Preparation method of substituted pyridine carbonylhydrazone metal corrosion inhibitor

Abstract

The invention discloses a preparation method of substituted pyridine carbonylhydrazone metal corrosion inhibitor. The method comprises the following steps: using methylisonicotinate and hydrazine hydrate in a molar ratio of 1:1-1.2:1 and absolute ethanol or methanol used as solvent of which volume is 3-6 times of hydrazine hydrate to react for 6-8h in a three-neck flask under the condition of refluxing at 70-80 DEG C and magnetic stirring, obtaining a product to perform reduced pressure distillation, recrystallizing with absolute ethanol, drying to obtain pyridine formylhydrazine, then using the obtained pyridine formylhydrazine and o-vanillin in a molar ratio of 1:1-1:1.2 and absolute ethanol or methanol used as solvent of which volume is 2-5 times of pyridine formylhydrazine to react for 7-9h under the condition of refluxing at 70-90 DEG C and magnetic stirring, cooling, performing suction filtration, washing with absolute ethanol, and recrystallizing. The preparation method of the invention designs the corrosion inhibitor molecule with good oil solubility which meets the environmental protection requirements; and the corrosion inhibitor molecule is characterized by good biodegradability, low toxicity and corrosion resistance within the pH value range of 4-9, and has good corrosion resistance to A3 carbon steel and copper.

Description

technical field The invention relates to a substituted pyridineformylhydrazone compound for metal material protection, belongs to the field of molecular design of green corrosion inhibitors, and particularly relates to a preparation method of a substituted pyridineformylhydrazone metal corrosion inhibitor. Background technique Compared with the most commonly used inorganic corrosion inhibitors (nitrite, phosphate, polyphosphate, carbonate, silicate, borate, chromate), there are more types of synthetic organic corrosion inhibitors . However, there are still many deficiencies in the molecular structure design, synthesis route and process, and application performance of organic corrosion inhibitors, and its theoretical progress still lags far behind practice. The selection and design of the molecular structure of green corrosion inhibitors must not only consider the corrosion inhibition effect, but also take into account the biological activity and versatility. In order to ad...

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Problems solved by technology

For example, the amount of corrosion inhibitor is large, the cost is high, the molecular design is unreasonable, the synthesis route and process are complex, the production of harmful industrial by-products, the yield is low, and the quality is poor, etc.

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