【摘要】 针对深井、超深井、大位移井和水平井等复杂境况带来的高温、高摩阻环境，利用DFT模拟了油酸酰胺亲水链段中伯胺基、仲胺基、酰胺基和羟基等极性片段在铁（001）表面的吸附作用力，进一步探究油酸酰胺类润滑剂在铁表面的吸附润滑机理。结果表明，酰胺基、伯胺基、羟基在Fe(001)面上的桥位产生稳定吸附，仲胺基在Fe(001)面上顶位产生最稳定吸附，吸附能从大到小依次为伯胺基、仲胺基、羟基、酰胺基。布居数分析结果表明，4种极性基团在吸附过程中轨道布居数均发生变化，从Fe(001)面得到电子，其中仲胺基得到0.16e电子，伯胺基和酰胺基得到0.09e电子，羟基得到电子数最少，为0.08e。态密度分析结果表明，仲胺基和伯胺基中N原子的2p轨道与铁原子的3p、4s轨道间有态密度重叠，存在化学成键作用。在极压润滑测试和四球摩擦实验中，油酸二乙烯三胺的润滑系数降低率为83.6%，高于油酸二乙醇酰胺的78.2%；摩斑半径为287.184μm，小于油酸二乙醇酰胺的摩斑半径，表明含有胺基与酰胺基的润滑材料润滑性能优于含有羟基的表面活性剂。更多还原

【Abstract】 DFT simulation was used to investigate the bonding effects of different polar segments on iron(001) surface. These polar segments were intercepted from the hydrophilic chain segments of oleic acid amide lubricants, include primary amine, secondary amine, amide, and hydroxyl. Results indicated that amide group, primary amine group, and hydroxyl group generated the most stable adsorption at the bridge site of Fe(001) surface, and secondary amino group generated the most stable adsorption on the top site of Fe(001) surface. The adsorption energy in descending order were primary amine group, secondary amino group, hydroxyl group,and amide group. Results of population analysis indicated that the orbital population of four polar groups changed during the process and obtained electrons from Fe(001) surface. Among them, secondary amino group obtained 0.16e electrons, primary amino and amide group obtained 0.09e electrons, and hydroxyl group obtained the lowest number of electrons at 0.08e. Results of DOS analysis showed that there exist DOS overlap between 2p orbitals of N and 3p、4s orbitals of iron, with chemical bonding effect. In the extreme pressure lubrication test and four ball friction test results, the lubrication coefficient reduction rate of oleic acid Diethylenetriamine is 83.6%, higher than 78.2% of oleic acid diethanolamide, and the wear scar radius is 287.184 μ m. The wear radius is lower than that of oleic acid diethanolamide. The experimental results indicate that surfactants containing amine and amide groups have better lubrication performance than surfactants containing hydroxyl groups.更多还原