咪唑啉型缓蚀剂中疏水基团对N80钢在CO2饱和的3%NaCl溶液中的缓蚀性能影响

合成了四种含有不同疏水基团的咪唑啉型缓蚀剂,即正丁基咪唑啉(IM-4)、壬基咪唑啉(IM-9)、十一烷基咪唑啉(IM-11)和十七烷基咪唑啉(IM-17),产物经红外,紫外光谱等进行表征.在静态及动态条件下,用失重法、电化学等方法研究各缓蚀剂对N80钢在CO2饱和的3%NaCl溶液中的缓蚀性能.结果表明,静态条件下,缓蚀剂的缓蚀性能与疏水基团的碳链长度、空间位阻及其水溶性有关;在介质流速为5 m/s的动态条件下,缓蚀剂的缓蚀效率显著降低,对缓蚀剂的疏水和屏障作用要求更高.

THE EFFECT OF HYDROPHOBIC GROUP ON THE INHIBITION BEHAVIOR OF IMIDAZOLINE FOR CO2 CORROSION OF N80 IN 3%NaCl SOLUTION

Four kinds of imidazoline inhibitors with different hydrophobic group i.e. 2-heptadecyl-aminoethyl-imidazoline (IM-17), 2-undecyl-aminoethyl-imidazoline (IM-11), 2-nonyl-aminoethyl-imidazoline (IM-9), 2-butyl-aminoethyl-imidazoline (IM-4) had been synthesized and characterized by IR and UV spectra. The inhibition performance of these imidazoline inhibitors for CO_2 corrosion of N80 in 3% NaCl solution was investigated through linear polarization resistance, polarization curve and electrochemical impedance spectroscopy under static and flow conditions. The results showed that the inhibition efficiency under static condition decreased in the order of IM-9>IM-4>IM-11> IM-17, i.e. the inhibition efficiency was related with both the solubility and the length of carbon chain of hydrophobic group of imidazolines. In contrast, the inhibition efficiency at 5 m/s decreased in the order of IM-9>IM-l>IM-17>IM-4, and solution flow (5 m/s) dramatically worsened the inhibition performance of imidazolines.