Synthesis of nanocapsules using safflower oil for self-healing material

The present work deals with the synthesis of nanocapsules containing an edible oil and corrosion-inhibiting component. Safflower oil is encapsulated in urea–formaldehyde polymeric shells using an ultrasound-assisted in situ polymerization approach. Safflower oil is an edible and semi-drying oil with a high polyunsaturated fat content. The particle size of the prepared nanocapsules is analyzed using a transmission electron microscope. Subsequently, the prepared nanocapsules are incorporated in epoxy–amine to develop a self-healing corrosion-inhibiting coating. The performance of the coating is evaluated based on studies involving the healing mechanism for the coating. Corrosion inhibition of healed areas has been evaluated using electrochemical impedance spectroscopy (EIS), Tafel plot and immersion test, considering standard epoxy–amine coating as the standard. The obtained results confirmed better corrosion protection in terms of the EIS data and Tafel plots. It was found that the current density decreases from 0·00021 A/cm² (for the standard epoxy coating) to 4·79 × 10⁻⁹ A/cm² with the addition of 2·5 wt% nanocapsules in the coating.