Hybrid sol-gel coatings for corrosion protection of copper

Thermal-cured coatings based on 3-glycidoxypropyltrimethoxysilane (GLYMO) have been prepared by a sol-gel process for use as corrosion resistant coatings on copper. GLYMO possesses both epoxy and silicon alkoxide functionality and so inter-linked inorganic–organic networks can be formed. It is found that corrosion resistance is enhanced by the addition of 3-mercaptopropyltrimethoxysilane (TPTMS), which improves adhesion of coatings to substrates. Coatings with suitable curing agent exhibited better corrosion resistance and longer pot life. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to evaluate the corrosion properties of these coatings.