H_2S水溶液中的腐蚀与缓蚀作用机理的研究V.咪唑啉衍生物在H_2S溶液中的缓蚀作用特征

STUDY ON CORROSION AND INHIBITION MECHANISMIN H_2S AQUEOUS SOLUTIONS V .The Inhibition Characteristics of Imidazoline Derivatives in H_2S Solutions

合成了１４种具有不同结构和官能团的咪唑啉衍生物,利用交流阻抗和动电位极化曲线,对其在Ｈ２Ｓ溶液中的缓蚀作用特征和性能,以及温度的变化对其缓蚀性能的影响进行了研究,结果表明咪唑啉化合物对Ｈ２Ｓ溶液中低碳钢的腐蚀具有良好的保护性能,这主要依赖于化合物分子与金属表面存在较强的化学作用;按其作用机制的不同,所研究的咪唑啉化合物大体可分为阳极型和阴极型缓蚀剂,且阳极型咪唑啉缓蚀性能优于阴极型;咪唑环上憎水或亲水支链的长短,或其它官能团的存在(如双键,羟基等),对化合物的缓蚀性能和作用机制有直接的影响．

A series imidazoline derivatives, which have different molecular structure and function group, were synthesized and investigated respectively for the inhibition characteristics, the effect of temperature on the inhibition efficiency by potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS) inH2S solutions. The results show that imidazoline derivatives have a good inhibition to the mild steel in H2S solutions, that is strongly dependent on the chemical interaction between imidazoline molecule and the surface of metals. When the number of carbon atom in hydrophobic side chain is less than 13 and there are some function groups (such as double - bond; hydroxyl) in hydrophobic side chain, the employed imidazoline compounds present anodic inhibitor's performance, whereas the compounds present cathodic type inhibitor's performance when the number of carbon atom in hydrophobic side chain is more than 13. The length of side chains (including hydrophobic and hydrophilic chain) and the different function groups (such as double- bond; hydroxyl) in imidazoline ring play an important role in the inhibition performance and mechanism.