Chemical Composition of the Copper/Benzotriazole Interface in the Presence of Acetic Acid Vapour at Low Humidities:

Studies were made of the chemical composition of the copper products formed at 43, 58 and 78% relative humidity (RH) in contaminated (10-ppm acetic acid vapour) and uncontaminated environments in the presence and absence of the volatile corrosion inhibitor benzotriazole (BTA) for 7 d at 30°C. Such studies were conducted using X-ray photoelectron spectroscopy (XPS). General XPS spectra over a wide binding energy region showed C and O peaks in addition to those corresponding to the different copper compounds. Copper specimens exposed to acetic acid vapour in the presence of BTA also exhibited N emissions. The main compounds formed were cuprite (Cu2O), copper hydroxide [Cu(OH)2], copper acetate and copper-benzotriazole (Cu-BTA) complexes.