Influence of oleic acid-treated LaF3 nanoparticles as an additive on extreme pressure properties of various grades of polyalphaolefins

2021 ◽  
pp. 1-22
Author(s):  
Homender Kumar ◽  
A. P. Harsha
Keyword(s):  
2013 ◽  
Vol 395-396 ◽  
pp. 149-153 ◽  
Author(s):  
Kai Ji He ◽  
Jia Liu ◽  
Hao Lv ◽  
Shu Min Zheng ◽  
Kai Ming Wang

The nanoMgO and active nanoSiO2 were prepared by the special liquid-phase precipitation method. Subsequently, Chrysotile nanotube was prepared of by hydrothermal method using the nanoMgO and active nanoSiO2 as precursors at 220°C under 23atm in basic solution. The surface topographies and composition of the Chrysotile nanotube were characterized by XRD and TEM. Then, the dispersive property of particles modified by oleic acid was analyzed by IR. The tribological properties) were explored by adding the modified nanomagnesium silicate hydroxide to 2# lithic-grease after dispersing uniformly. Compared with the blank sample, it can significantly reduce the friction traces of the metal surface, improve extreme pressure performance. The friction coefficient is still stable when the temperature is raised during the friction. Nanotube power can be adhered and spread on the worn metal surface. Thus self-repairing coating forms on the worn surface.


Author(s):  
Huan Chen ◽  
Jing Li ◽  
Tianhui Ren ◽  
Lei Zheng ◽  
Yidong Zhao

Three novel imidazoline-type thiadiazole derivatives are prepared and used as antiwear and extreme-pressure additives in biodegradable lithium grease, and their tribological performances are evaluated using a four-ball tester. Tribological tests show that all derivatives are effective in reducing wear, especially at lower additive concentrations. Oleic acid-imidazoline-type thiadiazole derivative is a preferred additive to reduce wear. For the friction-reducing property of base grease, improvements after using these derivatives are not remarkable. On the other hand, these derivatives are also effective extreme-pressure additives. In order to understand the friction process further, chemical composition of tribofilms under antiwear/extreme-pressure regime is analyzed by X-ray absorption near edge structure spectroscopy, and thermal films are also considered for comparison. Thermal films formed by these imidazoline-type thiadiazole derivatives consist of adsorbed organic sulfide and ferrous sulfide. Sulfur presents several chemical valences in the antiwear regime, and tribofilms generated by stearic acid and lauric acid-imidazoline-type thiadiazole derivatives at 1.0 wt% are composed of ferrous disulfide, ferrous sulfide and ferrous sulfate. The appearance of disulfide suggests that the interfacial temperature between the upper ball and three lower balls under antiwear conditions is considerably low. Composition of extreme-pressure films generated by oleic acid and lauric acid-imidazoline-type thiadiazole derivatives is only ferrous sulfide, and the extreme-pressure film for stearic acid imidazoline-type thiadiazole derivative is a mixture of ferrous sulfide, ferrous sulfate, and adsorbed organic sulfide.


Author(s):  
M.D. Bentzon ◽  
J. v. Wonterghem ◽  
A. Thölén

We report on the oxidation of a magnetic fluid. The oxidation results in magnetic super lattice crystals. The “atoms” are hematite (α-Fe2O3) particles with a diameter ø = 6.9 nm and they are covered with a 1-2 nm thick layer of surfactant molecules.Magnetic fluids are homogeneous suspensions of small magnetic particles in a carrier liquid. To prevent agglomeration, the particles are coated with surfactant molecules. The magnetic fluid studied in this work was produced by thermal decomposition of Fe(CO)5 in Declin (carrier liquid) in the presence of oleic acid (surfactant). The magnetic particles consist of an amorphous iron-carbon alloy. For TEM investigation a droplet of the fluid was added to benzine and a carbon film on a copper net was immersed. When exposed to air the sample starts burning. The oxidation and electron irradiation transform the magnetic particles into hematite (α-Fe2O3) particles with a median diameter ø = 6.9 nm.


1958 ◽  
Vol 34 (5) ◽  
pp. 901-909 ◽  
Author(s):  
Ervin Kaplan ◽  
Bernard D. Edidin ◽  
Robert C. Fruin ◽  
Lyle A. Baker

2015 ◽  
Author(s):  
LB Becnel ◽  
YF Darlington ◽  
S Orechsner ◽  
J Easton-Marks ◽  
CA Watkins ◽  
...  
Keyword(s):  

2019 ◽  
Vol 1 (1) ◽  
pp. 46
Author(s):  
F R Rangganita ◽  
L Hermida ◽  
A Angraeni ◽  
D Khoirunnisa

Sulfated zirconia functionalized SBA-15 catalsyt (SZr-SBA-15) was prepared byreacting SBA-15 with Zirkoniumoxychloride and urea at 90oC to form ZrO2-SBA-15. Then, ZrO2-SBA-15 was reacted with H2SO4 at room temperature to produceSZr-SBA-15 catalsyt.. The catalyst was characterized in terms of adsorptiondesorption nitrogen analysis, SEM-EDX and FTIR. Based on SEM-EDX andadsorption-desorption nitrogen analysis results, it was found that Zr had beenincorporated in SBA-15. By using the SZr-SBA-15 catalyst, esterification reactionof oleic acid with TMP to produce biolubricant oil of Trimethylolpropanetrioleatachieved 85% oleic acid conversion and selectivity of 63,7%. Reusability study ofSZr-SBA-15 catalyst was carried out for 3 rounds of reaction. It was found that thecatalyst could be used up to 3 rounds without significant decrease in activityKeywords: biolubricant oil, catalyst reusability, sba-15, sulfated zirconia.


2019 ◽  
Vol 1 (3) ◽  
pp. 68
Author(s):  
Puguh Setyopratomo ◽  
Edy Purwanto ◽  
H. Yefrico ◽  
H. Yefrico

The synthesis of glycerol mono oleic from oleic acid and glycerol is classified as an esterification reaction. This research is aimed to study the influent of reaction temperature and catalyst concentration on reaction conversion. During the experiment the temperature of reaction mixture was varied as 110 oC, 130 oC, and 150 oC, while the catalyst concentration of 1%, 3 %, and 5% was used. The batch experiment was conducted in a glass reactor equipped with termometer, agitator, and reflux condensor. The oleic acid – glycerol mol ratio of 1 : 2 was used as a mixture feed. To maintain the reaction temperature at certain level, the oil bath was used. After the temperature of reaction mixture was reached the expected value, then H2SO4 catalyst was added to the reactor.  To measure the extent of the reaction, every 30 minutes the sample was drawn out from the reactor vessel. The sample analysis include acid number, density, and viscosity measurement. From this research the optimum condition which is the temperature of reaction of 150 oC and 1% catalyst concentration was obtained. At this optimum condition the convertion reach 86% and the analysis of other physical properties of the product show the acid number of 24.12, the density of 0.922 g/cc, and the viscosity of 118.4 cp.


2005 ◽  
Vol 42 (4) ◽  
pp. 245-247 ◽  
Author(s):  
Xu Zhigang ◽  
Yuan Bing ◽  
Yan Jie ◽  
Li Zongshi ◽  
Qiao Weihong ◽  
...  

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