy-containing acrylic polymers were synthesized via solution polymerization using monomers such as butyl acrylate, methyl methacrylate, glycidyl methacrylate, and hydroxyethyl methacrylate. Concurrently, based on the thiol–ene click reaction, hexafluorobutyl methacrylate was reacted with pentaerythritol 3-mercaptopropionate, isophorone diisocyanate, and fluoroalcohols to prepare a fluorinated polythioamide. This was then side-grafted onto the aforementioned hydroxy-containing acrylate polymer to yield a hanging-chain-type polythioamide-acrylate polymer. By blending the photothermal filler MWCNTs–OH with the copolymer (SFPFM@CNT), the effects of the fluorinated monomer and the photothermal filler MWCNTs–OH on the coating’s hydrophobicity, photothermal performance, and deicing and defrosting capabilities were investigated. The photothermal performance of the SFPFM@CNT coating increased significantly with rising MWCNTs–OH content. After 360 s of illumination, the temperature of the SFPFM@CNT-5% coating reached 102 °C, an increase of 52.5 °C compared to the SFPFM@CNT-0% coating, representing a temperature rise rate of 106%. The ice-melting time for the SFPFM@CNT-5% coating was 42 s, which was 39 s shorter than that of the SFPFM@CNT-0% coating, representing a 93% increase in the ice-melting rate. The defrosting time was 19 s, a reduction of 47 s, corresponding to a 247% increase in the defrosting rate. This work paves the way for the development of photothermal anti-icing composite coatings.