INHIBITING EFFECT OF IMIDAZOLIDINE THIONAMIDE ON CORROSION OF SOFT STEEL IN CO2-CONTAINING MEDIUM

An imidazolidine thionamide compound was synthesized on the basis of 1-(2 -((2-amineethyl)-amine)ethyl)-imidazolidine-2-thione obtained from the reaction of thiocarbamide and triethylenetetramine at 1800 degrees C and a mixture of synthetic naphthenic acids derived from the paraffin-isoparaffin mixture separated from Balakhani oil. An effect of the obtained imidazolidine thioneamide on the corrosion of steel grade C1018 in the CO2 environment was studied. It found that the effect of protection of imidazolidinethioneamide at concentrations of 25 and 50 ppm made up 96 and 98%. Analysis of polarization curves of steel C1018 imidazolidinethioneamide at different concentrations shows that imidazolidinethioneamide inhibits both the anodic and cathodic process of steel. The adsorption energy below -40 kJ/mol(-1) shows that imidazolidinethionamide is chemisorbed on the metal surface. Analysis of the metal surface through the scanning electron microscopy shows that with the participation of imidazolidinedioneamide in CO2 medium no microcracks and corrosion damage are found on the metal surface.