AC and DC study of the temperature effect on mild steel corrosion in acid media in the presence of benzimidazole derivatives

• Published in: Corrosion science Vol. 45; no. 1; pp. 33 - 58
• Main Authors: Popova, A., Sokolova, E., Raicheva, S., Christov, M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2003; Elsevier Science
• Subjects: Acidic media; Applied sciences; Corrosion; Corrosion prevention; Electrochemical impedance spectroscopy; Exact sciences and technology; Inhibitors; Metals. Metallurgy; Temperature effect; Temperature effect; Inhibitors; Corrosion; Acidic media; Electrochemical impedance spectroscopy; Mild steel; Acid corrosion; Electrochemical method; Corrosion inhibition; Steel; Corrosion protection; Corrosion inhibitor; Sulfuric acid; Corrosion resistance; Benzimidazole derivatives; Chloric acid
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/S0010-938X(02)00072-0

The effect of benzimidazole derivatives on mild steel corrosion in 1 M HCl at five different temperatures has been studied. Impedance, polarization resistance, polarization curves measurement and gravimetric methods have been used. The inhibiting efficiency and the apparent activation energy ( E a) have been calculated in the presence and in the absence of the organic inhibitors. The comparative investigations carried out in 1 M H 2SO 4 and 1 M H 2SO 4+1×10 −4 M KI verify the assumption that the halogen ions facilitate the inhibitors adsorption. The electrostatic absorption of the compound cation form seems more probable. The behaviour of 2-mercaptobenzimidazole (2-SH-BI) contrasts that of the rest of the substances investigated. Chemisorptive adsorption is more probable in this case. The lower value of activation energy E a in the presence of 1-benzyl-benzimidazole when compared to that in 1 M HCl is explained with a partial compensation effect.