Highly thermally conductive, electrically insulating, thermal resistance polyimide-base composites with fibrillated carbon networks for thermal management applications

Polymer composites with excellent thermally conductive, electrically insulating, and thermal resistance proprieties are urgently needed due to the rapid development of modern high-performance electronic devices. In this present study, the highly thermally conductive polyimide/carbonized polyvinyl alcohol (PI/αPVA) composites membrane with continuous fibrillated carbon-base thermally conductive network was prepared by co-electrostatic spinning polyamide acid/polyvinyl alcohol (PAA/PVA) fibers and high-temperature treatment method. The fibrillated αPVA acts as thermally conductive fillers, which was penetrated in the PI fibers constructing continuous thermally conductive networks. The PI/αPVA composites membrane exhibits a high in-plane thermal conductivity (TC) of 2.43 W/(m·K) at 10 wt % αPVA addition, which increases by 1120% compared with that of the pure PI membrane. Meanwhile, the PI/αPVA composites membrane presents excellent thermal management performance for cooling the light-emitting diode (LED) lamp when it was used as a thermal interface material (TIM) in practice. In addition, the volume resistivity of the PI/αPVA composites membrane at 10 wt % αPVA content is about 2.88 × 1015 Ω cm, indicating that the composites membrane has excellent electrically insulating proprieties. At the same time, the composites show a thermal decomposition temperature of over 400 °C which can be used in high temperature environments. Thus, the proposed strategy is promising for the preparation of thermal management materials with high thermal conductivity, electrically insulating, and thermal resistance proprieties to meet the high heat dissipation demand of the new generation of electronic devices and even special high-temperature thermal management.