Synthesis of [(sulfamoylphenyl)carbamothioyl]benzamides as corrosion inhibitors in hydrochloric acid solution

Resumo

The Sulfamoylphenyl)carbamothioyl]benzamides were synthesized of three-component reaction ammonium thiocyanate, benzoyl chlorides and sulfanilamide in a single vessel at room temperature. The corrosion behavior of these compounds on carbon steel in 1 M HCl solution were investigated by using scanning electrochemical microscopy (SECM), potentiodynamic, and electrochemical impedance spectroscopy. SECM was operated in the substrate-generation/tip-collection mode using Fe²⁺/Fe³⁺ redox couple as redox mediator. The tip current values and local ferrous ion concentrations were obtained. Potentiodynamic polarization studies show that sulfaniamides act as a mixed inhibitor. The adsorption of these compounds on the carbon steel surface obeys the Langmuir’s adsorption isotherm.