Relation between Piezoelectic Constants and Elastic Constants of Poly(vinylidene Fluoride) Films

PVDF 필름의 압전상수와 탄성상수와의 관계

In this study, the relationship between the piezoelectrc and elastic constants of poly(vinylidene fluoride) films were derived. From these results, it was known that the piezoelectric behavior was highly anisotropic than the mechanical one. Ultimate tensile stress of poled films was higher than that of unploed films and modulus of films in normal to the drawing direction was higher than that in drawing direction after poling process. These results can be explained by the thermal effect of poling process. It was also proved that the piezoelectric activity is originated not from the volume change, but from the thickness change. And the piezoelectric constants were calculated from the elastic moduli and Poisson's ratios of the films and were discussed with the measured ones.