Plastic (from the Greek plassein, meaning to mold or shape a soft substance) was originally invented as a substitute for natural resources; by the end of the twentieth century, however, it had become a material in its own right, no longer simulating organic substances, but instead being used to create entirely new products, everything from tableware to car bodies to artificial hearts. More than any other material, plastic changed life in twentieth-century America even as it came to symbolize a particularly artificial and superficial culture concerned more with appearances than substance, more with imitation than reality. In the popular vernacular, "plastic" took on a pejorative connotation early on, to mean false or fake or disingenuous. Early Hollywood starlets were called "celluloid women"; in 1962, Ken Kesey used the phrase "her fixed plastic smile" in his writing. In an ironic statement on the condition of the culture, a character in the movie The Graduate confided these words of encouragement to Dustin Hoffman's character: "I just want to say one word to you, Ben. Just one word. Plastics." Proof that the material was durable enough to withstand the cybernetic age came when a commencement speaker declared to a 1999 graduating class at a major American university: "… Just one word.Plastics.com."
The first plastic-like material, celluloid (a derivative of cellulose), was invented in 1869 by John Wesley Hyatt, a man in search of a substitute for the ivory used in billiard balls. While celluloid was never successfully put to this recreational purpose, it did become a viable replacement for coral, marble, bone, and ivory and was used to make things such as piano keys, collars, cuffs, novelties, combs, and brushes. Celluloid democratized a host of consumer goods by making once-expensive goods out of a cheaper but equally functional substitute for those rare materials. In addition, it reflected the growing desire and willingness of people to harness the products of nature and control them for their own interests, expressed most often in the burgeoning industrial ethic.
Celluloid found many applications beyond domestic ones: in the 1920s, it was used as transparent sheeting in automobiles for rear windows and windshields. Cellulose acetate, a nonflammable version of celluloid, could be shaped through injection molding into a variety of objects, from adding machine keys and knife handles to bobbins and eyeglass frames. The use of celluloid that affected American culture the most—and on a grand scale—was its application in the photograph and movie industries. George Eastman revolutionized photography by improving upon a gelatin-coated flexible celluloid film in 1889, which enabled photographers to snap pictures without the encumbrance of a large apparatus and dark room. So popular was this new portable photographic technique that at the turn of the century, about 40,000 tons of the film were sold each year. Thomas Edison ordered film from Eastman to use in his Kinetoscope, and opened up the first "peep" shows in American cities in 1894. Adapted from projection techniques invented in France, Edison's films democratized image-making. Celluloid moving pictures took the power of cultural reproduction away from the academy, and took its products out of museums, exposing them to masses of people. As historian Stephen Fenichell pointed out, "celluloid film succeeded in raising the first plastic's cultural profile from a medium of mere mimicry into a priceless repository of human memory."
Derived from cellulose, celluloid had its roots in nature. Bakelite, in contrast, was the first chemically synthetic plastic; it was invented in 1907 by Leo H. Baekland, later dubbed "the father of plastics." Known as "the material of a thousand uses," Bakelite was marketed not as a substitute for natural materials, but as an innovative material in its own right. A major advantage of Bakelite over hard rubber and other materials was its ability to conform to the exact details of a mold. It found ready applications in the power industry as electrical insulators, but its formation into pipe stems, billiard balls, buttons, knife handles, radios, telephones, cigarette holders, jewelry, pens, and even airplane propellers indicated the degree to which Americans were willing to accept wholly new materials on their own terms, rather than as nature's substitutes. Indeed, Bakelite was the material of the Art Deco 1920s. Industrial designer Henry Dreyfuss used the plastic in his redesign of the Bell telephone, creating its quintessential shape by combining the ear and mouthpiece into a single handset, giving the entire object a streamlined silhouette. Raymond Loewy improved on the design of a mimeograph machine in 1929 by adding a Bakelite shell that concealed its inner workings, coming up with an artful yet utilitarian object for the office. Walter Dorwin Teague used brown Bakelite in 1934 for the body of the "Baby Brownie" camera he designed for Kodak; it was so popular that four million of them were sold in the first year—in the depths of the Depression.
