一种PN型极压润滑添加剂的性能研究

采用四球摩擦磨损试验机考察一种PN型添加剂在矿物油(MVI150)、聚α烯烃(PAO4)、合成酯(1936)以及聚醚(SDM-03C)中的极压性能,研究添加剂质量分数对油品极压性能的影响。结果表明,矿物油、PAO及合成酯中加入质量分数为3.0%的PN型添加剂时烧结负荷均超过8 000 N,MVI150和PAO4中加入质量分数为0.25%PN型添加剂时最大无卡咬负荷可分别提高至1 140 N和1 710 N,表明该PN型添加剂具有优异的极压性能。采用X射线光电子能谱仪对钢球磨痕表面的元素化学状态进行表征,并对其润滑机制进行分析。结果表明,PN型添加剂具有优异的极压性能主要是由于分子中大量的P元素及N元素在摩擦过程中与金属表面发生了摩擦化学反应,从而形成了具有良好抗承载性能的润滑膜。     

极压抗磨剂对复合锂钙基润滑脂性能及结构的影响

通过复合锂钙基润滑脂在加入极压抗磨添加剂前后的性能及结构变化,研究了极压抗磨剂对润滑脂的影响。结果表明:在标准实验条件下,极压抗磨剂磷酸三甲酚酯(T306)、二烷基二硫代磷酸锌(T202)、二丁基二硫代氨基甲酸钼(T351)、硫化异丁烯(T321)、硼酸钠(T361)等组合可大幅提高润滑脂的极压抗磨性能,对结构及其它性能无明显影响;在加水10%剪切10万次条件下,含上述极压抗磨剂组合的润滑脂的结构及性能变化比较明显,其复合结构被破坏,滴点大幅下降,含T361的脂极压性下降最多;经过高温后(180℃,24 h)含上述极压抗磨剂组合的润滑脂,能保持或提高原有的极压抗磨性,润滑脂的复合结构没有明显改变,润滑脂的稠化剂纤维结构破坏较大,一般会造成润滑脂的硬化。     

系列磷酸酯水溶性离子液体在水中摩擦学行为研究

基于分子设计的理念,将辛醇、十二醇、十八醇分别与五氧化二磷反应得到不同链长的磷酸酯,再与二乙醇胺反应制备出3种水溶性离子液体润滑添加剂。采用红外光谱分析定性确认添加剂的结构,并应用热重分析3种添加剂的热稳定性。通过四球摩擦磨损试验机评价3种添加剂在水体系中的摩擦学性能。采用扫描电子显微镜(SEM)和X射线光电子能谱(XPS)对磨损表面进行表征分析,探讨其摩擦化学机制。结果表明:3种添加剂的热分解温度较高,分别为130、165、178℃;3种添加剂均能显著提高水体系的减摩抗磨和耐极压性能,且其抗磨和耐极压性能随着链长的增加而增强,这可能与添加剂的吸附能力和反应活性有关,烷基链较长的添加剂更容易吸附在金属表面,高载荷下能更快地与金属发生反应形成边界润滑膜;添加剂在表面形成的反应膜主要由铁氧化物,磷酸铁构成;边界润滑膜的存在提高了水体系的摩擦学性能,丰富了水作为润滑介质的使用场合。     

绿色环保型螺杆式空气压缩机用油的开发及应用

针对螺杆式空气压缩机油在抗氧化、抗摩擦磨损性能以及油水分离等方面严格的性能要求,采用矿物油与合成油复配的基础油,通过添加合适的酚类抗氧剂、胺类抗氧剂、金属缓蚀剂、极压抗磨剂等功能添加剂,研发出一款抗氧化性能稳定和极压抗磨性能优异的螺杆式空气压缩机油.利用四球摩擦磨损试验机对其进行极压性能和摩擦磨损性能评价,并开展模拟氧...     

