Investigation on initial atmospheric corrosion of copper and inhibition performance of 2-phenyl imidazoline based on electrical resistance sensors

Abstract

The initial atmospheric corrosion of copper was investigated by electrical resistance sensor under different environmental factors (relative humidity, temperature, and NaCl loading density). The corrosion rate of Cu increases evidently with NaCl loading density, temperature and RH, but decreases with prolonged test. 2-phenyl imidazoline (2-PI) presents increasing inhibition efficiency on Cu with elevated temperatures at low NaCl loading density (≤40 μg/cm2), mainly due to that elevated temperature enhances the vapour pressure of 2-PI, however, 2-PI shows inferior performance on pre-corroded Cu at high NaCl loading density, possibly due to that the defective corrosion product layer formed at high RH retards the adsorption of 2-PI. Finally, molecular dynamic simulations were conducted to evidence the competitive adsorption advantage of 2-PI against H2O on Cu2O surface through chelation of 1-N of imidazoline with Cu(I).