Synthesis Of Imidazoline Inhibitor From Vegetable Oil And Analysis Of Its Inhibition Performance

Imidazoline corrosion inhibitor is a kind of environment friendly corrosioninhibitor, good solubility, good thermal stability, low toxicity. Imidazoline andits derivatives is a kind of inhibitor with excellent inhibition performance due totheir unique molecular structure． In acid pickling industry, imidazolinecorrosion inhibitor show good inhibition performance on metals and their alloy.However to synthesize this kind of corrosion inhibitor with high cost, the scopeof application is restricted.Imidazoline corrosion inhibitor with fatty acid methyl ester or fatty acid asraw materials, and polyamines by amidation, cyclization and quaternary ammo-nium modified imidazoline quaternary ammonium salt corrosion inhibitorformation. Chinese pine seed oil and arborvitae seed oil is rich in fatty acids,which are renewable natural plant resources, with the synthesis of imidazolinematerial conditions. This topic in plant seed oil （Pinus tabulaeformis seed oil,Platycladus orientalis seed oil） as raw materials, preparation of ImidazolineCorrosion inhibitor, raw material cost is small, good performance, and on Pinustabulaeformis seed and Platycladus orientalis seed depth development hasimportant theoretical guiding significance.With Pinus tabulaeformis seed oil and Platycladus orientalis seed oil as rawmaterials to synthesize corrosion inhibitor Y and C, orthogonal experiment, theoptimal conditions for the synthesis were determined, and then through theinfrared spectroscopy to determine the intermediate structure features, usingbromophenol blue method identification of end products of quaternaryammonium cationic effective content, and examines two kinds of corrosioninhibitor dissolved dispersion. The results showed that, the synthesis ofcorrosion inhibitor Y optimum conditions: Pinus tabulaeformis seed oil withtwo ethylene amines three ratio1:3.00（mol: mol）,cyclic phase reaction time3.0hour, xylene content30%; with bromophenol blue method to determine the end products of corrosion inhibitor Y effective content can reach92.07%;synthesis inhibitor inhibitor C optimum conditions: Platycladus orientalis seedoil and two ethylene amines three ratio1:3.25（mol: mol）, cyclic phase reactiontime3.5hour, xylene content25%; corrosion inhibitor Y and C in hydrochloricacid, citric acid and EDTA acid solution has good solubility dispersion.Weight loss measurement and electrochemical method were used toanalysis of the corrosion inhibitor performance from corrosion inhibitor Y and C.The results showed that: in the medium of hydrochloric acid, corrosion inhibitorY and C on A20steel has good corrosion resistance, corrosion inhibitor Yminimum dosage of150mg·L^-1 corrosion inhibitor C minimum dosage of200mg·L^-1, and good thermal stability; corrosion inhibitor Y allows Fe³⁺concentration limit for500mg·L^-1; corrosion inhibitor Y and C are cathodicinhibitor. In citric acid medium and EDTA medium, the single use of corrosioninhibitor Y and C on A20steel corrosion is very poor, two respectively andthiourea compound after corrosion inhibitor for A20steel corrosion hassignificant inhibitory effect, the effect of inhibition of above99%, and has verygood heat stability; corrosion inhibitor Y and thiourea compound inhibitorsallows Fe³⁺ concentration limit of900mg·L^-1; two kinds of corrosion inhibitorto control cathode corrosion inhibitor.