1-(β-羟乙基)-2-混合脂肪基咪唑啉的制备及缓蚀性能

Synthesis and corrosion inhibition of 1-(β-hydroxyethyl)-2-mixed fatty imidazoline

以地沟油水解产物混合脂肪酸和β-羟乙基乙二胺为原料,通过酰胺化-环化脱水缩合反应,合成了1-(β-羟乙基)-2-混合脂肪基咪唑啉,通过正交实验优化合成条件。结果表明,最佳合成条件为:混合脂肪酸和β-羟乙基乙二胺的质量比10∶4.6,酰化时间5 h,环化温度250℃,环化时间6 h。采用静态失重法、电化学极化曲线法考察了该化合物在5%HCl中对Q235钢的缓蚀性能。结果表明,在投药量100 mg/L、腐蚀时间6 h、温度60℃的实验条件下,碳钢的缓蚀率为95.43%,该缓蚀剂是一种混合型缓蚀剂。吸附热力学研究表明,缓蚀剂与金属表面的吸附符合Langmuir吸附等温式。

An imidazoline corrosion inhibitor,1-（ β-hydroxyethyl）-2-alkyl imidazoline,was synthesized withβ-hydroxyethyl-ethylenediamine and mixed fatty acid which is made from gutter oil as raw materials by amidation and cyclodehydration. The results showed that the optimum condition for the product synthesis were 10∶ 4. 6 of raw material mass ratio of mixed fatty acid and β-hydroxyethyl-ethylenediamine,amidation for 5 h,cyclodehydration for 6 h at 250 ℃. Besides,static weight-loss method and electrochemical polarization curves were used to evaluate its corrosion inhibition performance to Q235 steel in 5% HCl. It was found that,the inhibition efficiency was up to 95. 43% at 60 ℃ for 6 h while the mass concentration was 100 mg/L,the corrosion inhibitor can be classified as a mixed type inhibitor. The study also showed that the adsorption of the inhibitor on Q235 steel conformed to the Langmuir adsorption isotherm equation.