Submillimeter infrared absorption and chain conformations of poly(vinylidene fluoride) and copolymers. II. Phase transition analysis

Absorption spectra, and hence the dielectric properties, of poly(vinylidene fluoride-tri-fluoroethylene) copolymers have been obtained by far infrared spectroscopy in the frequency range 15–55 cm^?1. We have studied the evolutions of the absorption coefficient and imaginary part of the dielectric constant as a function of poling field and copolymer composition. During the phase transition from form II to form I, the whole absorption presents a strong increase. This behavior is explained by polarizability changes at phase transition.