Titre :

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

Auteur(s) :

Pepin, Julie [Auteur]
Gaucher, Valerie [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Rochas, Cyrille [Auteur]
Lefebvre, Jean-Marc [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]

Titre de la revue :

Polymer

Nom court de la revue :

Polymer

Pagination :

87-98

Éditeur :

Elsevier BV

Date de publication :

2019-06

ISSN :

0032-3861

Discipline(s) HAL :

Chimie/Matériaux
Chimie/Polymères

Résumé en anglais : [en]

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 ...
Lire la suite >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.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Non spécifiée

Établissement(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Ingénierie des Systèmes Polymères

Date de dépôt :

2020-01-07T15:25:04Z
2020-01-22T14:27:01Z