桥联环三磷嗪用作润滑油添加剂的摩擦学特性

合成了一种桥联环三磷嗪化合物,通过核磁共振磷谱（31P-NMR）和傅立叶变换红外光谱对其结构进行了表征.用Optimal SRV型摩擦磨损试验机考察了其作为季戊四醇酯（PET）添加剂对钢/钢的摩擦学性能.研究结果表明,作为高温润滑油添加剂,与四（3-三氟甲基苯氧基）-二（4-氟苯氧基）]环三磷嗪（X-1P）相比,合成的桥联环三磷嗪（L-2P）具有更为优良的摩擦学性能.通过对钢球的磨损表面进行扫描电子显微镜和X-射线光电子能谱仪分析,发现桥联环三磷嗪在摩擦中与摩擦副表面发生了复杂的摩擦化学作用,形成了含FeF2等物质组成的边界润滑膜.

Tribological Properties of Bridged Cyclotriphosphazene as Lubricating Oil Additive

The bridged cyclotriphosphazene(denoted L-2P) was synthesized.The chemical structure of L-2P was characterized by ~(31)P(-NMR) and FT-IR.The effect of tetrakis(3-trifluoromethylphenoxy)-bis(4-fluorophenoxy)-cyclotriphosphazene(X-1P) and a novel synthetic bridged cyclotriphosphazene as additives in pentaerythritol ester(PET) on the friction and wear behavior of a steel-on-steel system was investigated.The friction-reducing and antiwear behavior of PET containing L-2P to a steel-on-steel frictional pair was comparatively evaluated with that of PET containing X-1P to the same pair,using an Optimol SRV oscillating friction and wear tester in a ball-on-disc configuration.The action mechanism of the lubricants was explored based on the observation of the morphologies and elemental distributions of the worn steel surfaces with scanning electron microscopy equipped with energy dispersive spectroscopy attachment and the analysis of the chemical states of the worn surfaces by X-ray photoelectron spectroscopy.The results indicate that both additives are effective in improving the tribological performance of PET.In particular,L-2P as an additive in PET shows the best anti-wear ability and the highest load-carrying.Such a superiority of the L-2P in PET was more prominent at increased temperature and load.Tribochemical reaction was involved in the steel-against sliding lubricated with the bridged cyclotriphosphazene,with the generation of a surface-protective layer composed of inorganic fluoride FeF_2,which together with the adsorbed film of the additive contributed to improve the friction-reducing and antiwear behavior of the bridged cyclotriphosphazene as additive.