防腐剂在摩擦副表面的吸附性能探索

利用模拟轴承对润滑油中的防腐蚀添加剂进行吸附实验,通过对吸附前后润滑油的紫外吸光度的测量,表征实验前后润滑油中防腐剂的质量分数变化,进而证明摩擦副对防腐蚀添加剂的吸附作用;在含有定量防腐剂的润滑油中添加不同质量分数的抗磨剂,进行模拟轴承的吸附实验,通过紫外吸光度的测量发现抗磨剂对防腐剂在摩擦副表面的吸附性能有较大影响,说明防腐剂与抗磨剂在摩擦副界面存在竞争吸附效应。     

一种自修复功能添加剂的制备及性能研究

以有机钼作为自修复添加剂的主要功能成分,加入抗氧剂和适量的极压抗磨剂,制备一种摩擦副自修复功能添加剂;通过四球摩擦试验、齿轮台架试验考察其性能,使用扫描电镜(SEM)和X射线光电子能谱仪(XPS)等分析其作用机制。结果表明:该添加剂具有优良的减磨和摩擦副自修复性能;在中低负载下该自修复添加剂主要通过在摩擦副表面生成物理、化学吸附膜发挥减摩作用;随着负载的增加和温度的升高,添加剂中的有机钼和硫磷系极压抗磨剂组分发生分解并与摩擦副表面的金属反应生成二硫化钼、磷酸铁、硫化亚铁、三氧化钼等沉积物,从而发挥良好的润滑与抗磨作用;在高负载下,该自修复添加剂主要通过微流变作用实现磨损表面的平整与自修复。     

透明质酸体系与水界面稳定性的分子动力学模拟

为考察仿生黏液透明质酸体系与水相界面行为随时间的变化规律,结合Forcite模块,采用Nose扩展系统控温法、Atom based计算方法和Ewald计算方法,通过分子动力学研究,探讨仿生黏液-水界面的分子之间的变化。以透明质酸的水溶液为代表,模拟生物黏液,从微观层面探讨界面稳定性：从界面张力、界面相互作用能、径向分布函数和均方根位移等方面分析影响界面稳定性的因素。结果表明：仿生黏液在透明质酸高分子多聚体和水分子在质量比为1∶10时的界面张力最小为61.33 mN/m,此时的单位界面能最低为242.67 kJ/(mol·nm²),界面最稳定。根据MSD曲线和RDF(径向分布函数),从水分子和透明质酸分子相互作用的强弱和水分子的移动也间接地表明在质量比为1∶10时,体系界面稳定性最高。模拟结果与实验的稳定性结果一致,从微观层面解释了透明质酸体系和水界面的一些规律。     

几种纳米添加剂在环境友好润滑剂中的摩擦化学特性

采用机械化学修饰法研制了三种纳米润滑添加剂,二硫化钼(MoS2)、聚四氟乙烯(PTFE)和氟化石墨(CxFy),考察了这些纳米级润滑剂在环境友好润滑剂中的摩擦化学特性。结果发现：这些纳米添加剂在环境友好润滑剂中具有较好的抗磨性能和良好的减摩性能;减摩性能优于常用的极压抗磨剂,其机理是在摩擦副表面形成迁移膜,起“滚动微轴承”的作用。     

润滑油添加剂对陶瓷球接触疲劳的影响

利用自制的球-棒疲劳试验机研究了4种润滑油添加剂对Si3N4与GCr15钢摩擦副接触疲劳性能的影响，并借助于扫描电镜(SEM)和X射线能量色散谱(EDAX)分析了Si3N4陶瓷球表面疲劳成因及不同添加剂的抗疲劳机理。结果表明，4种添加剂都不同程度地提高了Si3N4陶瓷球的接触疲劳寿命，其中以极压抗磨剂效果较好；点蚀剥落是Si3N4陶瓷球的主要失效形式；添加剂抗疲劳的主要原因是在钢表面形成反应膜，在陶瓷球表面形成转移膜，降低了滑动摩擦力。     

