Substituted Propargylamines—Acid Corrosion Inhibitors for Steel in Petroleum Industry

Secondary and tertiary amines of the acetylene series of various structures (14 compounds) were synthesized based on propargylamine. The possibility of a significant inhibition with these substances of low-carbon steel corrosion in hot solutions of hydrochloric acid has been established. The protective effect of acetylenic amines rises with an increase in their content in an aggressive environment and with an increase in its temperature. The maximum protection effect is provided by tertiary amines containing 2,3-epoxypropyl or 2,3-epithiopropyl as a substituent. The presence of chemically active epoxy and epithio groups in the structure of these acetylenic compounds promotes the stimulation of their polymerization on the steel surface through the opening of C≡C bonds, which leads to the rapid formation of a protective polymer film on it.