Journal of Metallurgy and Materials Science
  • Year: 2006
  • Volume: 48
  • Issue: 4

Inhibiting properties of imidazole and 2-methyimidazole as corrosion inhibitor for mild steel in sulphuric acid

  • Author:
  • S. Elavarasan1, K. Kannan2,, M. Sivaraju1
  • Total Page Count: 12
  • Page Number: 221 to 232

1Department of Chemistry, Muthayammal Engineering College, Rasipuram.

2Department of Chemistry, Government College of Engg., Salem-636011.

*Corresponding author. E-mail: kannan_k2002@yahoo.co.in

Abstract

The inhibition effect of imidazole and 2-methylimidazole on the corrosion of mild steel in 1N Sulphuric acid has been studied by mass loss and polarization techniques between 303 K and 333K. The inhibition efficiency increased with increase in concentration of inhibitor and temperature from 303 K to 318 K in 1N Sulphuric acid. But higher temperature at 333 K the inhibition efficiency decreased. The corrosion rate increased with increase in temperature and decreased with increase in concentration of inhibitor compared to blank. The adsorption of this compound on the mild steel surface has been found to obey Temkin's adsorption isotherm. Potentiostatic polarization results reveal that imidazole and 2-methylimidazole act as mixed type inhibitor. The values of activation energy (Ea), free energy of adsorption (ΔG ads), enthalpy of adsorption (ΔH), and entropy of adsorption (ΔS) were also calculated.

Keywords

Mild Steel, Sulphuric acid, Corrosion inhibition, Temkin's adsorption isotherm, Potentiostatic polarization, imidazole, 2-methylimidazole