The use of unfilled pure elastomer parts is limited in friction wheels, roller tires, sealing elements, and dynamic friction air suspension applications requiring high wear resistance. This study investigates the mechanical and tribological properties of new nanocomposites obtained by adding hydroxyl-functionalized graphene nanoplatelets at 1, 4, and 8 phr (parts per hundred rubber) ratios to the carbon black filled main rubber compound of sealing elements designed for axle hubs. The synergistic effect of nanofiller materials on the wear behavior of nanocomposites was tested with a block-on-ring wear tester under dry sliding conditions at 1000 rpm and 15 N normal load conditions. The worn surfaces were examined with scanning electron microscopy and circularly polarized light–differential interference contrast topology microscopy to reveal the wear mechanism. The addition of functionalized graphene nanoplatelets to the nanocomposite compound caused significant changes in tensile strength and elongation values by changing the cross-link density. The wear rate of nanocomposites prepared with graphene nanoplatelets at 1, 4, and 8 phr ratios was 11.15%, 25.24%, and 36.54% lower than the main rubber mixture used, respectively. While the hysteresis loss decreased by 14.83% at 1 phr, this value increased in other filler ratios. Significant differences in temperature change occurred as the amount of filler increased. After the test, the temperature values of nanocomposites with 1 and 4 phr filler ratios were between about 85–89°C, while it was measured as 99°C in nanocomposites with 8 phr filler ratios. It has been observed that the homogeneous distribution of two-dimensional carbon allotropes such as graphene nanoplatelet added to the rubber matrix at the optimum rate will improve tribological properties such as better surface lubrication, low wear rate, and low friction coefficient.

This study investigated the crack propagation behavior of the graphene-reinforced synthetic rubber matrix nanocomposite materials. Graphene-filled rubber conductive nanocomposites developed within the scope of this study were obtained in two stages using mechanical mixers. The relationship between crack propagation and electrical resistance change was investigated using single-edge notched specimens in a tensile tester. Digital image correlation (DIC) technique was used to observe the crack resistance function depending on the local strain distribution. The results from the tests were evaluated to define the relationship between the crack length, the amount of conductive filler, and the change in electrical resistance. The sharp edges of the graphene nanoplatelets negatively affected the fracture resistance of the samples. In addition, it was observed that even at low strain values, gaps were formed in the areas close to the crack tip. The three-dimensional transmission network formed by graphene nanoplatelets dispersed in the matrix improved the electrical conductivity properties of the nanocomposites, so the relationship between crack propagation and electrical resistance change was determined.