Of synthetic lubricants

All these problems directly affect production efficiency. Recent developments have led to the introduction of synthetic lubricants that are fully compatible with all types of water-based cutting fluids, so helping the user to achieve maximum machine output. 

Solid acids can also be prepared from these materials by transformation of the sulphur group to the sulphonic acid, very closely related to sulphuric acid, one of the most commonly used acids industrially. The material can be easily recovered and easily handled since the acidity resides within pores, it cannot come into contact with living tissue. Important transformations, such as the formation of synthetic lubricants and intermediates for fragrances, have already been reported using these materials. The scope for such materials in future is enormous. 

Polypheny I Ethers. Both alkyl-substituted and iinsubxtiinlcd polypheny ethers are included in this class of synthetic lubricants. General preparation involves the (.llhiian ether synthesis. The unsubstituted polyphenyl ethers have outstanding thermal, oxidative and radiation resistance, however, poor low-temperature characteristics arc a major drawback. Alkyl substitution improves low-temperature viscosity, but detracts from stability. Most lubricant uses are developmental in nature and involve aircrali and aerospace applications. 

The most important source of lubricants is petroleum. There is hardly a chemical species (esters, ethers, sulfides, metal-or-gunic compounds, etc.) which has not contributed to the array of synthetic lubricants noxv available. Some chemicals, such as the pcrlluorocarhvm compounds and the siloxaite polymers were originally synthesized for just this service. 

Applications. Table 2.9 summarizes the possibilities of synthetic lubricants, by listing information on the main applications of some of the most important fluids (Bartz, 1999 Miller, 1993 Rudnick and Shubkin, 1999). 

SAE Paper 740118, February 1974, Use of Synthetic Lubricants in Multigrade Motor Oils. ... 

The selected sources are then evaluated—that is, sources expected to give the most information are listed first. This order would naturally depend on the subject being surveyed. In one case Chemical Abstracts would be first in another, some special treatise on the subject, either a monograph, such as Bailey s Retardation of Chemical Reactions (2), or perhaps a series of journal articles of a bibliographical nature, such as Pritzkers survey of synthetic lubricating oils (9) or the annual fatty oil surveys made by Piskur (8) might be checked first. 

Synthetic motor oils are made of a synthesized hydrocarbon base oil of hydrogenated polydecene, decanoic acid esters, zinc alkyl dithiophosphate, and synthetic poly alpha olefins. Most synthetic oils also contain additives, detergents, and corrosion inhibitors as well as viscosity modifiers. It is believed that the first synthesized polymeric hydrocarbons were synthesized in 1877, yet it was not until 1929 that the commercial development of synthetic lubricants was undertaken. Because of the availability of commercial petroleum-based lubricants, these synthetic lubricants were ultimately unsuccessful. The advent of commercial jet travel spurred the development of the first commercially successful synthetic lubricant, Mobil 1, in 1975. This lubricant had superior resistance to thermal breakdown and lower friction properties than petroleum-based products. 

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... 

Okazaki ME, Abernathy SM. (1993) Hydrolysis of Phosphate Based Aviation Hydraulic Fluids. Journal of Synthetic Lubrication, 10(2), 107-118. 

A further possible use is in the field of synthetic lubricants. The most likely use for the pyromellitate esters are as viscosity improvers(45), as the esters have quite high viscosities. They cannot be used at high temperatures, however, as at elevated temperatures they pyrolyse to form PMDA. There is an alternative use for PM LA in high temperature greases where pyrolysis is prevented by the formation of diimides, e.g. by reacting PMDA with p-aminobenzoic acid(46) and subsequently forming esters. Extreme pressure greases have also been claimed with the use of diimide derivatives(47). 

The product is called l,l,l—Trimethylolpropane (TMP) and is used mainly in the manufacture of triols by adduction with propylene oxide (PO), for flexible polyurethane foams and of synthetic lubricants by esterification with fatty acids. The allyl ethers of trimethylolpropane are used as crosslinking agents, for example, in acrylic resin systems. The world-wide capacity for TMP production is in an increasing trend. 

When the need for improved performance outweighs restrictions on price and desire for availability which ordinarily dominate the procurement of lubricants, then the purview expands to include fluids that can be made by synthetic chemistry. Even if we restrict ourselves to those fluids that promise reasonable potential for usefulness, there are as many as 20 broad generic classes which can come under consideration, and within each class there may be 10 or more subclasses gradated according to some property such as viscosity or molecular weight. A comprehensive survey of all the synthetic fluids with potential for practical use would be a major undertaking. In this chapter, therefore, we shall restrict ourselves to the examination of those types of synthetic lubricants that have been tested well enough to establish their usefulness and their limitations. 

TABLE 17-1. IMPORTANT CHEMICAL TYPES OF SYNTHETIC LUBRICANTS... 

Figure 17-2. Viscosity-temperature behavior of various types of synthetic lubricants. 1 White oil, VI 101. 2 4 -Undecy1-m-terphenyl. 3 Fluoroalkane. 4 -Di (chlorophenyl )pentane. 5 Polyphenyl ether. 6 Polyoxyalkylene glycol. 7 Di(2-ethylhexyl) sebacate. 8 Dimethyl silicone.

Sources Properties of Hydrocarbons of High Molecular Weight, Research Project 42, 1940-1966, American Petroleum Institute, New York J. Denis, The Relationship Between Structure and Rheological Properties of Hydrocarbons and Oxygenated Compounds Uses as Base Stocks, Journal of Synthetic Lubricants, vol. 1(1—3) 201—238 (1984) J. W. Nederbragt and J. W. M. Boelhouwer, Viscosity Data and Relations of Normal and Iso-Paraffins, Physica Xlll(6-7) 305-318 (1947) R. T. Sanderson, Viscosity-Temperature Characteristics of Hydrocarbons, Industrial Engineering Chemistry 41(2) 368-374 (1949). With permission. 

Source J. Denis, The Relationship Between Structure and Rheological Properties of Hydrocarbons and Oxygenated Compounds Used as Base Stocks, Journal of Synthetic Lubricants, vol. 1(1—3) 201—238 (19S4). With permission. 

FIGURE 3.19 VI as a function of CMRP content for group II and in base stocks. Source V. J. Gatto M. A. Grina, T. L. Tat, H. T. Ryan. The Influence of Chemical Structure on the Physical and Performance Properties of Hydrocracked Basestocks and Polyalphole-fins, Journal of Synthetic Lubrication 19 13-18 (2002). With permission. 

G. G. Pritzger, Production of Synthetic Lubricating Oils by Hydrogenation Reactions, Petroleum Processing 2 205-208 (1947). 

C-Prolube NNS. [Chemurgy Prods.] Blend of synthetic lubricants fiber lubricant and knitting oil. 

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