Catalyst-lean, microcapsule-based self-healing materials via ring-opening metathesis polymerization (romp)

Abstract

A self-healing composite material includes a polymer matrix, microcapsules filled with a ring-opening metathesis-active monomer (e.g., norbornene, norbornene derivatives such as ethylidene norbornene, or cyclooctadiene), and polymeric particles comprised of a polymer that is soluble in the monomer with which the microcapsules are filled and having catalytic endgroups derived from an olefin metathesis catalyst, such as a Grubbs'-type catalyst. In some embodiments, the polymer having catalytic endgroups is synthesized via solution polymerization of a ring-opening metathesis-active monomer (e.g., norbornene, norbornene derivatives, or cyclooctadiene) in the presence of an olefin metathesis catalyst (e.g., Grubbs' 1st generation catalyst). The polymer having catalytic endgroups may then be processed via a grinding operation, for example, to prepare the small polymeric particles. In other embodiments, the polymeric particles are synthesized directly as microparticles (e.g., microspheres, granules, beads, etc.) utilizing an analogous suspension polymerization.