The effect of silane layer drying temperature on epoxy coating adhesion on silane-pretreated aluminum substrate

In this study, 3-glycidoxypropiltrimethoxysilane was used as an adhesion promoter to enhance the adhesion strength of epoxy coating on an aluminum (Al) substrate. Silane layer drying temperature was investigated as a factor that has an influence on the adhesion of polymeric coating on metal substrate and also on its performance in wet and corrosive environments. FTIR tests were carried out to study Al/silane interactions. Drying the silane layer at high temperatures formed a condensed siloxane layer that improved the bonding strength as well as the performance of the protective coating in corrosive environments. The highest dry and wet pull-off strengths were obtained at drying temperatures of 100 and 125°C, respectively.