Enhanced dielectric thermal stability and permittivity of flexible composite films based on BaTiO3 nanoparticles highly filled PVDF/PAN blend nanofibrous membranes

Polymer film capacitors with high stability and reliability at elevated temperatures are promising for next-generation power electronic systems and hybrid electric vehicles. In this work, sandwich-structured composite films with good dielectric thermal stability were fabricated based on hybrid membranes of poly(vinylidene fluoride)/polyacrylonitrile blend nanofibrous skeleton highly filled with BaTiO 3 nanoparticles. Composite films with 64.7 vol% BaTiO 3 nanoparticles in the core layer exhibited high permittivity (38.1) and low loss (0.046) at 1 kHz and room temperature, and the dielectric permittivity and loss were only slightly increased to 41.5 and 0.08, respectively, at 120°C. Good dispersion and high loading of BaTiO 3 nanoparticles in the composites films contributed to enhanced dielectric thermal stability and permittivity. Moreover, the composite films showed good flexibility, which could be ascribed to its sandwich-structure. Our work paves a generic way to fabricate flexible composite films with excellent dielectric thermal stability via high loadings of ceramic nanoparticles. POLYM. COMPOS., 39:E1841–E1848, 2018. © 2018 Society of Plastics Engineers