The success of Bakelite and the subsequent popularity of other types of plastic—many of which were much more colorful and versatile than celluloid and Bakelite—moved America from the Machine Age into the Plastic Age. The word "plastic" became a household word between the world wars, and came to be a popularly understood symbol of modernity. As with all new things, however, the increasing intrusion of plastic items into people's lives was met with widespread ambivalence. It at once enabled people to escape the forces and often limited resources of nature and threatened an abrupt disjunction with past materials and manufacturing processes. During the 1920s and 1930s, the world of plastic was a hopeful and stable one, bright and unthreatened by rust and decay. By the late 1930s and 1940s, conservative utopians looked upon plastic as a substance that promised social stability by replacing scarcity with abundance and enabling many more people to own consumer goods. By the 1960s and 1970s, environmentalists were worried about the glut of plastic materials, especially throwaway food containers, disposable diapers, and plastic bags that were clogging landfills and littering the landscape.
Social utopianism, in part, led to the popularity of plastic products like cellophane, a French invention that DuPont purchased the rights to in the 1920s. The first American products wrapped in cellophane, Whitman's chocolates, were soon followed by cigarette packs, which promised to be fresh if wrapped in sheets of this crisp, clear plastic. During the rest of the decade, everything seemed to be wrapped in cellophane—from sheets and towels to tires and pianos. It offered a new sensibility based on ideas of cleanliness and sterility: people wanted to see the products they were buying, but also wanted to be assured of their purity and freshness. Lucite and Plexiglas, more substantial forms of clear plastic which also tapped into this popular ethos, both entered the market in 1937. Cellophane also made things glamorous, immediately conferring a kind of sparkle and sex appeal to the most mundane objects. Cole Porter's 1934 song "You're the Top" exclaimed, "You're the purple light of a summer night in Spain/You're the National Gallery/You're Garbo's salary/You're cellophane!" The thin plastic film also had practical uses besides heightening the fetishized aspects of consumer goods. In 1930, Richard Drew, an engineer at 3M (then the Minnesota Mining and Manufacturing Company), devised a way to coat cellophane with pressure-sensitive adhesive, coming up with "Scotch" tape, an enduring modern convenience. Cellophane was also used as the lens for gas masks in World War II, and served as an ideal semipermeable membrane for dialysis machines. In a 1940 poll, the most beautiful words in English were identified as "mother," "memory," and "cellophane."
Rayon, or viscose, also a cellulose derivative, was a fabric made out of cellulose fibers, which gave it an attractive sheen and silk-like luster. Elsa Schiaparelli, an avant-garde designer, incorporated this prosaic material into her fashions, immediately democratizing luxury with her drapey, form-fitting outfits. The sales of rayon underwear increased fivefold between 1925 and 1928, and by the mid-1930s, about 85 percent of all American dresses had rayon content, thus moving synthetics into the realm formerly monopolized by such organic materials as cotton, wool, silk, and linen. People were now willing to put plastics intimately close to their bodies ("wrap themselves in plastic," as an acidulous Ralph Nader would sneer in the 1970s).
Polyvinyl chloride (also known as PVC and more commonly called vinyl), was developed into a workable material in 1926 by Waldo Semon. He found that it was water-resistant and fireproof and that it could be molded and extruded into any number of forms. Semon put his new invention toward making things like shower curtains, raincoats, ship's upholstery, and color-coded electrical wires. A related synthetic, polyethylene, was used to coat coaxial cable, an innovation that enabled high-speed telecommunications and revolutionized the methods by which people communicated with one another.
Nylon, which had been primarily used for toothbrush bristles before World War II, was one of plastic's best success stories. Silk was expensive and not durable enough for wartime needs. In addition, most silk imports were coming from Japan, an unreliable supplier by the late 1930s. Invented by DuPont chemist Wallace Carothers, nylon was the first truly artificial fiber that could be woven. Even though nylon stockings (generally called "nylons") were more expensive than their silk precursors, women bought them en masse in the hope that they were more durable (they were, but only slightly); women also loved the sheerness of nylons, a welcome change from the opacity of silk stockings. Like the cellophane sheaths that enhanced and glamorized the products they wrapped, nylons functioned similarly for the women who wore them: they were seen as naughty but sexy. May 15, 1940, known as "N-day," marked the beginning of national sales of nylon stockings. They proved so popular that all five million pairs had been sold by the day's end.
