离子液体功能化石墨烯的制备及其聚氨酯复合材料的摩擦学行为研究

针对目前聚合物基水润滑轴承复合材料在制备和使役过程中存在的固体润滑剂分散困难及界面相容性差、干摩擦和边界润滑条件下材料的摩擦系数高等问题。本项目拟利用离子液体与石墨烯之间的π-π和阳离子-π相互作用对石墨烯表面进行离子液体功能化修饰，在石墨烯表面引入N、F、P或B等摩擦活性元素，同时提高石墨烯与聚氨酯基体的相互作用，并通过对聚氨酯的分子结构设计和两步法合成工艺，制备高性能离子液体功能化石墨烯/聚氨酯复合材料。系统研究离子液体的种类、离子液体功能化石墨烯的用量及其与基体材料的界面相互作用等因素对复合材料摩擦学、力学和热性能的影响，重点研究复合材料在摩擦过程中的摩擦化学反应机理、转移膜的形成和作用机制，进而揭示离子液体与石墨烯的协同润滑机理。为高性能聚合物基水润滑轴承材料的设计及制备提供理论基础。

There are many problems in the process of preparation and life in the course of service of polymer based water lubricated bearings. For example, the solid lubricants dispersion difficulties, poor interface compatibility and high friction coefficient under dry friction and boundary lubrication conditions. To address these problems, this project intends to use ionic liquids to modify graphene by cation-π and π-π stacking interactions. The N, F, P, B or other active elements are intruduced on the surface of graphene. Then the high performance of ionic liquids-graphene (IGNs)/polyurethane (PU) composites were prepared by a two-step synthesis route. The influences of the species of ionic liquids, amount of IGNs and interfacial interactions on the tribological, mechanical and thermal properties of IGNs/PU composites were systematically studied. Additionally, the chemical reaction mechanism and formation mechanism of transfer film were investigated to reveal the synergistic lubricating mechanism of ionic liquids and graphene. A solid theoretical foundation for the design and preparation of high performance polymer-based water lubricated bearings were provided.