Journal of Applied Polymer Science, Vol.109, No.6, 3878-3886, 2008
The effect of uniaxial orientation on the dielectric relaxation behavior of alpha-PVDF
alpha-crystalline phase poly(vinylidene fluoride) (PVDF) film was oriented uniaxially at different draw ratios. Morphological effects of orientation were investigated by X-ray diffraction and differential scanning calorimetry (DSC) measurements on the oriented samples. The dielectric loss factor was measured from 100 Hz to 1 MHz range between 80 and 400 K as a function of frequency and temperature. While the activation energy of the alpha-relaxation transition was not affected by the orientation, it was observed that there is a linear increase in the activation energy of the beta-relaxation transition with draw ratio. The relaxation time of the beta-relaxation transition was more affected by the orientation process at lower temperatures. (C) 2008 Wiley Periodicals, Inc.
Keywords:poly(vinylidene fluoride);orientation;dielectric loss factor;dielectric relaxation;activation energy