Some Thiophene Derivatives as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid

Corrosion inhibitive performance of some thiophene derivatives during the acidic corrosion of carbon steel surface in 1 M HCl was investigated by chemical technique (weight loss) and electrochemical techniques (potentiodynamic polarization, electrochemical frequency modulation, and electrochemical impedance spectroscopy). The effect of temperature on the corrosion rate was investigated by the weight loss method, and some thermodynamic parameters for corrosion and adsorption processes were determined and discussed. The results show that the inhibition efficiency increased with the increase in inhibitor concentration and temperature. The adsorption of thiophene derivatives on the carbon steel surface obeys Langmuir adsorption isotherm. The obtained results indicated that the investigated compounds are chemically adsorbed on the steel surface. Potentiodynamic polarization studies showed that these compounds are mixed-type inhibitors and the results obtained from the techniques are in good agreement.