Development of self-healing coatings using encapsulated linseed oil and tung oil as healing agents

Encapsulation of Linseed Oil and Tung Oil in urea-formaldehyde shells was performed using in-situpolymerization technique. Optimization of process parameters for preparation of microcapsules were carried out using calculated amounts of oil and urea-formaldehyde, subjecting to formation of spherical microcapsules of 25-45 micron size, varying with reaction time and stirring speed. The prepared microcapsules were analysed using optical microscopy (OM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), for its characteristic properties which clearly indicates the encapsulation of oil in the thin shells of ureaformaldehyde. Thin film self-healing coatings with uniform and quick self-healing ability were achieved with microcapsules at an optimized concentration of 3 wt%. Detailed analysis of the self-healing coatings were supported by the examining OM and SEM. The anti-corrosive performance was evaluated using immersion test and electrochemical impedance spectroscopy (EIS).