Flexible and lightweight PPyNT/EPDM foam for efficient electromagnetic waves absorption in X-band

Flexible and lightweight polypyrrole nanotubes/ethylene propylene diene monomer (PPyNT/EPDM) rubber foams with excellent electromagnetic waves (EMW) absorption performance in the X-band were prepared via a simple chemical foaming method. By adjusting the content of PPyNT, the cellular structure, density, and EMW absorption properties of the PPyNT/EPDM foams can be precisely tailored. The synergistic effect of the cellular structure and an optimal PPyNT content (15 phr) endows the PPyNT/EPDM foam with an excellent impedance matching and a high attenuation capacity, in turn resulting in excellent EMW absorption performance in the X-band, demonstrated by the minimum reflection loss (RL min ) of −27.01 dB at a thickness of 2.3 mm and the maximum effective absorption bandwidth (EAB) of 3.4 GHz at a thickness of 2.6 mm. Furthermore, this foam composite exhibits excellent lightweight characteristics with a density of only 0.795 g/cm 3 . Hence, this research presents a promising approach for the commercial development of flexible, lightweight, cost-effective, and highly efficient EMW absorption materials. Highlights Lightweight PPyNT/EPDM foam for X-band EMW absorption. Tailored porous structure and absorption performance by PPyNT content. Foam with 15 phr PPyNT achieves RL min of −27.01 dB and EAB of 3.4 GHz. Synergy of impedance matching, conduction loss, and multiple reflection.