Three-dimensional thermal network structured GnPs&MWCNTs@PBO/PEEK composites integrating high thermal conductivity and electromagnetic shielding

Abstract

This study presents dual-functional carbon-based poly(ether ether ketone) (PEEK) composites with enhanced thermal conductivity and electromagnetic interference shielding performance. A high-performance poly(p-phenylene benzobisoxazole) (PBO) polymer has been integrated within the composite to improve the thermal diffusion network. The composites comprising graphite nanosheets (GnPs) and multi-walled carbon nanotubes (MWCNTs)@PBO/PEEK exhibit outstanding in-plane thermal conductivity (TC) of 22.17 W m⁻¹ K⁻¹ at a filler loading of 19.31 vol%, representing a significant increase of 9540% and 1146% compared to pure PEEK and PBO@PEEK. Furthermore, the composites demonstrated exceptionally high electromagnetic interference shielding effectiveness (EMI SE) of 128.4 dB, with a total shielding efficiency of 99.99999999993%, which meets the aerospace shielding standard. The significant enhancement in TC and EMI is attributed to the π–π conjugation effect between carbon-based fillers and the main chains of PBO. According to the Agari and Foygel models, the addition of PBO establishes a robust and thermally conductive network, effectively reducing the heat flow barrier and facilitating the current tunneling effect. This study presents a straightforward and viable approach for developing thermally conductive and electromagnetic shielding bifunctional polymeric thermal management materials.