Effet de la température d'étirement sur la structure et la microstructure du poly (fluorure de vinylidène)

The stretching temperature effect on the phase transition of poly (vinylidene fluoride), obtained by extrusion, was investigated. The variation of the crystalline fraction of the phases was obtained as a function of stretching temperature via infra-red spectroscopy (IR), differential scanning calorimetry (DSC) and X-ray diffraction (X-ray). This variation is related to the dependence of the alpha -> beta phase transition on the stretching temperature; this facilitates the comprehension of certain results reported in the literature concerning crystalline phase transitions. The stretching of the sample of PVDF at a temperature lower than 72 degrees C causes the transition from a phase to beta phase.