Synergistic Inhibition Effect of Polyethylene Glycol-Polyvinyl Pyrrolidone Blends for Mild Steel Corrosion in Sulphuric Acid Medium

The corrosion inhibition of mild steel in sulphuric acid solution in the presence of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP), and their blends was investigated using weight loss and hydrogen evolution techniques at temperature range of 30-60 degrees C. It was found that inhibition efficiency (eta%) increases with increase in concentration of the homopolymers and decreases with increase in temperature. Inhibition efficiency was found to be synergistically enhanced on blending the two polymers with highest inhibition efficiency obtained for (PEG : PVP) blending ratio of 1 : 3. The experimental data obtained fitted well into Temkin adsorption isotherm model. Physical adsorption mechanism is proposed from the trend of inhibition efficiency with temperature. The proposed mechanism is also corroborated by kinetic and thermodynamic parameters obtained. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2072-2084, 2011