TEMPERATURE-COEFFICIENT OF CORROSION INHIBITION OF STEEL BY ADENINE

The inhibition of steel corrosion in 0.5 M sulfuric acid by adenine at different temperatures was shown to follow the Langmuir adsorption is otherm over a wide concentration range (10(-5) to 10(-3) M). The corro sion potential, corrosion current, corrosion rate, polarization resist ance, as well as activation energy and thermodynamic parameters were c alculated at different temperatures. From a comparison of the activati on energies of uninhibited and inhibited corrosion reactions, the heat of adsorption of adenine may be obtained. The temperature coefficient for corrosion inhibition has a negative value, which may be explained by assuming that the corrosion reaction is no longer the simple metal /acid reaction, but involves the adsorbed species directly.