Abstract: An imidazoline corrosion inhibitor was synthesized from diethylenetriamine and oleic acid using dimethylbenzene as a water carrying agent, and the synthetic reaction conditions, molecular structure and corrosion inhibiting capability to boiler water system were studied. Results show that the optimized parameters for the synthesis is as follows: the molar ratio of oleic acid to diethylenetriamine is 1∶1.4, the volume ratio of dimethylbenzene to reacting mixture is 1∶5 , temperature is programmed raised from 145 ℃ to 210 ℃, the reflux time is 8 h. under the optimum conditions, the yield is up to 96.5%, corrosion inhibition efficiencies on carbon steel is over 90% with imidazoline derivative concentration of 20 mg/L in boiler solutions．The imidazoline derivative was found to inhibit anode corrosion reactions greatly, and also to inhibit cathode corrosion to some extent, so it can be classified as a passivating anodic-type corrosion inhibitor. The mechanism of corrosion inhibition relies on the strong absorption of the imizadoline on metal surfaces which can prevent metal surface from contacting with water．

Key words: Imidazoline, Corrosion inhibitor, Synthetic conditions, Boiler solution

摘要： 以油酸和二乙烯三胺为反应物、二甲苯为带水剂，制备了烷基咪唑啉类缓蚀剂，研究了该缓蚀剂的合成条件、分子结构与在锅炉水系统的缓蚀性能的关系。结果表明，最佳的合成条件为酸/胺为1∶1.4，带水剂体积占反应物总体积的20％，在145 ℃左右回流，逐步升温至210 ℃，回流8 h，产物的收率为96.5％，烷基咪唑啉衍生物的用量为20 mg/L时在锅炉水中对碳钢的缓蚀速率可达90%以上，缓蚀剂强烈地抑制了腐蚀的阳极溶解过程，对阴极去极化过程也有一定的抑制作用，可认为该缓蚀剂是碳钢的以阳极为主的混合性缓蚀剂。该缓蚀剂抑制腐蚀的原因是在碳钢表面缓蚀剂吸附成膜，有效阻挡了钢表面与水的接触。

关键词: 咪唑啉, 缓蚀剂, 合成条件, 锅炉水