A deformable honeycomb sandwich composite felt with excellent microwave absorption performance at a low absorbent loading content

In this work, a novel deformable honeycomb sandwich composite felt (DCF) was fabricated through dipping method that using polyester felt (PET-F) as matrix, water-borne epoxy resin mixed with self-made microwave absorbent as microwave absorbing coating. The DCF with honeycomb-like sandwich structure possesses enhanced mechanical properties and excellent microwave absorption (MA) performance. In addition, the components of coating also endow DCF with shape memory behavior which makes it more suitable for various scenarios. The minimum reflection loss of the DCF with the optimal comprehensive performance can reach −55.90 dB with the thickness of only 1.4 mm and the effective absorption bandwidth is 4.87 GHz. The excellent MA performance of DCF is attributed to the well impedance matching and strong loss characteristics, which is closely related to moderate conductive network, multiple loss mechanism and special structural. This work may have reference significance for the practical application of MA materials.