Study of the propolis extract as a corrosion inhibitor of copper alloy in ethylene glycol/water 0.1 M NaCl

Abstract

The effect of propolis extract as a corrosion inhibitor of copper alloy in ethylene glycol / water 0.1 M NaCl solution was studied by electrochemical measurements. The Tafel polarization curves showed that the propolis extract at different concentration acts as mixed inhibitor, and the maximum value of the inhibitory efficacy is 73.28% at optimum concentration of 1.25 g/L of propolis extract. The activation parameters reveal that the inhibitor molecules on copper surface are absorbed by physisorption and obey Langmuir isotherm adsorption. These results were supplemented by IR Spectroscopy, Scanning electron microscopy (SEM) and EDX spectrum of chemical composition. The metal solution interface is simulated as a physical model by using Electrochemical Impedance Spectroscopy (EIS).

Keywords: Copper Alloy, Propolis extract, ethylene glycol; Corrosion inhibition; Adsorption, Electrochemical impedance Spectroscopy (EIS)