DIELECTRIC PROPERTIES OF EPOXY COMPOSITES WITH NANODISPERSED COPPER, CARBON MULTILAYER NANOTUBES AND COBALT WHEN MODIFYING THE ESHI BINDER

The paper presents the results of a study of molecular mobility in an epoxy binder containing nanofillers of various types: nanodispersed copper (Cu), cobalt (Co), and carbon multilayer nanotubes (CMLN) under modification by electric spark hydro-impact (ESHI). The research focuses on the dielectric characteristics of the formed composites, in particular on the dielectric loss tangent, which serves as an informative indicator of segmental mobility of polymer chains and the intensity of relaxation processes in the solid state. It has been established that the introduction of nanofillers into the epoxy matrix leads to a systematic shift of the temperature maximum of the dielectric loss tangent and to a change in the shape of relaxation peaks, which indicates a modification of the molecular mobility of macromolecular fragments and the formation of interphase layers with altered energy states. Comparative analysis of the influence of Cu, Co, and CMLN reveals different efficiencies in the formation of interfacial interactions, determining the nature of dipole relaxation, the degree of restriction of segmental motion, and the polarization behavior of the composite. Carbon multilayer nanotubes demonstrate the most pronounced effect on relaxation processes due to the formation of a branched conductive network and barrier layers, whereas metallic nanoparticles mainly influence local polarization mechanisms associated with surface defects and electronic polarization. The obtained results confirm that ESHI modification combined with nanofilling enables controlled tuning of dielectric and relaxation properties of epoxy systems. This creates prerequisites for the development of functional polymer composites with predetermined electrical, polarization, and operational characteristics for applications in electrical engineering, electronics, and protective coatings.