It is known that carbon nanomaterials have unique properties, which are determined by their surface chemistry and developed porous structure. They are widely used as fillers of composite materials, microporous adsorbents, catalyst carriers of organic synthesis processes, and are also excellent absorbers of electromagnetic radiation. In particular, they can be used as a material for stealth technologies in the production of protective coatings for the military. The development of methods for purposeful modification of the surface of carbon materials is relevant, which makes it possible to create special protective materials for shielding.

Different types of oxygen-containing groups are present on the activated carbon (AC) surface: carboxylic, lactonic, anhydride and phenolic, which can interact with functional groups of polymer matrices when creating composite materials, which is important for creating new classes of substances with predetermined properties. TGA, TPDIR and TPDMS methods were used, in particular, to determine the concentration and study the thermal stability of oxygen-containing functional groups of AC. The morphology of AC was studied by the SEM method. A series of samples in the form of films was obtained by the method of thermal pressing of polyvinyl chloride (PVC) powders and activated carbon in different mass ratios.

When studying the microwave properties of the obtained films of PVC/AC composite materials, it was found that with an increase in the percentage mass of AC, the reflection coefficient of electromagnetic waves from the sample increases, and it appears that this change occurs according to a linear law. Concentrations of AC up to 5% make changes in the reflection coefficient of the order of 10%, concentration of AC greater than 20% increases the reflection coefficient by 3 times. This trend is also visible from the results for the standing wave coefficient at AC concentrations greater than 20% (VSWR>∞).