The object of the research is the intermolecular interaction between a binder and a fibrous filler, which has a great influence on the tribotechnical and strength characteristics of products made of polymer composite materials. Given the above, the determination of the physical interaction between the components is an important task when creating new composite materials.The work examined the emergence of polyoxydiazole (Oxalon) and polysulfonamide (Tanlon T700) fibers on the structure of aromatic polyamide phenylone grade S-1 using X-ray diffraction analysis. An analysis of the studies shows that the introduction of the Oxalon chemical fiber leads to the ordering of the supramolecular structure of the binder: the interplanar and short interatomic distances decrease by 18 and 25 %, while the average crystallite size increases by 50 %.For organoplastics, a decrease in the width of the diffuse maximum of the polymer matrix in the region of scattering angles of 20-30° and a disappearance of the second amorphous halo in the region of angles of 40-60° are proportional to an increase in the fiber concentration in the polymer matrix. The reason for the observed phenomenon is obviously the short-range structuring of the polymer chains of the binder around the fiber, as a result of which new structural elements are formed - fibrils in the boundary layer and at the «matrix-filler» interface. When reinforcing the initial polymer with the Tanlon T700 polysulfonamide fiber, there is a slight decrease in interplanar and short interatomic distances (by 5 %) with an increase in the average crystallite size by 13 % compared to the initial polymer. The results are due to the fact that phenylone and filler have similar structural characteristics, and as a result, it can be concluded that an amorphous structure is inherent in the polysulfonamide fiber.Based on the obtained data, it is found that the best performance properties will be characterized by organoplastics reinforced with Oxalon fiber. These results are consistent with previous studies of tribological characteristics. This allows to recommend this composite for the manufacture of parts of friction units of machines and equipment mechanisms of modern technology instead of non-ferrous metals and their alloys due to the relatively high technical characteristics.