A correlation between kinetics of corrosion and the mechanism of inhibition by organic compounds

Abstract

Inhibition of corrosion by organic compounds is not only a function of their chemical properties and structure but depends also on the nature of the corroding metal, on the composition of the corrosive medium and on the conditions under which the corrosion process occurs. An organic substance which effectively protects a given metal under certain conditions could lose this ability entirely under other conditions, or with other metals. This specificity or selectivity of action, which is often considered as the most typical feature of organic inhibitors, has not been explained satisfactorily. The aim of the document is to show that at least in some cases the specific action of inhibitors could be understood if the nature of the corrosion process is taken into consideration. The discussion will be restricted, however, to the corrosion of metals in non-oxidizing mineral acids.