Lubricants
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2022
·Vol. 10
·期 10
·260
·
IF 3.584
Hua Jiang,Xianjun Hou,Yuxin Ma,Weiwei Guan,Haijun Liu,Yucong Qian
This study conducted a tribological investigation of base oil (PAO6 and 5W 40) and ionic liquids (IL)-modified lubricants through a four-ball tribometer for 30 min. The lubricants were fabricated via a two-step method using stirring magnetic and ultrasonic dispersion. IL, base oil, and lubricants were, respectively, characterized by XRD and FTIR analysis. In addition, multiple characterizations such as EDS, 3D morphology, and SEM were carried out to evaluate the wear and friction performance of steel balls. Ultimately, the results showed that the coefficient of friction (COF) and wear scar diameter (WSD) of wear scar lubricated by IL-modified lubricants were greatly decreased than that by base oil. IL can well improve the tribological properties of PAO 6 oil and 5W-40 oil due to the tribo-film appearance on the friction surface of wear scar by the effective role of IL. Fascinatingly, this investigation comprehensively and elaborately put a new sight into the lubrication mechanism of how IL reacted with a base oil and enhanced the tribological characteristics.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
Lubricants
·
2023
·Vol. 11
·期 4
·156
·
IF 3.5
Yuanyuan Li,Chen Chen,Qiong Tang,Lei Liu,Jinxiang Dong
Alkylnaphthalene as base oils are widely applied in the production of high-performance lubricating oils. Here, we report the synthesis of multi-butylnaphthalenes by alkylation of naphthalene andn-butene with trifluoromethanesulfonic acid as catalyst. Trifluoromethanesulfonic acid exhibited excellent catalytic performance with naphthalene conversion, as high as 98.5%, and the multi-butylnaphthalenes selectivity of 98.8% under optimum conditions. To investigate the effects of the side-chain numbers on naphthalene on the lubrication performance, two kinds of alkylnaphthalenes were obtained by controlling catalyst dosage, denoted as MBN-1 (90.3% mono/di-butylnaphthalenes) and MBN-2 (98.2% tri/tetra/penta/hexa-butylnaphthalenes), respectively. The primary physiochemical properties of the synthetic oils were tested, and their tribological performance was evaluated. MBN-2, with more side chains on naphthalene, displayed more effective friction reduction and anti-wear properties than MBN-1 and the commercial alkyl naphthalene base oil AN5.Keywords:naphthalene;trifluoromethanesulfonic acid;alkylation;synthetic lubricating base oil
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Ping-Ping Gao,Zi-Han Zhou,Biao Yang,Xu Ji,Mingwang Pan,Jian-Hua Tang,Hao Lin,Gan-Ji Zhong,Zhong-Ming Li
Regulating the micro-structure of microcapsules containing lubricant is paramount to their properties and the subsequent self-lubrication performance of the composites. In this study, poly(urea-formaldehyde) (PUF) microcapsules containing lube base oil as lubricant have been fabricated by in-situ polymerization technology. The structure and properties of PUF microcapsules are investigated by altering the emulsifier content, homogenization time, oil viscosity and synthetic method. The content of sodium lignosulfonate, an environment-friendly emulsifier, has important regulation effect on the regularity and core content of PUF microcapsules. The homogenization time and oil viscosity directly affect the particle size and distribution of PUF microcapsules. Moreover, the oil viscosity plays an important role in regulating the morphology and thermal behavior of PUF microcapsules. Specifically, by adding low content of emulsifier (0.2 wt %), well-dispersed spherical microcapsules are obtained. Adopting 15# oil as core material and 0.2 wt % emulsifier, high core content of up to 89.2 wt % is achieved. When using lube base oil (32#, 46# oil) with high viscosity, the microcapsules show compact spherical structure and high thermal stability, with the initial decomposition temperature of up to 251.8 °C. This research can provide guidance for fabricating PUF microcapsules with suitable structures and performances for improving the tribological properties of different polymers.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 13
·7944-7953
·
IF 3.108
