Development and Characterization of Poly(Vinylidene Fluoride)/Sn-Doped CaCu3Ti4O12 Thin Film with Enhanced Dielectric and Mechanical Properties
摘要
This work investigated the possibility of obtaining a relatively high-dielectric-constant polymer-ceramic composite by incorporating a giant-dielectric-constant material, Sn-doped CaCu3Ti4O12 (SnCCTO), in a poly(vinylidene fluoride) (PVDF) polymer matrix by a melt mixing and hot pressing process. SnCCTO was synthesized using the solid-state ceramic method, and PVDF/SnCCTO composites were fabricated via the melt extrusion technique. The structure, morphology, mechanical properties, and dielectric properties of the composites were characterized using x-ray diffraction, thermal analysis, scanning electron microscopy, Instron 3369 tensile testing, and impedance analysis. Interestingly, the composites exhibited a higher Young’s modulus than the pure PVDF. Notably, the dielectric permittivity of the PVDF matrix increased with a higher volume fraction of SnCCTO. The purpose was to analyze the dielectric relaxation behavior. In addition, the dielectric loss exhibited a slight increase with rising temperature but decreased as the frequency increased. Two distinct dielectric relaxations were observed: one in the low-frequency range, attributed to the Maxwell–Wagner–Sillar phenomenon, and another in the intermediate-frequency range linked to the glass–rubber transition (α). The activation energy for both dielectric relaxations was determined as well.