Molecular models and sandwiched friction models of pure PTFE and h-BN/ PTFE composite were respectively constructed to investigate the enhancement of mechanical and tribological performances of the polytetrafluoroethylene (PTFE) matrix by incorporating the hexagonal boron nitride (h-BN) nanosheets as reinforcements. The simulation results indicate that increases of 36.4% in the Young's modulus, 23.6% in the bulk modulus, and 37.3% in the shear modulus of the PTFE matrix are achieved respectively by the incorporation of h-BN nanosheets. Decreases of 3.48% and 10.27% in the Poisson's ratio and the ratio of bulk modulus to shear modulus of the PTFE matrix are also observed due to the incorporation of h-BN nanosheets, which shows that the ductility of the PTFE matrix could be somewhat decreased with the addition of h-BN nanosheets. Additionally, decreases of 69.23% and 69.06% in the coefficient of friction and friction stress of the PTFE matrix are obtained respectively with the introduction of h-BN nanosheets. To provide in-depth insight into the internal reason for these findings, the interaction energy between the PTFE matrix and h-BN nanosheets, the MSD and diffusion coefficient of PTFE chains, and the RDF of carbon and fluorine atoms in the PTFE backbone chains were evaluated and interpreted accordingly.

To comparatively investigate the mechanical, tribological, and interfacial properties of polytetrafluoroethylene (PTFE) strengthened by graphene (Gr) and hexagonal boron nitride (h‐BN) nanosheets, molecular models of PTFE nanocomposites containing a similar weight fraction of Gr and h‐BN nanosheets were established. The constant‐strain approach, the three‐layer friction structures, and the pull‐out simulations were respectively employed to calculate the mechanical, tribological, and interfacial properties of the nanocomposites. Results indicate that the Young's, shear, and bulk moduli of the nanocomposites are increased by 17.22%, 20.72%, and 4.78%, respectively, by introducing h‐BN nanosheets than those by introducing Gr nanosheets. Meanwhile, a decrease of 8.49% in the friction coefficient of the nanocomposites is obtained by incorporating h‐BN nanosheets than that by incorporating Gr nanosheets. In addition, 84.71% and 5.18 times higher in the interfacial cohesive strength and interfacial shear strength, and 91.58% and 128.7% higher in the interfacial fracture toughness of PTFE nanocomposites in the normal separation and shear separation, respectively, are achieved by incorporating h‐BN nanosheets than those by incorporating Gr nanosheets. To provide a deeper understanding of the enhancement mechanisms of h‐BN nanosheets, the interfacial interaction energies, radial distribution functions, and von Mises stress distributions of the two PTFE nanocomposites were evaluated and interpreted accordingly.