Mechanism of inhibition of iron corrosion in HCl by acetylenic alcohols

Abstract

Introduction The mechanism of the inhibition of the corrosion of iron in HCl by acetylenic alcohols, is investigated by weight change method, galvanostatic method and faradic impedance method. Propargyl alcohol offers greater protection than 3‐butyn‐2ol, 2‐methyl‐3‐butyn‐2‐ol and 2‐butyn 1,4 diol in hydrochloric acid solution of concentrations (1.0 to 8.0M). The corrosion of pure iron in hydrochloric acid solutions involves the participation of adsorbed FeOH intermediate and forms chlorhydroxy iron complex. The addition of ferrous ion is found to favour the three‐dimensional chelation with inhibitor molecule, leading to polymen film formation. With prolonged exposure the thickness of the polymer film increases.