Multiphasic inhibition of mild steel corrosion in H2S gas environment

Compounds like Octylpalmamide (OTP), Octylsteramide (OTS), Octylcaprylamide (OTC), Octylbenzamide (OTB) and one complex compound Dicyclohexylaminebenzotriazole (DCHAB) were synthesized and characterized by Fourier Transform infrared spectroscopy (FT-IR). These synthesized compounds were drawn as volatile corrosion inhibitor (VCI) in H2S gas environment on mild steel (MS) at 323 K. Surface morphology and elemental analysis have been examined by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) respectively. Various studies like weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used for evaluating corrosion rate, inhibitor behaviour and change in charge transfer resistance (Rct) value, respectively. All the above experiments proved that DCHAB was the most efficacious corrosion inhibitor. Adsorption behaviour of the inhibitor was evaluated and it obeys Langmuir adsorption isotherm.