Dielectric Properties of Piezoelectric Polyvinylidene Fluoride (PVDF)

Measurements were made of the free dielectric constant and the dielectric loss tangent of piezoelectric polyvinylidene. fluoride PVDF at frequencies between 1 kHz and 5 MHz and temperatures between -28 deg C and 51 deg C. Samples of nonvoided and voided PVDF were tested. The dielectric constant increases with increasing temperature andor decreasing frequency, ranging from about 3 to 11 for the voided material and from about 4 to 14 for the nonvoided material. The dielectric loss tangent dissipation factor ranged from about 0.02 at low frequencies and high temperatures to about 0.3 at high frequencies and high temperatures. The voided material was not as lossy as the nonvoided material with maximum values 0.2 for the voided material and 0.3 for the nonvoided material. A slight temperature aging effect was observed an increase of a few percent in dielectric constant resulted from cycling the samples to 51 deg C.