Robust polyamide 66 composites with hybrid fillers for thermal management and electromagnetic shielding

Abstract Carbon materials have been widely used in multifunctional composites with their high electrical and thermal conductivities. However, most current research focuses on nanocarbon materials such as graphene and carbon nanotubes, ignoring their high cost, inability to mass‐produce, and poor dispersion in polymers. To address these issues, we propose one‐step melt‐blending of commercial carbon materials to construct conductive pathways in polymer matrix. Thus, low‐cost and robust polymer composites can be fabricated in a green and scalable way to achieve efficient thermal management and avoid electromagnetic radiation pollution. Here, a continuous network of carbon materials with orientation‐aligned carbon fibers and well‐dispersed mesocarbon microbeads (MCMBs) induced by melt blending is shown to be an ideal structure for thermally conductive (1.77 W m −1 K −1 ) electromagnetic shielding (46.9 dB) composites. In addition, the excellent mechanical properties (tensile strength 162.7 MPa and flexural strength 250 MPa) and absorption property (39.4 dB) exhibited by the composites under the optimized filler ratio also really broaden the way for the preparation of high‐strength wave absorbing materials by melt blending. This work provides a general strategy for large‐scale production of thermally conductive electromagnetic shielding composites and opens up possibilities for the application of MCMBs in high‐power electronic devices.