A brief review of various theories for the function of organic inhibitors is presented to provide an introduction for the evidence of this investigation. The data herein were obtained from a theoretical study of inhibitor structure, galvanic electrochemical couple polarization measurements and results of a simple corrosion test on iron coupons. The experimental medium for studies of potential was 0.5 N HCl at 25 C. The steady state potential was determined and suggested to be a function of the structure and concentration of the organic molecule. The anodic and cathodic polarization values indicated that both anodic and cathodic areas were affected. In order to be effective, an organic inhibitor should act on each area.
The data are discussed in terms of a generalized corrosion inhibitor theory. The theory is substantiated by laboratory corrosion tests on 1020 mild steel using organic inhibitors developed from the galvanic electrochemical couple study. The corrosion tests were made in 10 percent hydrochloric acid. The measured changes and inhibiting effects were assumed to be due to an interaction of electrolyte-affected metal surface and the polar oriented portion of the organic molecule. 5.8.3
