Microwave properties of composites based on thermoplastic polyurethane and activated carbon

Films of composite materials based on thermoplastic polyurethane (TPU) with birch activated carbon (TPU/BAC) were obtained with a filler concentration from 0.5 to 40% by mass. The morphology of BAC was studied by the SEM method. The films’ average thickness varied from 0.22 to 1.47 mm. The microwave studies indicate that the investigated TPU/BAC composites are generally transparent in the X-band. They have small transmission losses (less than 0.8 dB for 0.5-30 wt.% concentration and 1.1–1.5 dB for 40 wt.%) and reflection coefficient remained below −10 dB for all investigated in the whole frequency range.