Synergistic effect of new imidazoline derivative and 2-aminopyridine as corrosion inhibitors for Q235: Experimental and theoretical study

In order to reduce the investment of corrosion inhibitors, based on experimental and theoretical studies, the corrosion inhibition and mechanism of new imidazoline derivatives (SMIS) and 2-aminopyridine (AMP) were investigated carefully. The best corrosion inhibition effect was at 0.7-g/L SMIS and 0.3-g/L AMP, the corrosion inhibition efficiency of weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization (Tafel) were 90.54%, 98.56% and 97.68%, respectively. Electrochemical research shows that SMIS& belongs to cathodic corrosion inhibition. SMIS& mainly increased the film resistance and charge transfer resistance in 1-M HCl, thus playing a certain role in corrosion inhibition. X-ray photoelectron spectroscopy and energy dispersive spectrometer proved that SMIS& can be adsorbed on the surface of Q235, molecular dynamics showed that there was a certain synergy between SMIS and AMP. This study confirmed that SMIS and AMP have a good synergistic effect, improve the corrosion inhibition efficiency, reduce the synthesis cost of SMIS, and have a certain guiding significance for synergistic corrosion inhibition.