MORPHOLOGY AND PROPERTIES OF COMPOSITES OF ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE AND FINELY-DIVIDED SILICON CARBIDE WITH NANOPARTICLES

摘要

The goal of the work is the investigation of the influence of finely-divided silicon carbide, synthesized in an electrothermal bubbling bed on the morphology and properties of polymer compositions based on ultrahigh molecular-weight polyethylene in obtaining block-type materials by the method of hot pressing and the coatings by the gas-flame spraying method. The methods of X-ray phase analysis, scanning electronic microscopy, X-ray microspectral analysis, as well as the standard methods of testing the physicomechanical, thermophysical, and tribotechnical properties of the resulting composites were used. The presence of SiC nanoparticles of size approximate to 50-70 nm distributed over the surfaces of synthesized SiC has been established by the electronic microscopy method. Nanoparticles are distributed on the surfaces of larger laminated and agglomerated structures of silicon carbide. In some places, threadlike formations from SiC nanoparticles with the aspect ratio approximate to 5-10 were observed. This is the advantage of application of synthesized SiC in polymer composites, since the manufacturing of products does not require special additional operations on distribution of SiC nanoparticles over the entire volume of composite material. It has been established that on obtaining block composites and coatings from dry mixture compositions one observes physical and chemical interaction of the composition components. Nanoparticles of finely-divided silicon carbide are built into supermolecular formations of the polymer which leads to its additional structuring and, with simultaneous formation of a physical grid of the introduced finely-divided filler, causes an increase in the wear resistance, heat resistance, thermal stability, thermal conductivity, and physicomechanical indices of composites and coatings and also decrease in the friction coefficient during operation in the conditions of dry friction.