During World War II, plastics reverted to their original purposes as replacements for scarce natural materials, and nylon was no exception. It was made into glider towropes, parachutes, and cords for synthetic rubber tires, among other things. As a result, women had to give up their beloved nylons and often sported the "bare-legged" look to signify their patriotism, often painting a line down the backs of their legs to simulate the otherwise absent stocking seam, so even in its absence, nylon was very much a cultural presence. Other plastics that figured into the war effort included Naugahyde, a form of vinyl, used to upholster military vehicles and furniture; bubbled windshields of Plexiglas that replaced glass in cockpits, allowing pilots to survey their surroundings without visual interference; phenolic resin, a relative of Bakelite, which substituted for steel as a viable helmet liner; and Teflon, whose durability and slipperiness made it ideal for coating the valves and gaskets used in uranium processing and testing at the Manhattan Project. The success of plastic during the war convinced the American public of its worth and value—people could trust it because it had helped the Allied cause win the war. As Fenichell stated, "If before the war plastic's image had been defined by frivolity, trumpery, and above all, a sleazy pretense at luxury, by the time Teflon was enlisted in the atomic bomb effort, plastic materials had matured under fire."
By the late 1940s, plastic, however artificial, was firmly rooted in the material life of all Americans, especially in the domestic sphere. Tupperware, made from polyethylene, was a brand of housewares developed by Earl S. Tupper in 1942. Even before the war's end, Tupperware and its home sales method of marketing and distribution, which combined entrepreneurialism with domestic duties, enjoyed large success among suburban housewives. Tupperware exploited the very plasticity of plastics—tumblers, bowls, tableware, and resealable containers—were durable yet soft, were strangely organic, and came in many forms and colors, as in pink, blue, orange, yellow, and green pastels. Dacron, another form of polyester, was invented in 1948 by DuPont chemist Hale Charch and woven into fabric to make clothing. Even though it melted, easily pilled, and caused static cling, such fabrics promised drip-dry suits that were machine washable instead of requiring dry cleaning. Magnetic metal particles imbedded in polyester film made audiotapes a viable option for consumers by 1949.
Vinyl experienced similar postwar popularity. Naugahyde, a cheaper and tougher substitute for leather, was now used to upholster recliners such as La-Z-Boys and Barcaloungers and came to symbolize a durable manliness in material form. In 1946, RCA marketed the first vinyl phonograph records, which performed better than earlier versions made from brittle shellac. These were further improved in 1949 as more grooves were pressed into the vinyl, thus producing the first "long-playing" record album. Saran wrap, a vinyl film, could stick to itself, and was therefore used to provide airtight protection; it found use as a kind of disposable Tupperware, covering food either under refrigeration or being transported.
Other plastics that had been around for decades did not experience their heydays until put to especially domestic postwar uses. The durable but slick Teflon, for example, which was invented in 1938 by Roy Plunkett, had unique qualities that made its application to normal life difficult at best: it would neither burn, freeze, nor conduct electricity. As the original space-age material, Teflon was used in space exploration and as an industrial lubricant. But it was not until Teflon was applied to cookware to render it non-stick that it gained a foothold in popular culture. Formica shared a similar history. Invented in 1913 by Westinghouse engineers Daniel J. O'Connor and Harold A. Faber, this cousin to Bakelite was used in institutional settings as an easily wipeable, durable, heat-resistant table surface most apt for hotels, diners, and soda fountains. Since Formica sheets could be manufactured with any number of designs, it frequently was used to simulate natural surfaces like wood grain or marble. After the war it appeared at, or rather on, the dinner table as a popular furniture surface. While utilitarian, it also "provided a blank screen for the unconscious projection of a prime fifties anxiety: the atom bomb.…Formica provided protection against internal and external attack, eternally vigilant in its struggle to wipe clean the past," in the words of Fenichell.
