The crosslinking and decrosslinking of fluorinated diblock copolymer from RAFT emulsion polymerization toward surface anti‐icing

Abstract

AbstractHere, we demonstrate disulfide‐crosslinked polyfluoroacrylate AB block copolymer films with excellent anti‐icing properties. The fluorinated latexes of AB block copolymers were synthesized via two‐step reversible addition‐fragmentation chain‐transfer (RAFT) emulsion polymerization using polyacrylic acid and its sodium salts as the hydrophilic A‐block, and polyhexafluorobutyl acrylate as the hydrophobic B‐block. Diacetone acrylamide was copolymerized in different blocks as a crosslinking anchor. A disulfide‐containing compound dithiodipropionic acid dihydrazide was chosen as the crosslinking agent to form disulfide‐crosslinked fluorinated films to enhance the mechanical properties, surface properties, swelling properties, and anti‐icing properties of the films. It has proved that the crosslinking site has a great impact on the film formation process which in turn affects the film performance. The B‐block crosslinked films showed better resistance to water while the A‐block crosslinked films were more organic solution resistant. The A‐block crosslinked films also possessed better anti‐icing properties due to the high F/O value. Furthermore, decrosslinking experiments were conducted using a reductant tris(2‐carboxyethyl)phosphine hydrochloride to break the disulfide bond. The recycling rate of the B‐block crosslinked films could reach >90% while the recycling rate of the A‐block crosslinked films reached >75%.