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Maintaining Optimum Pump Performance with Specially-Formulated Hydraulic Fluids

润滑油 2005年第4期20卷 61-64页

作者： Ping Y. Zhu the lubrizol corporation debra light WickliffeUSA

This paper describes a battery of tests, and related results, that were performed under normal and severe conditions designed to demonstrate that hydraulic fluids formulated with lubrizol’s high quality anti-wear hydraulic fluid technology can stand up to today’s increasing demands for longer life and provide excellent performance under higher operating temperatures and pressures.

关键词：液压机液体泵液体传动油产品性能

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Kinetics approach to modeling of polymer additive degradation in lubricants

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Science China Mathematics 2001年第S1期44卷 129-135页

作者： llyaI.KUDISH RubenG.AIRAPETYAN Michael J. COVITCH Science lubrizol corporation Wickliffe OH 44092USA

A kinetics problem for a degrading polymer additive dissolved in a base stock is *** polymer degradation may be caused by the combination of such lubricant flow parameters aspressure, elongational strain rate, and temperature as well as lubricant viscosity and the polymercharacteristics (dissociation energy, bead radius, bond length, etc.). A fundamental approach tothe problem of modeling mechanically induced polymer degradation is proposed. The polymerdegradation is modeled on the basis of a kinetic equation for the density of the statistical distribu-tion of polymer molecules as a function of their molecular weight. The integrodifferential kineticequation for polymer degradation is solved numerically. The effects of pressure, elongational strainrate, temperature, and lubricant viscosity on the process of lubricant degradation are *** increase of pressure promotes fast degradation while the increase of temperature delaysdegradation. A comparison of a numerically calculated molecular weight distribution with an ex-perimental one obtained in bench tests showed that they are in excellent agreement with eachother.

关键词： lubricants polymers additive degradation mechanical degradation

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PBT assessment of ZDDPs using category approach

PBT assessment of ZDDPs using category approach

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第二次全国计算毒理学学术会议暨中国毒理学会第一届计算毒理专业委员会第二次会议

作者：戎志毅 Len Sweet lubrizol corporation(Shanghai)

ZDDPs is a class of substances consist of a zinc atom with two dithiophosphate esters,surrounded by alkylated side *** substances are prepared by reacting phosphorous pentasulfide with one or more primary or secondary alcohols or aryl alcohol,to form the phosphorodithioic acid ester,and then neutralizing the resultant acide with zinc *** alkyl ester substituent groups are saturated hydrocarbon

关键词： ZDDPs PBT category read-across

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Compositionally Driven Viscometric Behaviors of Poly (Alkyl Methacrylates) in Lubricating Oils

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Advances in Chemical Engineering and Science 2022年第2期12卷 65-86页

作者： Reid A. Patterson Christopher P. Kabb David M. Nickerson Eugene Pashkovski Research and Development The Lubrizol Corporation Wickliffe USA

Viscosity index (VI) and shear stability index (SSI) are standard methods used in the lubricant industry to determine temperature-viscosity dependency and resistance to product degradation, respectively. A variety of oil-soluble polymers, including poly(alkyl methacrylates) (PAMAs) are routinely used to control these properties in fully-formulated liquid lubricants. In this report, we use reversible addition-fragmentation chain transfer (RAFT) polymerization to precisely target identical degrees of polymerization in a family of PAMAs with varying lauryl, hexyl, butyl, ethyl, and methyl groups. Then, expanding on previous methodology reported in the literature, we establish structure property relationships for these PAMAs, specifically looking at how intrinsic viscosity [η] and Martin interaction parameters KM relate to VI and SSI characteristics. While the intrinsic viscosity [η] is associated with the volume of macromolecules at infinite dilution, the parameter KM reflects the hydrodynamic interactions of polymer chains at actual polymer concentrations in lubricating oils. In this paper, we show that the dependence of VI on the non-dimensional concentration c/c* (or c[η]) can be presented in a form of master curve with shift factors proportional to KM that decreases with increasing size of alkyl groups. This finding implies that even in the dilute regime, the coil-expansion theory used to explain the effect of macromolecules on VI should be complemented with the idea of hydrodynamic interactions between polymer molecules that can be controlled by the choice of alkyl chains in the family of PAMAs.

关键词： Viscosity Index Shear Stability Index Polymethacrylates Lubricating Oils

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How Polymers Behave as Viscosity Index Improvers in Lubricating Oils

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Advances in Chemical Engineering and Science 2015年第2期5卷 134-151页

作者： Michael J. Covitch Kieran J. Trickett Applied Sciences Department The Lubrizol Corporation Wickliffe USA Applied Sciences Department Lubrizol Ltd. Hazelwood Derby UK

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.

关键词： Viscosity Index Improver Viscosity Modifier Polymer Small-Angle Neutron Scattering Rheology

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液压油性能的耐久性和保持性

液压油性能的耐久性和保持性

引用

中国汽车工程学会燃料与润滑油分会第11届年会

作者： Jerry Cochrac Ping Zhu The lubrizol corporation SAE China 2004

液压设备的发展趋势系统尺寸越来越小油槽大小减小操作压力增加液压油操作温度升高换油期延长越来越关注油品的清净性和过滤性控制噪声的法规愈加严格越少的油+更高的功率=更高的油品性能要求

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