新型曼尼希碱缓蚀剂的合成及缓蚀机理研究

Study on synthesis and mechanism of new Mannich base corrosion inhibitor

以芳香胺、芳香酮和对羟基苯甲醛为原料合成一种曼尼希碱缓蚀剂LDH-9。利用傅里叶变换红外光谱仪对缓蚀剂中的官能团进行表征,同时利用常压静态挂片失重法、高温高压动态腐蚀仪和电化学工作站评价缓蚀剂的缓蚀性能和缓蚀机理。结果表明,在50~140℃,20%盐酸环境中,LDH-9缓蚀剂对N80碳钢有良好的缓蚀效果,优于SY/T 5405—2019标准要求。通过电化学实验可知缓蚀剂LDH-9属于阴、阳混合抑制型缓蚀剂,该缓蚀剂的作用机理呈现几何覆盖效应。同时,该缓蚀剂在N80碳钢表面的吸附符合Langmuir单分子层等温吸附原理,此外,研究表明该吸附是自发的化学吸附。

Using aromatic amines,aromatic ketones and p-hydroxybenzaldehyde as raw materials to synthesize a Mannich base corrosion inhibitor LDH-9.Fourier transform infrared spectrometer was used to characterize the functional groups in the corrosion inhibitor.Moreover,the normal pressure static coupon weight loss method,high temperature and high pressure dynamic corrosion instrument and electrochemical workstation were used to evaluate the corrosion inhibition performance and mechanism of the corrosion inhibitor.The result showed that at 50~140℃,the corrosion inhibitor in 20%hydrochloric acid has a good corrosion inhibition effect on N80 carbon steel,which is better than the requirements of the SY/T 5405—2019 standard.The electrochemical experiment shows that the corrosion inhibitor LDH-9 is a mixed inhibitor of cathode and anode,and has a good inhibitory effect on both the cathode and anode.The mechanism of the corrosion inhibitor is the geometric coverage effect.Ultimately,the corrosion inhibitor conforms to the Langmuir monolayer isothermal adsorption principle on the surface of N80 carbon steel,and the adsorption is spontaneous chemical adsorption.