Thermodynamic characterisation of steel corrosion and inhibitor adsorption of pyridazine compounds in 0.5 M H_2SO_4

摘要

The influence of 5-(2-chlorobenzyl)-6-methylpyridazine-3(2H)-thione (P|) and 5-(4-chlorobenzyl)-6-methylpyridazine-3(2H)-thione (P_2) on the corrosion of steel in 0.5M H_2SO_4 solution has been studied using weight loss measurements at various temperature. The inhibiting action is more pronounced with PI than P2. The inhibition efficiency increases with PI concentration to attain the maximum value of 100 percent at 5 X 10~(-4) M. PI adsorbs on the surface of steel according to the Langmuir isotherm model. The thermodynamic data of activation and adsoiption are determined.