Esters

Randles, S. J.

doi:10.1201/9781420027181.ch3

Cited by 12 publications

(30 citation statements)

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“…This is not the case for density: for alkanes, the density increases with the molecule length, whereas for PEs, the density decreases with the number of methylene groups. ,, The PE with branched chains, PEB8, presents higher viscosities than those with linear chains (PEC5, PEC7, and PEC9). The trends found for PEs are consistent with previous studies − on ester lubricants, which concluded that the viscosity can be enhanced by increasing the branching degree, the acid chain length of the molecule, or the molecular weight. In their works, Niedzielski, Randles, , Eychenne and Mouloungui, and Nutiu et al studied the molecular-structure dependence of several tribological properties, including dynamic viscosity at atmospheric pressure of neopentylpolyol esters, as a function of their structure.…”

Section: Resultssupporting

confidence: 90%

Relationship between Viscosity Coefficients and Volumetric Properties: Measurements and Modeling for Pentaerythritol Esters

Pensado

Comuñas

Fernández

2006

Ind. Eng. Chem. Res.

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A rolling ball viscometer has been used in this work to determine the temperature and pressure dependencies of the dynamic viscosity of two pentaerythritol ester-based lubricants: pentaerythritol tetrapentanoate (PEC5) and pentaerythritol tetraheptanoate (PEC7). The viscosity measurements were performed along the six isotherms from 303.15 K to 353.15 K and at pressures up to a maximum of 60 MPa with an experimental uncertainty of (3%. It has been observed that the dynamic viscosity increases as the size and branching of the chains of the pentaerythritol esters each increase. Based on the viscosity experimental data, the pressure and temperature viscosity coefficients, together with the viscosity index, have been determined for these fluids. The experimental viscosity values, together with literature data of other pentaerythritol esters, 2,3-dimethylpentane, and squalane were analyzed with several models, based on free-volume or hard-sphere concepts. Furthermore, we have analyzed one of the expressions proposed by Schmelzer et al. [J. Chem. Phys. 2005, 122, 074511/1-074511/ 11] that relates the pressure-viscosity coefficient with the thermal expansion coefficient, the isothermal compressibility, and the temperature-viscosity coefficient. The Schmelzer et al. relation is valid for 2,3dimethylpentane but not for the other compounds. A more-general relation is proposed, which can explain the cases where the Schmelzer et al. equation fails.

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Section: Resultssupporting

confidence: 90%

Relationship between Viscosity Coefficients and Volumetric Properties: Measurements and Modeling for Pentaerythritol Esters

Pensado

Comuñas

Fernández

2006

Ind. Eng. Chem. Res.

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“…Gold et al 42 concluded that for each type of lubricant, the pressure-viscosity coefficient increases with the kinematic viscosity at 0.1 MPa, and at equal viscosity, the sequence of increasing pressure-viscosity coefficient is polyglycols<esters<PAOs<paraffinic oil<naphthenic oil. According with the studies of Randles on esters 14 , the viscosity-pressure coefficient of a lubricant is influenced by the length of the side chains in branched esters (the longer the higher) and the degree of branching (the more the higher). Our results on esters agree with these trends with the exception of DiPEC7, which has a lower α film than PEC7.…”

Section: Experimental Techniquesmentioning

confidence: 99%

“…Furthermore, these bases have the highest stability against acids and generally good hydrolytic stability but moderate compatibility with paints and seal materials. 14,15 POEs are used in compressors or gas turbines and as engine oil or aircraft turbine oil, amongst other applications. 14,16 The main disadvantage of synthetic oils is that they are more expensive in general than mineral oils and the majority is obtained from petroleum.…”

Section: Introductionmentioning

confidence: 99%

“…14,15 POEs are used in compressors or gas turbines and as engine oil or aircraft turbine oil, amongst other applications. 14,16 The main disadvantage of synthetic oils is that they are more expensive in general than mineral oils and the majority is obtained from petroleum. Vegetable oils (VOs) present an excellent VI and high lubricity, but most important, they are biodegradable, non toxic, renewable oils.…”

