油酸基咪唑啉缓蚀剂的合成与缓蚀性能

Inhibition Behavior of Imidazoline Corrosion Inhibitor Synthesized from Oleic Acid

以油酸和二乙烯三胺为主要原料,合成了一种咪唑啉缓蚀剂。采用傅立叶红外变换光谱仪(FTIR)测量产品的红外光谱,分析官能团,推断分子结构;采用失重法、Tafel曲线外延法、电化学阻抗技术等对合成的缓蚀剂在模拟气田水环境中的缓蚀性能及缓蚀机理进行了研究。结果表明,合成缓蚀剂的红外光谱中含有较强的咪唑啉特征吸收峰,其氮原子上存在孤对电子,可与金属原子配位结合形成牢固的化学吸附层。缓蚀剂对Q235试样在模拟气田水环境中具有较强的缓蚀作用,当浓度仅为100mg·L^(-1)时缓蚀率即可达到85%左右,并随缓蚀剂浓度增大而增大。缓蚀剂分子在金属表面吸附并成膜,阻止侵蚀性的离子在金属表面吸附和氧原子的扩散,从而起到保护金属的作用,缓蚀剂为阳极型缓蚀剂。

An imidazoline corrosion inhibitor was synthesized from oleic acid and diethylenetriamine. The infrared spectrum of the inhibitor was measured to analyze the functional groups and infer the molecular structure using a fourier transform infrared spectrometer. Weight loss method, Tafel curve extrapolation and EIS technology were used to investigate the inhibition performance and inhibition mechanism of the synthetic inhibitor in the simulated gas field water environment. The results showed that the strong imidazoline characteristic absorption peak was observed in the infrared spectra of the synthetic inhibitor. Lone-pair electrons, which can combine with the metal atom to form a strong chemical adsorption layer, were presented in the nitrogen atom of the synthetic inhibitor. The inhibitor had strong inhibition efficiency on the Q235 sample in the simulated gas field water environment. The inhibition efficiency was up to 85% when the concentration of the inhibitor was only 100 mg L-1 , and increased with the inhibitor concentration. The inhibitor molecules were adsorbed on the metal surface and formed a film, then prevented the adsorption of the aggressive ions and diffusion of oxygen atoms on the metal surface, which played the main role for protecting the metal. The synthetic imidazoline corrosion inhibitor is an anodic inhibitor for 0235 in the simulated gas field water environment.