A kind of preparation method of 2,6-diaminopyridine acetal acid double Schiff base corrosion inhibitor

Abstract

The invention discloses a preparation method of a 2,6-diaminopyridine glyoxylic acid bis-Schiff base corrosion inhibitor. (1) Place 1.1106 g of glyoxylic acid in a round bottom flask filled with 15 mL of absolute ethanol. (2) Add 0.5456 g of 2,6-diaminopyridine into 20 mL of absolute ethanol, dissolve it, and add it to the result of step (1). (3) Add 0.15 mL of glacial acetic acid dropwise, stir at 70°C, and react for 6 hours under nitrogen protection. (4) Cool at room temperature to obtain a brown precipitate, filter under reduced pressure, rinse with absolute ethanol, dry the filter cake in vacuum, put it into a beaker with 40 mL of absolute ethanol, stir, and filter under reduced pressure, the filter cake Vacuum drying to obtain 2,6-diaminopyridine glyoxylic acid bis-Schiff base corrosion inhibitor. Corrosion inhibitors can be used to prevent corrosion of carbon steel in pickling solutions. The invention has the advantages of simple process, good repeatability and high yield, and the corrosion inhibitor has good corrosion inhibition effect on carbon steel in dilute sulfuric acid.

Description

technical field [0001] The invention relates to the field of organic synthesis, and relates to a preparation method of a bis-Schiff base corrosion inhibitor, in particular to a preparation method of a 2,6-diaminopyridine acetal acid bis-Schiff base corrosion inhibitor. Background technique [0002] Carbon steel refers to an iron-carbon alloy with a carbon content of less than 2% and a small amount of impurities such as silicon, manganese, phosphorus, and sulfur [1]. It is widely used in all aspects of machinery manufacturing, especially since the industrial revolution in the 18th century, the global demand for carbon steel as a raw material for various products and structures, including buildings, vehicles, electronic equipment, pipes and household appliances, etc. Increase. Corrosion layers are inevitably formed during daily transportation, hot rolling, surface treatment, operation and storage. At the same time, steel rolling in the iron and steel industry needs to be pick...

AI Technical Summary

Problems solved by technology

Corrosion layers are inevitably formed during daily transportation, hot rolling, surface treatment, operation and storage. At the same time, steel rolling in the iron and steel industry needs to be pickled to remove iron oxide scale and other dirt on the steel surface. The pickling process has no effect on the pickling end point. OK, so it is easy to cause "over-pickling" phenomenon

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