Object of research: effects and physical phenomena that cause structural modification of polymeric materials under severe plastic deformation conditions. Aim of the work: establishment of the regularities of formation and evolution of structures at different scale levels of their organization (nano-, micro and macro-scale) in polymers of different structure (amorphous and semicrystalline) and composites of different architecture as a result of severe plastic deformation realized by simple shear deformation and high pressure, identification of the nature of the dependence of the properties of these materials on the structural state. Research methods and equipment: scanning and transmission electron microscopy, infrared and Raman spectroscopy, X-ray diffraction analysis, differential scanning calorimetry, dynamic mechanical analysis, mechanical and tribological tests, dilatometry, measurement of electrical resistance, water absorption, density. Theoretical and practical results: changes in the degree of homogeneity and fragmentation of elements of supramolecular structure, the nature of the orientation order and distribution of oriented fibrils in the preferred directions of orientation, volume fraction and degree of perfection of crystallites with variation of the scheme and parameters of severe plastic deformation (deformation intensity, deformation rate deformation, the method of accumulation of plastic deformation) have been determined. Regularities of influence of structure, molecular weight and morphology of initial polymers, presence, type and morphology of nano- and microfillers on the course of structural and phase transformations occurring in polymeric materials under the influence of severe plastic deformation have been established. A set of physical and functional properties of semicrystalline, amorphous polymers and composites formed under conditions of severe plastic deformation has been determined. Multifunctional materials have been created, which are characterized by a unique combination of repeatedly increased values of hardness, strength (with low anisotropy) and wear resistance while maintaining plasticity at the level of the original samples. Compared to the original one, the density, melting/glass transition temperatures increase, and an increase in elastic, strength, impact and plastic characteristics has been achieved simultaneously and independently of the load direction. In bulk samples of semicrystalline polymers and composites based on them, the biaxial "invar" effect has been realized, when in a wide range of temperatures the values of the coefficient of linear thermal expansion are observed both in cross and longitudinal sections, comparable to the values of the coefficient of linear thermal expansion of invar alloys. In the case of dispersed electrically conductive nanofillers (carbon nanoplates, nanotubes) the possibility of improving the electrical conductivity of composites without the appearance of its anisotropy has been shown. The possibility of forming special structures, such as gradient or hybrid, under the action of severe plastic deformation has been revealed. Novelty: for the first time, an important scientific problem has been solved to identify opportunities, general patterns and features of methods of severe plastic deformation in activating and controlling self-organization processes occurring at different levels (nano-, micro- and macroscale) of structural organization of polymeric materials of different structure and architecture. Scope (branch) of use: microfabrication, general, average and exact mechanical engineering.
