High tribology performance of Poly(vinylidene fluoride) composites based on three-dimensional mesoporous magnesium oxide nanosheets

Three-dimensional mesoporous MgO nanosheets (MgO_NS) were synthesized by a facile non-hydrothermal method for the improvement of the tribological properties of poly(vinylidene fluoride) (PVDF) composites. The interactions and structural properties of the MgO_NS composites were systematically compared with those of commercially available MgO beads (MgO_B). It was found that the incorporation of MgO_NS decreased the polar β phase of the PVDF crystallinity owing to an intimate contact and good interactions between the mesoporous MgO_NS filler and PVDF matrix. Recipro-mode tribology tester results for a long measurement time of 3 h showed that the friction coefficients of the PVDF composites decreased with the increasing filler content for both MgO_B and MgO_NS, indicating an important role of MgO as a self-lubricating material. In particular, the PVDF/MgO_NS 5.0% composite exhibited an outstanding initial friction coefficient of 0.091 and specific wear rate of 1.8 × 10⁻⁵ mm³/N m as compared with MgO_B, this performance being among the best for PVDF-based composites. The results indicated that mesoporous MgO_NS composites with their small crystal size, large surface area, good dispersion, and intimate contact with the PVDF matrix were more effective than randomly organized MgO_B.