Inventor: Dr. Ameel Mohammed Rahman/Department of Biochemical Engineering, Al-Khwarizmi College of Engineering, University of Baghdad
The present invention regards the use of rosemary oil extracted from rosemary plant which is available locally in Iraq, as anti-corrosive to Mild Steel. In this invention, potentiostate method was used to measure the polarization efficiency of rosemary oil as inhibitor for Mild Steel in 0.5M HCl acid solution. The results showed that the increase in the concentration of the inhibitor from 0 to 400 ppm reduces the corrosion current and thus increasing efficiency of protection. The Gibbs free energy of for this corrosion reaction is -38.7 kJ /mol, which in turn indicates the spontaneous adsorption of rosemary oil molecules on the surface of the metal and the mechanism of adsorption of these molecules on the surface of the metal is chemical adsorption type. Also retardant molecules formed on the metal surface were characterization by using FTIR spectrophotometer.