纳微米硼酸盐添加剂与硫系添加剂复配的摩擦学性能研究

本文研究了纳微米硼酸盐添加剂（简称MB添加剂，下同）与SO复配体系的协同效应及其作用机理。结果表明：MB添加剂与SO复配体系的极压抗磨性具有协同效应。当WMB=0.40%时，极压抗磨性最好；摩擦改进剂ASBT对上述复配体系的抗磨性有较大改善。当WASBT－0．10－0．15％时，复配体系的抗磨性最好。在MB添加剂与SO复配体系油润滑条件下，摩擦表面生成了含元素C、S、B和N复杂摩擦化学反应膜；摩擦改进剂ASBT的加入，改变了摩擦化学反应膜的化学组成和摩擦表面形貌，提高了以应膜的承载能力和耐磨性。     

First principles study of organophosphorus additives in boundary lubrication conditions: Effects of hydrocarbon chain length

We apply first principle calculations to investigate the effects of the hydrocarbon chain length in additive molecules under boundary lubrication conditions. In these conditions, occurring in high‐pressure applications, the thickness of the oil film becomes extremely thin, and the additive molecules remain confined between the two solid surfaces in contact. We consider two types of organophosphorous additives having the same phosphite group but hydrocarbon chains of different lengths. By comparing the molecular behavior under uniaxial stress applied, we elucidate the atomistic mechanisms that control the molecular capacity of maintaining an interfacial spacing under compression and the load‐induced molecular dissociation. This insight is relevant not only for a rational design of lubricant additives but also to provide understanding on the activation mechanisms of tribochemical reactions.     

The effects of a demulsifier on the interface of marine engine oil and water

The water‐shedding property and the interfacial tension of marine engine oils with various additives have been assessed and analysed in this paper. It is concluded that the weak water‐shedding property was mainly due to the molecular structure and the interfacial property of sulphonate detergent, which can adsorb on the oil–water interface intensely to form a strong interfacial film and prevent coalescence of droplets. The impact of a demulsifier to the water‐shedding property and the interfacial tension indicated that demulsifier improved the water‐shedding property of marine engine oil in the manner of being much easy to adsorb onto the interface but formatting a flimsy interfacial film. Copyright © 2011 John Wiley & Sons, Ltd.     

Computational Chemistry of Soluble Additives for Perfluoropolyalkylether Liquid Lubricants

Computational chemistry has been applied in a practical manner to a perfluoropolyalkylether (PFPAE) liquid lubricant research and development program. Additives have been previously shown to be effective in a PFPAE liquid lubricant candidate gas turbine engine oil base fluid as oxidation inhibitors/metal deactivators, lubricity additives and antirust additives. In this effort, low energy configuration computer models of the base fluid and of selected additives were created. Simulated docking of the additive molecules in the base fluid media, onto low carbon steel and onto iron oxide substrates, provided information on the strength of the substrate/additive interactions. Also, the visual representation of each additive molecule's alignment on the metallic surface has provided insight into selection of the optimnum functionality in designing new additives. Data on the additive/metal attraction and corresponding additive effectiveness are presented.     

In situ observation of phosphorous and non-phosphorous antiwear films using a mini traction machine with spacer layer image mapping

Since 1940s the principal source of an antiwear additive in crankcase applications has been due to a family of additives known as zinc dialkydithiophosphate (ZDDP). In this study, we have applied a novel technique, the mini traction machine with spacer layer image mapping (MTM SLIM), to study film formation characteristics of monoblend oils containing only basestock and ZDDP and also fully forrmulated oils containing a boron antiwear additive. The purpose of this study was initially to understand the build up of ZDDP film and then to establish whether boron compounds alone could provide significant antiwear films under mixed rolling and sliding contact.     

