Pogrebova I.S. The scientific basis for the creation of synergistic adsorption corrosion inhibitors multifunctional purposes. - Qualifying scientific work on the rights of the manuscript (dissertation for the degree of Doctor of Technical Sciences in specialty 05.17.14. - Chemical resistance of materials and corrosion protection. - National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Kyiv, 2021).
The dissertation is devoted to the solution of an important scientific and technical problem namely increase of corrosion resistance and operational and technical properties of metal products, equipment and devices by use of synergistic adsorption corrosion inhibitors of a wide range of protective action. A scientifically substantiated approach to the creation of the effective corrosion inhibitors based on polyfunctional organic compounds and combinations of organic compounds and metal salts has been developed, which is based on a comprehensive study of adsorption processes and the role of the structure of organic compounds in its course. The features the kinetics of partial reactions of specific types of corrosion and the ways of influencing them by inhibitors, taking into account the effects of intra- and intermolecular synergism which occur at the process of the corrosion inhibition was determined.
The regularities of adsorption and protective action in case of acid corrosion of iron and carbon steels of monofunctional and polyfunctional organic compounds of different chemical composition have been studied. The role of amine, pyridinium, carbonyl, thiocarbonyl, carboxyl groups in the protective action of these inhibitors is revealed. Modern scientific provisions on the mechanism of protective action of organic corrosion inhibitors and the role of various partial effects of its inhibition have been developed. An equation is proposed and experimentally substantiated, which establishes the relationship between the kinetic parameters of corrosion processes, the protective action of inhibitors and their adsorption properties, taking into account the mechanism of anodic dissolution of iron.
The effects of intra-and intermolecular synergism arising from the inhibition of metal corrosion by polyfunctional organic compounds with nitrogen, oxygen, sulfur atoms and mixtures of organic and inorganic compounds of different protective action have been studied and scientifically substantiated. The relationship between the nature of the forces of interaction between the adsorbed parts and their protective effect in acid corrosion of iron is highlighted. A new type of synergistic inhibitors of zinc acid, salt and alkaline corrosion based on mixtures of organic compounds and metal cations is proposed. The role of modification of surface properties of zinc, which occurs due to various electrochemical processes in the protective action of this type of corrosion inhibitors, has been established.
The developed model of adsorption of organic compounds on metals is based on the notions of the formation of complexes with partial charge transfer and prediction of its course using Pearson’s Hard–Soft Acid–Base Principle. Based on the application of the proposed adsorption model, the directions of creation of new effective corrosion inhibitors are developed, based on taking into account the adsorption properties of metals, the specifics of corrosion mechanisms, the effects of synergism of their protective action.
A new series of organic corrosion inhibitors based on Quaternary pyridinium salts with carbonyl groups with a broad spectrum of action and multifunctional purpose (acid corrosion, microbial corrosion of metals under conditions of bacterial sulfate reduction, acid corrosion-mechanical destruction of steels) has been developed.
The relationship between the protective effect of organic compounds, electronic and steric properties of their substitutes and the nature of additional functional groups prone to direct adsorption on steel has been studied. The effect of synergism of protective action of organic compounds under the influence of products of bacterial metabolism (HS-, H2S) is scientifically substantiated.
The influence of inhibitors on self - discharge, electrical and discharge characteristics of zinc and cadmium anodes of chemical current sources has been studied. Based on the use of the developed corrosion inhibitors, improved lead-zinc and lead-cadmium elements with acid electrolytes, manganese-zinc elements of water-salt and water-alkaline system are proposed. The prospects of combined anticorrosion protection of carbon steels in water aggressive environments on the basis of joint use of diffusion coatings and corrosion inhibitors are established.
Key words: inhibitors, acid, salt, alkaline corrosion, corrosion in the conditions of sulfate reduction, nitrogen-, oxygen-, sulfur-containing organic compounds, galvanic elements, diffusion coatings.
