Properties of polyurea greases on a synthetic base

Borisenko, L. I.; Ishchuk, Yu. L.

doi:10.1007/s10553-005-0011-x

Cited by 5 publications

(4 citation statements)

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“…Polyureas have some special properties, like hydrolysis resistance, 1 excellent mechanical properties 2,3 and anti-corrosion 4,5 and thus they have wide applications in coatings, 6 greases [7][8][9] and microcapsules. 10,11 As we know, traditional polyureas are usually produced based on the reaction of a diamine with isocyanates, [12][13][14] urea, [15][16][17] and diphenyl carbonate.…”

Section: Introductionmentioning

confidence: 99%

Utilization of carbon dioxide to build a basic block for polymeric materials: an isocyanate-free route to synthesize a soluble oligourea

Zhao

Zhang

et al. 2015

RSC Adv.

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A water soluble oligourea was synthesized by an isocyanate-free route from carbon dioxide and diamine in the absence of any organic solvents or additives. The chemical structure of the product was confirmed by FTIR and 13 C NMR analysis, and the average molecular weight was estimated with MALDI-TOF MS. The weight average molecular weight of the obtained oligourea is about 2210 Da reacting under 180 C and 11 MPa for 12 h. Moreover, the prepared oligourea has a moderate thermo-stability, it has an initial decomposition temperature at $220 C and a melting temperature of 110 C, as confirmed by TGA and DSC. As a soluble oligomer, it could be used as a building block to synthesize CO 2 -based polymeric materials due to it possessing a chemically active amino end group. For example, foaming plastics, greases, spun fibers and high strength polymer materials may be fabricated by reaction of the oligomer with a chain extender like a diisocyanate, diester or diacid.

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Section: Introductionmentioning

confidence: 99%

Utilization of carbon dioxide to build a basic block for polymeric materials: an isocyanate-free route to synthesize a soluble oligourea

Zhao

Zhang

et al. 2015

RSC Adv.

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“…Since 2010 there has been a continuous development and improvement of urea-based greases. This involved improving the processing in the production of urea greases [20,21], investigations of the influence of the base oil [22][23][24][25][26], variation of the reaction components [27] and development of additives to further improve the lubricant properties [28][29][30][31][32][33][34][35][36][37][38].…”

Section: Introductionmentioning

confidence: 99%

Polyurea Thickened Lubricating Grease—The Effect of Degree of Polymerization on Rheological and Tribological Properties

Jopen

Degen²,

Henzler³

et al. 2022

Polymers

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Lubricating greases based on urea thickeners are frequently used in high-performance applications since their invention in 1954. One property that has so far been neglected in the further development of these systems due to their low solubility and the resulting difficulty of analysis, is to better understand how the degree of polymerization affect such polyurea lubricating systems. In this work, we prepared three different oligo- or polyurea systemswith different degrees of polymerization (DP) and investigated the influence of DP on rheological and tribological properties. The results showed that the DP has an influence on the flow limit in rheology as well as on the extreme pressure (EP) and anti-wear (AW) properties as examined by tribology measurements. By optimizing the DP for a thickener system, comparable EP and AW properties can be achieved through the use of additives. The DP showed an increasing influence on the flow limit. This could reduce damage to rolling bearings due to lateral loading at rest. Therefore, modifying the DP of the polyurea systems shows similar effects as the addition of external additives. Overall, this would reduce the use of additives in industrial applications.

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“…3 Because of its excellent properties, such as high oxidation stability, hightemperature performance and high-mechanical stability, 4 polyurea grease have been applied widely in the steel, auto, mechanical and military industries. 5 As we know, the microstructure of a thickening agent is very important for the properties of lubricating grease, and this applies to the polyurea grease as well. Currently, there are several research initiatives that are focusing on synthesis and properties.…”

Section: Introductionmentioning

confidence: 99%

Impact of polyurea structure on grease properties

Liu¹,

Sun²

2010

Lubrication Science

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The thickener structure of polyurea grease has a crucial effect on its properties. Therefore, it is very important to study the relationship between a thickener structure and physical and performance properties. In this study, polyurea greases were synthesised, having a different number of urea groups in per polyurea thickener molecule. Properties such as dropping point, penetration, oil separation, shear stability and four-ball wear and extreme pressure (EP) were evaluated. The result shows that properties of polyurea grease vary with the number of urea group per polyurea molecule. Based on molecular theory, the mechanisms explaining these effects are briefly discussed.

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Properties of polyurea greases on a synthetic base

Cited by 5 publications

References 0 publications

Utilization of carbon dioxide to build a basic block for polymeric materials: an isocyanate-free route to synthesize a soluble oligourea

Utilization of carbon dioxide to build a basic block for polymeric materials: an isocyanate-free route to synthesize a soluble oligourea

Polyurea Thickened Lubricating Grease—The Effect of Degree of Polymerization on Rheological and Tribological Properties

Impact of polyurea structure on grease properties

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