INHIBITION OF MILD STEEL CORROSION IN ACID MEDIA BY N-(2-THIOPHENYL)-N/-PHENYL THIOUREA

Abstract

The corrosive behavior of mild steel in 0.05 M and 0.1M HCl, 0.025 M and 0.05 M H2SO4 solutions containing different concentrations of N-(2-thiophenyl)-N/-phenyl thiourea (TPTU) was investigated using potentiodynamic polarization technique. The results obtained reveal that TPTU is an efficient anodic inhibitor in the acid environment and it is more effective in reducing corrosion of mild steel in HCl than in H2SO4 media. The adsorption of the inhibitor on the mild steel surface in both acids obeys the Temkins’ adsorption isotherm. The thermodynamic parameters of adsorption deduced reveal a strong interaction and spontaneous adsorption of TPTU on the mild steel surface. The influence of temperature and inhibitor concentration on the corrosion of mild steel has also been investigated.