Skip to main content
Select Source:

rubber

rubber, any solid substance that upon vulcanization becomes elastic; the term includes natural rubber (caoutchouc) and synthetic rubber. The term elastomer is sometimes used to designate synthetic rubber only and is sometimes extended to include caoutchouc as well.

Chemistry and Properties

All rubberlike materials are polymers, which are high molecular weight compounds consisting of long chains of one or more types of molecules, such as monomers. Vulcanization (or curing) produces chemical links between the loosely coiled polymeric chains; elasticity occurs because the chains can be stretched and the crosslinks cause them to spring back when the stress is released. Natural rubber is a polyterpene, i.e., it consists of isoprene molecules linked into loosely twisted chains. The monomer units along the backbone of the carbon chains are in a cis arrangement (see isomer) and it is this spatial configuration that gives rubber its highly elastic character. In gutta-percha, which is another natural polyterpene, the isoprene molecules are bonded in a trans configuration leading to a crystalline solid at room temperature. Unvulcanized rubber is soluble in a number of hydrocarbons, including benzene, toluene, gasoline, and lubricating oils.

Rubber is water repellent and resistant to alkalies and weak acids. Rubber's elasticity, toughness, impermeability, adhesiveness, and electrical resistance make it useful as an adhesive, a coating composition, a fiber, a molding compound, and an electrical insulator. In general, synthetic rubber has the following advantages over natural rubber: better aging and weathering, more resistance to oil, solvents, oxygen, ozone, and certain chemicals, and resilience over a wider temperature range. The advantages of natural rubber are less buildup of heat from flexing and greater resistance to tearing when hot.

Natural Rubber

Natural rubber is obtained from the milky secretion (latex) of various plants, but the only important commercial source of natural rubber (sometimes called Pará rubber) is the tree Hevea brasiliensis. The only other plant under cultivation as a commercial rubber source is guayule (Parthenium argentatum), a shrub native to the arid regions of Mexico and the SW United States. To soften the rubber so that compounding ingredients can be added, the long polymer chains must be partially broken by mastication, mechanical shearing forces applied by passing the rubber between rollers or rotating blades. Thus, for most purposes, the rubber is ground, dissolved in a suitable solvent, and compounded with other ingredients, e.g., fillers and pigments such as carbon black for strength and whiting for stiffening; antioxidants; plasticizers, usually in the form of oils, waxes, or tars; accelerators; and vulcanizing agents. The compounded rubber is sheeted, extruded in special shapes, applied as coating or molded, then vulcanized. Most Pará rubber is exported as crude rubber and prepared for market by rolling slabs of latex coagulated with acid into thin sheets of crepe rubber or into heavier, firmly pressed sheets that are usually ribbed and smoked.

An increasing quantity of latex, treated with alkali to prevent coagulation, is shipped for processing in manufacturing centers. Much of it is used to make foam rubber by beating air into it before pouring it into a vulcanizing mold. Other products are made by dipping a mold into latex (e.g., rubber gloves) or by casting latex. Sponge rubber is prepared by adding to ordinary rubber a powder that forms a gas during vulcanization. Most of the rubber imported into the United States is used in tires and tire products; other items that account for large quantities are belting, hose, tubing, insulators, valves, gaskets, and footwear. Uncoagulated latex, compounded with colloidal emulsions and dispersions, is extruded as thread, coated on other materials, or beaten to a foam and used as sponge rubber. Used and waste rubber may be reclaimed by grinding followed by devulcanization with steam and chemicals, refining, and remanufacture.

Synthetic rubber

The more than one dozen major classes of synthetic rubber are made of raw material derived from petroleum, coal, oil, natural gas, and acetylene. Many of them are copolymers, i.e., polymers consisting of more than one monomer. By changing the composition it is possible to achieve specific properties desired for special applications. The earliest synthetic rubbers were the styrene-butadiene copolymers, Buna S and SBR, whose properties are closest to those of natural rubber. SBR is the most commonly used elastomer because of its low cost and good properties; it is used mainly for tires. Other general purpose elastomers are cis-polybutadiene and cis-polyisoprene, whose properties are also close to that of natural rubber.

Among the specialty elastomers are copolymers of acrylonitrile and butadiene that were originally called Buna N and are now known as nitrile elastomers or NBR rubbers. They have excellent oil resistance and are widely used for flexible couplings, hoses, and washing machine parts. Butyl rubbers are copolymers of isobutylene and 1.3% isoprene; they are valuable because of their good resistance to abrasion, low gas permeability, and high dielectric strength. Neoprene (polychloroprene) is particularly useful at elevated temperatures and is used for heavy-duty applications. Ethylene-propylene rubbers (RPDM) with their high resistance to weathering and sunlight are used for automobile parts, hose, electrical insulation, and footwear. Urethane elastomers are called spandex and they consist of urethane blocks and polyether or polyester blocks; the urethane blocks provide strength and heat resistance, the polyester and polyether blocks provide elasticity; they are the most versatile elastomer family because of their hardness, strength, oil resistance, and aging characteristics. They have replaced rubber in elasticized materials. Other uses range from airplane wheels to seat cushions. Other synthetics are highly oil-resistant, but their high cost limits their use. Silicone rubbers are organic derivatives of inorganic polymers, e.g., the polymer of dimethysilanediol. Very stable and flexible over a wide temperature range, they are used in wire and cable insulation.

