Effect of <scp> Fe ₃ O ₄ </scp> Particle Size on Microwave Absorption Performance of <scp>PPS</scp> / <scp>CB</scp> / <scp> Fe ₃ O ₄ </scp> / <scp>HGB</scp> Composites

ABSTRACT This study investigates the preparation and microwave‐absorbing properties of Polyphenylene Sulfide (PPS)/Carbon Black (CB)/Fe 3 O 4 /Hollow Glass Beads (HGB) composites. The composites were prepared by in situ polymerization and subsequent mixing with hollow glass microspheres (HGB) and Fe 3 O 4 filler of different particle sizes. The results show that the incorporation of Fe 3 O 4 filler does not significantly affect the crystalline structure of PPS but enhances the thermal stability of the composites. The dielectric and magnetic properties of the composites are significantly influenced by the particle size of Fe 3 O 4 . The composites containing 20 nm Fe 3 O 4 particles exhibit the highest dielectric loss factor and magnetic loss factor, indicating stronger capabilities for dielectric and magnetic energy loss. The impedance matching performance is also optimized with smaller Fe 3 O 4 particles. The absorption performance of the composites is evaluated in the X‐band and Ku‐band. The PPS/CB/Fe 3 O 4 (20)/HGB composite achieves the best absorption performance with a minimum reflection loss of −42.31 dB at 9.74 GHz and an effective absorption bandwidth of 2 GHz in the X‐band, and a maximum reflection loss of −27.8 dB at 15.21 GHz with a broad effective absorption bandwidth of 4 GHz in the Ku‐band. The enhanced absorption is attributed to the synergistic effects of impedance matching, dielectric loss, and magnetic loss. The study demonstrates that controlling the particle size of Fe 3 O 4 is crucial for tailoring the microwave‐absorbing properties of the composites, with smaller particle sizes (20 nm) offering superior absorption bandwidth and efficiency.