Abstract:Integrating high-loading dielectric nanoparticles into polar polymer matrices potentially can make full use of the intrinsic polarization of each phase and allow for greatly enhanced dielectric properties in polymer nanocomposites. However, it is hugely difficult to make nanoparticles disperse and maintain interfacial compatibility in highly filled polar polymer composites, which is closely related to the overall dielectric properties, such as dielectric loss. Here, a polyfluorosiloxane with controlled amounts of trifluoropropyl was synthesized by anionic polymerization and highly filled barium titanate/fluorinated silicone rubber (BT/FSR) nanocomposites were fabricated by ‘thiol-ene click’ technique. The results indicate BT nanoparticles are uniformly coated and adhered with fluorinated silicone rubber. The polar group (—CH2CF3) of the polymer matrix does not affect the microstructure of highly filled polymer nanocomposites. Then the uniform dispersion of nanoparticles and compact interface avoid interfacial defects and restrain interfacial polarization. In addition, the dielectric constant of 88% BT/FSR nanocomposite reaches 60.1, which displays 23.9 enhancement to that of 88% BT/SR nanocomposite at 103 Hz, while their dielectric losses are no more than 0.03. Besides, the dielectric properties of BT/FSR nanocomposite can be tailored via controlling the amount of trifluoropropyl in fluorinated silicone rubber.