Design and manufacturing of protective barriers on Fe 430 B substrates by phenyl methyl polysiloxane coatings: micromechanical response, chemical inertness, and corrosion resistance

In the present investigation, scratch resistance, chemical inertness, and corrosion resistance of methyl phenyl polysiloxane coatings on Fe 430 B structural steel with or without an organo-silane intermediate layer were analyzed. The role of Al–Mg pigments dispersed in the resin was studied, too. The high molecular weight of the polysiloxane resin ensures good adhesion to the substrate, low porosity, and high mechanical stability. The good ductility and low steric hindrance of the methyl groups coupled with the chemical inertness of the phenyl groups yields coatings with utmost endurance to aggressive chemicals and, above all, that are suitable as corrosion retardants on sensitive steel substrates. Last, the dispersion in the resin of particles, which act as a corrosion inhibitor, as well as the interposition of organo-silane layers between substrate and polysiloxane resin, can improve further the potential of the designed barrier coatings.