In this paper, the objects of study are heterogeneous cation-exchange materials Polykon, obtained on a fibrous system that has undergone preliminary preparation by low-temperature high-frequency argon plasma at power of 400 W for 10 min at a pressure of 5 × 10–5 mbar. As a fibrous system, a fabric made of novolac phenol-formaldehyde fibers—Kynol was used. The surface of the fibrous system before and after plasma treatment using scanning electron microscopy was studied. The hydrophilic/hydrophobic balance was examined on the surface of a fabric made of phenol-formaldehyde novolac fibers—Kynol (before and after treatment) and on heterogeneous cation-exchange materials Polykon, it was noted that on the treated FS and materials, a decrease in the rate of change in the work of wetting was observed. The paper presents the characteristic IR spectra of the samples under study, as well as a thermogravimetric analysis of heterogeneous cation-exchange materials Polykon (obtained on fibers before and after plasma treatment). The presented results indicate a significant effect of low-temperature ion-plasma treatment on the structure of novolac phenol-formaldehyde fibers and Polykon materials based on them.