Preparation and Tribological Properties of Self-Lubricating Epoxy Resins with Oil-Containing Nanocapsules

The design and development of self-lubricating materials aid in enhancing the tribological performance and prolonging the service life of aero self-lubricating spherical plain bearings. Herein, monodisperse hollow mesoporous carbon nanospheres (HMCNs) with thin shell thickness and uniform particle size were synthesized. Afterward, oil-containing nanocapsules (Oil@HMCNs) were obtained by the impregnation method, which was an innovative approach to prepare nanoscale capsules. The Oil@HMCNs were monodispersed, and the oil content rate could reach 45 wt %. The nanocapsules were applied as additives to achieve the self-lubricating properties of epoxy resin (EP). It was revealed that the coefficient of friction (COF) and the wear rate of EP in dry friction can be decreased from 0.56 to 0.084 and from 50.15 × 10^-6 to 0.27 × 10^-6 mm³/N/m, respectively. The tribological properties of EP composites in dry friction are better than those of EP with external oil. According to the analysis of friction pairs, the antifriction performance was contributed by the released automatic transmission fluid 6HP (ATF6) from nanocapsules. Meanwhile, the presence of ATF6 effectively could inhibit fatigue wear, and the decrease of compressive strength and surface hardness led to plastic deformation and mechanical polishing. Both resulted in a lower wear rate of EP. In conclusion, this work explored the application possibility of hollow mesoporous materials in lubrication. The prepared EP composites exhibited excellent tribological performances and self-lubricating properties, which were expected to be applied to self-lubricating spherical plain bearings and other mechanical parts.