Evaluation and failure analysis of linseed oil encapsulated self-healing anticorrosive coating

In this study, a linseed oil encapsulated self-healing coating was developed by incorporating 10 wt% synthesized microcapsules into an epoxy-polyamine coating matrix. The linseed oil encapsulated polyurea-formaldehyde (PUF) microcapsules had 80 wt% core content with 80 urn diameter. The influence of embedded micro capsules on the anticorrosive property of the self-healing coating had been studied by electrochemical impedance spectroscopy. The intact self-healing coating exhibited excellent anticorrosive property as the intact pure epoxy coating, although the addition of microcapsules into the epoxy matrix resulted in a higher water uptake. The scratched self-healing coating showed excellent healing ability and corrosion inhibition function for microcracks, but It still cannot recover the barrier property as good as the intact coating. The failure of the scratched self-healing coating had been analyzed and the possible reason may be the formation of conductive pathways at the interface between the linseed oil film and the epoxy matrix and/or PUF microcapsule shell.