The exuberance expressed in postwar America as it reveled in its material abundance was most clearly seen in plastic objects. Children were surrounded by plastic toys, from educational Legos to quirky Silly Putty and faddish Hula-Hoops and Frisbees. Adult versions of these novelties included pink-flamingo or elfin lawn ornaments. Velcro ("velvet hook"), perfected in 1957, was inspired by the sticking power of the cockbur in nature. Pieces of Velcro stuck together could be easily peeled apart from each other, but required considerable shear strength to pull the pieces sideways. The Houston Astrodome, complete with Lucite sky and Astroturf grass, was an almost wholly plasticized environment. The creation of Disneyland and other similar fantasy places during this time symbolized America's willingness to settle for the artificial rather than the real and to prefer the human-made world of plasticized fakery over that of nature. This comfort with the unreal would, by the 1980s and 1990s, emerge in a postmodern culture of simulacra that accepted not only artificial replicas of nature, but also replicas of the replicas.
The 1960s pop aesthetic, influenced by modernity, space flight, and the interrelationships of human and machine, embraced the colors, textures, and forms of plastic, highlighting the materiality of plastic. Inflatable furniture, vinyl go-go boots, and plastic bubble helmets all enjoyed great popularity. Paco Rabanne connected hard plastic pieces to each other with metal rings, creating chain mail-like dresses, vests, and pieces of jewelry. Betsey Johnson designed an entire line of see-through clothing made out of cellophane. Conceptual artist Christo made it his trademark to wrap buildings and landscapes in plastic fabrics, like part of the Australian coast, to celebrate the beauty of synthetic materials as juxtaposed against the natural landscape.
By the 1970s, any clinging romance between people and plastic had disappeared. In this decade, the links between plastics and cancer were becoming clearer, even to the plastics industry, which found that its toxic fumes threatened the health of industrial workers. The wholesale disposability of convenient plastic goods—from contact lenses to cups to diapers—was seen to pose acute environmental hazards. Many forms of plastic would not biodegrade, making them a polluter of seashores and a threat to marine life. In the late 1980s, an anti-Styrofoam campaign launched in a Milford, New Jersey, lunch-room eventually came to pressure McDonald's into finding a more ecologically sound alternative to its Styrofoam sandwich containers and coffee cups. Consumers also debated the relative merits of plastic and paper bags in grocery stores with little consensus; by the end of the twentieth century, both were still offered in most U.S. stores, though the "green" movement seems to have had more of an impact on these matters in Europe. Around this same time, doctors diagnosed a new malady variously called "environmental illness," "twentieth century disease," or "sick building syndrome," which made some people develop an oversensitivity to the toxic environment around them. Concurrently, the first artificial heart made of plastic, the Jarvik-7, was successfully implanted in Barney Clark, underscoring the fact that plastic no longer existed just in people's external world, but that it could also become, literally, a part of them.
Plastic has entered Americans' material lives to such a degree that extricating themselves from their reliance on the simulated stuff would now be impossible without serious impact on the U.S. standard of living. The material has become so "naturalized" that it often seems more real, tangible, and honest than nature itself. It permeates every aspect of daily life, even to the extent that many consumer transactions are carried out via credit cards that are generically referred to as "plastic." As a descriptive term applied to people, "plastic" has come to reflect the larger trends in American culture that have blurred the distinction between animate beings and the inanimate goods that surround them. Ronald Reagan enjoyed notoriety as the "Teflon President" because nothing terrible that happened during his time in office stuck to his reputation. In attempts at self-beautification, large numbers of women and men turned to plastic surgery to alter noses and brows and to dispense with wrinkles and fat—perhaps in emulation of their idealized plastic counterparts, Barbie and Ken, whose sleek figures remain a sometimes unreachable goal to millions of overweight and aging Americans. In little over a century, the plastic ethos has embraced not only the versatile material but also the lifestyle and mindset that accompanied it, turning America into a prefabricated, simulated environment filled with people hungry for bright surfaces devoid of decay, even including their own.
Fenichell, Stephen. Plastic: The Making of a Synthetic Century. New York, Harper Business, 1996.
