Corrosion Inhibition of Carbon Steel in 1 M HCl using Monopolar Surfactants Derived From 3-Methyl-1,2,4- Triazole-5-Thione

In this work, we have synthesized the surfactant compounds derived from 2-(N-Alkyl-3-methyl-1,2,4-triazolthioyl) acetic acid (MTSACCn; n=10, n=11 and n=12). These compounds have been purified and identified using several spectroscopic methods such as 1H NMR; 13C NMR spectroscopy. The molecular aggregation of MTSACCn has been foxed using tensiometer apparatus. The electrochemical study was carried out using a coupling of potentiodynamic and electrochemical impedance methods. The polarization curves indicate that the MTSACCn act as mixed-type inhibitors of carbon steel in 1M HCl solution. The electrochemical impedance spectroscopy measurements showed that all synthesized compounds act by establishing a barrier layer on the steel surface. Therefore, we noted that the inhibition efficiency increases with increasing of concentrations inhibitors. Also, the MTSACC12 is the best inhibitor, its inhibition efficiency reached a maximum value of 95% at 510-4 M. The adsorption of all surfactants studied follows the Langmuir isotherm.