Polymethacrylate Viscosity Modifiers and Pour Point Depressants

Kinker, Bernard

doi:10.1201/9781420059656-c11

Cited by 8 publications

(9 citation statements)

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“…Unsurprisingly, the VI increases with increasing the polymer concentration from 1 to 2 wt % and is mainly attributed to a significant elevation of the kinematic viscosity (ν) at 100 °C (Figure , stripped columns), while the low-temperature viscosity remains relatively unaffected (Figure , solid columns). This observation is consistent with the generally accepted mechanism for polymethacrylate-based viscosity improvers, which involves temperature-enhanced coil swelling. ,,− This behavior is beneficial for typical (automotive) engine environments since it safeguards efficient lubrication at elevated service temperatures (≈ 100 °C), while practically retaining the cold-starting facility of the neat base oil …”

Section: Resultssupporting

confidence: 85%

“…The thermal stability of Yubase 4 solutions containing 2 wt % of the various additives decreased marginally as evident from slightly lower decompositions temperatures. Nevertheless, for all solutions, the T d5% remained above 190 °C which is significantly higher than typical automotive lubricant operating temperatures (100 °C). , …”

Section: Resultsmentioning

confidence: 65%

“…Lubricants play a pivotal role in enhancing the durability and efficiency of applications ranging from automotive engines to high-performance turbines. Commercial, fully formulated lubricants employed in automotive (engine) environments are highly complex fluids composed of a base oil containing a variety of additives including antiwear agents, friction reducers, antioxidants, detergents, pour point depressants, and viscosity improvers. − To enhance oil performance and longevity as well as to meet ever-rising industrial and environmental demands regarding fuel consumption and pollution reduction, development of improved viscosity modifiers and boundary lubricants has attracted significant industrial and academic attention. − …”

Section: Introductionmentioning

confidence: 99%

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Triple Function Lubricant Additives Based on Organic–Inorganic Hybrid Star Polymers: Friction Reduction, Wear Protection, and Viscosity Modification

Ravensteijn¹,

Zerdan²,

Seo³

et al. 2018

ACS Appl. Mater. Interfaces

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Polymer-based lubricant additives for friction reduction, wear protection, or viscosity improvement have been widely studied. However, single additives achieving all three functions are rare. To address this need, we have explored the combination of polymer topology with organic–inorganic hybrid chemistry to simultaneously vary the temperature- and shear-dependent properties of polymer additives in solution and at solid surfaces. A topological library of lubricant additives, based on statistical copolymers of stearyl methacrylate and methyl methacrylate, ranging from linear to branched star architectures, was prepared using ruthenium-catalyzed controlled radical polymerization. Control over the polymerization yielded additives with low dispersity and comparable molecular weights, allowing evaluation of the influence of polymer architecture on friction reduction, wear protection, and bulk viscosity improvement in a commercial base oil (Yubase 4). Structure–performance relationships for these functions were assessed by a combination of a high-speed surface force apparatus (HS-SFA) experiments, wear track profilometry, quartz crystal microbalance analysis, and solution viscometry. The custom-built HS-SFA provides a unique experimental environment to measure the boundary lubrication performance under extreme shear rates (≈107 s–1) for prolonged times (24 h), mimicking the extreme conditions of automotive applications. These experiments revealed that the performance of the additives as boundary lubricants and wear protectants scales with the degree of branching. The branched architectures prohibit ordering of the additives in thin films under high-load conditions, leading to a thicker absorbed polymer brush boundary layer and therefore enhanced film fluidity and lubricity. Additionally, star polymers with increasing arm number lead to bulk viscosity modification, reflected by a significant increase in the viscosity index compared to the commercial base oil. Although outperformed by linear polymers for bulk viscosity improvement, the (hybrid) star polymers successfully combine the three distinct lubricant additive functions: friction reduction, wear protection, and bulk viscosity improvementin a single polymeric structure. It should also be noted that, judging from HS-SFA experiments, hybrid stars carrying a silicate-based core outperform their fully organic analogues as boundary lubricants. The enhanced performance is most likely driven by attractive forces between the silicate cores and the employed metallic surfaces. Combining three function in one minimizes formulation complexity and thus opens a route to fundamentally understand and formulate key design parameters for the development of novel multifunction lubricant additives.

