Insights into concomitant enhancements of dielectric properties and thermal conductivity of PVDF composites filled with core@double‐shell structured Zn@ZnO@PS particles

Abstract

AbstractIn order to synchronously improve dielectric permittivity (ε′), breakdown strength (Eb), and thermal conductivity (TC) while inhibiting dissipation factor (tan δ) of raw Zn (Zinc)/PVDF (poly[vinylidene fluoride]) composites, two kinds of core‐shell structured particles of Zn@ZnO (zinc oxide) and Zn@ZnO@PS (polystyrene) were synthesized by high‐temperature oxidation followed by suspension polymerization, then they were composited with PVDF to elaborately generate morphology‐controllable high‐ε′ but low loss, and high TC composites. The results confirm that both the Zn@ZnO/PVDF and Zn@ZnO@PS/PVDF composites show markedly improved ε′, suppressed tan δ and conductivity over the original Zn/PVDF because of the induced multiple polarizations in the Zn@ZnO and Zn@ZnO@PS configurations and the barrier effect of constructed shells on direct contact of Zn particles. The second organic PS shell inhibits the loss and conductivity due to its high‐electrical resistivity, and further boosts the Eb and TC of the composites owing to enhanced interfacial compatibility between the Zn@ZnO and PVDF, which lessens the local electric field distortion and concentration, and therefore, promotes phonon transport across the interfaces through suppressing the thermal interfacial resistance. The prepared Zn@ZnO@PS/PVDF with a high Eb and ε′ but low tan δ, as well as enhanced TC, exhibit appealing potential applications in microelectronic devices and power equipment.