Enhanced thermal conductivity and dielectric property of polyphenylene oxide/SiO2 composite by adding functional boron nitride strategy

Abstract

Polymer composites with high thermal conductivity and excellent dielectric properties are ideal materials for high-speed electronic devices used in information processing. In this work, a high-speed microwave composite is designed by incorporating functional boron nitride (f-BN) into the polyphenylene oxide (PPO)/vinyl trimethoxysilane modified SiO2 (V-SiO2) composite. The dispersion of BN was significantly improved through surface coating followed by covalent modification. Adding f-BN into the PPO/V-SiO2 composite significantly enhances its dielectric properties and thermal conductivity, resulting in a lower dielectric constant (3.06–3.24) and dielectric loss (2.2×10−3@10 GHz). An effective thermal conductivity path is established by an optimal interface combination of f-BN and the PPO/V-SiO2 composite at a f-BN content of 15 wt%, the thermal conductivity of the composite reaches 0.858 W/(m·K). Moreover, the composite exhibits high thermal stability, low moisture absorption (<0.36 %), and possesses lightweight and flame retardant characteristics. This research provides a novel approach for PPO-based composites in high-speed devices and demonstrates the promising potential for applications in high-frequency substrates.