engleski

Corrosion inhibitors for bronze protection in polluted atmosphere

The aim of this work was to investigate the possibility of bronze protection in atmospheric conditions by three protective systems. Two of them were based on environmentally friendly corrosion inhibitors: 4-methyl-1-(p- tolyl)imidazole and a vapor phase corrosion inhibitor. The third protective system was water based acrylic primer containing the mixture of non-toxic corrosion inhibitors. The research was carried out in the solution of 0.2 g dm-3 NaNO3, 0.2 g dm-3 Na2SO4 and 0.2 g dm-3 NaHCO3 at pH 3. This electrolyte simulated the composition of acid rain characteristic for polluted urban environment. Measurements were performed by the means of electrochemical methods – Tafel extrapolation method, linear polarization method and electrochemical impedance spectroscopy. Stability of the applied protection was also tested in humidity chamber at two temperatures (25 °C and 35 °C). Results of the investigation showed that each of the applied corrosion inhibitors provided protection to bronze in the tested conditions. However, the maximum inhibiting efficiency of 4- methyl-1-(p-tolyl)imidazole was about 68 %, that of vapor phase inhibitor about 98 %, while acrylic coating containing corrosion inhibitors had an efficiency of almost 100 %.

bronze; acid rain; corrosion inhibitors; electrochemical methods; humidity chamber

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