An Investigation of Corrosion Behavior of Epoxy/Amine Micro/Nanocapsule Based Smart Coatings

Micro/nanocapsules containing self-healing agents have been introduced into epoxy coatings to self-heal the defects and improve the anti-corrosion behavior. To provide epoxy based coating with self-healing ability, two-component healing system consisting of urea–formaldehyde micro/nanocapsules containing epoxy and nano-porous hollow glass microspheres containing diethylenetriamine (DETA) were synthesized. When the defect was made, the micro/nanocapsules released the healing materials to fill the defected area. The coatings containing loaded micro/nanocapsules were applied on carbon steels and their self-healing behavior was investigated using scanning electron microscopy (SEM) observation and electrochemical impedance spectroscopy (EIS) technique. In order to obtain the optimum concentration of micro/nanocapsule in the coatings, coatings with 0 %, 5 %, 15% and 20 % micro/ nanocapsules were synthesized and characterized. The results confirmed that the optimum amount of micro/nanocapsules addition to the epoxy coating was found to be 15wt.%.. The results also reveal that the addition of micro/nanocapsules does not damage the barrier properties of the non-scratched epoxy coating during immersion time.

Keywords:

Micro/nanocapsules , Self-healing coating , Epoxy , Amine , EIS