Effect of thermal processing conditions on the structure and dielectric properties of PVDF films

The effect of annealing and quenching temperatures on the crystallinity, beta phase fraction and dielectric behavior of poly (vinylidene fluoride) (PVDF) have been studied. The crystallinity and beta phase fraction of these films were evaluated using X-ray diffraction and FTIR techniques for different annealing and quenching temperatures. It is seen that the thermal processing conditions play a crucial role in determining the dominant phase in PVDF. The beta phase PVDF is the most desired phase for device applications such as sensors and actuators. Hence, the thermal processing conditions are optimized for obtaining beta rich PVDF films. The beta rich phase of PVDF is obtained for films which are annealed at 80 degrees C and quenched at 20 degrees C. The as-synthesized films for the optimized processing conditions was studied for their dielectric behavior and was found to exhibit dielectric constant as high as similar to 60.