New thiadiazole derivatives as effective corrosion inhibitors for the control of copper-nickel alloy in sulphide polluted synthetic sea water

Inhibitive effect of new class of thiadiazole derivatives namely 2-(benzyl thio)-5-((4-methoxybenzyl)thio)-1,3,4-thiadiazole(BTMT), 2-((2,5-dimethylbenzyl)sulfanyl)-5-((4-methoxybenzyl)sulfanyl)-1,3,4- thiadiazole(DBMT) and 2-((4-tert-butylbenzyl)Sulfanyl)-5-((4-methoxybenzyl)sulfanyl)-1,3,4- thiadiazole (TBMT) on the corrosion of copper-nickel alloy in sulphide polluted synthetic sea water has been investigated by gravimetric measurements, potentiodynamic polarization and electrochemical impedance spectroscopic techniques. Gravimetric measurements showed that, the thiadiazole derivatives exhibit excellent corrosion inhibition on the cupro-nickel alloy in sea water medium. Potentiodynamic polarization techniques revealed that, the corrosion current density decreases and inhibition efficiency increases with increasing concentration of inhibitors. Electrochemical impedance spectroscopic techniques showed that, charge transfer resistance value increases and double layer capacitance value decreases with increasing concentrations of thiadiazole compounds. Inductively coupled atomic emission spectroscopy revealed that, the thiadiazole derivatives excellently control the denickelification of copper-nickel alloy in sulphide polluted synthetic sea water. (author)