Additives for Rape Seed Oil 3: Synthesis and Tribological Behaviour of Boron‐Sulphur‐Modified Rape Seed Oil Lubricant Additive

A type of boron‐sulphur‐modified rape seed oil for use as a lubricant additive was prepared. The tribological properties of the additive in rape seed oil were evaluated using a friction tester. The morphologies and tribochemical species of the worn surfaces of the test balls were analysed by means of X‐ray photo‐electron spectroscopy. The results show that the additive is very good in increasing the load‐carrying capacity and improving the antiwear and friction‐reducing properties of a rape seed base oil. The inferred lubrication mechanism is that a high‐strength adsorption film and a tribochemical reaction film form on rubbing surfaces due to the carrier effect of the long‐chain fatty acid molecules, to the high reactivities of sulphur and boron, and to the electron deficiency of boron, and their synergism.     

The synthesis and tribological behaviour of boron‐nitrogen‐modified fatty acid water‐based lubricant additives

A new type of boron‐nitrogen‐midified fatty acid as a water‐based lubricant additive was prepared and the chemical structure characterised by infrared spectroscopy. The tribological properties of the additive in water were evaluated using friction testers. The morphologies and tribochemical species of worn surfaces were analysed by means of X‐ray photoelectron spectroscopy (XPS). The results show that the additive is very good at increasing the losdcarrying capacity and the antiwear and friction‐reducing properties of wter. A lubrication mechanism is inferred in which a lhigh‐strength adsorption film and a tribochemical reaction film form on the rubbing surfaces as a resuly of the carrier effect of long‐chain fatty acid molecules, the high reaction activities of nitrogen, and the electron deficiency of boron, as well as the interactions of these factors.     

油溶性异辛氧基硼酸锌在菜子油中的摩擦学性能研究

合成了含硼及锌润滑油添加剂——异辛氧基硼酸锌(ZnOB)。采用四球摩擦磨损试验机评价了其摩擦学性能。结果表明:在菜子油(RO)中加入异辛氧基硼酸锌以后,其承载能力明显提高,磨斑直径和摩擦因数均明显降低。从磨斑表面XPS分析结果可以推断,添加剂在摩擦过程中发生了摩擦化学降解反应,生成的产物ZnO和B2O3沉积在摩擦表面而起到润滑作用,从而改善抗磨减摩性能。     

十二烷氧基改性硼酸铜的合成及抗磨减摩性能研究

合成了一种新型的油溶性含硼润滑油添加剂———十二烷氧基硼酸铜。采用四球和环-块摩擦磨损试验机评价了其摩擦学性能。结果表明,在HVI500中性矿物油中加入十二烷氧基硼酸铜以后,其承载能力明显提高,磨斑直径和摩擦因数均显著降低。从磨斑表面XPS分析结果可以推断,添加剂在摩擦过程中发生了摩擦化学降解反应,生成的产物Cu2O和B2O3沉积在摩擦表面而起润滑作用,从而改善抗磨减摩性能。     

Additives for Rape Seed Oil 1: Preparation and Tribological Behaviour of a Sulphurised Rape Seed Oil Lubricant Additive

A new type of environmentally friendly lubricant additive ‐ a sulphurised rape seed oil additive ‐ was prepared, and the chemical structure characterised using infrared spectroscopy. The tribological properties of the additive in a rape seed base oil were evaluated using a friction tester. The morphologies and tribochemical species of worn surfaces were analysed by means of X‐ray photoelectron spectroscopy. The results show that the additive increased the load‐carrying capacity and improved the antiwear and friction‐reducing properties of the rape seed oil. The inferred lubrication mechanism is that a high‐strength adsorption film and a tribochemical reaction film form on rubbing surfaces due to the carrier effect of the long‐chain rape seed oil molecules, the high reactivity of sulphur, and their synergism.     

