Abstract
The adsorption of various long chain amines, amine acetates, quaternary, salts, and ethylene oxide-octade-cylamine condensates from benzene solution onto steel was determined. The acid dissolution of steel with previously adsorbed inhibitor and the dissolution of steel in aqueous inhibited acid solution were also studied. For the dodecyl compounds of each series, 1) adsorption for a di-amine can take place through both amine groups, 2) amine salts are not as effectively adsorbed as amines and 3) a high molecular weight quaternary salt is strongly adsorbed even though it has no available bonding electrons.
Inhibitor effectiveness for these compounds adsorbed from benzene solution onto steel are in decreasing order, 1) quaternary salt, 2) di-amine, 3) mono-amine, and 4) mono-amine acetate. In inhibited acid solutions, long chain amine acetates and quaternary salts furnish better than 90 percent inhibition in the concentration range of 3.75 to 15 × 10−4 molar. Ethylene oxide and octadecylamine condensation products were less effective, in this concentration range, providing approximately 85 percent inhibition. However, they were more effective than the amine acetates and quaternary salts where less than 3.75 × 10−4 molar.
