Relaxation time of a polymer glass stretched at very large strains
Résumé
The polymer relaxation dynamic of a sample, stretched up to the stress hardening regime, is measured, at room temperature, as a function of the strain λ for a wide range of the strain ratė γ, by an original dielectric spectroscopy set up. The mechanical stress modies the shape of the dielectric spectra mainly because it aects the dominant polymer relaxation time τ , which depends on λ and is a decreasing function ofγ. The fastest dynamics is not reached at yield but in the softening regime. The dynamics slows down during the hardening, with a progressive increase of τ. A small inuence ofγ and λ on the dielectric strength cannot be excluded.
Domaines
Physique [physics]
Origine : Fichiers produits par l'(les) auteur(s)