Enhanced dielectric properties of polypropylene composites via surface‐modified boron nitride with amorphous carbon coating

Abstract As a petrochemical derivative, polypropylene finds widespread application in microelectronics and wireless communication. Developing polypropylene‐based composites with enhanced dielectric performance and minimal loss is of great interest for capacitor dielectric applications. In this work, we propose a novel filler to optimize the dielectric properties of polypropylene. A thin amorphous carbon layer was coated onto boron nitride (BN) via glucose hydrothermal crosslinking, yielding BN@aC. Composites were then fabricated by melt blending polypropylene with varying concentrations of BN@aC. The influence of filler type (pristine BN vs. BN@aC) and loading on dielectric behavior was thoroughly examined. Notably, BN@aC outperformed pristine BN in enhancing dielectric performance. At 1 kHz and a low filler content of 1.5 wt%, the composite achieved a dielectric constant of 2.85 while maintaining an exceptionally low loss tangent of 3.04 × 10 ⁻³ . Furthermore, given the thermal challenges associated with miniaturized electronic devices, the thermal stability of the composites was preliminarily assessed. This innovative BN@aC design provides a viable pathway for engineering dielectric materials with superior performance. Highlights Preparation using glucose as a carbon source BN@aC core‐shell structural materials. Improved the interface interaction between boron nitride and PP. BN@aC promotes an increase in the dielectric constant and a decrease in the dielectric loss of PP. Composites have good thermal properties.