Synthesis of Thiourea Derivatives and its Evaluation as Corrosion Inhibitor For Carbon Steel

• Published in: Phosphorus, sulfur, and silicon and the related elements sulfur, and silicon and the related elements, 2015-08, Vol.190 (8), p.1366-1377
• Main Authors: de Oliveira, Clara G. M., Faria, Vitor W., de Andrade, Gabriel F., D'Elia, Eliane, Cabral, Murilo F., Cotrim, Bruno A., Resende, Gabriel O., de Souza, Flávia C.
• Format: Article
• Language: English
• Subjects: EIS experiments; Thiourea derivatives; weight-loss measurements
• ISSN: 1042-6507; 1563-5325
• DOI: 10.1080/10426507.2015.1035719

The inhibitory effect of thiourea-based compounds was evaluated using carbon steel body specimens in hydrochloric acid media. Thiourea derivatives, N-(pyrimidin-2-ylcarbamothioyl)benzamide and N-(6-methylpyridin-2-ylcarbamothioyl)benzamide, were synthesized using a simple route with good yields of approximately 70%. The inhibitory efficiencies were obtained by means of weight-loss experiments and electrochemical techniques (e.g., polarization curves and electrochemical impedance spectroscopy). The presence of a methyl functional group showed a better inhibitory efficiency compared with the derivate inhibitor without such modification. Analyzing Langmuir isotherms, ΔG 0 ads values indicate the chemical adsorption of thiourea-based compounds. The E Corr values obtained for the thiourea derivative with the methyl functionality was cathodically shifted by approximately −0.08 V, with an inhibition efficiency of 81%.