Hybrid organo-ceramic corrosion protection coatings with encapsulated organic corrosion inhibitors

To improve corrosion protection properties of sol-gel derived hybrid coatings; two organic corrosion inhibitors (mercaptobenzothiazole and mercaptobenzimidazole) have been encapsulated within the coating matrix in either the presence or absence of beta-cyclodextrin. Corrosion protection performance of the developed coatings on AA 2024-T3 has been examined by potentiodynamic scan method and scanning vibrating electrode technique. Superior corrosion protection properties have been found for formulations that contain beta-cyclodextrin and can be explained by the act of slow release of the inhibitor from the cyclodextrin/inhibitor inclusion complexes and by the self-healing of corrosion defects. The effectiveness of the approach for long-term protection of the high strength aluminum alloys against atmospheric corrosion is discussed. (C) 2003 Elsevier B.V. All rights reserved.