AbstractFilms of carbon-polymer nanocomposite polyacrylonitrile/single-wall carbon nanotubes (PAN/SWCNTs) with various filler concentrations varying from 0.5 to 30 wt % are synthesized. It is found that use of fillers as the SWCNTs in a polymer composite based on PAN significantly influences the mechanical properties of the polymer; in particular the tensile strength increases. Studying the electrophysical properties shows that the electric conductivity increases by two orders of magnitude due to the degree of percolation and by 7 orders of magnitude in comparison with pure PAN, on introducing SWCNT fillers ranging from 0.5 to 30 wt %. Thermal analyses of the nanocomposite are carried out and they show that the thermal stability of the samples increases and the weight losses decrease at an increase of the SWCNT concentration. The dielectric capacitivity and the coefficients of reflection, transfer, and absorption in the terahertz range are measured. It is found that the coefficient of reflection nonlinearly depends on the concentration of carbon nanotubes (CNTs). The minimum reflection coefficient of 0.55 per unit values is observed at the concentration of 0.5 wt %, whereas materials with an SWCNT concentration of more than 5 wt % show almost the same reflection coefficient at s sufficiently low transfer coefficient.