Studies on the inhibitive effect of (Z)-4-chloro-N-((2-chloroquinolin-3-yl)methylene)aniline Schiff base on the corrosion of mild steel in 1 N HCl solution

Abstract

The effect of novel synthesized Schiff base, namely (Z)-4-chloro-N-((2-chloroquinolin-3-yl)methylene)aniline (4-CCMA) on the corrosion of mild steel in 1 N HCl was investigated using weight loss, potentiodynamic polarization, linear polarization, electrochemical impedance spectroscopy, and scanning electron microscopy. The experimental results showed that 4-CCMA revealed good corrosion inhibition and that the inhibition efficiency increases with the increase of concentration of inhibitor to attain 99.04 % for 4-CCMA at 25 ppm. Polarization measurements suggest that 4-CCMA acts as a mixed-type inhibitor. Electrochemical impedance spectroscopy measurements show an increase of the transfer resistance with the inhibitor concentration. The temperature effect on the corrosion behavior of mild steel in 1 N HCl without and with the inhibitor at 5–25 ppm were studied in the temperature range from 298 to 318 K, and the associated activation energy has been determined. Adsorption of 4-CCMA on the mild steel surfaces in 1 N HCl follows the Langmuir adsorption isotherm model.