Ferroelectric properties of vinylidene fluoride-trifluoroethylene copolymers

Abstract

The ferroelectric properties of vinylidene fluoride‐trifluoroethylene copolymers were studied. According to the x‐ray diffraction patterns, the crystalline form of the copolymers with VDF molar content less than 80% was different from that of the copolymer with 82 mole % VDF. The Curie temperature was observed for the copolymers with the molar composition ranging from 37 to 80% in VDF by measuring the dielectric constants and endothermic peaks. The copolymers with low Curie temperature had the crystalline with wide interplanar spacing and small saturation polarization. The copolymer with 55 mole % of VDF showed a typical ferroelectricD‐E hysteresis loop at 25 °C and showed a double hysteresis loop at just below the transition temperature.