Viscosity index improvers and thickeners

Stambaugh, R. L.

doi:10.1007/978-94-017-1021-3_5

Cited by 8 publications

(1 citation statement)

References 30 publications

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“…Polymeric additives known as viscosity index improvers or viscosity modifiers are currently used in almost all multigrade engine oils and in many transmission and hydraulic oils, where their main role is to modify the bulk rheological properties of the fluids in which they are blended. For use in engine oils, they are also often functionalised with nitrogen-based groups in order to provide soot-dispersancy properties and thus augment the conventional dispersant additives used in these lubricants [4].…”

Section: Introductionmentioning

confidence: 99%

Reduction of Friction by Functionalised Viscosity Index Improvers

Fan

Müller²,

Stöhr³

et al. 2007

Tribol Lett

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A range of functionalised polymethacrylate copolymers have been synthesised with different functionalities, polymer architecture and molecular weight. It is shown that appropriately functionalised block copolymers give enhanced film thickness and greatly reduced friction under low entrainment speed conditions, even with polymer concentration as low as 1% wt. This behaviour almost certainly results from the formation of an adsorbed brushlike film of thickness ca 20 nm on each polar surface. These films provide a highly viscous inlet that promotes fluid entrainment and thus maintains a separating film down to very low entrainment speed. The adsorbed polymer films are also able to maintain separation in stationary contact conditions. Randomly distributed copolymers do not show this type of behaviour. The friction reduction observed is more effective in unidirectional, mixed slidingrolling than in reciprocating, sliding conditions. However, it is found that functionalised polymers and conventional organic and molybdenum-based friction modifiers can be combined to provide effective friction reduction over the whole range of rubbing conditions.

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Section: Introductionmentioning

confidence: 99%

Reduction of Friction by Functionalised Viscosity Index Improvers

Fan

Müller²,

Stöhr³

et al. 2007

Tribol Lett

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Functionalized polyethylene on property enhancement of lubricating oil and their performance evaluation study

Baruah

Saikia

Bora

et al. 2022

J of Applied Polymer Sci

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Methyl methacrylate (MMA) functionalized polyethylene additives for improving the properties of lubricating oil has been investigated in which poly(MMA-co-ethylene) were synthesized by using three different polymerization techniques such as miniemulsion, post polymerization and reverse atom transfer radical polymerization with 1.0 molL À1 of MMA and 20 bar of ethylene pressure. The copolymers are block in nature with the composition of 1:3 molar ratios of ethylene:MMA which is independent of polymerization techniques used. 1 H NMR analysis confirmed the successful incorporation of the copolymers in the lubricating oil. Thermogravimetric analysis reveals that the addition of poly(MMA-co-ethylene) increases thermal stability of the additive doped lubricating oil by approximately 40 C with a single stage decomposition pattern. Flash point measurements show an increasing flash point values for copolymer doped lubricating oil. From rheological study, the viscosity index of base lubricating oil has found significant increases from 102 to 129 with the addition of poly(MMA-co-ethylene) and the higher molecular weight (MW) of this copolymer provides better thickening efficiency. However, copolymer with higher MW seems to be more susceptible to mechanical degradation resulting in lower shear stability whereas copolymer with lower MW acts as a better pour point depressant.

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Terpolymerization kinetics of N,N‐dimethylaminoethyl methacrylate/alkyl methacrylate/styrene systems

Šoljić¹,

Jukić²,

Janović³

2009

Polymer Engineering & Sci

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Low conversion kinetics of terpolymerization of N,N‐dimethylaminoethyl methacrylate (DMAEM) and dodecyl methacrylate (DDMA) with methyl methacrylate (MMA) or styrene (ST) was investigated. Reactions were performed at 70°C, in toluene solutions, using peroxide initiator. The interdependence between terpolymer and monomer feed composition was successfully described by Alfrey‐Goldfinger equation and the unitary, binary, and ternary azeotropes were calculated. In MMA‐containing system, the wide pseudoazeotropic region with existence of true azeotropic point was observed and experimentally confirmed at the DMAEM:MMA:DDMA molar ratio of 56:41:3. In the ST‐containing system compositional heterogeneity was significant, more than 10 mol%. Required copolymerization reactivity ratios were determined by linear and nonlinear methods. The glass transition temperatures of synthesized terpolymers are found to be between those of the corresponding homopolymers and relative to their content. Increase in the MMA or ST contents and decrease in the DDMA content in terpolymers results in an increase in their glass transition temperatures. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers

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Viscosity index improvers and thickeners

Cited by 8 publications

References 30 publications

Reduction of Friction by Functionalised Viscosity Index Improvers

Reduction of Friction by Functionalised Viscosity Index Improvers

Functionalized polyethylene on property enhancement of lubricating oil and their performance evaluation study

Terpolymerization kinetics of N,N‐dimethylaminoethyl methacrylate/alkyl methacrylate/styrene systems

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