Vapor-phase deposition of polymer siloxane coatings on aluminum and magnesium alloys

Adsorption and polymerization of vinyltrimethoxysilane (VS) on the surface of aluminum AMG and magnesium alloy M20 in the presence of water vapor and ethylene glycol (EG) was investigated. It is shown that ethylene glycol is an effective polymerization promoter due to the crosslinking of hydroxyl and ethanol groups during polycondensation of VS and EG molecules on the surface of alloys. The main factors influencing the polymeri-zation rate and protective properties of coatings are determined. Using XPS methods, it was found that ethylene glycol molecules interact with magnesium hydroxides to form magnesium glycolate polymolecules in the form of developed three-dimensional structures. The variation of the composition of the vapor-gas mixture makes it possible to obtain protective coatings with a different ratio of siloxane and poly-oxy magnesium structures. Azeotropic mixtures of vapor-gas deposition of coatings and optical methods for controlling the chemical composition of working solutions have been developed. Electrochemical and EIS studies of siloxane coatings on smooth and oxidized surfaces of alloys have been carried out. Impregnation of oxidized aluminum and mag-nesium alloys with organosilanes by vapor-gas gas deposition significantly increases their corrosion and me-chanical resistance.

Automated summary

This study investigated the adsorption and polymerization of vinyltrimethoxysilane (VS) on the surface of aluminum AMG and magnesium alloy M20 in the presence of water vapor and ethylene glycol (EG). The results showed that ethylene glycol acted as an effective polymerization promoter due to the crosslinking of hydroxyl and ethanol groups. XPS analysis revealed the formation of magnesium glycolate polymolecules with developed three-dimensional structures. Different ratios of siloxane and poly-oxy magnesium structures in protective coatings were achieved by varying the composition of the vapor-gas mixture. Moreover, the impregnation of oxidized aluminum and magnesium alloys with organosilanes significantly enhanced their corrosion and mechanical resistance.