Influence of acetic acid vapor on the atmospheric corrosion of lead

The present study investigates the influence of low concentrations of acetic acid vapor on the atmospheric corrosion of lead. The samples were exposed to synthetic air with careful control of relative humidity (95%), temperature (22.00 degrees C), acetic acid concentration (170-1100 ppb), CO2 concentration (350 ppm), and flow conditions. The exposure times were between 1 and 4 weeks. Mass gain results are reported. The corrosion products were analyzed by ion chromatography, quantitative carbonate analysis, and X-ray diffraction. The surface morphology of the exposed samples was investigated with environmental scanning electron microscope. The results show that low concentrations of acetic acid vapor are very corrosive toward lead. The mass gain is linear with time and depends linearly on the acetic acid concentration. It is suggested that the corrosion of lead in the presence of traces of acetic acid vapor is electrochemical in nature. The corrosion products found were plumbonacrite, Pb10O(OH)(6)(CO3)(6), lead acetate oxide hydrate (Pb(CH3COO)(2)center dot 2PbO center dot H2O), and lead oxide, PbO. (c) 2005 The Electrochemical Society