Evaluation of the Effect of Mixing Ratio of Epoxy Silicon Resin and Aminosilane on the Coating Protective Properties by Electrochemical Impedance Spectroscopy

This work intends to study the effect of epoxy silicon resin mixture ratio with aminosilane hardener on corrosion protection properties of the coating. Coatings with different mixture ratio ranging 15-50% resin: hardener were prepared and cured for 1 h at 120 °C. To evaluate corrosion protection properties, electrochemical impedance spectroscopy (EIS) was employed after 240 h exposure of samples to salt spray. In addition, pull-off adhesion strength was measured after salt spray exposure. Results showed deterioration of protection properties and adhesion strength of the coatings below and above 20% mixture ratio. According to the tests results, the optimal mixture ratio of epoxy silicon to aminosilane was 20%.