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。     

The tribological behaviour and mechanism of action of sulphur-containing borate esters in rape seed oil

Three sulphur-containing borate esters and one borate ester based on boric acid and n-octanol were synthesised. The antiwear and friction-reducing properties of these synthetic compounds as additives in rape seed oil were examined using a four-ball machine. The relationship between the additive structure and tribological properties was explored, and the lubrication mechanisms of the additives investigated. The worn surfaces of a steel ball lubricated with the additive-containing rape seed oil were analysed using X-ray photoelectron spectroscopy and scanning electron microscopy. The elemental compositions of, and distributions in, the worn steel surfaces were determined with an electron probe micro-analyser. It was found that sulphur-containing borate esters as additives in rape seed oil at appropriate concentrations can be effective in improving antiwear and friction-reducing behaviour. The rape seed oil base stock experiences competitive adsorption and tribochemical reactions with additives on the rubbing steel surface. The introduction of the active element sulphur into the borate ester additives functions to improve the tribological behaviour of the base stock by increasing the rate of formation of a protective layer on the rubbing steel surface. However, the tribological behaviour of the additives is not dependent on the number of sulphur atoms in the additive molecules, and further work is needed to investigate the possible dependence of this behaviour on the ratio of boron to sulphur in the additive molecules.     

硼氮型改性菜籽油润滑添加剂的制造及其摩擦学性能

在菜籽油（RO）中引入硼,氮,合成了新型润滑油添加剂－硼氮型改性菜籽油添加剂,并利用红外光谱对其主要官能团进行了鉴定,通过四球机考察了它在菜籽油和水中的抗磨性能与极压性能,结果表明：硼氮型改性菜籽油添加剂具有明显的减摩,抗磨和极压性能,其润滑作用机理是由于长链菜籽油分子的载体作用,硼的缺电子,氮的反应活性以及三的协同作用与摩擦金属表现形成了一层高强度的吸附膜和／或摩擦化学反应膜。     

Preparation of borate ester and evaluation of its tribological properties as an additive in different base oils

N‐containing borate ester (MEBE) with five‐member ring structure as a lubricant additive was synthesised. The tribological properties in liquid paraffin (LP), poly‐alpha‐olefin (PAO) and dioctyl sebacate (DOS) were evaluated, and the action mechanisms in different base oils were also explored. It was found that as‐synthesised borate ester possesses excellent antiwear performance in LP and PAO. XPS analysis suggests that the additive forms a protective film on the rubbing surfaces which is composed of BN, Fe₂O₃, polyoxyethylene ether and N‐containing organic compounds. The inorganic and organic protective films in the metal surface effectively improve the antiwear ability of the base stock. However, when the additive MEBE was introducted into DOS base oil which is prone to adsorbing to the metal surface because of the high polarity of DOS, it influences the compactness of the film formed by the DOS, resulting in weak antiwear property. Copyright © 2016 John Wiley & Sons, Ltd.     

Tribological performance of poly(sodium 4‐styrenesulphonate) as additive in water–glycol hydraulic fluid

The tribological behaviour of poly(sodium 4‐styrenesulphonate) (PSS) as additive in the base fluid of water–glycol hydraulic fluid was evaluated with four‐ball machine and Optimol SRV‐IV (Optimol Instruments, Munich, Germany) oscillating friction and wear tester, and its viscosity‐enhancing performance was also investigated. The results show that PSS exhibits excellent friction‐reducing and anti‐wear properties in the base fluid and can significantly improve the latter's welding load and viscosity. The worn surfaces were characterised by scanning electron microscope and X‐ray photoelectron spectroscopy. The analytical results of typical elements on the worn surfaces demonstrate that PSS molecules adsorb on the rubbing surface and form a stable chemically absorbed film through the interactions between the sulphonate anions and surface metallic atoms during the sliding process, which contributed to improve the tribological properties of the base fluid. Copyright © 2012 John Wiley & Sons, Ltd.     

