Volatile inhibitors of atmospheric corrosion of ferrous and nonferrous metals. V. Study of the adsorption of inhibitors on steel from an aqueous electrolyte solution

Abstract

Adsorption of ten Mannich and Schiff bases on steel from a mixed electrolyte solution (30 mg/dm 3 NaCl + 50 mg/dm 3 Na2SO4) was studied. The adsorption isotherms show linear segments in the medium coverage range, which may be equally attributed to both the Frumkin and Temkin isotherms. Unfortunately, experimental data are insufficient to distinguish among them. It was demonstrated that the mechanism of action of the inhibitors in vapor phase differs from that in a model electrolyte solution and that testing of volatile inhibitors in electrolytes provides no accurate pattern of corrosion inhibition in the vapor phase. The VNKh-L-21 and VNKh-L-408 inhibitors form nanoclusters that merge on the surface into a polymolecular adsorption layer.