PHYSICOMECHANICAL PROPERTIES OF COMPOSIT MATERIALS ON BASIS OF COPPER AND POLYOLEFINS

The paper presents the results of a study of the effect of copper concentration on the physicomechanical properties of composites based on high density polyethylene and low density polyethylene. The properties of metal-filled composites, such as ultimate tensile stress, elongation at break, elastic module, melt flow rate, and heat resistance, were studied. Loading of copper into the composition of low density polyethylene contributes to a monotonic increase in the ultimate tensile stress and the elastic module. When copper is loading into the composition of high density polyethylene, on the contrary, a natural decrease in the ultimate tensile stress and elongation at break of the composites is observed. It is shown that when using a compatibilizer, which is polyethylene modified with maleic anhydride, a significant increase in the ultimate tensile stress of high and low density polyethylene composites is observed. A schematic representation of the structure of composites with an interpretation of the probable mechanism of hardening of the material in the presence of a compatibilizer is given. It is shown that the crystallinity of the initial polyethylene has a significant effect on the hardening effect of composites. It is assumed that polyethylene of high density macrochains free of maleic anhydride are involved in the formation of crystalline formations, and small sections of macrosegments containing polar groups are concentrated mainly in amorphous regions and in defects in crystalline structures in the form of passage chains. The concentration of copolymer of polyethylene with maleic anhydride macrosegments in the narrow amorphous space of polyethylene of high density favorably affects the increase in the adhesive forces of interaction on the surface of copper particles, which affects the preservation of the ultimate tensile stress at a relatively high level over a wide range of copper concentrations.