不同分子结构聚酰亚胺固-液复合摩擦学行为与润滑机理研究

设计合成了一种新型热固性聚酰亚胺(TPI)材料，利用DMA242C型动态热机械分析仪、万能试验机以及接触角测量仪等对其机械性能、热学性能以及表面基础油PAO10的润湿性能进行表征，并与商业化的热塑性聚酰亚胺YS-20作对比，考察了两种不同分子结构的聚酰亚胺(PI)在PAO10润滑下的摩擦学行为. 球-盘摩擦试验结果表明，无论是在模拟的多次“启-停”往复运动，还是模拟一次“启-停”的旋转接触运动，TPI与PAO10的固-液复合体系均具有优异的抗磨减摩性能，主要归因于TPI与PAO10之间较好的润湿性与物理吸附作用. 通过分子动力学模拟的方法，进一步验证了空间化学交联TPI的空间化学交联结构增强了其表面与PAO10之间的物理吸附作用，有助于提高边界膜的构筑速度与承载能力，进而改善了两者复合体系的摩擦学行为.

A novel thermosetting polyimide (TPI) material was designed and synthesized. Its mechanical properties, thermal properties, and wettability with the base oil PAO10 on its surface were characterized using a DMA242C dynamic thermomechanical analyzer, universal testing machine, and contact angle measuring instrument, among other instruments, and compared with the commercial thermoplastic polyimide YS-20. The tribological behaviors of two polyimides (PI) with distinct molecular structures under PAO10 lubrication were investigated. The results of ball-on-disk friction tests demonstrate that the solid-liquid composite system of TPI and PAO10 exhibits excellent anti-wear and friction-reducing performance across both simulated multiple "start-stop" reciprocating motions and simulated single "start-stop" rotational contact motions. This performance is primarily attributed to the favorable wettability and physical adsorption between TPI and PAO10. Through molecular dynamics simulations, it was further validated that the spatially chemically cross-linked structure of TPI strengthens the physical adsorption between its surface and PAO10, which helps improve the formation rate and load-bearing capacity of the boundary film, thereby enhancing the tribological behaviors of the TPI-PAO10 composite system.