Antiwear function and mechanism of action of cadmium dialkyldithiophosphate additive

A four‐ball tester was used to evaluate the antiwear performance of cadmium dialkyldithiophosphate as an additive in mineral oil. The results indicate that it exhibits good antiwear properties and load‐carrying capacity. Surface analysis was performed to investigate the topography of test specimens and the presence and chemical states of elements such as sulphur, phosphorus, and cadmium and their compounds on rubbing surfaces. The tribological performance and antiwear mechanism of the additive are discussed, and a scheme for the formation of atomic cadmium is proposed.     

绿色润滑油抗磨极压添加剂研究

矿物基润滑剂存在着生物降解性差的弊端，它所造成的污染已经引起人们的高度重视。通过四球机实验考察了猪血清在菜籽油中的抗磨和极压性能，并和传统的矿物油抗磨剂T321、T305进行对比研究。实验结果表明：和传统的矿物油添加剂相比，猪血清在菜籽油中具有很好的抗磨性能，其润滑性能是与血清中的蛋白质的组成元素有关，即碳、氢、氧、氮、硫、磷、铁等元素在钢球表面形成一层化学反应油脂膜。     

聚合十六烷氧基硼酸钾的合成及作为润滑油抗磨减摩添加剂的摩擦学性能

本文合成了一种含硼及钾的油溶性化合物-聚合十六烷氧基硼酸钾并将其用作润滑油抗磨减摩添加剂,用四球及环块摩擦试验机研究了它的摩擦学性能.结果发现:500SN基础油的抗磨性能得到明显改善,其承载能力明显提高,摩擦系数明显降低,有—最佳添加剂含量,超过此量,油品的承载能力不升反降.将磨斑分别在石油醚及蒸馏水中用超声波清洗后用扫描电子显微镜表征,结果发现磨斑表面存在有含硼沉积物.聚合十六烷氧基硼酸钾在表面发生了摩擦化学反应,如分解、缩合等,这些反应产物形成了一层具有抗磨减摩性能的膜.     

含硫氮硼酸酯在菜子油中的摩擦学性能研究

合成了一种新型含硫氮硼酸酯润滑油添加剂，利用四球摩擦磨损试验机考察了其在菜子油中的摩擦学性能，并用x射线光电子能谱仪分析了磨斑表面的元素化学状态。结果表明：含硫氮硼酸酯可显著改善菜子油的减摩抗磨性能和承载能力；含上述添加剂的菜子油在摩擦过程中发生了摩擦化学反应，生成了含菜子油甘油酯、有机硫化物、硫酸亚铁、三氧化二硼等组成的边界润滑膜，从而改善了菜子油的摩擦学性能。     

X‐ray absorption near‐edge structure analysis of tribofilms generated by highly efficient,friction‐reducing additive in water–polyglycol–glycol lubricant

The development of environment‐friendly lubricant additives can make a valuable contribution to addressing human health and energy problems. In the present work, the compound ammonium tetrathiomolybdate was synthesised and used as a highly efficient, friction‐reducing additive in water–polyglycol–glycol lubricants. Its tribological properties were tested by a four‐ball machine, and the composition of the tribofilm was identified by X‐ray absorption near‐edge structure (XANES) spectroscopy. The tribological test results indicated that the additive cannot only reduce the friction coefficient value, but can also shorten the rubbing time needed to produce a ‘stable friction coefficient value’. The XANES results showed that the tribofilm is mainly composed of an adsorbed layer and a tribochemical layer; the formation of sulphate and molybdenum trioxide in the tribofilm on the metal wear surface is responsible for the excellent anti‐friction performances of the additive. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and tribological behaviour of phosphorus—nitrogen‐modified rape seed oils as biodegradable lubricant additives

Two types of phosphorus—nitrogen‐modified rape seed oils as biodegradable lubricant additives were synthesised and characterised by infrared spectroscopy. Their tribological properties in rape seed oil and in mineral oil were evaluated in a four‐ball tester. The morphologies of the worn surfaces were analysed by scanning electron microscopy. The results show that the modified rape seed oil additives improve the load‐carrying capacity and the antiwear and friction‐reducing properties of rape seed oil more than they do those of mineral oil. The inferred mechanism of lubrication is that a high‐strength adsorption film and/or tribochemical reaction film forms on the rubbing surfaces, due to the carrier effect of long‐chain rape seed oil molecules and to the high reaction activities of phosphorus and nitrogen and their synergism.     