Friedel, Robert. Pioneer Plastic: The Making and Selling of Celluloid. Madison, Wisconsin, The University of Wisconsin Press, 1983.
Katz, Sylvia. Plastics: Common Objects, Classic Designs. New York, Harry N. Abrams, Inc., 1984.
Mossman, Susan, editor. Early Plastics: Perspectives, 1850-1950. London/Washington, Leicester University Press, 1997.
PLASTICS. Perhaps the most prevalent manufactured material in society today is plastics. About 200 billion pounds of plastics are produced annually in the world, 90 billion pounds in the United States alone. In the 1967 movie The Graduate, the title character, played by Dustin Hoffman, was offered one word of advice for future success: "plastics." It is difficult to imagine society without plastics. Plastics come in innumerable forms, types, and items. They can take the form of adhesives, casting resins, coating compounds, laminates, or molded plastics. They are formed through extrusion, injection, compression, blowing, transfer (fusing), or by a vacuum. There are thermoplastics of nylon, polyester, polyethylene, polypropylene, polyvinyl chloride, polystyrene, and many other substances. There are also thermoset plastics, made of phenols, urea-formaldehydes, melamines, or epoxies. A single object may involve many different types of plastics. For example, the plastics in a car include phenolic and glass (fiberglass), acetal, nylon, polypropylene, fluorocarbon, polyethylene, acrylic, butyrate, and melamine. Plastic can be a natural substance or a synthetic one. In other words, "plastics" can mean any number of different substances and products.
Resin is the key to plastics. Until the mid-nineteenth century, societies used natural plastic materials such as amber, sealing wax, shellac, or animal horns. These materials could be softened and molded. When cooled, they retained the new shape. Sealing wax was used to close documents with a personal mark. Items made from animal horns included buttons, cups, hornbooks, and lantern windows. Shellac (a gutta-percha molded plastic) was often
used for lamination and for phonograph records (until vinyl was introduced).
In the mid-nineteenth century, the organic chemical industry began, which led to a study of the chemical makeup of materials and many man-made products. Early plastics were created from cellulose wood fibers treated with nitrate. A German, Christian Friedrich Schönbein, was one of the first to develop cellulose nitrate plastics in 1846. Later, in England, Alexander Parkes developed Parkesine, a pressure-molded collodoin (cellulose nitrate in ethanol). He displayed many Parkesine objects at the 1862 London International Exhibition. However, as happened with so many inventions from Europe, it was the Americans who developed them as commercial successes. John Wesley Hyatt and his brother created the Celluloid Manufacturing Company in Newark, New Jersey, in 1872; this company became the renowned Celanese Corporation of America, renamed CelaneseAG in 1999. Hyatt used camphor as a plasticizer with cellulose, which proved safer and, therefore, more commercially viable. Camphor is still used as a natural plasticizer. Hyatt also introduced injection molding, extrusion molding (forcing molten plastics through an opening), and blow molding (like glass blowing). His work in celluloid made possible motion picture film for Thomas Edison, photographic film for George Eastman, and other products such as collars, eyeglass frames, and side curtains for automobiles. The great disadvantage of celluloid nitrate was its flammability. However, by World War I (1914–1918) the Tennessee Eastman Corporation had developed cellulose fibers mixed with acetate, which proved much less flammable and was used widely on airplane wings.
Leo Baekeland, a Belgian who came to the United States in 1889, developed the first commercial synthetic resin and the first thermoset resin in the early 1900s. He created a substance from phenolics (found in coal tar) and formaldehyde to impregnate fibrous sheets. His new synthetic was called Bakelite, which became the foremost name in plastics.
The work of Hermann Staudinger in Zurich in the 1920s was critical in explaining how the plastic molecules, polymers, were created. Once his work was accepted in the 1930s, the plastics industry developed rapidly with diversified products for commercial uses. In the 1930s the new plastics materials included urea resins, acrylics, and polyethylene in 1931; vinyl resins in 1933; melamine, fiberglass, and styrene in 1937; Teflon and epoxy in 1938; and nylon in 1939. After World War II (1939–1945), society entered the "Plastics Age."
What Are Plastics?
