Abstract:

Synthetic ester-based lubricants, owing to their excellent lubricating performance and biodegradability, align with the requirements of energy conservation and environmental protection, serving as a critical alternative to mineral oils. To adapt to practical operating conditions, the development of specialized lubricant additives for ester-based oils is essential. This work focused on molybdenum disulfide (MoS₂), a typical two-dimensional nanomaterial with remarkable lubrication properties. Through a novel strategy combining tannic acid-iron ion (TA-Fe³⁺) complexation followed by annealing, an oleylamine-modified carbon-coated MoS₂ composite (MoS₂@C) was fabricated. The carbon coating served as a protective barrier to prevent the inherent oxidation-induced degradation of MoS₂, while the long-chain alkyl groups of oleylamine (OAm) were grafted onto the MoS₂@C surface via chemisorption or coordination bonding. The resultant OAm-MoS₂@C additive demonstrated stable dispersion in the ester-based oil trimethylolpropane trioleate (TMPTO) over 30 days. The material's structure was characterized using multiple characterization techniques. Notably, with the addition of 0.3% OAm-MoS₂@C-300, the average friction coefficient and average wear scar diameter were reduced by 33.0% and 14.4%, respectively, compared to the base oil under a load of 392N. Furthermore, the maximum non-seizure load (P_B) and sintering load (P_D) were enhanced by 94.9% and 25%, respectively. Finally, the tribological surface was characterized using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, revealing a lubrication mechanism characterized by optimized film formation and synergistic lubrication effects. This approach showed promise for applications in cutting fluids, where it could effectively reduce friction and wear.

Key words: molybdenum disulfide, nanomaterials, composites, attrition, tribological properties, synthetic ester lubricants

摘要：

合成酯类润滑油因其良好润滑及降解性能，契合节能环保需求，已成为矿物油的重要替代方案。为适配实际工况，需开发专用酯类油润滑添加剂。本文针对二硫化钼（MoS₂）这一典型二维纳米润滑材料，通过单宁酸-铁离子（TA-Fe³⁺）络合作用包覆后退火制备MoS₂@C复合材料，通过碳包覆保护内部MoS₂抵抗其固有氧化失效问题，同时通过化学吸附或配位作用将油胺（OAm）的长链烷基枝接到MoS₂@C表面。所得OAm-MoS₂@C改性材料在酯类基础油三羟甲基丙烷油酸酯（TMPTO）中稳定分散30天。通过多种表征方法对材料结构进行了表征。添加0.3%（质量分数）OAm-MoS₂@C-300（300℃退火制备得到的MoS₂@C经OAm改性后命名为OAm-MoS₂@C-300）时，在392N载荷下TMPTO与基础油相比平均摩擦系数和平均磨斑直径分别减小了33.0%和14.4%，最大无卡咬负荷P_B及烧结负荷P_D分别提升了94.9%及25%。最后通过X射线光电子能谱（XPS）、拉曼光谱对摩擦表面进行了表征，其表现出优化成膜及协同润滑的润滑机理，未来可应用于切削油领域，有效减少摩擦磨损。

关键词: 二硫化钼, 纳米材料, 复合材料, 磨损, 摩擦学性能, 合成酯类润滑油