Abstract
The rosin as natural product became a source for production of eco-friendly bio-surfactants which widely used in environmental protection issues. In this respect, nonionic surfactant was prepared from reaction of rosin maleic anhydride acid chloride with triethylene tetramine followed by etherification with poly (ethylene glycol600 to produce etherified rosin imide (ERIT-PEG) surfactant. The surface activity parameters of the prepared surfactant such as surface excess concentration (Γmax), the area per molecule at interface (Amin), and the effectiveness of surface tension reduction were measured in aqueous and 1M HCl solutions to determine the micellization and adsorption characteristics of the prepared surfactants at water/air interface. The inhibition effects of the etherified rosin imide (ERIT-PEG) surfactant on the corrosion of steel in 1 M HCl solution was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Inhibition efficiency (%IE) increased with increasing inhibitor concentration. Etherified rosin imide (ERIT-PEG) surfactantacts as a mixed-type inhibitor with a capability of blocking both anodic and cathodic sites on the steel surface immersed in 1M HCl. The inhibition efficiencies calculated from EIS are in good agreement with those obtained from potentiodynamic polarization.