Plastics are inexpensive substances that are soft and malleable during manufacturing and are fabricated into lightweight, tough, rigid or flexible, clear or opaque, corrosive-resistant objects. There are some inorganic substances that conform to this definition—concrete, mortar, and plaster of Paris for example. However, as we think of them, plastics are organic substances made up of huge molecules called polymers. The organic material generally used is coal, oil, natural gas, or wood. Plastics have a high molecular weight; for instance, the molecular weight of oxygen is 32, and that of a polymer is between 10,000 and 500,000. Chemicals are used to distill and modify the organic substance. Chemicals found in plastics include carbon, hydrogen, oxygen, and nitrogen. Chlorine, fluorine, sulfur, or silicon may also be present. To make the polymers more flexible or tougher, a plasticizer is added. There are many different plasticizers, and it is important to use the right one in the right amount for the particular substance or object desired. If the wrong plasticizer is used, the polymer loses its plasticity in a short time. In the early days of the plastics industry, this happened often with raincoats, handbags, curtains, and other objects, which soon became brittle and cracked.
There are two types of plastics—thermoplastics and thermoset plastics. Thermoplastics are formed from long linear chains of molecules (polymers). These polymers can be softened and when cooled regain a solid state. These plastics can be first formed as sheets, pellets, films, tubes, rods, or fibers. These forms can then be reheated and molded into other shapes. For example, nylon thread can be made into fabric. The various chemical and molecular properties of thermoplastics determine whether they are called nylon, polyester, polypropylene, polystyrene, polyethylene, polyvinyl chloride (PVC), or other names.
Thermoset plastics are different. These polymers are formed from two directions and produce three-dimensional networks of molecules, not linear chains. Such substances cannot be remelted. They are formed through compression molding or casting. Thermoset plastics include phenolic laminates (the original Bakelite), urethane, melamine, epoxy, acrylic, silicone, fluorocarbons, and others.
Uses of Plastics
Plastics are prolific and have many advantages over other heavier, easily corroded, breakable, or more expensive materials. A home provides a good example of the ubiquity and versatility of plastics. The house may use vinyl concrete, vinyl siding, vinyl window frames, vinyl wallpaper, and vinyl venetian blinds. These are long lasting and require little upkeep. The wiring in the house could be polyethylene with epoxy coating. The insulation may be silicone or polystyrene. The house will also have polyvinyl chloride pipes. The outdoor furniture is likely to be molded PVC. Windows may be acrylic and so, too, the sofa. Seat cushions and pillows will likely be made with urea-formaldehyde foam; the carpets, nylon. The tables and cabinets may be polyurethane. Dishes may be melamine, which is easily dyed, durable, and very scratch resistant. The family car is also likely to be melamine coated. Pots and pans often use Teflon, a fluorocarbon invented in 1943. Serving dishes may be the acrylic Lucite,
and small windows may be of another acrylic, Plexiglas. Clothing may also be of plastics, including nylon stockings and nylon underwear. In the late 1960s, clothing often was all polyester; today, polyester fibers are often mixed with natural fibers such as wool or cotton for a more natural look. The home's air ducts are also likely to be polyester, and if there is a boat, it is most likely fiberglass, made from polyester and glass fiber mix. The glass fibers reinforce the plastics and allow for repairs. Foods in a home, especially meats, are packaged in Styrofoam, made from polystyrene, as are some carry-out containers. Polystyrenes are thermoplastics that are easily molded, rigid, and good insulators.
The five most prevalent plastics are all thermoplastics and account for 90 percent of the plastics of the early twenty-first century. These include polyethylene, used in all types of bags, diaper liners, agricultural covers, and milk and juice jugs; polyethylene terephthalate (PET), used principally for soda bottles and videotapes; polystyrene, used as clear packaging, as a foam (Styrofoam), or for furniture, toys, utensils, and dishes; polypropylene, used for battery cases, crates, film, molded car parts, appliances, fish nets, and wire coating; and polyvinyl chloride, used as a flexible substance in film, hoses, rainwear, and wall coverings, or as a rigid substance in pipes, buildings, and credit cards. The most prevalent thermoset plastics are phenolics, used with formaldehyde and fillers in plywood, fiberglass, and circuit boards; and urea resins, used in polyurethane foam fillers.
