INHIBITING EFFICIENCY OF POLYMETHYLENEBIS-2,2-BENZIMIDAZOLES

The effect of various derivatives of polymethylenebis-2,2-benzimidazol e on the corrosion and electrochemical behavior of steel in H2S-contai ning acids has been studied. Pentamethylenebis-2,2-benzimidazole appea red to be the best inhibitor. The test compounds inhibit both electroc hemical (anodic inhibition) and chemical corrosion. Stress corrosion t ests also showed the inhibitors to be efficient. Rough estimates sugge st that the blocking effect dominates over the energetic psi(1) and ki netic effects in the optimum mechanism of inhibition.