Biopolymer Corrosion Inhibition of Mild Steel: Electrochemical/Mössbauer Results

Abstract

Metallic corrosion is the destructive attack of a metal by its environment. Organic inhibitors, amongst others, adsorb directly onto the surface of the metal and can thus inhibit corrosion. Chitosan, tri-methyl chitosan and dodecyl amine hydrochloride were studied with a view to assessing their potential use as adsorption inhibitors for mild steel in acid chloride and sulphate solutions. The inhibition efficiency was studied successfully by potentiostatic polarisation (Tafel plots), Mössbauer spectroscopy (CEMS and transmission) and corrosion experiments in static acidified electrolytes. Inhibition efficiencies ranged from 20 to 93%. The chemical compositions of the corrosion products were determined by means of Mössbauer spectroscopy, which identified iron hydroxides as the main corrosion products forming in the presence of the inhibitors.