Corrosion inhibition by N coco‐amine‐2‐proprionic acid on mild steel in CO₂ saturated 5 per cent NaCl at pH 6.5 Available to Purchase

Work has been performed to assess the corrosion inhibiting performance of a tertiary amine possessing two carboxylic acid groups (N coco‐amine‐2‐proprionic acid), on initially clean and pre‐corroded mild steel. Using linear polarisation and AC impedance high levels of efficiency were measured within the first hour of inhibitor addition at a concentration level of 10ppm. Simultaneously rapid anodic changes in corrosion potential were observed. With increasing pre‐corrosion decreased efficiencies were obtained, but still greater than 90 per cent, and this coincided with a less rapid alteration in steady state potential. The good response of the inhibitor has been attributed to the adsorption of negatively charged oxygens at the anodic sites on the metal surface, although pitting was detected once testing was terminated. Previously using inhibitors possessing positive charges (short and long chained quarternary amines), under the same environmental conditions, efficiencies > 90 per cent after the first hour were not achieved.