Investigation of the Process of Structural Modification of UHMWPE With CuO Nanoparticles on the Frequency and Temperature Dependence of the Dielectric Characteristics of the Composite

Using vacuum-arc synthesis, ultrahigh molecular weight polyethylene (UHMWPE)/nano CuO composite samples with a CuO nanoparticle content of 0 to 3 wt% were obtained. It was found that with an increase in the concentration of nanoparticles, their agglomeration is possible. In addition, with an increase in the concentration of CuO nanoparticles and accordingly an increase in the time of the polymer modification process, some of the nonpolar groups >CH2 are converted into polar groups >C=O, which are easily embedded in the UHMWPE crystal lattice. The electrical properties of pure UHMWPE and UHMWPE/CuO composites were studied by impedance spectroscopy in the frequency range from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{2}}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{8}}$ </tex-math></inline-formula> Hz and temperatures from 300 to 420 K. It was found that the dielectric properties of the composite with a CuO nanoparticle content of up to 1 wt% do not undergo any special changes. The permittivity does not depend on frequency, while the dielectric losses are associated only with through conductivity. With increasing temperature, due to thermal expansion of the polymer and a decrease in its density, the permittivity decreases. With an increase in the nanoparticle content from 2 to 3 wt% at a frequency of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{6}}$ </tex-math></inline-formula> Hz, dielectric relaxation in UHMWPE/nano CuO associated with the formation of polar groups is observed. With increasing temperature, dipole polarization is activated. As a result, dielectric losses increase.