Synthesis And Mechanism Of The Corrosion Inhibitor

The first-line task in the acidification is to solve the problem of metal corrosion, especially in the acidification of high temperature-deep well. The use of corrosion inhibitor is a effective way.Imidazoline is a kind of excellent acidizing corrosion inhibitor. It's anti-corrosion ability is very good, and it is conveniently and widely used in the production of oil and gas. Therefore, imidazoline is the hotspot of acidizing corrosion research.In this article a kind of imidazoline quaternary-ammonium-salt is synthesized with benzyl acid, vinyl amine and benzyl chlorine. First, synthesize imidazoline. Reaction condition: benzyl acid and vinyl amine (mol ratio)2:l,concentration of activator: 0.2%~0.5%H3BO3,solvent:15%~25% dimethylbenzene, temperature for acyl: 140~160C, temperature for ring: about 220C, time: 4h. Second, synthesize imidazoline quaternary-ammonium-salt. Reaction condition: benzyl chlorine and imidazoline (mol ratio)l.2:1, temperature:80~ 100C , time: 3~5h.The product was characterized by IR. And weight-losing corrosion test proved that the imidazoline quaternary amines showed good effect as acidizing corrosion inhibitors. The corrosion-inhibiting rate of the imidazoline quaternary -ammonium -salt in the concentration of 1.0~2.0% is above 99.0%. In order to achieve a perfect anti-corrosion effect, the compounding of inhibitor is very necessary. Therefore, the compounding between the synthetics and I" is studied, 0.8% synthetics and 3 10"3 mol/1 can provide a very good effect.The mechanism of corrosion inhibition is analyzed by means of stable polarization curve, electrochemical impedance spectroscopy. It shows the corrosion inhibitor is a mainly cathode-controlling corrosion inhibitor.