Coaxial electrospun fibres with graphene oxide/PAN shells for self-healing waterborne polyurethane coatings

Encapsulation of linseed oil, a self-healing agent, in graphene oxide reinforced PAN shells was realized by coaxial electrospinning. The electrospun fibres were embedded in waterborne polyurethane coatings to prepare self-healing coatings. When cracks/microcracks occurred and caused the rupture of the core-shell fibres, the core material, linseed oil, would be released and filled in the cracks. Linseed oil will react with oxygen and solidify, so that the cracks/microcracks can be healed autonomously. The addition of graphene oxide in the PAN shells increased the thermal stability of the shells. The thickness of the fibre shells was 30-50 nm, suggesting that the microcracks in submicron-scale may trigger the self-healing process. The loading capacity of the fibres was about 45 wt%. The self-healing properties of the waterborne polyurethane coatings were improved with increasing content of the core-shell fibres.