Low-Temperature Low-Frequency Dielectric Relaxation in Polytrifluoroethylene

The complex dielectric constants of as-cast, quenched and annealed polytrifluoroethylene （PTrFE） are measured by the improved dielectric relaxation spectrameter. The three-dimensional dielectric spectra is obtained in the range of-120～40℃, 10^-2～10⁴Hz. The frequency spectra of PTrFE below the room temperature consist of β-relaxation ascribed to the micro-Brownian motions of molecular segments in noncrystalline regions and γ-relaxation attributed to the local motions of small-scale segments, which is similar to the dielectric properties of VDF/TrFE copolymers at low-temperature low-frequency. The behavior of dielectric relaxation indicates that T_g of PTrFE is -18℃ and the activation energy of local relaxation is 63.7kJ /mol.