The effect of Gum Tragacanth powder on corrosion inhibition of mild steel in sulphuric acid was investigated by weight-loss method, potentiodynamic polarization and electrochemical impedance spectroscopy studies. The inhibition efficiency is found to increase with temperature as well as with increase in concentration of the inhibitor. The activation energy and thermodynamic parameters for inhibition process were calculated. These thermodynamic parameters indicate a strong interaction between the inhibitor and the mild steel surface. The inhibition is assumed to occur via adsorption of inhibitor molecules on the mild steel surface, which obeys Langmuir adsorption isotherm. The polarization measurements showed that the inhibitor behaves as a mixed type inhibitor and the higher inhibition surface coverage on the mild steel was predicted. Inhibition efficiency values were found to show good trend with weight-loss method, potentiodynamic polarization and electrochemical impedance spectroscopy studies.

Keywords : Mildsteel, Sulphuric acid, Gum Tragacanth powder, Inhibition, Isotherm.