氧化石墨烯接枝碳纤维及其树脂涂层在不同载荷下的摩擦学性能

Tribological Properties of Graphene Oxide Grafted Carbon Fiber and Its Resin Coating under Different Loads

目的提升碳纤维(CF)在水性聚酰胺酰亚胺(PAI)树脂涂层中的界面性能,从而使PAI复合涂层获得优异的摩擦学性能。方法以硅烷(KH550)为偶联剂,制备氧化石墨烯(GO)化学接枝CF增强体(CF&GO),研究CF接枝前后的热稳定性和添加CF&GO的PAI复合涂层在不同载荷下的摩擦学行为和磨损机理。利用红外光谱仪(FTIR)、X射线衍射仪(XRD)和扫描电子显微镜(SEM)对样品的官能团、成分和表面形貌进行表征;利用热失重仪(TGA)对接枝前后CF的热稳定进行表征;利用SEM、摩擦磨损试验机和白光干涉仪分别对CF&GO在PAI复合涂层中的分布和摩擦学性能进行表征。结果GO通过与硅烷改性后的CF形成酰胺键成功接枝,接枝后,CF形成多尺度增强体,且表面形貌粗糙。此外,接枝后,CF的热稳定性降低,热稳定性规律为GO<CF&GO<CF。添加CF&GO的PAI复合涂层在10、15、20 N载荷下的摩擦学性能呈现不同现象:载荷为10 N时,摩擦因数最高为0.212,磨损率最低为2.64×10^(6)μm^(3)/(N·m);载荷为20 N时,摩擦因数最低为0.168,磨损率最高为3.74×10^(6)μm^(3)/(N·m)。结论接枝后,纤维表面粗糙度和界面性能提升,热稳定性降低。随着载荷的增加,CF&GO增强PAI复合涂层的摩擦因数降低,磨损率升高。

To improve the interfacial properties of carbon fiber(CF)in the water-based polyamideimide(PAI)resin coating to obtain the PAI composite coating with excellent tribological properties.Silane(KH550)was used as the coupling agent to prepare graphene oxide(GO)chemically grafted CF reinforcement(CF&GO).The thermal stability before and after CF grafting and the tribological behavior and wear mechanism of PAI composite coating with CF&GO under different loads were studied.The infrared spectrometer(FTIR),X-ray diffractometer(XRD)and scanning electron microscope(SEM)was used to characterize the functional groups,composition and surface morphology of the sample;thermal weight loss instrument(TGA)was used to characterize the thermal stability of CF before and after grafting SEM,friction and wear tester and white light interferometer were used to characterize the distribution and tribological properties of CF&GO in the PAI composite coating.GO was successfully grafted by forming an amide bond with the silane-modified CF.After the grafting,the CF formed a multi-scale reinforcement and the surface morphology was rough;in addition,the thermal stability of the grafted CF was reduced,and the thermal stability law was GO<CF&GO<CF.The tribological properties of the PAI composite coating with CF&GO under the load of 10 N,15 N and 20 N showed different phenomena:when the load was 10 N,the friction factor was the highest 0.212,and the lowest wear rate was 2.64×10^(6)μm^(3)/(N·m);when the load was 20 N,the friction factor was the lowest 0.168,and the highest wear rate was 3.74×10^(6)μm^(3)/(N·m).After grafting,the fiber surface roughness and interface properties were improved,and the thermal stability was reduced.With the increase of the load,the CF&GO reinforced PAI composite coating indicated that the friction factor decreases under different loads,and the wear rate increases.