Compositionally graded hydrophobic UV-cured coatings for the prevention of glass stress corrosion

Abstract

The use of glass in architecture is growing and is moving towards structural applications. However, the tensile strength of glass cannot be fully exploited because of stress corrosion. This is a corrosion triggered by stress applied to the material and dependent on environmental factors such as humidity and temperature. To protect glass from stress corrosion, we developed a UV-cured coating, characterized by hydrophobicity, barrier to water vapor properties, and good adhesion to glass, thanks to a compositional profile. The coating was obtained by combining a cycloaliphatic diacrylate resin with a very low amount of a perfluoropolyether methacrylate co-monomer, which migrated to the free surface, creating a compositionally graded coating. The adhesion to glass was improved, using as a primer an acrylated silane able to co-react with the resins. With a mechanical load test using the coaxial double ring set-up, we proved that the coating is effective in the inhibition of stress corrosion of glass plates, with an increase of 76% of tensile strength.