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

The effect of annealing and quenching temperatures on the crystallinity, β phase fraction and dielectric behavior of poly (vinylidene fluoride) (PVDF) have been studied. The crystallinity and β 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 β phase PVDF is the most desired phase for device applications such as sensors and actuators. Hence, the thermal processing conditions are optimized for obtaining β rich PVDF films. The β rich phase of PVDF is obtained for films which are annealed at 80 °C and quenched at 20 °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 ~60.