Effect of Fullerene Concentration on Tribological Characteristics of Polymethylmethacrylate Films during Finger–Disc Testing

Comparative physical, mechanical, and tribotechnical studies of the effect of various C60 fullerene contents in polymethylmethacrylate (PMMA) polymer films on sliding friction have been carried out during finger–disc testing. It is shown that an increase in the concentration of the fullerene modifier to 1% leads to a decrease in surface roughness at the nanoscale and the coefficient of friction of PMMA paired with aluminum alloy D16. As the concentration of C60 fullerenes in polymer films increases to 3%, they coagulate and form inhomogeneously distributed nano-concentrators with a diameter of about 150 nm. At the same time, the tribological properties of polymer films deteriorate. The coefficient of friction of PMMA paired with D16 aluminum alloy increases compared to the initial state. With an increase in the content of C60 fullerene in polymer films, their density and microhardness increase, and the burgundy color appears and unambiguously increases. When PMMA was rubbed in its initial state (without the addition of C60) in combination with aluminum alloy D16, adhesive processes were detected, and as a result, aluminum was transferred to the polymer film with an increase in the coefficient of friction. The studied films turned out to be heterogeneous in composition and properties, subject to warping, with insufficient dispersion of the material at the nanoscale.