Synthesis of multicore phenol formaldehyde microcapsules and their application in polyurethane paint formulation for self-healing anticorrosive coating

Background: This paper describes the microencapsulation of linseed oil along with drier and corrosion inhibitor in polyurethane coating. Results: Linseed oil along with drier and corrosion inhibitor was encapsulated in phenol formaldehyde microcapsules successfully by in situ polymerization process. These microcapsules were characterized by Fourier transform-infrared and nuclear magnetic resonance spectroscopies, and their surface morphology was studied by scanning electron microscopy. The particle size of the prepared microcapsules was estimated by optical microscopy and confirmed using a particle size analyzer. The self-healing properties as well as anticorrosive performance of encapsulated microcapsules were studied in polyurethane coating. Corrosion protection of coatings with microcapsules containing linseed oil, corrosion inhibitor, and drier was compared with pristine coating free from microcapsules. Conclusions: The cracks in the paint film could be successfully repaired by the release of linseed oil from microcapsules ruptured under stimulated mechanical action, while corrosion inhibitor plays an important role to prevent the corrosion in a scribed line region.