吸波型聚酰亚胺导热相变复合材料的制备及性能研究

The trend toward high-power, miniaturized electronic components has intensified challenges related to heat accumulation and electromagnetic wave pollution, creating an urgent demand for phase change composites that simultaneously offer high thermal conductivity and excellent wave-absorption properties. In this work, porous polyimide (PI) fibers were fabricated via blend electrospinning coupled with phase separation. Heterostructured BN@FeCo particles, serving as dual-functional fillers for thermal conduction and microwave absorption, were synthesized using an “electrostatic spray-high-temperature sintering” method. These particles were then uniformly deposited onto the porous PI fiber skeleton via electrostatic spraying, thereby establishing efficient thermally conductive pathways within the fiber network. Subsequently, the resulting BN@FeCo/PI framework was impregnated with paraffin wax (PW) to produce the BN@FeCo/PW/PI composites. Results demonstrated that the BN@FeCo/PW/PI composites with a BN@FeCo mass fraction of 55% and a thickness of 2.1 mm exhibited optimal wave absorption performance, achieving a minimum reflection loss (RL_min ) of −33.1 dB, alongside a thermal conductivity of 3.22 W/(m·K). This combination of effective electromagnetic wave attenuation and significant heat dissipation capability positions the composite as a promising solution for thermal management in advanced electronic systems.