Guangbin Yang,Junhua Zhao,Lu Cui,Shiyong Song,Shengmao Zhang,Laigui Yu,Pingyu Zhang
A kind of N-containing borate ester (DEBE) with a double five-member-ring structure as a lubricant additive was synthesized by using boric acid, diethanolamine and alkylphenol polyoxyethylene ether as the starting materials. The tribological performance of the as-prepared DEBE was evaluated using a four-ball friction and wear tester in different base oils, such as liquid paraffin (LP), poly-alpha-olefin (PAO) and dioctyl sebacate (DIOS), while the morphologies of the worn scars of the steel balls were observed using a scanning electron microscope. The chemical components on the worn surfaces of the steel balls were analyzed using X-ray photoelectron spectroscopy. The tribological mechanisms in base oils of LP, PAO and DIOS were also explored. The results show that as-prepared borate ester DEBE possessed good antiwear properties in LP and PAO and can be used as a promising S- and P-free environmentally acceptable lubricating oil additive. However, the antiwear ability decreased when the additive DEBE was added to DIOS base oil. The antiwear ability of the DEBE borate esters used as an additive in DIOS might be closely related to competitive adsorption between DEBE borate ester and DIOS ester oil. Namely, compared with the DEBE additive, the DIOS base oil is first to adsorb to the metal surface because of the higher polarity. Moreover, a small amount of the additive absorbed on the metal surface may influence the continuity and compactness of the oil film formed by DIOS alone, resulting in destruction of the tribological properties of DIOS.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Hongling Fang,Yi Li,Songwei Zhang,Qi Ding,Litian Hu
Ionic liquids (ILs) have recently been demonstrated as a promising lubricating material. However, data on ILs with splendid solubility in non-polar oil and their low-temperature lubricating performances are rarely reported. In this paper, we synthesized four novel oil-miscible protic ionic liquids (PILs) containing different fatty acid anions. They possess low pour point, good low-temperature fluidity, non-corrosiveness and higher thermostability. These PILs were selected as additives in PAO base oil, respectively, and their lubricating performances were tested using a steel ball reciprocating sliding against steel stationary disc at room and low temperatures. At room temperature (~30 ℃), [N888H]C6 with shorter alkyl chains exhibited good lubricating behaviors, both in terms of steady-state friction coefficient and wear volume. However, the lubricating performances of [N888H]OA with longer alkyl chains were relatively poor because the lubricating film formed by it is disordered. At low temperature (-20 ℃), these PIL additives produced excellent antiwear performances, while their friction-reducing properties were unobvious, attributing to the restriction of high kinematic viscosity of PAO base oil.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
·
2014
·Vol. 39
·期 10
·7355-7361
·
IF 0.367
Hu Zhide,Yan Hua,Yang Jianjian,Wang Xuemei,Yu Rongsheng
Magnetorheological (MR) fluid has been widely used in many engineering field because of its unique magnetorheological effect. However, the poor lubrication of it needs to be considered seriously. Otherwise, the engineering applicability of MR fluid may be hindered. The friction property of several MR fluids based on different components was investigated on a modified four-ball tester. Two kinds of experimental conditions were designed, namely off-field and steady magnetic field. The results show that tribological properties of MR fluid are mainly decided by base oils. The friction properties of mineral oil-based MR fluid are better than that based on synthetic oil. The effect of two kinds of thixotropic agents on the tribological properties of MR fluid is exact opposite with and without magnetic field. Silica is superior to clay without magnetic field. Under steady magnetic field condition, the friction coefficient of MR fluid is over three times larger than that of MR fluid in off-field. The effect of base oil on the friction property is similar to that without magnetic field. But clay is better than silica due to the effect of magnetic field.
