A newly synthesized green corrosion inhibitor imidazoline derivative for carbon steel in 7.5% NH4Cl solution

Corrosion and corrosion inhibition behaviors of steel Q-235 were studied in 7.5% NH₄Cl solution with the newly synthesized inhibitor by potentiodynamic polarization together with tests of electrochemical impedance spectroscopy and weight loss measurements in 298–338 K temperature range. The new inhibitor 2-(2-heptadecyl-4, 5-dihydro-1H-imidazole-1-yl) ethanol (HDIE) is synthesized with the help of microwave radiations in solvent free conditions. The results showed that inhibition efficiency above 90% is achievable at 298 K with 0.5 mML^?1 inhibitor concentration. The Adsorption studies revealed that HDIE follows Langmuir model and its adsorption mechanism was mixed-type with predominant effect on anodic half cell. It was seen from the EDS characterization of corroded steel surfaces that the HDIE retarded the corrosion by impeding the chloride attack. Quantum chemical calculations demonstrated that the imidazoline ring and hetero-atoms were active sites. Moreover, an inhibition mechanism was proposed on the basis of the quantum chemical calculations and experimental corrosion studies.