Title :
Dielectric measurements and X-ray investigations on the phase transitions of poly (vinylidene fluoride-hexafluoropropylene) copolymers
Author :
Latour, Mireille
Author_Institution :
Lab. de Physique Moleculaire et Cristalline, Univ. des Sci. et Techniques du Langeudoc, Montpellier, France
Abstract :
Paraelectric-to-ferroelectric phase transition has been observed under low electrical stresses in vinylidenefluoride-hexafluoropropylene (VDF-HFP) copolymers with 15% HFP molar content. This phase transition, detected by thermodepolarization processes and differential scanning calorimetry techniques, is confirmed in the present work by X-ray and dielectric measurements. These results showed the structural evolution of the copolymer from the α nonpolar to the δ polar configuration under electrical stress of 0.5 MV/cm
Keywords :
X-ray diffraction examination of materials; dielectric polarisation; electrets; ferroelectric materials; ferroelectric transitions; polymer blends; polymer structure; PVDF-HFP; X-ray; dielectric measurements; differential scanning calorimetry; electret; low electrical stresses; paraelectric to ferroelectric transition; phase transitions; poly (vinylidene fluoride-hexafluoropropylene) copolymers; structural evolution; thermodepolarization processes; Calorimetry; Crystallization; Dielectric measurements; Diffraction; Ferroelectric materials; Phase detection; Piezoelectric polarization; Resins; Temperature; Thermal stresses;
Conference_Titel :
Electrets, 1991. (ISE 7) Proceedings., 7th International Symposium on (Cat. No.91CH3029-6)
Conference_Location :
Berlin
Print_ISBN :
0-7803-0112-9
DOI :
10.1109/ISE.1991.167261
