In-situ SAXS/WAXS investigations of the ...
Document type :
Article dans une revue scientifique: Article original
Permalink :
Title :
In-situ SAXS/WAXS investigations of the mechanically-induced phase transitions in semi-crystalline polyamides
Author(s) :
Pepin, Julie [Auteur]
Gaucher, Valérie [Auteur]
Rochas, Cyrille [Auteur]
Lefebvre, Jean-Marc [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Gaucher, Valérie [Auteur]
Rochas, Cyrille [Auteur]
Lefebvre, Jean-Marc [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Journal title :
Polymer
Abbreviated title :
Polymer
Pages :
87-98
Publisher :
Elsevier BV
Publication date :
2019-06
ISSN :
0032-3861
English abstract : [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 ...
Show more >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.Show less >
Show more >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.Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Non spécifiée
Administrative institution(s) :
Université de Lille
CNRS
INRA
ENSCL
CNRS
INRA
ENSCL
Collections :
Research team(s) :
Ingénierie des Systèmes Polymères
Submission date :
2020-01-07T15:25:04Z