Role of Smart-Release Pigments in Preventing Corrosion Driven Cathodic Disbondment of Organically Coated Hot Dip Galvanised Steel

The role of smart-release corrosion inhibitive pigments in preventing cathodic delamination organically coated hot-dip galvanized steel (HDG) is investigated. consisted hydrotalcite (HT) exchanged with a range inorganic and organic anionic species were dispersed model PVB coating. A scanning Kelvin probe (SKP) technique was used to determine rates, the inhibition efficiencies obtained for ions increased order CO 3 2 − < ${{{\rm{MoO}}}_{4}}^{2-}$?> mathvariant="normal">MoO 4 ${{{\rm{NO}}}_{3}}^{-}$?> mathvariant="normal">NO ${{{\rm{VO}}}_{4}}^{3-}$?> mathvariant="normal">VO ${{{\rm{WO}}}_{4}}^{2-}$?> mathvariant="normal">WO ${{{\rm{PO}}}_{4}}^{3-}$?> mathvariant="normal">PO ${{{\rm{CrO}}}_{4}}^{2-}.$?> mathvariant="normal">CrO . organic-based triazole <phenylphosphonate <trans-cinnamate <benzoate <salicylate <benzotriazole. efficiency afforded by best performing inhibitor, benzotriazole (BTA), rivalled that HT containing stored chromate anions. Findings are consistent HT-BTA acting sequester anions from underfilm electrolyte, releasing BTA − which subsequently strongly adsorbs on metal surface but can also form an insoluble Zn-BTA precipitate at coating-defect boundary.