石墨烯纳米片对多孔PI复合材料含油性能及摩擦学性能的影响∗

多孔聚酰亚胺(PI)应用广泛,但其摩擦磨损特性有待进一步提升。 采用石墨烯纳米片(GNS)为改性剂,制备多孔 PI 复合材料,系统研究 GNS 填充剂对多孔 PI 材料的冲击性能、含油性能和摩擦学性能的影响,探究 GNS、PI 和润滑油三者的协调润滑机制。 结果表明:添加一定量的 GNS 可以提高多孔 PI 材料的含油率和含油保持率。 加入 GNS 填料后,复合材料的孔径和孔隙率均有所增大,使复合材料对油液的吸附力更强,提高了其贮油能力。 复合材料的冲击强度随着 GNS 含量的变化为先升高后降低,少量的 GNS 分散在基体中,可以起到增韧的结果,而大量的 GNS 削弱了 PI 颗粒之间的结合性,且容易团聚导致界面结合性变差。 添加 0. 5% GNS 时,多孔 PI 复合材料表现出最佳的摩擦学性能,相比纯 PI,摩擦因数降低了 37. 2%,磨痕宽度减小了 26. 5%。 适量的 GNS 可以进一步提高材料的含油性能和摩擦性能。

Effect of Graphene Nanosheets on the Oil-bearing Properties and Tribological Properties of Porous PI Composites

Porous polyimide (PI) is widely used, but its friction and wear characteristics need to be further improved. Graphene nanosheets (GNS) were used as modifiers to prepare porous PI composites. The impact of GNS fillers on the impact performance, oil content and tribological properties of porous PI materials were studied, and the coordinated lubrication mechanism of GNS, PI and lubrications were explored. The results show that adding a certain amount of GNS can increase the oil content and oil retention rate of porous PI materials. After adding the GNS filler, the pore size and porosity of the composite material are increased, which makes the composite material have a stronger adsorption force for oil and improves its oil storage capacity. The impact strength of the composite material increases first and then decreases with the change of GNS content. A small amount of GNS is dispersed in the matrix, which can achieve toughening results, while a large amount of GNS weakens the bonding between PI particles. GNS is easy to agglomerate leads to poor interface bonding. When 0. 5% GNS is added, the porous PI composite exhibits the best tribological performance. Compared with pure PI, the friction factor is reduced by 37. 2%, and the wear scar width is reduced by 26. 5%. A proper amount of GNS can further improve the oil-containing properties and friction properties of the material.