改性咪唑啉与烷基磷酸酯用作缓蚀剂的协同效应

THE SYNERGISTIC EFFECT OF MODIFIED IMIDAZOLINE COMPOUND AND ALKYL-PHOSPHATE ESTER AS CORROSION INHIBITORS

应用电化学方法在饱和CO2的模拟盐水中对改性咪唑啉和烷基磷酸酯抑制A3碳钢腐蚀的效果进行了评价,并考察了二者复配使用抑制A3碳钢腐蚀的协同效应。结果表明,改性咪唑啉与烷基磷酸酯复配使用具有明显的正协同效应,当二者比例为1∶1时,缓蚀率比单独使用时提高20%。改性咪唑啉的缓蚀作用是由于其在金属表面形成吸附膜而产生的结果,烷基磷酸酯则是在金属表面形成沉淀膜而使其具有缓蚀作用,二者共同使用既可以增强保护膜的强度又可以最大限度地保持膜的完整性。在实验研究的范围内,改性咪唑啉主要抑制由于阴极反应引起的腐蚀,而烷基磷酸酯主要抑制阳极反应引起的腐蚀,二者复配使用可同时抑制阴、阳极反应引起的腐蚀,因而缓蚀效果更好。

The effects of modified imidazoline and alkyl-phosphate ester on inhibiting the corrosion of carbon steel A3 in synthetic brine saturated with CO2 were investigated by electrochemical method. Their synergistic effect was also studied. The experimental results indicated that a appreciable positive synergistic effect could be seen when modified imidazoline and alkyl-phosphate ester were used together with the proportion of 1 ： 1. The corrosion inhibition rate for carbon steel A3 rose up by 20 %, compared to isolation use of them. The inhibition effect of modified imidazoline was mainly due to the formation of adsorption film on the surface of metal, while for alkyl- phosphate ester was mainly due to the formation of deposition film. A film on the metal with great strength and well integrity could be obtained when imidazoline and alkyl-phosphate ester were used together. Within the range of experimental investigation, modified imidazoline could mainly inhibit the corrosion caused by cathode reaction, while alkyl-phosphate ester could mainly inhibit the corrosion caused by anode reaction. The both corrosions caused by cathode and anode reactions could be effectively inhibited by the co-use of modified imidazoline and alkyl-phosphate ester.