The uses of plastics are always expanding and new polymers are being created. One example of thermoset plastics whose uses are expanding is silicone. It is an oxygen-based, and not the usual carbon-based, substance. Because it is highly resistant to ozone, chemicals, sunlight, and aging, it has a wide variety of uses, such as polishes, insulation, waterproofing, adhesives, and implants. Two very versatile thermoplastics are polyethylene and polycarbonate. Polyethylene is used for toys, electronic devices, wires, and milk carton coatings. Polyethylene is also now used widely in medical procedures, for example, to replace aortas or as prosthetic devices. Polycarbonates are fairly new polymers that are formed from bonding oxygen and silicon. Polycarbonates are easy to use yet highly rigid and very corrosive resistant. They have replaced phenol laminates in spacecraft, automobiles, and ships.
Disadvantages of Plastics
Though plastics are ubiquitous and versatile, they also have several disadvantages. The original plastic, cellulose nitrate, was highly flammable; celluloid acetate lessened that danger. Later plastics have included flame retardants, which delay the outbreak of flames but not the decomposition before reaching flammable temperatures. Because of the flame retardants, plastics produce thick, dense smoke that is acrid from the chemicals, especially carbon monoxide. In some of the most disastrous fires, more people suffocated from the plastics smoke and soot than died from the flames. Also, once plastic does flame, it burns faster and hotter than natural substances.
Decomposition is another issue. Because plastics are made from long chains of molecules that receive high heat to set or mold them, decomposition can emerge as weaknesses in the chain. When thermoplastics are remolded, weaknesses can increase. Some plastics also decompose more rapidly than others, especially the less expensive plastics such as PVC and urethane foam. Some critics claim that the phthalate plasticizers used in PVC create low-level toxicity. The urethane foam cushions begin to break down fairly quickly, leaving bits of foam and dust. Leaving plastics exposed to sunlight and heat also causes decomposition and cracking. As plastics decompose, they release chemicals such as carbon monoxide, chlorine, and benzene into the air. For example, the "office worker's illness" is caused by decomposing polymers of the air ducts, furniture, and equipment, and too little fresh air.
Another problem with plastics is waste disposal. In the United States alone, some 60 billion pounds of plastics
are discarded annually and over 90 percent of the waste is not yet recycled. Thermoset plastics cannot be reused; neither can some thermoplastics because of impurities (including disposable diapers, food packaging, and trash bags). Nevertheless, in the United States and Europe plastics recycling has become a major industry, tripling in the United States since 1990. Recycled bottles alone have grown from 411 million pounds in 1990 to 1,511 million pounds in 2000. There are over 1,400 products made from recycled plastics, most of the same items as new synthetic plastics—furniture, packaging, household items—but also new items such as lumber and posts.
Composting is a principal method of recycling plastics. Synthetic plastics may decompose through photo-degradation, oxidation, or hydrolysis—naturally or chemically. Success in composting depends on the environment and the chemicals used in the plastics. Some, such as the polyolefins, are hydrophobic (water-resistant) and thus highly resistant to biodegradation.
The newest research and development in plastics is in bioplastics, biodegradable plastics whose components are principally derived from renewable raw materials. This often means a return to many of the natural polymers used in the nineteenth century, with late-twentieth or twenty-first-century technology added. In 1941 Henry Ford produced a prototype Ford made of soybean plastics. Due to war needs and the rise of synthetic plastics, the work was abandoned, but such innovation is typical of today's research and development. Bioplastics are already used in a wide variety of products including all types of bags, packaging, fishnet and lines, pet toys, wall coverings, razors, and golf tees.
Starch is a prolific raw material that makes a good plastic. It is now used in many fast-food containers and for the "peanuts" used in shipping. The water solubility of starch is both an advantage for decomposition and a limitation, which technology may overcome. For example, some eating utensils are now made of 55 percent cornstarch and 45 percent poly(lactic acid), which is insoluble in water but biodegradable in seawater. Poly(lactic acid) is a polyester synthesized from lactic acid. It shows solid commercial production growth and is used, for example, in compost bags, agricultural films, fibers, and bone repair. Cellulose is another bioplastic from the past. It is contained in 40 percent of organic matter and thus is renewable. Its limitation is that it is not thermoplastic, though it can be made into films.