Section: Introductionmentioning

confidence: 99%

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Pressure‐viscosity behaviour and film thickness in elastohydrodynamic regime of lubrication of ionic liquids and other base oils

Fernández

Paredes

Gaciño

et al. 2013

Lubrication Science

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Viscosities at high pressures for 16 base oils (six polyolesters, three polyglycols, six ionic liquids and squalane) were used to analyze the influence of their chemical structure on the pressure‐viscosity coefficient, α. Comparisons with literature α values for vegetable bases (canola, soybean and jojoba oils) are also performed. For the molecular lubricants, we found trends that are coherent with the literature, whereas for ionic liquids (ILs), new trends were found. ILs based on tris(pentafluoroethyl)trifluorophosphate anion [FAP]−are those which present higher α values. The role of the lubricants in the central thickness in the isothermal elastohydrodynamic regime of lubrication was evaluated through the product η00.69 α0.56, η0 being the viscosity at 0.1 MPa. One of the [FAP]− ILs provides film thicknesses close to the polyglycols with similar viscosity. Bis(trifluoromethylsulfonyl)imide ILs and the shorter polypropyleneglycoldimethyl ethers are the lubricants that better avoid the changes on the film thicknesses with the temperature owing to a high viscosity index. Copyright © 2013 John Wiley & Sons, Ltd.

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“…It is a useful polymer building block because they are able to impart the highly desirable properties of flexibility, elasticity and high impact strength to many polymer products. Besides polyamides, C 36 dimerate esters which commonly used as chain oils, 2T and 4T oils (Randles, 2006) can be derived by esterification of C 36 dimer acid and alcohol. Dimerate esters generally have good thermal and oxidant stability which make them an excellent lubricant.…”

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confidence: 99%

Synthesis of Dimerate Esters by Solvent-Free Method

Armylisas¹

2017

JOPR

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SYNTHESIS OF DIMERATE ESTERS BY SOLVENT-FREE METHOD Journal of Oil Palm Research Vol. 29 (1) March 2017 p. 110 -119 INTRODUCTIONDimer acids are commonly derived from unsaturated fatty acids mainly consist of oleic and linoleic acids such as tall oil and high oleic tallow (Elsasser and McCargar, 2001). Some dimer acids are produced from erucic acid, a monounsaturated omega-9 fatty acid of rapeseed oil (Morway et al., 1954). Palm oil or so-called golden crop, that contains oleic acid as one of the major fatty acid (37.1%) as well as linoleic acid (8.1%) (Tan and Nehdi, 2012) can be used as a renewable feedstock for production of dimer acid. This dimer acid appeared as very viscous light yellow liquid and is widely used as raw material in the polymeric synthesis of fatty polyamides for application as resins (Mohammad et al., 2013) and hot melt adhesives (Ghasem, 2014). It is a useful polymer building block because they are able to impart the highly desirable properties of flexibility, elasticity and high impact strength to many polymer products. Besides polyamides, C 36 dimerate esters which commonly used as chain oils, 2T and 4T oils (Randles, 2006) can be derived by esterification of C 36 dimer acid and alcohol. Dimerate esters generally have good thermal and oxidant stability which make them an excellent lubricant. Furthermore, the stability can be improved by hydrogenation of the double bonds. This diester is commonly used in two-stroke, predominantly in marine application as it provides low smoke properties and good biodegradability for spilled or combusted oil. The degree of biodegradability of esters are generally higher than corresponding hydrocarbons (Buenemann et al., 2003). Several patents have been filed on the use of dimer esters for many non-polymer industrial chemicals such as synthetic lubricants (Henry and Tierney, 1962;Matuszak and Craven, 1958;Tierney, 1960) and lubricant additives (Rutkowski and Szykowski, 1976

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Esters

Cited by 12 publications

References 0 publications

Relationship between Viscosity Coefficients and Volumetric Properties: Measurements and Modeling for Pentaerythritol Esters

Relationship between Viscosity Coefficients and Volumetric Properties: Measurements and Modeling for Pentaerythritol Esters

Pressure‐viscosity behaviour and film thickness in elastohydrodynamic regime of lubrication of ionic liquids and other base oils

Synthesis of Dimerate Esters by Solvent-Free Method

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