History

Pre-Columbian peoples of South and Central America used rubber for balls, containers, and shoes and for waterproofing fabrics. Mentioned by Spanish and Portuguese writers in the 16th cent., rubber did not attract the interest of Europeans until reports about it were made (1736–51) to the French Academy of Sciences by Charles de la Condamine and François Fresneau. Pioneer research in finding rubber solvents and in waterproofing fabrics was done before 1800, but rubber was used only for elastic bands and erasers, and these were made by cutting up pieces imported from Brazil. Joseph Priestley is credited with the discovery c.1770 of its use as an eraser, thus the name rubber.

The first rubber factory in the world was established near Paris in 1803, the first in England by Thomas Hancock in 1820. Hancock devised the forerunner of the masticator (the rollers through which the rubber is passed to partially break the polymer chains), and in 1835 Edwin Chaffee, an American, patented a mixing mill and a calender (a press for rolling the rubber into sheets).

In 1823, Charles Macintosh found a practical process for waterproofing fabrics, and in 1839 Charles Goodyear discovered vulcanization, which revolutionized the rubber industry. In the latter half of the 19th cent. the demand for rubber insulation by the electrical industry and the invention of the pneumatic tire extended the demand for rubber. In the 19th cent. wild rubber was harvested in South and Central America and in Africa; most of it came from the Pará rubber tree of the Amazon basin.

Despite Brazil's legal restrictions, seeds of the tree were smuggled to England in 1876. The resultant seedlings were sent to Ceylon (Sri Lanka) and later to many tropical regions, especially the Malay area and Java and Sumatra, beginning the enormous East Asian rubber industry. Here the plantations were so carefully cultivated and managed that the relative importance of Amazon rubber diminished. American rubber companies, as a step toward diminishing foreign control of the supply, enlarged their plantation holdings in Liberia and in South and Central America.

During World War I, Germany made a synthetic rubber, but it was too expensive for peacetime use. In 1927 a less costly variety was invented, and in 1931 neoprene was made, both in the United States. German scientists developed Buna rubber just prior to World War II. When importation of natural rubber from the East Indies was cut off during World War II, the United States began large-scale manufacture of synthetic rubber, concentrating on Buna S. Today synthetic rubber accounts for about 60% of the world's rubber production.

Bibliography

See P. W. Allen, Natural Rubber and the Synthetics (1972); M. Morton, Rubber Technology (3d ed. 1987).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rubber." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"rubber." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/rubber

"rubber." The Columbia Encyclopedia, 6th ed.. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/rubber

Rubber

RUBBER

RUBBER. Although rubber-yielding plants are native to Africa and Asia as well as to the Americas, the first mention of rubber in the West was made by Pietro Martire d'Anghiera, the Italian representative to the court of Spain (De Rebus Oceanicis et Novo Orbe, 1516). In the early seventeenth century, Juan de Torquemada (Monarquía Indiana, 1615) described how the Mexican Indians used a milk-like fluid drawn from a tree for religious rites and sport, and for making crude footwear, waterproof bottles, and garments. Although a little rubber was used in Europe in the eighteenth century to make erasers—it derived its name "rubber" for its property of rubbing out (erasing) pencil marks—along with elastic thread, surgical tubes, and experimental balloons, the rubber manufacturing industry was not established until the nineteenth century.

The first record of rubber in the United States is a patent for gum elastic varnish for footwear issued to Jacob F. Hummel in 1813. This was followed by a patent for a grinding and mixing machine granted to John J. Howe in 1820. Prompting these first steps was the profitable trade in crude rubber shoes imported into Boston and New York City from Brazil. By 1833, America's pioneering rubber factory was established at Roxbury, Massachusetts. Other rubber shoe and clothing factories soon appeared elsewhere in Massachusetts, as well as in New Jersey, Rhode Island, Connecticut, New York, and Pennsylvania. By 1840, the infant industry had experienced a speculative boom (about $2 million in stock was issued) and a disastrous collapse. The primary cause for the loss of confidence was that rubber products had not proven reliable—they softened in the heat and stiffened in the cold—but the downturn in general business conditions that began in the fall of 1837 only added to the industry's distress. So great were the industry's troubles that in 1843 the Roxbury Rubber Company sold the "monster" spreading machine (built by Edwin Marcus Chaffee in 1837) for $525; it had been purchased for $30,000.

