The investigation of alpha -> beta phase transition in poly(vinylidene fluoride) (PVDF)

• Autor(a) principal: Constantino, CJL
• Data de Publicação: 2005
• Outros Autores: Job, A. E., Simoes, R. D., Giacometti, J. A., Zucolotto, V, Gozzi, G., Chinaglia, D. L.
• Tipo de documento: Artigo de conferência
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://www.academicpub.com/map/items/3984015.html; http://hdl.handle.net/11449/34014

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 for being a non-destructive technique. Films of alpha-PVDF were subjected to stretching under controlled rates and at 80 degrees C, the transition to beta-PVDF being monitored by the decrease in the Raman band at 794 cm(-1) characteristic of the a-phase, with the concomitant increase in the 839 cm(-1) band characteristic of the beta-phase. Poling with negative corona discharge was found to affect the alpha-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, viz. X-ray diffraction and infrared spectroscopy.