Multi-branched mannich base corrosion inhibitor and preparation method thereof

Abstract

The present invention relates to a multi-branched Mannich base corrosion inhibitor and the method for preparing thereof. The method comprises (1) adding 3˜7 moles ketone and 3˜7 moles aldehyde to reaction kettle, adjusting pH to 2˜6 with acid, controlling temperature to 20˜50° C. and stirring for 20˜30 mins; (2) adding 1 mole organic polyamine to the reaction kettle under stirring, or adding the pH-adjusted ketone, aldehyde and organic solvent to organic polyamine, controlling temperature to 60˜90° C. and reacting for 1˜3 hrs, and after completion of the reaction, heating the system to 110° C. under nitrogen to remove water; the organic polyamine is organic compound comprising three or more primary amine groups and/or secondary amine groups. The Mannich base corrosion inhibitor of the present invention shows characters of strong adsorption force, high film strength, high film compactness, increase in corrosion inhibition efficiency by at least 2%, and overcomes the disadvantages in prior art of few adsorption centers, single adsorption group and weak adsorption force to metal surfaces.