Studies of 80/20 Mol% Vinylidene Fluoride-Trifluoroethylene Copolymer by Brillouin Scattering

Abstract

The hypersonic behavior of oriented and isotropic copolymer of vinylidene fluoride-trifluoroethylene (80/20 mol%) has been investigated by Brillouin scattering. For the oriented samples, the elastic constants have been measured. For both oriented and isotropic sample, the glass and ferroelectric transitions have been observed. The ferroelectric transition behavior observed in the temperature dependence of sound velocity along the stretch direction (X-axis) seems to be different from that deduced from data of sound velocity along the Y-axis (perpendicular to X but in the plane of the sheet). This behavior is discussed from a structural point of view. An independent transition is suggested.