盐酸介质中N,N′-二（二苯基膦基）-1-苯乙胺对碳钢的缓蚀性能研究

目的对N,N'-二(二苯基膦基)-1-苯乙胺(NPM)的合成、结构表征及其在盐酸介质中对碳钢的缓蚀性能进行研究。方法用红外光谱、元素分析和熔点测试等方法对NPM的结构进行表征,采用静态失重法、动电位极化曲线法和电化学阻抗法研究NPM在盐酸介质中对碳钢的缓蚀作用,研究腐蚀体系温度、HCl浓度、NPM浓度和腐蚀体系静置时间对NPM缓蚀率的影响,探讨NPM在碳钢表面上的吸附机理。结果动电位极化曲线法研究结果表明NPM是一种混合型缓蚀剂。NPM的缓蚀率随NPM浓度的增加而增大,当NPM的质量浓度为140 mg/L时,NPM在25℃的1.0 mol/L HCl溶液中的缓蚀率达到94.71%;NPM的缓蚀率随腐蚀体系温度的升高而降低,随HCl浓度的增大而减小,但随腐蚀体系静置时间的延长缓蚀率逐渐增大。NPM在碳钢表面的吸附符合Langmuir吸附等温方程式,属于自发进行的物理和化学吸附。结论所合成的化合物NPM是一种高效的混合型有机缓蚀剂。

Investigation on Corrosion Inhibition of N,N'-Bis(diphenylphosphino)-1-phenylethylamine for Carbon Steel in Hydrochloric Acid Solution

Objective To study the synthesis, structure characterization and inhibition performance of N,N′-bis( di-phenylphos-phino)-1-phenylethylamine ( NPM) on carbon steel in hydrochloric acid solution. Methods The structure of synthesized NPM was characterized by means of infrared spectroscopy, elemental analysis and melting point test. And the inhibitive efficiency of NPM on carbon steel in hydrochloric acid solution was investigated using the static weight loss method, potentiodynamic polarization curve and electrochemical impedance. The influences of the corrosion system temperature, NPM concentration, hydrochloric acid concen-tration and standing time of the corrosion system on the corrosion inhibition efficiency of NPM on carbon steel were studied, and the adsorption mechanism of NPM on carbon steel surface was also discussed. Results The potentiodynamic polarization curves indica-ted that NMP acted as a mixed-type inhibitor. The results for influencing factors of the inhibitive efficiency of NPM showed that the inhibitive efficiency of NPM increased with increasing NPM concentration, and the inhibition efficiency reached up to 94. 71% at 140 mg/L NPM in 1. 0 mol/L hydrochloric acid solution at 25 ℃. It decreased gradually with the increase of the corrosion system temperature and the hydrochloric acid concentration, while increased with increasing standing time of the corrosion system. The ad-sorption process of NPM on carbon steel surface obeyed Langmuir isotherm and belonged to spontaneous physical and chemical ad-sorption. Conclusion The synthesized organic compound NPM was a highly efficient mixed-type corrosion inhibitor.