N-酰基苯丙氨酸的合成及其在水基中润滑和防锈性能研究

将脂肪酸酰氯和苯丙氨酸在碱性溶液中反应得到的N-酰基苯丙氨酸，用红外光谱对其结构进行表征；用四球摩擦磨损试验机考察了N-酰基苯丙氨酸以三乙醇胺为助溶剂时在水溶液中的摩擦磨损性能，并用俄歇电子能谱研究了磨斑表面边界膜的化学组成和元素分布。结果表明：N-酰基苯丙氨酸的水溶液表现出很好的抗磨和减摩特性，这可能是N-酰基苯丙氨酸三乙醇胺盐中的极性基团吸附在钢球的表面，长碳链疏水性的烃基在金属表面形成较厚的保护膜，在较高载荷运行下，发生化学反应形成高强度的摩擦化学反应膜；N-酰基苯丙氨酸三乙醇胺盐还有较好的防锈性。经细菌试验表明其具有较好的抗菌能力。     

六方氮化硼负载纳米铜润滑添加剂的制备及其摩擦学性能研究

采用水热吸附及热解还原制备六方氮化硼负载纳米铜复合润滑添加剂(Cu/h-BN),利用透射电镜(TEM)、X射线衍射仪(XRD)、热重分析仪(TGA)以及红外光谱仪(FT-IR)对样品进行表征.将纳米润滑添加剂分散到聚α-烯烃(PAO10)中,采用球盘摩擦试验考察其摩擦学性能.采用扫描电子显微镜(SEM)对典型的磨痕进行...     

Boundary Lubrication of Oxide Surfaces by Poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) in Aqueous Media

In this work, we have explored the application of poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) as an additive to improve the lubricating properties of water for metal-oxide-based tribo-systems. The adsorption behavior of the polymer onto both silicon oxide and iron oxide has been characterized by optical waveguide lightmode spectroscopy (OWLS). Several tribological approaches, including ultra-thin-film interferometry, the mini traction machine (MTM), and pin-on-disk tribometry, have been employed to characterize the frictional properties of the oxide tribo-systems in various contact regimes. The polymer appears to form a protective layer on the tribological interface in aqueous buffer solution and improves both the load-carrying and boundary-layer-lubrication properties of water.     

Understanding the tribological chemistry of chlorine-, sulfur- and phosphorus-containing additives

It is demonstrated that the surface chemistry of simple-model extreme-pressure lubricant additives, measured in ultrahigh vacuum, corresponds to that measured at higher pressures, where film growth rates are monitored using a microbalance. This chemistry and reaction kinetics are used to explain the extreme-pressure lubrication behavior by successfully modeling the measured seizure load vs. additive concentration curves. It is also demonstrated, by growing ferrous chloride films on iron substrates in ultrahigh vacuum, that these have the same friction coefficients as those found for model extreme-pressure lubricants. It is found that a monolayer of a solid boundary lubricant film is sufficient to lower the interfacial friction coefficient to its minimum value. These results demonstrate that the chemistry measured under conditions of thermodynamic equilibrium at some temperature can be successfully applied to the formation of a boundary film, in the extreme-pressure regime.     

Polysiloxane substituent influence on the foaming of polyolesters and polyolester turbine engine lubricants

Parts-per-million (ppm) quantities of polysiloxanes with different molecular structures have varying effects on the foaminess of a polyolester, trimethylolpropaneheptanoate (TMPH), and a formulated synthetic polyolester gas turbine engine lubricant. At the 100 ppm concentration evaluated in a standard foam test, TMPH-polysiloxane mixtures that exhibit lower interfacial surface tension produced copious quantities of foam. Estimates of Lewis acid-base interaction and solubility of the additive in the polyolester are not helpful in predicting foaminess. Consideration of additive polymeric structure, the potential for increased additive molecular entanglement due to substituent length, and interaction of adjacent polysiloxane molecules at the surface, are helpful in rationalising differences observed in foaming. Some lubricant additives, such as antioxidants and antiwear agents, appear to enhance the profoamant tendencies of selected polysiloxanes.