PHYSICAL-MECHANICAL PROPERTIES OF NANOCOMPOSITES BASED ON GRAPHITE AND MODIFIED POLYOLEFINS

Abstract

The influence of the graphite concentration on the main physical-mechanical properties of nanocomposites based on such polyolefin as high density polyethylene, low density polyethylene and polypropylene is considered. Properties such as tensile yield stress, ultimate tensile stress, and ultimate bending strength, elongation at break, heat resistance, flexural strength, MFI, and melting points are analysed. To improve the compatibility of the mixed components of the mixture, we used an Exxelor PO1040 compatibilizer for all grades of polyethylene and Exxelor PO1020 for polypropylene. Graphite was introduced into the composition of polyolefin at the following concentrations: 1.0, 3.0, 5.0, 10, 15, 20, and 30 wt%. As a result of the research, it was found that the introduction of graphite into the composition of polyolefin was accompanied by an improvement in strength characteristics with maximum at various concentrations. For high density polyethylene, the maximum values of strength characteristics are observed at 3.0 wt%, for low density polyethylene at 10 wt%, and for polypropylene at 5.0 wt% content of graphite. It revealed that such a difference in the value of the threshold concentration of graphite which provides the maximum value of strength indicators,was directly related to the degree of crystallinity of the polymer matrix.