作者：Ke Zhao, Yingbo Chen*, Siyu Wei, Meng Wang, Pengfei Li, Hao Li, Xianglin Zhang
关键字：PI-BN composite film; Thermal conductivity; Hierarchical structure
论文来源：期刊
具体来源：Ceramics International 50 (2024) 19228-19236
发表时间：2024年

Ceramics International 50 (2024) 19228-19236

DOI: 10.1016/j.ceramint.2024.03.022

With the advent of the 5G era, the demand for heat dissipation using high thermal conductivity (TC) materials is becoming increasingly urgent. The electrical insulation and thermal stability of dielectric polymer composites are also notable in electrical and electronic applications. Nevertheless, the improvement in TC of dielectric polymer composites is typically accomplished at the expense of electrical insulating capabilities. Herein, we fabricated polyimide (PI) composites with ordered structure by combining electrostatic spinning, vacuum filtration deposition and blade-coating. The modified boron nitride nanosheets (mBN) not only enhanced the interaction between filler and PI matrix, but also reduced the interface thermal resistance. Benefiting from the hierarchical structure, the in-plane TC of prepared composite was 17.44 W/mK at 18.79 vol% mBN content, which is 9.6 times higher than that of pure PI. Moreover, the composites were electrically insulating, with the volume resistivity of about 10^13 Ω cm, and exhibited great flexibility, exceptional thermal stability (THRI > 269 °C), excellent thermal dissipation capability and low dielectric characteristics. In summary, this work offers a novel perspective to design highly thermally conductive composites and these composites have vast application potential in flexible electronic devices or circuits.