HISTORICAL NOTE

cants with lower volatility, better high- temperature performance, and greater rire A History of Lubricants résistance hâve been developed for naval craft, missiles, and other weapons. The In a civilization that dépends on ma­ lubricate his spindles. He found the lubri­ raw materials for thèse synthetically pre- chines, materials that lubricate moving cant blend to be much more satisfactory pared neutral substances are plasticizers, parts are absolutely essential. A "lubri­ than the straight sperm oil and continued resin polymers, and organic solvents. The cant" is any substance placed between sur­ to use the new lubricant for 10 years, while most common synthetic liquid lubricants faces to decrease friction and wear, though keeping it a secret from his competitors. frequently used in aircraft turbines are di- lubricants can also act as codants, cleans- Fifteen years later, when Colonel Edwin L. basic acid esters, which hâve low freezing ing agents, electrical insulators, and rust Drake drilled the first acrual oil well, petro­ points and excellent viscosity-temperature préventives. leum lubricants began replacing non- properties, retaining their viscocity over Primitive man probably noticed how minerai materials throughout industry. wide température ranges. much easier it was to haul logs that had Silicone polymers, too, hâve superior been srripped of bark because of the lubri- viscosity-temperature properties and are cation provided by sap oozing from the used for lubrication at high températures. wood. Other prehistoric lubricants were In a civilization that While fluorinated and chlorinated com- mud or crushed reeds placed under dépends on machines, pounds do not hâve good viscosity- dragged sledges for hauling game or tim- temperature characteristics, they can be bers and rocks for building construction. materials that lubricate used in the présence of reactive com- More extensive use of lubrication was re- moving parts are pounds. Fluorinated silicones combine the quired with the invention of the wheel and best properties of fluorinated hydrocar- axle. The first carts were made with crude absolutely essential. bons and silicones. Other synthetic lubri­ wooden axles and bearings. Eventually, cants include polyethylene glycols and people discovered that smearing a lump of their derivatives, and also phosphate esters. animal fat on the dry and squeaking parts Petroleum lubricants, like their animal made the wheel run quietly and smoothly. and vegetable oil predecessors, are liquids. Modem semisolid lubricants, such as However, without the scientific concept of Liquid lubricants hâve an advantage over grease, consist of thickening agents in a friction, no one knew why. semisolid lubricants (such as grease and minerai oil or synthetic liquid base. Vegeta­ When iron and brass replaced wood as animal fat) in that they can be drawn be­ ble and animal fats, resins, gels, waxes, moving parts in machinery, crude lumps of tween moving parts by hydraulic action. fatty acids, saponified fats, and naphtha- animal fat proved to be inadéquate lubri­ The most important material property of lenic acids can be used as thickening cants. The second génération of fatty and liquid lubricants is their viscosity, or their agents; the most common are metallic oily substances were derived from animal ability to resist flow. Various methods of re- soaps made with calcium, barium, so­ oils, vegetable oils, or a mixture of the two. fining petroleum byproducts created lubri­ dium, or lithium. For some applications, Some of thèse lubricants—tallow, olive oil, cants with différent ratings of viscosity. greases hâve a base made of synthetic liq­ uid, such as fluorocarbon Liquid or silicone castor oil, peanut oil, and râpe oil—are still Since early machines were relatively liquid. used for specialized purposes. After about simple, lubricants more sophisticated than the 16th century, whale oil and porpoise oil simple crude oil were unnecessary. Most When the operating conditions of tem­ came into wide use. industrial shops kept a barrel of oil in the pérature and pressure are too severe for liq­ With the rise of the petroleum industry corner for refilling cans used to squirt oil uids or semisolids, solid lubricating in the 19th cenrury, petroleum-based lubri­ into the machines. Some employée would materials can be used. In rocket-propelled cants quickly dominated the field. Petro­ get the messy job of dribbling oil into ail devices, the lubricant actually cornes into leum itself had been known long before bearings, using the same type of lubricant contact with oxidants and reactive fuels. this—since the ancient Assyrians and for each moving part, no matter what its Unfortunately, solid lubricants usually lack Egyptians, who used it for lighting and purpose. good adhesive properties, requiring the use of binder materials to bond the lubri­ embalming. American Indians used crude The development of larger machines cant to the surfaces of the moving parts. petroleum medicinally. The American col- used at greater speeds and with tighter The most common powdered solid lubri­ onists who discovered petroleum while spécifications for mass production led to cants are graphite, tungsten disulfide, mo- drilling for sait considered it a nuisance specialization in lubricating materials. A lybdenum disulfide, zinc oxide, and boron and poured it away as waste. general-purpose oil that worked well nitride. Thèse materials can function as lu­ One of the earliest références to crude oil enough on a simple machine could not bricants up to températures as high as used as a lubricant is from a cotton spin- meet the new requirements for higher tem­ 650°C; with such properties, they are used ning mill in Pittsburgh, Pennsylvania, in pératures and speeds. Operational failures in many hot metalworking opérations. 1845. The owner apparently tiied a sample that could be traced directly to friction and of minerai oil obtained from a sait well wear became more and more fréquent. Chemists, physicists, engineers, oil re- drilled on the Allegheny River. Minerai Better lubricants, spécial additives, and finers, and metallurgists hâve ail combined oils, derived from crude petroleum, con- automatic dispensing Systems hâve been their expertise to develop new materials for sist of a complex mixture of saturated and major advances in the science of lubrica­ lubrication that can withstand the most unsaturated aliphatic and aromatic hydro- tion. Applications for automobiles, air- rigorous spécifications for jet engines, carbons. planes, turbojets, diesel locomotives, and space flight, and ultrafast processing, as The Pittsburgh cotton-mill owner experi- high-power machinery hâve led to special­ well as new applications still being devel­ mented with his minerai oil by mixing it ized lubricants. oped for industry and research. with the sperm oil he had been using to Since the 1950s, synthetic liquid lubri­ Kevin]. Anderson

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