两种新型曼尼希碱缓蚀剂的性能及吸附行为研究

Performance Evaluation and Adsorption Behavior of Two New Mannich Base Corrosion Inhibitors

通过Mannich反应合成ZJ-1、ZJ-2两种曼尼希碱缓蚀剂,利用红外光谱对产物进行表征,采用极化曲线、电化学阻抗谱和分子动力学模拟等方法评价两种缓蚀剂对P110钢的缓蚀效果,并探讨其缓蚀作用机理和吸附行为。结果表明:合成的缓蚀剂在1 mol/L NaCl+CO2环境中对P110钢均有一定的缓蚀效果,其中ZJ-1缓蚀剂的缓蚀效果更好,缓蚀效率可达92.06%;两种缓蚀剂均为阳极控制为主的混合型缓蚀剂,通过缓蚀剂在金属表面上形成的吸附膜使得腐蚀过程的电极反应都难于进行,从而起到减缓腐蚀的作用;ZJ-1和ZJ-2缓蚀剂分子均可驱替水分子而吸附在金属表面,其活性原子N和O提供的孤对电子与金属表面Fe原子的空轨道形成配位键,具有较强的吸附作用力,相比于ZJ-2曼尼希碱缓蚀剂,ZJ-1曼尼希碱缓蚀剂分子与Fe表面的吸附能更高,缓蚀性能更好。

Two Mannich base corrosion inhibitors,ZJ-1 and ZJ-2,were synthesized by Mannich reaction.The products were characterized by infrared spectroscopy.Corrosion inhibition effect of these two inhibitors on P110 steel were studied by means of polarization curve measurement,electrochemical impedance spectroscopy and molecular dynamics simulation.While the relevant corrosion inhibition mechanism and adsorption behavior were also discussed.Results showed that the two synthesized corrosion inhibitors presented obvious corrosion inhibition effect on P110 steel in 1 mol/L NaCl+CO2 environment,however,ZJ-1 had better corrosion inhibition effect with a corrosion inhibition efficiency up to 92.06%.These two corrosion inhibitors were belonged to mixed corrosion inhibitors based on anode control.Both the anode reaction and the cathode reaction were restrained in the corrosion process due to the adsorption film formed on the metal surface by corrosion inhibitors.Furthermore,ZJ-1 and ZJ-2 can displace water molecules and adsorb on the metal surface,the lone pair electrons provided by the active atoms N and O could form coordination bonds with the vacant orbital of Fe.Therefore,corrosion inhibitor molecules can be adsorbed on the metal surface and the corrosion inhibition effect is enhanced due to strong chemical forces of the bonds.Compared with ZJ-2 inhibitor,ZJ-1 inhibitor molecule has higher adsorption energy and better corrosion inhibition performance to the surface of Fe-based alloys.