Protection of graphene supported ROMP catalyst through polymeric globular shell in self-healing materials

Protected Ru-catalyst, immobilized on graphene sheets, was prepared and used for Ring Opening Metathesis Polymerization (ROMP) in strongly reactive environments based on epoxy resins. The protection mechanism, proposed in this paper, is based on the formation of a micrometric globular shell that partially englobed the catalytic site, causing hindrances for the deactivation of the catalyst due to an equimolecular reaction between the catalyst complex and the oxirane ring. The catalytic performance evaluated in reactive self-healing systems showed the overcoming of several critical drawbacks. The proposed system allows curing temperatures typical of structural materials and, in addition to preventing the agglomeration of the catalyst particles, a remarkable reduction from 5% to 0.3% by wt of expensive catalyst in the self-healing composite material.