ZHANG Xing-yuan, FURUKAWA Takeo. EFFECT OF THE DEGREE OF CRYSTALLINITY ON DIELECTRIC RELAXATIONS OF VDF/TrFE COPOLYMERS[J]. Acta Polymerica Sinica, 1995,(2):161-169.
ZHANG Xing-yuan, FURUKAWA Takeo. EFFECT OF THE DEGREE OF CRYSTALLINITY ON DIELECTRIC RELAXATIONS OF VDF/TrFE COPOLYMERS[J]. Acta Polymerica Sinica, 1995,(2):161-169.DOI:
slowly-cooled andallnealed copolymers of vinylidene fluoride with trifluoroethylene (VDF/TrFE) (73/27
65/35
52/48 mold )are measured by an improved dielectric relaxation spectrometer in the range of-120-130℃
10-2-104Hz.The Curie point (Tc) of slowlycooled and annealed samples is lower than that of quenched ones because of a disordered ferrophase in the former and an ordered one in the latter. The dielectricconstant around T. increases with the rise of crystallinity. The frequency spectra od copolymers below the room temperature consist of β-relaxation ascribed to the micro-Brownian motions of molecular segments in the noncrystalline regions and γ-relaxa-tion designated as the local motions of small-scale segments. With increasing the crystallinity
β-relaxation peaks of low-frequency part diminish and γ-relaxation pe-aks of high-frequency part enlarge
the relaxation strength of noncrystalline decrea-ses and that of crystalline increases.