Self-healing materials represents a crucial tool to overcome the difficulties connected to damage generated by microcracks in polymers and polymer composites during their service in structural applications.[1] A self-repair material can be manufactured by the storage of healing agents able to restore the strength of the materials after damage. Among the self-healing systems, one specific for aeronautic applications was developed by White et al. and involves a microencapsulated healing agent and a catalytic chemical trigger within an epoxy matrix [2]. Recently, some of us reported on a self-healing system based on the metathesis polymerization of 5-ethylidene-2-norbornene (ENB) activated by Hoveyda–Grubbs (HG) first generation catalyst that showed to work at -50°C maintaining the performance of the current structural composites and allowing a cure temperature up to 180°C without becoming deactivated [3]. Moreover, HG second generation catalysts with N-heterocyclic carbene backbone substitution were shown to be highly air and moisture stable both in the solid state and in solution for extended periods of time [4]. Herein, performances of self-healing systems based on HG catalysts sketched in figure or HG catalyst-functionalized graphene and ENB as healing agent are reported. The inclusion of graphene in the self healing systems allows both to introduce a filler covalently bound to the polymer in the repairing material and to cut down the amount of the expensive Ru-catalysts.
Self-healing materials based on Ru and Ru-functionalized-graphene catalysts
COSTABILE, Chiara;Mariconda, Annaluisa;GRISI, Fabia;GUADAGNO, Liberata;LONGO, Pasquale
2015-01-01
Abstract
Self-healing materials represents a crucial tool to overcome the difficulties connected to damage generated by microcracks in polymers and polymer composites during their service in structural applications.[1] A self-repair material can be manufactured by the storage of healing agents able to restore the strength of the materials after damage. Among the self-healing systems, one specific for aeronautic applications was developed by White et al. and involves a microencapsulated healing agent and a catalytic chemical trigger within an epoxy matrix [2]. Recently, some of us reported on a self-healing system based on the metathesis polymerization of 5-ethylidene-2-norbornene (ENB) activated by Hoveyda–Grubbs (HG) first generation catalyst that showed to work at -50°C maintaining the performance of the current structural composites and allowing a cure temperature up to 180°C without becoming deactivated [3]. Moreover, HG second generation catalysts with N-heterocyclic carbene backbone substitution were shown to be highly air and moisture stable both in the solid state and in solution for extended periods of time [4]. Herein, performances of self-healing systems based on HG catalysts sketched in figure or HG catalyst-functionalized graphene and ENB as healing agent are reported. The inclusion of graphene in the self healing systems allows both to introduce a filler covalently bound to the polymer in the repairing material and to cut down the amount of the expensive Ru-catalysts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
