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The thickening efficiency is defined by the amount of polymer needed to increase kinematic viscosity and is often recorded as the kinematic viscosity of a blend of a polymer-containing product at a certain weight percent in a standard base oil. For shear stability, most oil and lubricant analysis measure and report the kinematic viscosity ...
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The chemistry, manufacture, dispersancy and utility of each class are described. The comparative functions, properties, thickening ability, dispersancy and degradation of VIIs are discussed. ... J.P.R. (1983) Degradation of polymers in multigrade lubricants by mechanical shear. Polym. Degrad. Stab. 5 425-447. Article CAS Google …
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Here, linear polymer-based liquid lubricants were designed via a strategy of complementary advantages, by esterifying the hydrogenated hydroxyl-terminated …
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Polyglykol P41/3000. Polyglykol P41/3000 is a water-soluble polyalkylene glycol (PAG) to be used as thickener in fire-resistant hydraulic fluids and in water-based quenchants. Clariant is one of the world's leading suppliers of water-soluble polyalkylene glycols used as thickeners and quenching polymers.
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There is a growing demand to understand the shear thickening mechanism to explain the mechanical behavior of STF in different applications. Thus, this review discusses five different shear thickening mechanisms, i.e., order-disorder theory, hydro-clustering theory, dilation theory, jamming theory, friction contact theory.
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Finished Lubricants Saving Energy with Polymer Greases estaff - November 16, 2015. Share. M etal soaps are the most common thickening technology for lubricating greases, accounting for around 90 percent of grease production. Consequently, the majority of studies into the lubricating properties of greases have been performed …
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1. Introduction. Shear thickening fluid (STF) is a non-Newtonian fluid that exhibits an abrupt increase in viscosity by a few orders of magnitude with increasing shear rate [1,2,3].STF behaves as a solid-like material under applied stress due to increasing viscosity, and when the loading is removed from the medium, the STF turns to the initial …
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Progress. The Carbopol® polymer family is based on crosslinked acrylic acid chemistry. This technology provides highly efficient thickening and excellent clarity, suspending power and emulsion stability. As the inventor of this technology, Lubrizol has a team full of technical resources that deeply understand its use in formulating for ...
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The chemistry and structure of base oil and polymer additive molecules in lubricants directly affect key performance metrics such as viscosity index, thickening efficiency, and traction coefficient.
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First, fluids with similar kinematic viscosities at 100 °C were formulated with five different polymers. Then, the simulation-calculated Newtonian viscosities at 40 and 100 °C, viscosity index, thickening efficiency, and traction coefficient in full film lubrication at 40 °C were validated by direct comparison to experimental data.
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Effect of polymer structure and chemistry on viscosity index, thickening efficiency, and traction coefficient of lubricants
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Increasingly restricted availability and environmental impact of mineral oils have boosted the interest in sustainable lubrication. In this study, the thickening properties of sodium carboxymethyl celluloses …
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Conventional personal protective equipment is usually made in multilayer stacks, and appears clumsy and uncomfortable, offering limited protection. In recent years, a newly-developed nanosuspension, shear thickening fluids (STFs), has been commonly applied to buffer and shock absorption. In this study, nonwoven fabrics are impregnated …
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Understanding shear thickening in colloidal suspensions is of great practical importance. Hsu et al. create responsive polymer-coated silica particles whose rheology can be tuned in situ ...
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Viscosity Modifiers. Viscosity Modifiers (VM) are used to reduce the influence of temperature on the viscosity of lubricants. Also known as Viscosity Index Improvers (VII) VMs used in crankcase lubricants are polymers. VMs are used in the majority of engine oils and many transmission oils. Viscosity Modifiers.
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The addition of a small optimum quantity of polymer based VII, which possesses viscosity thickening power [3,4] as a result of its high molecular weight [5,6], is able to minimize viscosity variation over a wide temperature range, increase the viscosity index (VI), improve the quality, and broaden the application temperature range of …
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The chemistry and structure of base oil and polymer additive molecules in lubricants directly affect key performance metrics such as viscosity index, thickening efficiency, and traction coefficient. However, the relationship between molecular properties and these metrics is still not fully understood, inhibiting the design of new fluids with ...
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HiTEC ® 7389. Thickeners and viscosity index improvers are polymeric, and are added to reduce lubricant viscosity changes at high and low temperatures. Mineral oil lubricants become less effective at high temperatures because heat reduces their viscosity and film-forming ability. The traditional solution to this problem was to make seasonal ...
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Lubricant Performance. Our primary goal was to test the performance of these polymers/oligomers as viscosity index improvers. In addition, the relatively high density of heteroatoms was expected ...
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Download White Paper: "Polymer Thickened Lubricant" In this white paper, we highlight a new and patented lubricant concept based on polymer technology. Originally developed and patented by SKF in response to specific problems in roller bearing applications, this has now been further refined into a whole range of new products with properties vastly …
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What is a Performance Polymer? PPs are a versatile class of polymers . with unique architecture that offer supe-rior thickening efficiencies, low trac-tion coefficients and high shear stabil-ity. Depending on the end use applica-tions, PPs can be used both as viscosity . Lowering the Temperature of Gear Oils . with Performance Polymer Technology
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Thickening Efficiency, and Traction Coefficient of Lubricants Pawan Panwar 1, Emily Schweissinger 2, Stefan Maier 2, Stefan Hilf 2, Sofia Sirak 2, and Ashlie Martini ... These studies demonstrate that there is a wide range of functionality and behavior of polymers in lubricant formula-tions. The structure and chemistry of the polymers vary ...
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Shear thickening fluid (STF) is a dense colloidal suspension of nanoparticles in a carrier fluid in which the viscosity increases dramatically with a rise in shear rate. Due to the excellent energy absorption and energy dissipation of STF, there is a desire to employ STFs in a variety of impact applications. In this study, a comprehensive review on STFs' …
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How do shear-thickening, energy-absorbing materials actually work? A simple explanation. Shear-thickening plastics are gels, with long-chain polymers suspended in a liquid lubricant that lets them flow smoothly past one another at slow speeds. Coax them slowly and the chains have plenty of time to slither about, like …
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Shear thickening fluids (STFs) are dense colloidal suspensions exhibiting an abrupt increase in viscosity with increasing shear rate [1], [2], [3], [4]. The main favorable …
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Viscosity index improvers, VIIs, are comprised of five main classes of polymers: polymethylmethacrylates (PMAs), olefin copolymers (OCPs), hydrogenated …
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Furthermore, their viscosity index is usually lower and polymer thickening agent was needed for practical application [10]. ... In summary, linear polymer-based liquid lubricants were designed by overcoming one's own shortcomings by learning from others' strong points with the main two synthetic lubricants, PAOs and synthetic esters. ...
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The use of polymers as independent thickeners for lubricating greases provides an alternative to the widely used lithium thickeners. This underlines the …
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Carbopol ® Fusion S-20 polymer is an inherently biodegradable rheology modifier that provides thickening, suspension and clarity similar to acrylates copolymer and is ideal for skin cleansing and hair care applications. It is also the first Carbopol ® polymer to address all 12 Principles of Green Chemistry in its manufacturing process.
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Thickening Efficiency at 100C 9 8 7 6 5 4 3 2 1 0 Thickening Efficiency per SSI on a Solid Poymer Basis Conventional PMA Asteric The thickening efficiency advantage of Asteric VMs compared to conventional PAMA VMs is seen in Figure 2. Greater thickening translates to lower polymer treat levels in the formulation.
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