Pantheon SEMPARIS Le serveur des séminaires parisiens Paris

Status Confirmed
Seminar Series SEM-PHYS-ENS
Subjects cond-mat.soft
Date Tuesday 14 November 2017
Time 17:15
Institute DPT-PHYS-ENS
Seminar Room Salle Dussane (45 rue d'Ulm)
Speaker's Last Name Leibler
Speaker's First Name Ludwik
Speaker's Email Address
Speaker's Institution ESPCI
Title From glass to vitrimers: a story of exchangeable links
Abstract During cooling, amorphous silica, the archetype glass-former gradually increases its viscosity over a wide temperature range and it becomes so viscous that for all practical purposes it behaves like a hard solid, the glass. In striking contrast and without exception all organic glass-formers increase their viscosity and rigidify very abruptly when cooled. Moreover, silica is not soluble. We imagined, vitrimers, organic materials that undergo gradual glass transition and are not soluble just like silica. Vitrimers are molecular networks that through thermo-activated exchange reactions are able to change their topology without changing the total number of bonds. Solid at low temperatures and malleable when heated yet insoluble whatever the temperature, vitrimers constitute the third class of polymers along with thermoplastics and thermosets (elastomers). First vitrimers were made from epoxy resins. Today most plastics and rubbers can be transformed into vitrimers. Since vitrimers can be shaped, assembled, repaired and recycled while showing exquisite chemical and thermomechanical resistance they should rapidly find applications in electronics, automotive, airplane, and coatings industries. And as for inorganic glass-formers, the question whether amorphous silica is a vitrimer opens intriguing perspectives.
arXiv Preprint Number
Comments !! Unusual location: Salle Dussane, 45 rue d'Ulm !!

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