Microstructure and Electrical Properties of Fluorene Polyester Based Nanocomposite Dielectrics

• Main Authors: Wenchao Zhang, Kuo Zhao, Feng Guan, Jinghua Yin, Yu Feng, Jialong Li, Yanpeng Li
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Polymers
• Subjects: dielectric; fluorene polyester; composite film; corona aging lifetime
• Online Access: https://www.mdpi.com/2073-4360/13/18/3053

As a new type of dielectric material, the low dielectric constant and corona resistance life of fluorene polyester (FPE) restricts the range of its applications. In order to simultaneously achieve a high dielectric constant and the long corona aging lifetime of FPE, SiO₂ nanoparticles were chosen as additive to prepare FPE-based composite films. The microstructure of the composite film was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (IR) and small-angle X-ray scattering (SAXS). The dielectric performances of the composites, including the dielectric constant, breakdown strength and corona resistance lifetime, were investigated. The results show that the introduced SiO₂ does not destroy the structure of the FPE molecular chain and that it increases the thickness of the filler-matrix interface. The dielectric constant of SiO₂/FPE composites increased from 3.54 to 7.30 at 1 Hz. Importantly, the corona resistance lifetime increased by about 12 times compared with the pure FPE matrix. In brief, this work shows what possibilities there might be when considering the potential applications of high-strength insulating materials.