Abstract
The developing effective and eco-friendly corrosion inhibitor plays a vital role in protecting Q235 steel in acid solution. Accordingly, novel pyrimidine derivatives, namely 4-Amino-2-phenyl-1,2-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitrile (APC), were synthesized and applied as the corrosion inhibitor under hydrodynamic conditions in 15% HCl. The inhibition performance was investigated by weight-loss experiment, potentiodynamic polarization curve, electrochemical impedance test, scanning electron microscope (SEM), atomic force microscopy (AFM), contact angle measurement, and X-ray photoelectron spectroscopy. The research showed that APC exhibited good inhibition nature for Q235 steel in 15% HCl medium, and the inhibition efficiency is correlated with APC concentration. The change of impedance parameters showed that the corrosion inhibitor adsorbs on the surface of Q235 steel in forming a protective film. The protective performance results come to 92.83% at 400 mg/L. Langmuir isotherm represents the excellent fitting. SEM, AFM, and XPS observation on the surface of Q235 steel showed that the metal matrix has a good anti-corrosion effect in the corrosion inhibitor solution. Density functional theory (DFT) and Molecular dynamic simulation (MD) were used to determine the inhibitor's and metal interactions' relationship.