Water uptake, adhesion and corrosion performance of silicone-epoxy coating on 2024 Al-alloy treated with different GLYMO were systematically studied by gravimetry, electrochemical measurements, DSC, pull-off adhesion and salt spray tests. The results showed that GLYMO not only enhanced the cross-linking of the silicon-epoxy coating but also enhanced the bonding between the coating and the Al-alloy interface. This gives the coating better wet adhesion, less water absorption and improves the corrosion resistance of the coating. The micro-nano silane layer, preferentially between the coating and Al-alloy oxide layer, was validated by the model of the water concentration jump.
Keywords: 3-glycidoxypropyltrimethoxy silane; Al-alloy; DSC; EIS; model validation; silicone-epoxy coatings; water uptake.