研究领域:
材料科学
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流变学
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摩擦学
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功能材料
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智能材料
✓ 已验证
DOI
高影响因子
TRIBOLOGY LETTERS
·
2023
·Vol. 71
·期 4
·1-11
·
IF 3.2
Tang Qiong,Zhao Zhiping,Li Ting,Ge Leizhen,Xu Hong,Liu Lei,Dong Jinxiang
A novel dual-functional group base oil was synthesized by alkylation of methyl oleate from biomass and tetralin from coal chemical industry. Interestingly, the monoalkylated product (MOAT) exhibited low pour point, high flash point, and viscosity index compared with the traditional alkyl aromatic lubricating oil (AN5), owing to the combination of the naphthenic aromatic (tetralin) and the methyl oleate framework. MOAT as co-base oil with PAO8 was studied to prepare lithium-based greases for the first time, and their rheological and tribological properties were evaluated in detail. The microstructure of the MOAT-based grease displayed high entanglement of lithium fiber. The 20% MOAT-based grease markedly reduced friction and wear compared with PAO8-based grease and 20% AN5-based grease. The excellent tribological performances were attributed to the strong interaction between the ester group and the soap fiber that provides more relative elasticity of grease and improves tribological behavior. Our finding clearly demonstrated that MOAT had the potential as a new class of base oil for obtaining high-performance lithium grease. Graphical Abstract
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Guangping An,Xiaoqiang Liu,Junying Hao
Reducing the friction of base oils to a superlubricity state is highly expected at engineering scale. However, it still is a great challenge for the most of viscous base oils to achieve superlubricity on the conventional tribopairs up to now. Here we report the strategy of solid-oil composited lubrication constructed with an ultra-smooth epoxy resin (EP) coating and base oils for achieving superlubricity. Especially, the frictional results showed that the proposed strategy in this study could be suitable for multiple base oils, including nonpolar and polar base oils as lubricants. The friction coefficient of steel/EP tribopair lubricated by the base oils containing hydroxyl group can be as low as 0.001. Meanwhile, the composited lubrication system did not undergo an obvious running-in stage to achieve the superlubricity state regardless of the type of base oils. The surface hydroxylation of the steel counter ball sliding against EP coating was observed by time-of-flight secondary ion mass spectrometer, even when lubricated by nonpolar base oils without hydroxyl group. This could be a critical factor for the base oils to achieve superlubricity. This finding provides a new and facile approach to realize robust superlubrication for different base oils at engineering scale.
研究领域:
材料科学
·
摩擦学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Zongpeng Liu,Shaojian Hu,Yuning Zhang,Bencheng Wu,Jianhua Zhu
Synthetic esters are expected to have broad application prospects in the high-end lubrication sectors owing to their fascinating custom-tailored properties. Herein, we synthesized a novel complex polyolester (CPE) via a stepwise esterification procedure using stannous oxide as a heterogeneous catalyst. Response surface methodology coupled with the Box–Behnken design (BBD-RSM) was employed to optimize the experimental parameters and elucidate the interactions among the operating variables on the low-temperature fluidity of CPE. The optimization results indicated that the lowest pour point (−42 °C) could be obtained under the catalyst dosage of 1.2 wt%, the first step reaction temperature of 164 °C, the first step reaction time of 100 min, and the second step reaction temperature of 178 °C. Particularly, there is a significant interactive effect between the catalyst dosage and the second step reaction temperature. Followed by the molecular distillation of the crude ester prepared under the optimal conditions, the refining results revealed that the non-ideal components had been effectively removed and the total acid number of the final product was substantially reduced to below 0.1 mg KOH/g. The molecular structures of the as-synthesized esters were confirmed by FT-IR, NMR, GPC, ESI–MS, and TGA characterization and their physicochemical and tribological properties were also evaluated according to standard methods. In view of the unique molecular structural design, the developed CPE displayed plentiful prominent technological specificities, which makes it plausible to be served as a potential high-performance base stock. Therefore, the findings of this study may provide some valuable insights for expanding the application scope of synthetic esters into various special industrial scenarios.
