Pickering emulsion-based fabrication of epoxy and amine microcapsules for dual core self-healing coating

Facile and efficient encapsulation of epoxy and tetraethylenepentamine (TEPA) in polyurea (PU) microcapsules are accomplished with Pickering emulsion templates by one-step, interfacial polymerization. The formation of microcapsule is deftly achieved by lightly shaking Pickering emulsions. The whole process is time andenergy saving hardly with any waste and residual. Epoxy microcapsules keep the spherical shape with core content of more than 90 wt%. Amine microcapsules shrink a little for evaporation of water and the conserved TEPA after air-dried is 82.1 wt%. The shell walls of two microcapsules are about 1 μm. With the protection of PU shells, both microcapsules exhibit excellent thermal resistance. Furthermore, self-healing function of epoxy and amine microcapsules is measured by incorporating microcapsules into epoxy coating, and tested by brine-submersion corrosion-accelerating experiment. The dual core self-healing coatings demonstrate excellent self-repairing performance with the crack of embedded microcapsules and reaction between epoxy and amine. The core materials can outflow from microcapsules and form isolations for metal substrate from corrosion hazard, therefore, make for good self-repairing and preserving function of the self-healing coating.