The inhibition mechanism of imidazoline phosphate inhibitor for Q235 steel in hydrochloric acid medium

The inhibitive effect of a newly synthesized imidazoline phosphate inhibitor against Q235 steel and its adsorption behavior were investigated in 1 M HCl solution using weight-loss method, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results showed that the inhibition efficiency increased with the increase of the inhibitor concentration. The imidazoline phosphate is a mixed-type inhibitor whose adsorption behavior onto Q235 steel can be well fitted by Langmuir isotherm equation. The quantum chemistry calculation exhibited that the imidazoline ring and heteroatoms of N, O, and P were the active sites of the inhibitors. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.