Preparation and absorption performance of CNTs/PUR honeycomb composite absorbing material

Abstract In this paper, a carbon nanotubes/polyurethane resin (CNTs/PUR) honeycomb composite absorbing material was prepared, and the influence of the content of carbon nanotubes on the absorbing performance of single-layer and double-layer honeycomb composite absorbing materials was investigated. The mechanical properties of single-layer and double-layer materials are discussed. The honeycomb core and carbon nanotubes are compounded together by the impregnation method to form a CNTs/PUR honeycomb composite absorbing material. The microstructure shows that the carbon nanotubes are uniformly dispersed in the water-based polyurethane resin, and the impregnated layer and the honeycomb wall are well combined. The reflectivity of the material shows that as the content of carbon nanotubes increases, the absorption performance of the material first increases and then decreases; when the content of carbon nanotubes is 5.6%, the single-layer honeycomb composite absorbing material has the best absorption performance. The effective absorption bandwidth is 10.6 GHz (2~18GHz), and the maximum absorption strength is -24.5 dB; when the combination mode is 2-4, the double-layer honeycomb composite absorbing material has good absorption performance, and the maximum absorbing strength is -32.2dB, the bandwidth is 13.7GHz (2~18GHz).