The thesis is devoted to creation of composites of tribotechnical appointment with the increased operational properties based on mechanically activated polytetrafluoroethylene and fillers of various chemical nature. An approach of preparation of a matrix and fillers of various chemical nature for obtaining PTFE-composites by the reasonable choice of a ratio of ingredients and technology of their modifying is offered. The optimum modes of process of mechanical activation of PTFE-matrix, fibrous and disperse fillers are set. Influence of technological parameters of process of mechanical activation on structure, physical and mechanical and tribotechnical properties of the PTFE-composite is studied. It is shown that under the influence of mechanical activation the ordered spherolitic supramolecular structure of matrix PTFE is formed which is characterized micro- and the nanoscale and leads to an increase in the thermal resistance of a modified polymer on (293-353) K. It is established that mechanical activation does not result in noticeable destruction of polytetrafluoroethylene molecular chain, but there are conformational changes which consist in an increase in concentration of the valent and finite CF2 groups that can lead to enhanced physical, mechanical and service properties of the polymer. It is revealed that the main factors that determine tribotechnical and physical and mechanical properties of PTFE are the time of activation and rotating speed of working organs of a mill. It is mathematically proved the practical experimental mode of mechanical activation at which operational characteristics of matrix PTFE are maximum (n = 9000 min.-1, t = 5 min.). In comparison with non-activated polymer the level of breaking strength has grown by 2,6 times, relative elongation - by 4,3 times, wear resistances - by 1,86 times. Different technological methods of increasing the adhesive interaction between the ingredients of PTFE-composites are investigated. The prospects of using mechanical activation not only of the matrix but also fillers of various chemical nature for improving of operational characteristics of composites are shown. The determining factor of increase in a complex of operational properties of mechanically activated PTFE-composites is forming spherolitic composite structure under the influence of active particles of disperse layered fillers which playing a role of germs of crystallization and formation on a surface of fibers and coke of the interfacial layer of PTFE which contributes to the emergence of a stable spatial cluster of a filler in volume of a matrix of composition and allows to reach the maximum reinforcing effect, thereby, raising strengthening characteristics of the material and its wear resistance. It is revealed that introduction of a binary filler increases wear resistance of the developed composites by (2,6-4,1) times in comparison with two-component composites. The greatest increase in wear resistance at preservation of high values of physical and mechanical properties of PTFE-composites is watched at synergetic effect of application of mechanical activation of a matrix, fillers, their mixing by two-stage mode and use of a binary filler of various chemical nature. The feature of the developed manufacturing technology of PTFE-composites consists in preliminary separate preparation of a matrix and fillers before their mixing by mechanical activation at various modes of the equipment therefore there is an increase in level of their breaking strength by 1,4 times and wear resistances by (3,7-6,0) times in comparison with industrial analogs that increases durability of work of frictional units of the compressor by (1,8-2,3) times. Piston rings and packing seals of piston-type compressors 4ГМ 2,5 У-3,4/2,8-251 are made of developed PTFE-material that successfully passed industrial tests at LLC "Scientific and innovative enterprise SumyPlastPolymer" and they are not worse than the industry samples. Technological process of PTFE-composite production is developed.
