Synthesis and electromagnetic absorbing performances of CNTs/PMMA laminated nanocomposite foams in X-band

The carbon nanotubes (CNTs)/PMMA nanocomposite foam with laminated configuration was synthesized by the combination of melt hot pressing and physical constraint SCCO2 foaming method without any tackiness agent. The structure and thickness of the laminated nanocomposite foam was well controlled. Then the electromagnetic absorbing performances of the laminated foam were investigated. The results show that the electromagnetic absorbing properties are improved by the laminated structure of the nanocomposite foams. The absorbing bandwidth of the laminated foam is 3.5 GHz (8.9-12.4 GHz), which is 0.8 GHz wider than that of the single layer nanocomposite foam with the thickness of 2 mm. The reflection loss of the laminated nanocomposite foam is lower relative to that of the single layer foam in a wide frequency range. This is mainly due to the laminated structure, which reduces the microwave reflectivity in the top layer, while improve the microwave loss in the bottom layer simultaneously.