A coated composite was prepared on polyester-cotton plain weave fabric, using PU2540 polyurethane as the matrix. The influences of the content of nickel powders on the dielectric constant (the real and imaginary parts and loss tangent value), reflection loss and shielding effectiveness of single-layer coated composites were mainly investigated. The results showed that within the frequency range of 1–1000 MHz, the value of the real part of the dielectric constant of the coated composites was the largest, and the polarisation ability with regard to electromagnetic waves was the strongest when the content of nickel powders was 40%. Within the frequency range of 15–225 MHz, the value of the imaginary part of the dielectric constant of the coated composites was the largest and the loss ability with regard to electromagnetic waves was the strongest when the content of nickel powders was 40%. Within the frequency range of 250–800 MHz, the loss tangent value of the dielectric constant of coated composites was the largest, and the attenuation ability with regard to electromagnetic waves was the strongest when the content of nickel powders was 40%. Within the frequency range of 1220–3000 MHz, the reflection loss value was the smallest when the content of nickel powders was 40%, and its absorption ability with regard to electromagnetic waves was the strongest. Within the frequency range of 760–3000 MHz, the shielding effectiveness of the coated composite was the largest when the content of nickel powders was 40%.

In this paper, polypyrrole coated conductive fabrics were prepared using pyrrole as the monomer, p-toluene sulfonic acid as the doping agent and ammonium persulfate as the oxidant, adopting the simple method of situ polymerization of the liquid phase. Six types of conductive polypyrrole coated fabrics were prepared adopting polyester-cotton blended fabrics, nylon fabrics, wool fabrics, silk fabrics, basalt fabrics and aramid fabric respectively as base materials and using the same process conditions; its electrical conductivity was compared, and the distribution and resistance of the washing fastness of polypyrrole on the surface of those fabrics were studied. Results showed that under the same process conditions, the conductivity of polypyrrole coated terylene fabrics was the best, followed by the polypyrrole coated nylon fabrics and polypyrrole coated wool fabrics. Observed by electron microscope, the distribution of polypyrrole was more homogeneous on different base cloths. After washing, it was concluded that the combination fastness of polypyrrole with polyester-cotton, nylon and wool was better, while the combination fastness of polypyrrole with basalt and aramid was poor.