Lubricants synthetic bases

Concrete hardening compounds Core oil and binders Core wash Core wax Correction fluid Corrosion preventive lubricant, synthetic base for jet engines Deicing fluid Desalter kits, sea water Dextrime sizes Drilling mud Dyes, household Essential oils Ethylene glycol antifreeze preparations Eucalyptus oil Exothermics for metal industries... 

Vegetable and seed oils as well as some synthetic base stocks present a new class of biodegradable base stocks. These fluids (10) have excellent biodegradation properties as measured by criteria developed by the Environmental Protection Agency (EPA) or Organization of Economic Cooperation and Development (OECD). OECD 301 and EPA 560/6-82-003 measure the biodegradation of lubricants. These tests were developed to measure the degradation of oil, especially two-cycle ok, on waterways. Aquatic toxicity criteria toward fish is also found to be acceptable for this class of fluids as measured by EPA 560/6-82-002 and OECD 203 1-12. 

Hydraikic fluids are the second largest use of lubricants for automotive and iadustrial markets. Estimates for 1992 are that 1.089 x 10 L(81 x 10 gal) of hydraikic fluids were sold out of 8.9 x 10 L(2.3 x 10 gal) of total iadustrial lubricating fluids. The world market is shown ia Table 6. Most hydraikic fluids were mineral ok-based products. The remainder represented principally fire-resistant hydraikic fluids and synthetic-based lubricants. 

Synthetic latices, 14 707 Synthetic linalool, 24 501 Synthetic lubricants, 13 687-688 Synthetic lubricating oil base stocks,... 

Lubricants are formulated products composed of a base stock, which is either a mineral or synthetic oil, and various specialty additives designed for specific performance needs. Additive levels in lubricants range from 1 to 25% depending on the application. Synthetic base stocks are oligomers of small molecules, synthesized to a defined molecular weight. Important performance indicators include viscosity index which measures the viscosity index behavior over a temperature range, oxidative stability, and pour point. The performance of synthetic and mineral oils (Morse, 1998 Shubkin, 1993) is summarized in Table 2.7. 

Total removal of phosphorus and sulfur would require the use of synthetic base-oils and new additive systems to provide antiwear antioxidation protection. Synthetic base-oil PAOs or esters have high values of viscosity improver VI and low temperature operating properties. The lubricants in diesel engines require a reduction in Ca carbonate-sulfonate concentrations. This may be less of a problem when ultra low sulfur diesel fuel is widely deployed, since a significant part of the requirement for these additives arises from the need to neutralize sulfur oxides from combustion processes. 

Diester synthetic base stock lubricants formulated with 2-ethylhexanol (e.g., di-2-ethylhexyl adipate) provide excellent low temperature starting properties in automotive crank case applications and are also employed as lubricants for industrial machinery such as compressors and turbines. 

For many years the quality of lubricant base oils has been categorised by the American Petroleum Institute, API, into Groups and used in lubricant specifications worldwide [10]. The latest base oil categories are described in API 1509 (API 2007) only the first three Groups, the mineral oil-derived, non-synthetic, base oils, are described in this chapter. The full categorization, to include up to Group V, is described and discussed in the next chapter. Groups I-III base oils are defined as follows ... 

Abstract The chemical nature and technology of the main synthetic lubricant base fluids is described, covering polyalphaolefins, alkylated aromatics, gas-to-liquid (GTL) base fluids, polybutenes, aliphatic diesters, polyolesters, polyalkylene glycols or PAGs and phosphate esters. Other synthetic lubricant base oils such as the silicones, borate esters, perfluoroethers and polyphenylene ethers are considered to have restricted applications due to either high cost or performance limitations and are not considered here. Each of the main synthetic base fluids is described for their chemical and physical properties, manufacture and production, their chemistry, key properties, applications and their implications when used in the environment. 

Synthetic lubricants have been available for many years in the early 1930s, synthetic hydrocarbon and ester technologies were simultaneously developed in Germany and the United States. Development of a catalytic polymerisation process of olefins in the United States led to the formulation of automotive crankcase lubricants with improved low-temperature performance [1,2]. These products were not commercialised due both to the inherent cost of these new synthetic base fluids and to performance improvements of mineral oil-based lubricants. In Germany, low-temperature performance drove the development of similar products [3], although the main objective was to overcome the general shortage of petroleum base stocks. 

Other than the special supply circumstances of the Second World War, synthetic lubricants were not commercially significant until after the war. In general, the improved properties of lubricants achieved with early synthetic base stocks could be obtained more cost effectively by improved formulations based on mineral oils. But the requirement for lubricants to perform over increasing temperature ranges, led by military and aero-engine performance, stimulated continuing development of synthetic lubricant technology. Synthetic lubricants are now found in all areas of... 

I vo-stroke engine lubrication Synthetic lubricants virtually eliminate engine problems associated with deposition and fouling, commonly seen with mineral oil lubricants. Although esters are predominant in this application, PAGs tend to have special uses, for example, with model engines where a mixture of PAG/methanol provides a cleaner alternative to castor oil-based fuels. 

Phosphate esters have been produced commercially since the 1920s and now have important applications as plasticisers, lubricant additives and synthetic-based fluids for hydraulic and compressor oils. Their first use in lubrication was as anti-wear additives. Later developments in aircraft hydraulic control systems, particularly during the Second World War, introduced phosphate esters as less flammable hydraulic fluids. As esters of orthophosphoric acid they have the general formula OP(OR)3, where R represents an aryl or an alkyl group or, very often, a mixture of alkyl and/or aryl components. The physical and chemical properties of phosphate esters can be varied considerably depending on the choice of substituents [59, 60], selected to give optimum performance for a given application. Phosphate esters are particularly used in applications that benefit from their excellent fire-resistant properties, but compared to other base fluids they are fairly expensive. 

MIL-PRF-23699. Performance Specification. Lubricating Oil, Aircraft Turbine Engine, Synthetic Base, NATO Code Number 0-156. 

Snyder CE. (1980) Utilization of Synthetic-Based Hydrauhc Iduids in Aerospace Applications. Lubrication Engineering, 36, 160-167. 

To meet enhanced lubricant performance and service interval life, base oils are already moving upwards, away from Gp.I towards the more highly treated and refined mineral base oils of Gps.II and III and also the synthetic base oils of PAOs and esters. Their relative costs and benefits will determine the base oil mix. Chapters 1 and 2. 

Synthetic bases or synthetics are products created by the chemical reaction of several ingredients. Two main classes are used for lubricants esters and synthetic hydrocarbons (in particular polyalphaolefms manufactured from ethylene). These products have excellent physical properties and exceptional thermal stability. 

Figure 11-16. Interaction of organosulfides and fatty esters as extreme-pressure additives. Pin and disk wear test at 85.85 cm/s with hardened steel. I Di-sec-octyl disulfide, 1.17% S in lubricant. II Methyl laurate, 8.8% in lubricant. Ill Di-sec-octyl disulfide (17 mmoles/IOOgm) + methyl laurate (33 mmoles/100 gm), 1.06% S + 7.2% ester in lubricant. IV Base oil. V Synthetic 1,20-dicarbomethoxy-9,12-diroethyl-l0,11-dithiaeicosane (18 mmoles/100 gm). Data by A. Dorinson [63].

Source M. P. Smith, A. J. Stipanovic, G. P. Firmstone, W. M. Cates, and T. C. Li, Comparison of Mineral and Synthetic Base Oils Using Correlations for Bench and Engine Tests, Lubrication Engineering 52(4) 309-314 (1996). With permission. 

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