Effect of Annealing Temperatures and Time on Structural Evolution and Dielectric Properties of PVDF Films

In this paper, we investigate the effect of thermal annealing on the degree of crystallinity, the fraction of electro-active phase (β-phase) and the dielectric properties, such as dielectric constant and loss tangent. Through control the thermal annealing conditions, dramatic improvements have been achieved. The degree of crystallinity is greatly enhanced up to 45.2%. The relative content of electro-active phase increases remarkably by 61% and the dielectric constant is improved greatly by 17.8% and reaches its maximum value of 9.9 meanwhile the dielectric loss being as low as 0.026.