Polyurethane Foams Decorated with Carbon Nanotubes Applied in Microwave Absorption

Well-designed mono-layered and multi-layered polyurethane/carbon nanotubes (PU/CNTs) foams with excellent microwave absorption property were prepared by simple ball-milling and impregnation method. The formation of PU/CNTs was studied using scanning electron microscopy (SEM) and Energy dispersive spectrometer (EDS). The microwave absorption property of the PU/CNTs foams was investigated. The results show that the mono-layered PU/CNTs foams exhibit excellent microwave absorption performance with strong absorption (reflection loss is -43.5 dB at 13.8 GHz), thickness (10 mm) and broad bandwidth (effective absorption bandwidth is 10.5 GHz). For multi-layered PU/CNTs foams, the reflection loss can reach - 54.1 dB at 15.1 GHz, with a broad band absorption from 2 GHz to 40 GHz, in 30 mm thickness. The fabricated PU/CNTs foams can be used as commercial broad band microwave absorbing materials for antenna measurements, telecom and electromagnetic compatibility.