咪唑啉类缓蚀剂的合成及缓蚀性能研究

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8h,产物的收率为96.5%,烷基咪唑啉衍生物的用量为20mg/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。

Preparation and Performance Evaluation of Imidazoline Corrosion Inhibitor

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.