石墨烯/多孔聚酰亚胺自润滑保持架材料的制备及其性能

Preparation and Performances of Graphene/Porous Polyimide Self-Lubricating Cage Materials

为提高航天长寿命轴承用多孔聚酰亚胺(PPI)保持架材料的自润滑性能,采用机械混合和原位聚合的方式分别制备了石墨烯(GP)改性多孔聚酰亚胺材料,通过扫描电镜、压汞仪、万能拉伸试验机及摩擦试验机等设备对其微孔性能、力学性能以及摩擦学性能进行分析,结果表明:原位聚合能形成“蜂窝状”多孔结构,有利于制备低孔隙率和小孔径的多孔聚酰亚胺材料;石墨烯含量0.5%时,机械混合和原位聚合工艺所制得复合材料的拉伸强度均最高,较未改性PPI分别提高了13.0%和42.3%;石墨烯含量0.5%和1.0%时,原位聚合试样具有更优异的耐磨性,磨损量较未改性PPI分别降低了73.3%和47.8%。

In order to improve the self-lubricating performances of porous polyimide(PPI)cage materials for aerospace long-life bearings,the graphene(GP)modified PPI materials are prepared by mechanical mixing and in-situ polymerization,respectively.The microporous properties,mechanical properties and tribological properties of the materials are analyzed by scanning electron microscopy,mercury porosimeter,universal tensile tester and friction tester.The results show that in-situ polymerization can form a"honeycomb"porous structure,which is conducive to preparation of PPI materials with low porosity and small pore diameter;when the content of GP is 0.5%,the tensile strength of composites prepared by mechanical mixing and in-situ polymerization processes is the highest,which is 13.0%and 42.3%higher than that of unmodified PPI,respectively;when the content of GP is 0.5%and 1.0%,the in-situ polymerized samples have better wear resistance,and the wear amount is reduced by 73.3%and 47.8%compared with unmodified PPI,respectively.