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Structural changes induced by deformation in an ethylene–(vinyl alcohol) copolymer: simultaneous measurements of uniaxial stretching and in situ wide‐angle X‐ray scattering
Author(s) -
Cerrada María L,
Fauth François,
FernándezBlázquez Juan P,
Pérez Ernesto
Publication year - 2010
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2840
Subject(s) - monoclinic crystal system , materials science , crystallite , copolymer , vinyl alcohol , deformation (meteorology) , synchrotron , diffraction , composite material , small angle x ray scattering , crystallography , phase (matter) , ethylene , scattering , crystal structure , optics , polymer , chemistry , organic chemistry , catalysis , physics , metallurgy
The deformation process of a semi‐crystalline ethylene–(vinyl alcohol) copolymer (with a vinyl alcohol content of 68 mol%) has been evaluated using simultaneously real‐time synchrotron X‐ray diffraction and stress‐strain experiments at 150 °C. Small changes are observed during the initial elastic region in monoclinic crystallites. However, significant modifications are found along the development of a neck in the yielding region. These involve the disappearance of the monoclinic crystals and the appearance of a strain‐induced phase of mesomorphic ordering that is rapidly oriented. This alignment is further slightly enhanced during the propagation of deformation through the specimen, leading to a final orientation function of around 0.92. Copyright © 2010 Society of Chemical Industry