Inhibition efficiency of synthesized petroleum sulfonates mixtures against the acidic corrosion of mild steel

The inhibiting effects of surfactants synthesized by sulfonation from algerian petroleum products (crude oil,gasoil,kerosene and platformat) of local origin (field of hassi messaoud in the south of algeria) against the acidic corrosion of mild steel were determined by electrochemical techniques: polarization resistance (rp),polarization curves (tafel slopes) and electrochemical impedance spectroscopy (eis). the results showed that the inhibition effectiveness is a function of the nature and the families' contents of hydrocarbons in the initial products on one hand and of the physicochemical properties such as: solubility and critical micelle concentration (cmc) on other hand. it increases in the direction: platformat,kerosene,gasoil and crude oil. the examination of the isotherms showed that adsorption verifies the model of temkin for the crude oil surfactant and the model of frumkin in the other cases. the rise of temperature,in the field 30-60°c,decreases the effectiveness which indicates a physisorption of surfactants at steel surface,however it remains relatively significant compared with inhibitors of same type.