Kaolin‐Reinforced Carbon Black/Glass Fiber/Polyamide 6 Composites With Enhanced Microwave Absorption and Mechanical Properties

ABSTRACT Structural engineering is an effective strategy for preparing high performance microwave absorbing composites. Herein, carbon black/kaolin/glass fiber/polyamide 6 (CB/K/GF/PA6) composites were fabricated by using the layered structure of kaolin. A core‐shell‐like structure was created by CB nanoparticles and kaolin microparticles, which improved the conductive loss and polarization loss of the composites. Based on the heterogeneous atoms in the kaolin lattice and the adsorbed metal cations, by utilizing the capacitor mechanism, under the action of the alternating electric field of electromagnetic waves, the micro‐capacitors constructed with CB and kaolin achieve constant charging and discharging, thereby improving the polarization loss and impedance matching of the composite and enhancing microwave absorption. Benefitting from the above advantages, the composites exhibit efficient microwave attenuation with an optimal reflection loss of −59.78 dB at a thickness of 2.5 mm. In addition, the composites exhibited excellent mechanical properties by virtue of the synergistic effect of kaolin particles and GF reinforcement, whose flexural strength was enhanced to 244.5 MPa and the pendulum impact strength was 85.4 kJ/m 2 . This work suggests that layered kaolin containing heteroatoms can effectively improve microwave absorption performances of CB/GF/PA6 composite.