Metathesis reactions catalyzed by ruthenium complexes for the self-healing of aeronautical materials

Abstract

In this PhD thesis work, Ruthenium catalysts were covalently and non-covalently linked to carbon-based nanomaterials, in order to give self-repairing ability to the aeronautical materials. These supported catalysts have been characterized and their activity has been evaluated in metathesis reactions. The 1st and 2nd generation Grubbs and Hoveyda-Grubbs catalysts were covalently bonded to graphite oxide and tested in the ring-opening metathesis polymerization reaction of tensed monomers, and subsequently their catalytic activity was verified in the aeronautical composites. To optimize the performance of such supported catalysts, catalytic sites have been protected from the highly reactive environment by a polymeric globular shell. These catalysts have been further supported on multi-walled carbon nanotubes and graphite by an alternative covalent synthetic approach that allows to preserve the chemical and physical properties of the carbon nanotubes employed, avoiding the initial oxidation step. For non-covalent functionalization, the same catalysts were first linked to pyrene molecules and then, by π-stacking, anchored on graphite. Their activity was determined in metathesis reactions and their conductivity was estimated within aeronautical composites. Such complex pyrene-catalyst, highly versatile, have been used to synthesize polymers having a terminal pyrene capable of improving the dispersion of the same carbon nanotubes used in aeronautical materials in order to improve their performance. Lastly, was evaluated the possibility of self-repairing the aeronautical material through radical polymerization of monomers such as styrene, using Copper catalysts.[edited by author]