Piezoelectricity Revealed in the Copolymer of Vinylidene Cyanide and Vinyl Acetate

The piezoelectric properties of an alternative copolymer of vinylidene cyanide and vinyl acetate were investigated in connection with the results of dynamic modulus, X-ray diffraction, and electrostriction effect. The rolled and polarized copolymer showed piezoelectricity strong enough to be comparable to that in poly(vinylidene fluoride) films treated by the same poling conditions, but the piezoelectric activity prevailed at high temperature exceeding 100°C. This strong piezoelectricity is considered due to the introduction of large dipole moments such as C–CN groups in the molecule and to the orientation of this large dipole moment in the film.