SYNERGISTIC INFLUENCE OF PROPARGYL ALCOHOL AND ZINC SULFATE ON INHIBITION OF CORROSION OF ALUMINUM IN 0.5M H2SO4

This paper describes the use of the Tafel polarization and electrochemical impedance spectroscopy technique (EIS) in order to study the corrosion inhibition process of aluminum in 0.5M H2SO4 solution in presence of propargyl alcohol and zinc sulfate at the open circuit potential (OCP) in the room temperature. The Nyquist diagrams consisted of a capacitive semicircle at high frequencies followed by a well defined inductive loop at low frequency values. The impedance measurements were interpreted according to a suitable equivalent circuit. The results obtained showed that the addition of the propargyl alcohol inhibits the sulfuric acid corrosion of the aluminum. The inhibition efficiency increases with an increase in the propargyl alcohol concentration. The inhibition occurs through adsorption of the propargyl alcohol on the metal surface without modifying the mechanism of corrosion process. The inhibiting action propargyl alcohol is considerably enhanced by addition of zinc sulfate. Both the inhibitors obeyed the Langmuir isotherm and the thermodynamic calculations revealed that the adsorption of inhibitors was of physical nature.