Polyurea/polyaniline hybrid shell microcapsules loaded with isophorone diisocyanate for synergetic self-healing coatings

Polyurea/polyaniline (PU/PANI) hybrid shell microcapsules loaded with isophorone diisocyanate (IPDI) as core material were successfully synthesized by combining Pickering emulsion formation and interfacial polymerization. The self-healing coatings containing 10wt.% IPDI–loaded PU/PANI microcapsules showed a remarkable healing ability and corrosion protection for microcracks after 30 days of immersion in 10wt.% NaCl solution. EIS tests revealed that the impedance modulus of scratched coatings filled with 10wt.% IPDI-loaded PU/PANI hybrid shell microcapsules sustained at 106 Ω·cm2 after 15 days of immersion in 3.5wt.% NaCl solution. The excellent anticorrosion performance was attributed to the effective synergistic effects of both conductive PANI and IPDI healing agent.