Although experiments to cure rubber have been attributed to the eighteenth-century Swedish physician and pharmacist Petter-Jonas Bergius, it remained for Charles Goodyear to solve the basic technical problem confronting early rubber manufacturers. He did so in 1839, at Woburn, Massachusetts, when he developed the "vulcanization process," which gives rubber durability and consistent qualities across a broad range of temperatures by treating it with sulfur and white lead at a high temperature. His samples of "cured" rubber, with which he tried to raise funds in England, prompted the English inventor Thomas Hancock to make his own "discovery" of vulcanization. The "elastic metal" provided by these two inventors would soon prove indispensable to the Western world.

Nowhere was this more marked than in the development of the automobile industry. Yet long before the automobile appeared at the end of the nineteenth century, America's consumption of raw rubber had grown twenty fold—from 1,120 short tons in 1850 to 23,000 tons in 1900 (two-fifths of the world total of 59,000 short tons). Wherever elastic, shock-absorbing, water-resistant, insulating, and air-and steam-tight properties were required, vulcanized rubber was used. Most of the raw rubber came from Brazil, with Africa the second-most important source. The problem was not to find rubber but to find the labor to collect it in the almost inaccessible forests and ship it to the factories of the Northern Hemisphere. Until the systematic development of plantation rubber in Southeast Asia in the twentieth century made collection and transportation a comparatively easy task, the growing demand for crude rubber could only be met at increased cost. In 1830, Para rubber was 20 cents a pound; in 1900 the annual average wholesale price had risen to about a dollar.

Between 1849 and 1900, the industry's output of manufactured goods—chiefly footwear, mechanicals (for use with machinery), proofed and elastic goods, surgical goods, bicycle tires, and toys—increased in value from $3 million to $53 million. In the same years, the industry's workforce grew from 2,500 to 22,000. Because of the economies of scale and the absence of product differentiation, the market for rubber products was fiercely competitive—hence the tendency for the early rubber manufacturers to band together. Before the Civil War, marketing arrangements were already in existence to control the sale of footwear and other products. By the eve of World War I, production had come to be dominated by the "Big Four": Goodyear Tire and Rubber Company, United States Rubber Company, B. F. Goodrich Company, and Firestone Tire and Rubber Company. Partly to be close to the carriage-making industry—at the time the rubber industry's major consumer—the center of rubber manufacture had shifted from the towns of New England to Akron, Ohio. The industry's first branch factories were established in Western Europe in the 1850s.

The most dramatic phase of the industry's growth followed the introduction of the internal combustion engine, cheap petroleum, and the widespread use of the pneumatic tire in the early 1900s. Between 1900 and 1920, consumption of raw rubber increased tenfold—to 231,000 short tons. Even the world depression of the early 1930s only temporarily halted the industry's rapid expansion. By 1940, the United States was consuming 726,000 tons of a world total of 1,243,000 tons of crude rubber. Between 1900 (when the first four tons of Southeast Asia plantation rubber had reached the market) and 1910, the annual average wholesale price per pound of crude rubber doubled from $1 to $2. By 1915, more than twice as much rubber was coming from the plantations of Southeast Asia than from America and Africa combined, and prices had fallen to a quarter of their 1910 level; on 2 June 1932, the price was just three cents a pound.

Partly because of the great fluctuations in the price of crude rubber, and partly because the plantation industry of the Far East was largely in British hands, the industry began a search for rubber substitutes in the 1920s. In the next decade, manufacturers produced a few hundred tons a year of a special type of synthetic rubber. As Japan seized the rubber lands of Southeast Asia during World War II, U.S. production of synthetic rubber increased a hundredfold—from 9,000 short tons in 1941 to 919,000 tons in 1945, at which point synthetic rubber met four-fifths of America's needs. By 1973, of a world output of 6.3 million metric tons, the United States produced about 40 percent, almost three times more than the next greatest producer, Japan. That year, the United States had consumed only 696,000 metric tons of a world output of approximately 3.5 million tons of natural rubber.

Chemists succeeded in not only synthesizing rubber by making a wide range of elastomers and plastomers available, they changed the character of the industry until it was no longer possible to distinguish between rubber and rubber substitutes. The price of the synthetic compared favorably with that of the natural product, and for some uses synthetic rubber was preferable.

