Noncrystalline Dielectric Relaxation of VDF（52）/TrFE（48） Ferroelectric Copolymers

Ferroelectric copolymers VDF（52）/ TrFE（48） with crystallinity of 20% and 60% were prepared by cooling rapidly in liquid nitrogen and annesling at 130°C for 2hrs. The investigations of dielectric relaxation showed that the frequency spectra of copolymers below room temperature consisted of low-frequency part ascribed to the micro-Brownian motion of molecular segments in the noncrystalline regions and high-frequency part designated as the local motions of small-scale segments. Based on the results of fitting and calculated with WLF equation and Arrhenius formula, We obtained T_R（-24°C） and the activation energy of local relaxation（46.4kJ/mol） of copolymers.