Premium
Structural Study of Phase Transition Behavior of Uniaxially‐Oriented Ethylene‐Tetrafluoroethylene Alternating Copolymer
Author(s) -
Phongtamrug Suttinun,
Tashiro Kohji,
Funaki Atsushi,
Arai Kiyotaka,
Aida Shigeru
Publication year - 2006
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200651037
Subject(s) - tetrafluoroethylene , raman spectroscopy , materials science , orthorhombic crystal system , phase transition , crystallite , phase diagram , copolymer , phase (matter) , crystallography , analytical chemistry (journal) , crystal structure , optics , chemistry , condensed matter physics , composite material , polymer , organic chemistry , physics , metallurgy
Crystal modifications and phase transition behavior have been investigated for the uniaxially‐oriented ethylene‐tetrafluoroethylene alternating copolymer samples of equimolar content by the temperature‐dependent X‐ray diffraction and Raman spectral measurements. The X‐ray fiber diagram measured for the sample drawn at 0 °C has been found to be quite different from that drawn above 100 °C or the normal orthorhombic‐type sample. The new X‐ray diagram is characterized by the sharpness of the reflections and the positional shift from the horizontal lines, indicating the tilting phenomenon of the crystallites. This sample was found to transform into the hexagonal phase in the temperature region around 110 °C with keeping the tilting phenomenon. The molecular motion of the more or less conformationally disordered chains was enhanced above this transition region as seen from the increase in the half‐width of trans bands and the intensity increment of gauche bands in the Raman spectra.