STUDY OF MECHANICAL PROPERTIES OF THE COMPOSITION BASED ON LOW-DENSITY POLYETHYLENE MODIFIED WITH CARBON NANOTUBES

The composition and concentration of carbon nanotubes leading to a significant improvement in the electro-physical properties of low-density polyethylene (LDPE) of 10803-020 grade have been experimentally determined. Modified multi-wall carbon nanotubes (MWCN) were used as modifying additives. The difference of developed LDPE nanocomposite was that for the first time a small amount of carbon nanotubes was introduced into the LDPE, which varied within the range of 0.01–0.1 % wt. It was found that the content of 0.05 % wt. of carbon nanotubes in the composition of low-density polyethylene (LDPE + 0.05 % wt. of NC) significantly increased its electric strength. The temperature dependences of dielectric loss tangent (tgσ), specific volumetric resistivity (ρV) and permittivity (ε), as well as the kinetics of physical and mechanical changes in them under the influence of electric discharges in the air and UV irradiation were studied. Specific volumetric resistivity significantly increases in the optimal LDPE nanocomposite and dielectric loss tangent is reduced, i.e. a good correlation is observed between these characteristics. It is shown that the addition of carbon nanotubes in an amount of 0.05 % wt. significantly increases its resistance to the effects of electric discharges and UV irradiation. Based on the experiments, it was concluded that the observed improvement in the dielectric properties of the LDPE film after the introduction of 0.05 % wt. of carbon nanotubes into its composition is associated with a change in the supramolecular structure of the LDPE.