Anticorrosive and self-healing waterborne poly(urethane-triazole) coatings made through a combination of click polymerization and cathodic electrophoretic deposition

Abstract

To prepare a robust corrosion resistant coating with the ability to heal its scratched/damaged area, a waterborne clickable system appropriate for deposition on the metallic surface through cathodic electrophoretic technique was developed. For this purpose, two reactive components with terminal azide and propargyl functional groups and build-in tertiary amine atoms were prepared. Deposition of these components from acidic aqueous media via applying proper voltage under optimized condition led to the cathode surface coverage. Final coatings were obtained after mild thermal click polymerization of deposited components present on the cathode surface. All of the materials and final coatings were fully characterized by conventional methods and the ability of the produced poly(urethane-triazole) for protection of metallic substrate against corrosive media was evaluated based on electrochemical impedance spectroscopy (EIS). Controlled type of scratches was created on the coated substrates and then, the healing ability and regeneration of the damaged area via thermal click reaction of residual azide and propargyl groups were investigated. Consequently, the preservation of the anticorrosive property of the repaired coating was approved based on the EIS method.