Self‐healing corrosion‐resistant coatings based on fluorinated alkyl silane microcapsules

In this study, microcapsules are prepared by in situ polymerization using the repairing agent fluorinated alkyl silane (FAS) as the core material and urea‐formaldehyde as the covering shell. Self‐healing coatings (FEP coatings) with repairing ability in water are prepared by adding FAS microcapsules in an epoxy resin matrix. The morphology, composition, and thermal properties of the microcapsules are studied. In addition, electrochemical impedance spectroscopy is used to study the barrier properties and self‐healing properties of the coating. The results show that FEP coating has good self‐healing ability, with the semiquantitative index of 105 Ω·cm2, which is greater than that of pure epoxy coating (EP coating). This is because that FAS leaked from the microcapsules reacts with water molecules to form a dense water‐insoluble film, which blocks the contact of corrosive ions with the substrate and inhibits the progress of metal corrosion. Moreover, the scratch width and depth results of the FEP coating after self‐healing also confirm the formation of the new film by FAS.