研究领域:
化学工程
·
材料科学
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润滑技术
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Hao Xu,Run-Song Wang,Yang-Yang Yan,Xing Fan,Xiang Bai,Wen-Long Mo,Xian-Yong Wei
Twelve kinds of base oils were characterized by a series of analytical methods to obtain detailed composition and structure information. Mineral oil and poly alpha olefin oil were mainly composed of long-chain alkanes, while ester oil was mainly composed of ester compounds. Ten of the 12 base oils were selected to synthesize barium lubricating greases . Both base oils and greases were evaluated by molecular simulation , and the corresponding molecular models were constructed based on the structural information of base oils. Grease models constructed by barium 12-hydroxystearate and ester oil exhibited the largest surface adsorption energy and intermolecular interaction energy, respectively, because polar groups in lubricant tend to adsorb on metal surface and form an absorbing film. Comparing physicochemical properties of the synthesized barium lubricating greases. The temperature resistance of grease presents a positive correlation with the simulated intermolecular interaction energy.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Lubrication Science
·
2022
·Vol. 34
·期 6
·428-439
·
IF 1.307
Feiming Wang,Xing Gao,Shuliang Zang,Guichun Deng,Shuang Yue
Two borate ionic liquids 1-Butyl-3-(2-methoxy-2-oxoethyl)-imidazole bis(mandelato)-borate [MABIM][BMB]) and 1,3-Dioctylbenzotriazole bis(mandelato)-borate ([DOBI][BMB]) were synthesised and utilised as the lubricating additives. Their corrosion degrees were measured and the results show that [DOBI][BMB] and [MABIM][BMB] exhibit remarkable anti-corrosion properties ([DOBI][BMB]: 1a, [MABIM][BMB]: 1b). The 4-ball machine was employed to evaluate their tribological properties in 500 N base oil. When [DOBI][BMB] and [MABIM][BMB] were added at the concentration of 3.0 wt%, the friction coefficient of 500 N was reduced by 37.5% and 29.5%. It can be concluded from the results of XPS and SEM that a lubricating film containing iron oxide, B 2 O 3 and organic N-containing compounds have formed. And a model is proposed so as to describe the lubricating mechanism.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
TRIBOLOGY LETTERS
·
2024
·Vol. 72
·期 2
·1-14
·
IF 2.9
Peng Feng,Fan Shuguang,Song Ningning,Gao Chuanping,Zhang Shengmao,Zhang Yujuan
Nickel acetyl acetonate (Ni(acac) 2 ), a metal-organic compound, was directly dispersed in base oils alkylated naphthalene (AN-5), diisooctyl sebacate (DIOS), poly-α-olefin (PAO6), and mineral oil (liquid hydrocarbon mixtures:150 N) in the presence of commercial dispersant RF1151 (monoallyl poly(isobutylene succinimide). The tribological properties of the lubricants were tested with a four-ball friction and wear tester. The friction-induced in-situ formation of carbon films on rubbed steel surfaces under the catalysis of Ni(acac) 2 was investigated, and the as-formed carbon films were characterized by scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The results show that Ni(acac) 2 added in the base oils can decompose to form metallic nickel to form nickel layer on the rubbed metal sub-surfaces and catalyze the degradation of the base oil molecules adsorbed to form carbon-based tribofilms. The carbon film formed from AN-5 with aromatic ring structure has a high degree of graphitization and the best friction-reducing and antiwear abilities, and those formed from PAO6 and 150 N with linear structure have a low degree of graphitization as well as good tribological properties. Under the lubrication of DIOS with Ni(acac) 2 , however, there is no carbon film formation while the tribological properties of the lubricant are relatively poor, due to the absence of the catalytic metallic nickel and nickel oxide layer on the rubbed metal sub-surface. Thanks to the catalytic effect of metallic nickel released from Ni(acac) 2 for the degradation of various base oils with different molecular structure, the present approach could provide a rational pathway to tune the in-situ formation of carbon-based tribofilm on rubbed steel surfaces so as to effectively reduce the friction and wear of steel-steel sliding pair.
研究领域:
材料科学
·
化学工程
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）