Corrosion-resistant Self-healing Coatings

he use of polymeric coatings with self-healing ability is a viable approach for a new smart corrosion protection strategy. Polymer systems are usually applied on a metal surface to provide an effective barrier against the corrosive species. The protective coatings have to delay the inexorable water uptake, blister or crack formation and delamination. Among self-repairing polymers, in this area of interest, Diels-Alder epoxy resins arc particularly appealing for coating application, because the products and intermediates obtained during the healing treatment are stable to aggressive environments. such as the major oxidation agents, air and water. In addition, the chemical stability and crosslinked structure of epoxies are preserved and ensure the coating functionality. An intrinsic mendable epoxy system, containing bifunctional adducts, has been prepared by Diels-Alder reaction. Optical microscopy and nanoindention tests validated the morphological and structural recovery of the coating. Immersion test in saline solution revealed the complete restoration of the corrosion protection for a healed sample.