含硫咪唑啉衍生物对氢氟酸中钢的缓蚀作用机理

INHIBITION MECHANISM OF SM INHIBITORS FOR CARBON STEEL IN HYDROFLUORIC ACID

咪唑啉衍生物与硫脲的缩合物(简称 SM)对低碳钢在氢氟酸、盐酸、硫酸、柠檬酸中的具有优异的缓蚀作用,本工作主要研究了它们对氢氟酸中钢的缓蚀机理。一、实验方法1.样品准备SM 缓蚀剂是硫脲与咪唑啉衍生物按不同分子比例制得的缩合物。S 代表硫脲基,M 代表1-氨乙基-2-十一烷基咪唑啉基。经筛选,本研究选取 S 与 M

The inhibition effect of polycondensates of thiourea and imidazoline derivativatives(i.e.SM)to carbon steel in hydrofluoric acid solution has been studied by means of chemical and electrochemical methods and the adsorption rule of SM has been discussed. It is shown that,in acidic solution,SM can be adsorbed on the metal surface through rather strong multiple centres adsorption.The ethylene radical in the molecule plays a role of segregation,which makes SM possess both the inhibiting characters of imidazoline and thiourea,and the fatty radical forms a hydrophobic film towards the solution,all these make SM present strong inhibiting action.At lower concentration, the adsorption rule of SM obeys Langmiur isothermal equation,but at higher concentration(1.8×10^(-5)mol/L),it will be in accordance with Frumkin isothermal equation. The mechanism of multiple centers adsorption can be proved indirect ly by the adsorbing model and by the calculated electron density. It would be meaningful for designing new molecules of organic inhibitors.