Page 9 - Дисертація_Сободош_Наталія_Йосипівна

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additional demands on the composition and mechanism of action of inhibitory

compositions.

Based on a literature review, the directions and main objectives of the

scientific research have been identified, in particular, the development of an

effective, environmentally safe inhibitory composition based on sodium alginate

polysaccharide to protect aluminum alloys from corrosion and tribocorrosion. The

use of sodium alginate, due to its ability to form films, form complexes, and modify

surface properties, offers wide possibilities for creating effective protection systems

that combine high inhibitory activity with environmental safety.

The second chapter provides a description of the materials and research

methods. It describes the chemical composition and surface condition of the D16T

aluminum alloy, the methods for preparing inhibitor solutions, and the experimental

conditions. It provides descriptions of electrochemical methods for investigating

corrosion behavior (potentiostatic polarization curves, electrochemical impedance

spectroscopy), methods for investigating repassivation processes, tribocorrosion

tests, and physicochemical methods for analyzing the structure, morphology, and
composition of protective films. The choice of methods and experimental conditions

is justified.
The third chapter investigates the inhibitory efficacy of a sodium alginate-

based composition against the corrosion of D16T aluminum alloy in a neutral
chloride-containing environment. It has been demonstrated that sodium alginate

alone does not provide an adequate level of protective action (efficacy does not

exceed 65–70%), necessitating the development of synergistic binary systems.

The influence of the anion nature in the zinc salt on the protective efficacy of

the composition in combination with sodium alginate has been analyzed. It has been

established that the protective capacity of the compositions depends significantly on

the nature of the anion in the inorganic zinc salt and follows the order: sulfate <

nitrate < acetate. The choice of zinc acetate as the most effective synergist, enabling

a protection level of 96–98%, is justified. Based on electrochemical studies, the

developed composition exhibits a mixed anodic-cathodic inhibition mechanism and