目的 探究在全膜润滑状态下，矿物油中不同官能团极性的有机摩擦改进剂分子原位吸附对球-盘点接触润滑状态的影响。方法 利用球-盘油膜润滑试验机对500SN和分别含有质量分数为4%油醇、4%油酸酰胺和4%油酸的500SN(分别标记为500SNOH、500SNCONH2和500SNCOOH)进行油膜厚度和摩擦因数的测量，通过接触角测量仪(CA)、傅里叶红外光谱仪(FTIR)和原子力显微镜(AFM)对吸附在钢球表面上的有机摩擦改进剂进行表征。结果 在相同试验工况下，500SNOH、500SNCONH2和500SNCOOH的中心膜厚和摩擦因数均低于500SN，并且降幅随着有机摩擦改进剂分子官能团极性的增强而增加。其中，在卷吸速度为32 mm/s、滑滚比为0.05的工况下，500SNOH、500SNCONH2和500SNCOOH的中心油膜厚度与500SN相比分别下降了15.32%、22.58%和26.61%;在滑滚比为0.05的工况下，500SNOH、500SNCONH2和500SNCOOH在卷吸速度为1~512 mm/s范围内的平均摩擦因数降幅最高，与500SN相比分别下降了6.07%、15.79%和24.57%。结论 验证了不同官能团的有机摩擦改进剂分子均能够在钢球表面通过原位吸附形成疏油边界膜，从而降低了润滑剂对钢球表面的润湿性。同时也验证了有机摩擦改进剂分子官能团极性越强，疏油边界膜的润湿性越差。

The work aims to investigate the effect of in-situ adsorption of organic friction modifier molecules with various functional group polarities on elastohydrodynamic lubrication (EHL). Mineral oil 500SN and 500SN with 3 organic friction modifiers, i.e. 4% oleyl alcohol, 4% oleamide and 4% oleic acid (labeled respectively 500SNOH, 500SNCONH2 and 500SNCOOH) were used as the lubricants. With an optical ball-on-disk test machine, the oil film thickness and the friction coefficient of 500SN, 500SNOH, 500SNCONH2 and 500SNCOOH were measured at various slide-roll ratios and entrainment speeds. The organic friction modifiers adsorbed on the surface of steel balls were characterized by contact angle (CA) measuring instrument, Fourier transform infrared spectrometer (FTIR) and atomic force microscope (AFM), and the relationship between the strength of adsorption of organic friction modifier molecules and the functional group polarity was determined. Under the same working conditions, the central film thickness and the friction coefficient of 500SNOH, 500SNCONH2 and 500SNCOOH were all lower than those of 500SN, and the greater the polarity of the functional group of the organic friction modifier the lower the film thickness and the friction coefficient. The oleic acid molecule in 500SNCOOH had the greatest polarity and the strongest adsorption capacity, resulting in the lowest film thickness and friction coefficient, while the oleyl alcohol molecule had the weakest adsorption, presenting the lowest film thickness and friction coefficient of 500SNOH among the lubricants with organic friction modifiers. Under the conditions of low slide-roll ratios, the friction coefficients of 500SN, 500SNOH, 500SNCONH2 and 500SNCOOH all showed a trend of first decreasing and then increasing with the increase of entrainment speed. At the slip-roll ratio of 0.05, the average friction coefficients of 500SNOH, 500SNCONH2 and 500SNCOOH presented decrease by 6.07%, 15.79% and 24.57%, respectively, in the range of 1-512 mm/s, compared with 500SN. Under the condition of large slip-roll ratio, the friction coefficients of 500SN, 500SNOH, 500SNCONH2 and 500SNCOOH all decreased first, then increased and decreased with the increase of entrainment speed. Under the condition of low entrainment speed, due to shear thinning and some heat generation, the central oil film thickness of 500SN, 500SNOH, 500SNCONH2 and 500SNCOOH decreased with the increase in the slip-roll ratio. At the entrainment speed of 32 mm/s and slip-roll ratio of 0.05, the central oil film thickness of 500SNOH, 500SNCONH2 and 500SNCOOH decreased by 15.32%, 22.58% and 26.61%, respectively, compared with 500SN. When increased entrainment speed was used, with the increasing slide-roll ratio, more heat was generated and the temperature-viscosity wedge was induced, where the central oil film thickness of 500SN, 500SNOH, 500SNCONH2 and 500SNCOOH could not decrease, which was contrary to those at the entrainment speed of 32 mm/s. The measurement results of contact angle, Fourier infrared spectrometer and atomic force microscope show that the organic friction modifiers with different functional groups can form an oleophobic boundary film on the surface of the steel ball by in-situ adsorption, thus reducing the wettability of the lubricant on the surface of the steel ball. It is also verified that the stronger the polarity of the organic friction modifier molecular functional group, the stronger the adsorption capacity of the organic friction modifier molecule and the poorer the wettability of the formed oleophobic boundary film.