In-situ SAXS/WAXS investigations of the mechanically-induced phase transitions in semi-crystalline polyamides - Université de Lille Accéder directement au contenu
Article Dans Une Revue Polymer Année : 2019

In-situ SAXS/WAXS investigations of the mechanically-induced phase transitions in semi-crystalline polyamides

Julie Pepin
Cyrille Rochas
  • Fonction : Auteur

Résumé

The structural evolution under uniaxial tension of both Polyamide-11 (PA11) and Polyamide-6 (PA6) crystallized under various crystal forms has been investigated as a function of draw temperature with respect to the Brill transition. The use of in-situ synchrotron two-dimensional wide-angle X-ray diffraction and small-angle X-ray scattering allows to discriminate thermal from mechanical effects, leading to a revisited scheme of the strain-induced phase transitions in polyamides. It is demonstrated that only the H-bonded sheet-like structures transform mechanically into a pseudo-hexagonal form with a random distribution of H bonds around the chain axis. This order-disorder transition occurs during the fibrillar transformation and seems systematically preceded by a twinning mechanism at low deformation. By contrast, the mesophases and the High Temperature forms are mechanically stable, the latter transforming thermally into the H-bonded sheet-like structures as soon as samples are cooled down below the Brill transition temperature.
Fichier principal
Vignette du fichier
S0032386119304021.pdf (3.57 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-02448905 , version 1 (22-10-2021)

Licence

Identifiants

Citer

Julie Pepin, Valérie Gaucher, Cyrille Rochas, Jean Marc Lefebvre. In-situ SAXS/WAXS investigations of the mechanically-induced phase transitions in semi-crystalline polyamides. Polymer, 2019, Polymer, pp.87-98. ⟨10.1016/j.polymer.2019.04.073⟩. ⟨hal-02448905⟩
61 Consultations
69 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More