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Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 65%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Triple Function Lubricant Additives Based on Organic–Inorganic Hybrid Star Polymers: Friction Reduction, Wear Protection, and Viscosity Modification

Ravensteijn¹,

Zerdan²,

Seo³

et al. 2018

ACS Appl. Mater. Interfaces

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“…The chemistry, architecture and molecular weight of these polymers can vary significantly depending on the application. Some of the most commonly used polymers in lubricating oils include olefin copolymers (OCP), polyalkylmethacrylates (PMA) and hydrogenated poly (styrene-co-conjugated dienes) [2] [3].…”

Section: Introductionmentioning

confidence: 99%

How Polymers Behave as Viscosity Index Improvers in Lubricating Oils

Covitch¹,

Trickett²

2015

ACES

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One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearing characteristics. Viscosity Index (VI) is one approach used widely in the lubricating field to assess the variation of viscosity with temperature. The VI of both mineral and synthetic base oils can be improved by the addition of polymeric viscosity modifiers (VMs). VI improvement by VMs is widely attributed to the polymer coil size expanding with increasing temperature. However, there is very little physical data supporting this generally accepted mechanism. To address this issue, intrinsic viscosity measurements and Small-Angle Neutron Scattering (SANS) have been used to study the variation of polymer coil size with changing temperature and concentration in a selection of solvents. The results will show that coil size expansion with temperature is not necessary to achieve significant elevation of viscosity index.

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“…One of the essential requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load bearing characteristics. It is therefore desirable to have a fluid whose viscosity-temperature dependence is small [2,3].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Evaluation of Multifunction Co-Polymer as Lubricating Oils Additives

Hi¹

2018

PPEJ

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α-Olefin derivatives are one of a variety of techniques have been employed in order to reduce problems caused by the crystallization of paraffin during the production and/or transportation and improved of properties of petroleum oils and derivatives. Addition of chemical modifications has been proved to be an efficient way for improving properties of lube oils. This article describes synthesis, characterization and performance evaluation of copolymers, having as an initial step the synthesis of the alkyl methacrylate monomers by esterification of methacrylic acid (MA) with C16 fatty alcohol. The alkyl methacrylate monomer was polymerized with α-olefin C16 (1-Hexadecene) to give copolymer then reacted with vinyl acetate monomer to give finally graft copolymer. The prepared graft copolymer was characterized by FT-IR, 1 HNMR spectroscopy, and gel permeation chromatography (GPC), and use to improving the properties of different types (high and low viscositys) of Egyptian lubricating oils. Lubricating oils with different concentrations of graft copolymer (1000, 3000, 5000 and 10000 ppm) were investigated by pour point depressant (PPD), viscosity index (VI) and rheological measurements (RM). The lubricants formulated with chemically modified exhibit a large reduction in the pour point temperatures, good rheological behaviors and better friction and wear properties. Oil samples containing 5000 ppm of the graft copolymer show-18 C reductions in their pour points and give good performances properties for this lube oils, thus establishing the large efficiency of the products synthesized in this work.

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Polymethacrylate Viscosity Modifiers and Pour Point Depressants

Cited by 8 publications

References 0 publications

Triple Function Lubricant Additives Based on Organic–Inorganic Hybrid Star Polymers: Friction Reduction, Wear Protection, and Viscosity Modification

Triple Function Lubricant Additives Based on Organic–Inorganic Hybrid Star Polymers: Friction Reduction, Wear Protection, and Viscosity Modification

How Polymers Behave as Viscosity Index Improvers in Lubricating Oils

Synthesis and Evaluation of Multifunction Co-Polymer as Lubricating Oils Additives

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