Phase transition in poly(vinylidene fluoride) investigated with micro-Raman spectroscopy
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
20/05/2014
20/05/2014
01/03/2005
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Resumo |
The phase transition from the non-polar a-phase to the polar beta-phase of poly(vinylidene fluoride) (PVDF) has been investigated using micro-Raman spectroscopy, which is advantageous because it is a nondestructive technique. Films of alpha-PVDF were subjected to stretching under controlled rates at 80 degrees C, while the transition to P-PVDF was monitored by the decrease in the Raman band at 794 cm(-1) characteristic of the a-phase, along with the concomitant increase in the 839 cm-1 band characteristic of the P-phase. The alpha ->beta transition in our PVDF samples could be achieved even for the sample stretched to twice (2 X -stretched) the initial length and it did not depend on the stretching rate in the range between 2.0 and 7.0 mm/min. These conclusions were corroborated by differential scanning calorimetry (DSC) and X-ray diffraction experiments for PVDF samples processed under the same conditions as in the Raman scattering measurements. Poling with negative corona discharge was found to affect the a-PVDF morphology, improving the Raman bands related to this crystalline phase. This effect is minimized for films stretched to higher ratios. Significantly, corona-induced effects could not be observed with the other experimental techniques, i.e., X-ray diffraction and infrared spectroscopy. |
Formato |
275-279 |
Identificador |
http://dx.doi.org/10.1366/0003702053585336 Applied Spectroscopy. Frederick: Soc Applied Spectroscopy, v. 59, n. 3, p. 275-279, 2005. 0003-7028 http://hdl.handle.net/11449/32747 10.1366/0003702053585336 WOS:000227680400002 |
Idioma(s) |
eng |
Publicador |
Soc Applied Spectroscopy |
Relação |
Applied Spectroscopy |
Direitos |
closedAccess |
Palavras-Chave | #poly(vinylidene fluoride) #PVDF #micro-Raman spectroscopy #differential scanning calorimetry #DSC #X-ray diffraction #XRD |
Tipo |
info:eu-repo/semantics/article |