scholarly journals INVESTIGATION OF INFLUENCE OF ESTER STRUCTURE ON THERMAL-OXIDATIVE OILS STABILITY

2018 ◽  
Vol 61 (2) ◽  
pp. 73 ◽  
Author(s):  
Boris P. Tonkonogov ◽  
Leonid N. Bagdasarov ◽  
Kseniya A. Popova ◽  
Sergey S. Agabekov
Keyword(s):  
Oxidative Stability ◽  
High Performance ◽  
Viscosity Index ◽  
Oxidation Stability ◽  
High Viscosity ◽  
Test Method ◽  
Turbine Engines ◽  
Oil Composition ◽  
Frequent Change ◽  
Thermal Oxidative Stability

This work aims are analysis the influence of the structure of esters on their thermo-oxidative stability. Then we select the composition of additives to improve the oxidation properties of aviation turbine engines. As the main method we used the following study: Standard Test Method for Corrosiveness and Oxidation and Stability of hydraulic oils, aircraft turbine engine lubricants and other highly refined oils ASTM 4636-99. It has been found that the esters of dicarboxylic acids and aliphatic alcohols have a low thermal oxidative stability, which may result in frequent change in the oil lubrication system and washing with gasoline or jet fuel. Thus, compositions based on esters of dibasic acids and aliphatic alcohol are good plasticizers having abrasion resistance and frost resistance. Thought they have low pour points and high viscosity index. As a basis for aviation oil hindered esters are recommended, which have high thermal oxidative stability. In the industry esters obtained by etherification of the mixture of acids and a polyhydric alcohol are used. Esters are optimal on its viscosity-temperature properties which were obtained in the reaction of etherification of pentaerythrit and trimetilolpran alcohols, and mixtures of hexane, heptane, nonanoic, octanoic acids. Physico-chemical parameters of esters are improved with increasing in number of functional groups in the molecule. The reason for this is that the esters were obtained by the reaction of etherification of n-C9 acids with pentaerythritol alcohols which forms a sterically hindered ester. This structure has no hydrogen atom in the molecule in β-position, which prevents the formation of cyclic hydrocarbons. However, to get oils with high performance require it is necessary to add additives. Therefore, domestic and foreign literatures and requirements for oxidation stability were analyzed. Based on these data the main requirements were formulated for oil composition of aircraft gas turbine engines. As the results of the oxidative stability testing it were found that to obtain oil which satisfies to all modern requirements for thermal oxidative stability, it requires the use of complex of antioxidants of phenolic and amine types. Forcitation:Tonkonogov B.P., Bagdasarov L.N., Popova K.A., Agabekov S.S. Investigation of influence of ester structure on thermal-oxidative oils stability. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 73-79

Development and study of new oil compositions on industrial dioktylcebacylic oils adding esters of 2.5,5.5-tetrametylolcyclopethane

2021 ◽  
pp. 39-43
Author(s):  
M.A. Mammadyarov ◽  
◽  
G.N. Gurbanov ◽  
L.M. Yusifova ◽  
G.Z. Hasanova ◽  
...  
Keyword(s):  
Oxidative Stability ◽  
Gas Turbine ◽  
Viscosity Index ◽  
Flash Point ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Thermal Oxidative Stability ◽  
The Future

Complex esters of 2.5,5.5-tetrametylolcyclopethane with heptanedioic and hexanoic acids, as well as methyl and 2-ethylhexyl alcohols have been synthesized and studied. Few compositions have been obtained adding these esters to the industrial ones of 5-20 % diisooktyl sebacylic. It was defined that exploitation characteristics of these compositions are significantly higher than those of DOS: viscosity index, flash point, thermal oxidative stability and lubricating characteristics. Based on these parameters, it is recommended to use in the future these compositions in the preparation of aircraft oils of gas-turbine engines instead of DOS esters.

Evaluation of the tribological properties and oxidative stability of epoxidized and ring opened products of pure rice bran oil

2020 ◽  
pp. 135065012095053
Author(s):  
Ananthan D Thampi ◽  
Abhishek R John ◽  
M Muhammed Arif ◽  
S Rani
Keyword(s):  
Hydrogen Peroxide ◽  
Vegetable Oils ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Research Work ◽  
Viscosity Index ◽  
Oxidation Stability ◽  
High Viscosity ◽  
Molar Ratio ◽  
Four Levels

Vegetable oils constitute a potential base stock for bio-lubricants, which has good biodegradability, high flash point, high viscosity index and excellent boundary lubrication properties. They also possess some limitations like low thermal and oxidation stability, poor low temperature properties and narrow range of viscosities. These limitations can be altered by modifying the vegetable oils chemically or by providing additives into the oils. This research work focused on the chemical modification of pure rice bran oil by epoxidation process using 30% hydrogen peroxide and glacial acetic acid. The epoxidized rice bran oil was then subjected to ring opening process using butanoic acid. The epoxidation process was optimized with four factors (Temperature, Time, Weight % of Catalyst, Hydrogen Peroxide molar ratio), each factors having four levels. The lubricant properties of pure rice bran oil (RBO), epoxidized rice bran oil (ERBO) and ring opened rice bran oil (RRBO) were studied. It was noted that the lubricant properties of ERBO and RRBO were better compared to pure RBO.

New conditions in test method for determining thermal-oxidative stability of inhibited turbine oils

1981 ◽  
Vol 17 (4) ◽  
pp. 228-230
Author(s):  
E. D. Vilyanskaya ◽  
T. N. Kulikovskaya ◽  
L. Sh. Seregina ◽  
O. A. Znamenskaya ◽  
T. A. Mutovkina
Keyword(s):  
Oxidative Stability ◽  
Test Method ◽  
Thermal Oxidative Stability

Preparation and performance evaluation of mPAO8 using olefin from coal as raw material

2017 ◽  
Vol 69 (5) ◽  
pp. 678-682 ◽  
Author(s):  
Yuefeng Ma ◽  
Jian Xu ◽  
Xiangqiong Zeng ◽  
Haizhen Jiang ◽  
Jiusheng Li
Keyword(s):  
Thermal Stability ◽  
Oxidative Stability ◽  
Thermo Gravimetric Analysis ◽  
Viscosity Index ◽  
Oxidation Stability ◽  
Molecular Structures ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
Content Type ◽  
Base Oil

Purpose The purpose of this paper is to prepare metallocene polyalphaolefin 8 (mPAO8) by the oligomerization of olefin from coal with metallocene catalyst system and compare it with commercially available polyalphaolefin 8 (PAO8) from Chevron. Design/methodology/approach Molecular structures, component and mass were determined by nuclear magnetic resonance spectroscopy, gas chromatography and gel permeation chromatography, respectively. The physico-chemical properties, including Noack volatility, viscosity index and elemental analyses, were studied. The oxidative stability was evaluated by pressurized differential scanning calorimetry, whereas the thermal stability was studied by thermo-gravimetric analysis. Findings The produced mPAO8 consisted of a large part of tetramer, pentamer and a small part of trimer and hexamer. Additive T501 significantly improved the oxidation stability of PAO8 from Chevron and the synthesized mPAO8. Both samples had similar properties, such as oxidative stability, additive response, pour point and Noack volatility loss. But mPAO8 possessed a higher thermal stability, better viscosity index and flash point than PAO8. Therefore, the mPAO8 prepared by the oligomerization of olefin from coal could be used as base oil for lubricant development. Originality/value The mPAO8 base oil was successfully prepared by successive carbon numbers and shows similar properties with commercially available PAO8 products from Chevron. The findings can cover the shortage of the synthesis lubricants market in China.

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