The rise of other industrialized nations in the twentieth century reduced America's domination of the industry; even so, its output in 1970 (including plastics) was worth about $15 billion and the industry employed more than half a million workers. In 1987, the American rubber industry shipped $24.9 billion in goods, of which automobile tires accounted for $10.5 billion of that amount. According to the Environmental Protection Agency, more than 230,000 people were employed in the rubber industry in the United States in 1987. Although rubber was used in thousands of ways, automobile tires—with which the major technical developments in manufacture have been associated—continued to account for more than one-half of the industry's consumption of raw materials. The overwhelming size of the major rubber corporations (a fifth giant was added to the Big Four in 1915 when the General Tire and Rubber Corporation was formed at Akron) did not lessen the industry's competitive nature. After World War II, the tendency toward global expansion increased, and, in the late twentieth century, the major rubber manufacturers were worldwide in scope and operation.

BIBLIOGRAPHY

Allen, P. W. Natural Rubber and the Synthetics. New York: Wiley, 1972.

EPA Office of Compliance Sector. Profile of the Rubber and Plastic Industry. Washington, D.C.: U.S. Environmental Protection Agency, 1995.

Howard, Frank A. Buna Rubber: The Birth of an Industry. New York: Van Nostrand, 1947.

Phillips, Charles F. Competition in the Synthetic Rubber Industry. Chapel Hill: University of North Carolina Press, 1963.

Schidrowitz, Philip, and T. R. Dawson, eds. History of the Rubber Industry. Cambridge, U.K.: Heffer, 1952.

Woodruff, W. "Growth of the Rubber Industry of Great Britain and the United States." Journal of Economic History 15, no. 4 (1955): 376–391.

WilliamWoodruff/c. w.

See alsoBoot and Shoe Manufacturing ; Chemical Industry ; Indian Technology ; Industrial Revolution ; Petrochemical Industry .

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Rubber." Dictionary of American History. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"Rubber." Dictionary of American History. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/history/dictionaries-thesauruses-pictures-and-press-releases/rubber

"Rubber." Dictionary of American History. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/history/dictionaries-thesauruses-pictures-and-press-releases/rubber

rubber

rub·ber1 / ˈrəbər/ • n. a tough elastic polymeric substance made from the latex of a tropical plant or synthetically. ∎  (rubbers) rubber boots; galoshes. ∎  Baseball an oblong piece of rubber or similar material embedded in the pitcher's mound, on which the pitcher must keep one foot while delivering the ball. ∎ inf. a condom. ∎ Brit. an eraser for pencil or ink marks. DERIVATIVES: rub·ber·i·ness n. rub·ber·y adj. rub·ber2 • n. a contest consisting of a series of successive matches (typically three or five) between the same sides or people in tennis, cricket, and other games. ∎  (usu. rubber match or rubber game) a game played to determine the winner of a series: Clemens will pitch in the rubber game of this tied-up series. ∎  Bridge a unit of play in which one side scores bonus points for winning the best of three games.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rubber." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"rubber." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber-1

"rubber." The Oxford Pocket Dictionary of Current English. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber-1

rubber

rubber rubber-chicken relating to a series of dinner and lunch appearances made by a politician or other public figures (so called because of the mediocre food typically served at such functions).
rubber stamp a person or organization that gives automatic approval or authorization to the decisions of others, without proper consideration (literally, a hand-held device for inking and imprinting a message or design on a surface).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rubber." The Oxford Dictionary of Phrase and Fable. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"rubber." The Oxford Dictionary of Phrase and Fable. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber

"rubber." The Oxford Dictionary of Phrase and Fable. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber

rubber

rubber Elastic solid obtained from the latex of the rubber tree. Natural rubber consists of a polymer of cis-isoprene and is widely used for vehicle tyres and other applications, especially after vulcanization. Synthetic rubbers are polymers tailored for specific purposes.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rubber." World Encyclopedia. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"rubber." World Encyclopedia. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/rubber-0

"rubber." World Encyclopedia. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/rubber-0

rubber

rubber2 set of (usu.) three games, as of bowls, whist, etc. XVI (the earliest exx. have (play) a rubbers). of unkn. orig.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rubber." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"rubber." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber-2

"rubber." The Concise Oxford Dictionary of English Etymology. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber-2

rubber

rubber See HEVEA.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rubber." A Dictionary of Plant Sciences. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"rubber." A Dictionary of Plant Sciences. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/rubber

"rubber." A Dictionary of Plant Sciences. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/rubber

rubber

rubberblubber, clubber, grubber, lubber, rubber, scrubber, snubber •Columba, cumber, encumber, Humber, lumbar, lumber, number, outnumber, rumba, slumber, umber •cucumber • landlubber •Addis Ababa • Córdoba •Aqaba • djellaba • mastaba •Berber, disturber, Djerba, Thurber

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rubber." Oxford Dictionary of Rhymes. . Encyclopedia.com. 25 Jul. 2017 <http://www.encyclopedia.com>.

"rubber." Oxford Dictionary of Rhymes. . Encyclopedia.com. (July 25, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber-0

"rubber." Oxford Dictionary of Rhymes. . Retrieved July 25, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rubber-0