氧化石墨烯/PBO多尺度增强体制备及其改性复合材料高温摩擦学性能研究

The mechanical and anti-wear properties of pure polyimide resin significantly decrease in high temperature ambient , which limits the application in aeronautic and space fields.Based on the physicochemical characteristics of Poly(p-phenylene benzobisoxazole) (PBO) fiber and Graphene Oxide(GO), The PBO/PI composites with remarkable properties of interface and high temperature tribology are prepared in this topic. Multi-scale structure of RE-GO-RE-PBO fiber is obtained by introducing GO on PBO fiber surface using rare earth (RE) modifier. The evolvement law of chemical composition and structure of RE-GO-RE-PBO fiber surface caused by the technical parameters of modification is discussed, and the optimum technological process of Multi-scale structure of fiber is acquired. Mechanical properties of composites under normal and high temperature are studied, and formation mechanism and evolvement law under high temperature of composite interface are analyzed. The effects of test parameters such as normal load and sliding velocity on the friction and wear behavior of composite in high temperature environment are studied, and the mechanism of friction and wear of composite in high temperature environment is ascertained. The action mechanism of interface characteristics due to compound modification of RE-GO to the high temperature tribological properties of composite is clarified. This research topic can develop a new technology of the surface modification of PBO fiber, providing an effective way to the failure problem of engineering machinery arise from large friction and wear in high temperature environment, enriching the interfacial science and tribological theory of composites.

在高温环境中，聚酰亚胺(PI)树脂的力学和抗磨损性能显著降低，限制了其在航空航天领域的应用。本课题基于聚对苯撑苯并双噁唑(PBO)纤维和氧化石墨烯(GO)的物理化学特性，制备具有优异界面性能和高温摩擦学性能的PBO/PI复合材料。采用稀土(RE)改性剂将GO引入PBO纤维表面，获得RE-GO-RE-PBO纤维多尺度结构。探讨改性工艺参数对RE-GO-RE-PBO纤维表面化学组成与结构的演变规律，获得纤维多尺度结构的最佳制备工艺方法；研究复合材料的常、高温力学性能，分析其界面形成机理及在高温环境下的演变规律；研究高温环境中法向载荷、滑动速度等试验参数与复合材料摩擦磨损行为之间的关系，探明其高温摩擦磨损机制；阐明RE-GO复合改性所形成的界面特征对材料高温摩擦学性能的作用机理。本研究有望发展PBO纤维表面改性新技术，解决高温环境PI摩擦磨损过大问题，并有助于丰富复合材料界面科学及其摩擦学理论。

针对高温条件下聚酰亚胺(PI)树脂的力学和抗磨损性能较差的问题，利用聚对苯撑苯并双噁唑(PBO)纤维和氧化石墨烯(GO)优异的物理化学特性，以稀土(RE)元素为“纽带”制备多尺度结构的RE-GO-RE-PBO纤维，对PI树脂进行复合增强以提高其常、高温力学和摩擦学性能。通过工艺参数优化和力学试验探讨了复合材料的界面形成机理，分析其界面结构特征与力学性能之间的关系。系统地研究了RE-GO-RE-PBO/PI复合材料常、高温条件下的摩擦磨损性能，探讨了法向载荷、滑动速度与复合材料摩擦学性能之间的关系，阐述了多尺度结构增强复合材料所形成的界面特征对其摩擦学性能的作用机理。本项目的完成为解决高温环境PI树脂摩擦磨损过大问题的研究提供了一条新途径，并有助于丰富复合材料界面科学及其摩擦学理论。