A study of the synergistic effect of a triazine‐dithiocarbamate derivative with tcp in vegetable oil

A novel, potential ashless S—N‐style additive, 2‐(N,N‐dibutylamino)‐4,6‐bis‐(dibutyldithiocarbamate)‐1,3,5‐triazine (DBTT), was synthesised and its synergistic tribological effect with a traditional additive, tricresyl phosphate (TCP), in rape seed oil was evaluated using a four‐ball tester. The results show that the load‐carrying capacity of the vegetable oil could be improved greatly by the presence of the TCP and/or DBTT additives; at certain mass ratios TCP and DBTT show a good synergistic effect in improving the tribological performance of the base oil. The elemental composition and chemical nature of antiwear films generated at a steel interface were investigated using Kevex energy dispersive X‐ray analysis and X‐ray photoelectron spectroscopy. Scanning electron microscopy was also used to study the rubbed surface morphology. It was found that FeS, organosulphur compound, sulphate, phosphate, and nitrogen‐containing compounds were present in the complex boundary lubrication film.     

Tribological properties of h‐BN nanoparticles as lubricant additive on cylinder liner and piston ring

Friction and wear behaviour of different concentrations of hex‐boron nitride (h‐BN) nanoparticles in engine oil of grade SAE 20W50 were studied at various loads. These tribological studies were conducted using a four‐ball wear test machine and a pin‐on‐disc universal tribometer. Anti‐wear properties of SAE 20W50 + h‐BN were studied on the four‐ball wear test machine as per ASTM D4172 standard. Friction and wear properties of SAE 20W50 + h‐BN on piston ring and cylinder liner tribo‐pair were studied using the universal tribometer. Nanoparticles of h‐BN mixed in lubricant showed excellent tribological performance. In most of the cases, h‐BN nanoparticles as additive reduced the wear loss by 30–70% at various loads. The minimum value of coefficient of friction (0.0401) was found with SAE 20W50 + 3 wt% of h‐BN at normal load of 100 N. Scanning electron microscopy and Raman spectroscopy were used for characterisation of h‐BN and wear scars. Copyright © 2016 John Wiley & Sons, Ltd.     

Study on antiwear and reducing friction additive of nanometer ferric oxide

Amorphous ferric oxide with a particle size of about 20–50 nm was prepared using the ethanol supercritical fluid drying technique. The tribological properties of 500 SN oil containing nanometer particles were measured using four-ball and block-on-ring tribotesters. Results indicated that the wear resistance and load-carrying capacity of the oil was raised and its friction coefficient was decreased. Excessive nanometer additive was disadvantageous for the load-carrying capacity of lubricating oil. The dispersing agent played an important role in the improvement of the tribological properties, and copper stearate was markedly superior to sorbitol monostearate. Nanometer ferric oxide took effect by its deposition on the rubbing surface.     

添加纳米磁性微粒的润滑油摩擦学行为研究

用化学方法制备纳米MnZnFe2O4磁性微粒，在四球摩擦磨损试验机和立式万能摩擦磨损试验机上考察了MnZnFe2O4纳米磁性微粒作为润滑油添加剂的抗磨减摩性能及对磨损表面的修复作用，并用扫描电子显微镜观察分析了磨斑表面形貌。实验表明，MnZnFe2O4纳米微粒添加剂可以显著提高基础油的承载能力，减小磨斑直径；磁性颗粒有利于加强吸附在摩擦副表面上形成物理吸附膜，并在摩擦表面形成自修复膜，对磨损表面具有一定的修复作用。