Though bioplastics have limitations such as tensile strength, solubility, and cost, they produce less toxicity to humans and the environment and are based on renewable resources. Improved technology may overcome the limitations.
Hooper, Rodney. Plastics for the Home Craftsman. London: Evans Brothers, 1953.
Simonds, Herbert R., and James M. Church. A Concise Guide to Plastics. New York: Reinhold Publishing Company, 1963.
Stevens, E. S. Green Plastics: An Introduction to the New Science of Biodegradable Plastics. Princeton, N.J.: Princeton University Press, 2002.
Wallace, Deborah. In the Mouth of the Dragon. Garden City Park, N.Y.: Avery Publishing Group, 1990.
Plastics are a subspecies of a class of materials known as polymers. These are composed of large molecules , formed by joining many, often thousands, of smaller molecules (monomers) together. Other kinds of polymers are fibers, films, elastomers (rubbers), and biopolymers (i.e., cellulose, proteins, and nucleic acids). Plastics are made from low-molecular-weight monomer precursors, organic materials, which are mostly derived from petroleum, that are joined together by a process called "polymerization." Plastics owe their name to their most important property, the ability to be shaped to almost any form to produce articles of practical value. Plastics can be stiff and hard or flexible and soft. Because of their light weight, low cost, and desirable properties, their use has rapidly increased and they have replaced other materials such as metals and glass. They are used in millions of items, including cars, bullet-proof vests, toys, hospital equipment, and food containers. More than a hundred billion pounds of plastic were produced in 2000. Their increased use has resulted in concern with (1) the consumption of natural resources such as oil, (2) the toxicity associated with their manufacture and use, and (3) the environmental impact arising from discarded plastics.
Industrial practices in plastic manufacture can lead to polluting effluents and the use of toxic intermediates, the exposure to which can be hazardous. Better industrial practices have led to minimizing exposure of plant workers to harmful fumes; for example, there have been problems in the past resulting from workers being exposed to toxic vinyl chloride vapor during the production of polyvinyl chloride. Much progress has been made in developing "green processes" that avoid the use of detrimental substances. For example, phosgene, a toxic "war gas," was formerly used in the manufacture of polycarbonates. New processes, now almost universally employed, eliminate its use. Also, the "just in time" approach to manufacture has been made possible by computer-controlled processes, whereby no significant amounts of intermediates are stored, but just generated as needed. In addition, efforts are ongoing to employ "friendly" processes involving enzyme-catalyzed low-temperature methods akin to biological reactions to replace more polluting high-temperature processes involving operations like distillation.
Spillage of plastic pellets that find their way into sewage systems, and eventually to the sea, has hurt wildlife that may mistake the pellets for food. Better "housekeeping" of plastic molding facilities is being enforced in an attempt to address this problem. Most plastics are relatively inert biologically, and they have been employed in medical devices such as prosthetics, artery replacements, and "soft" and interocular lenses. Problems with their use largely result from the presence of trace amounts of nonplastic components such as monomers and plasticizers. This has led to restrictions on the use of some plastics for food applications, but improved technology has led to a reduction in the content of such undesirable components. For example, the use of polyacrylonitrile for beverage bottles was banned at one time because the traces of its monomer, acrylonitrile, were a possible carcinogen. However, current practices render it acceptable today. There has been concern about endocrine disruption from phthalate-containing plasticizers used for plastics such as polyvinyl chloride (PVC). The subject of this possible side effect is controversial, but caution in use is warranted pending further study. Plastics may also result in problems resulting from their improper use, and there is need of better education concerning limitations of use, for example, precautions that should be taken with items such as frying pan coatings and microwavable containers. When exposed to high temperatures, some plastics decompose or oxidize and produce low molecular weight products that may be toxic.
Reduced Use and Recycling
There is growing concern about the excess use of plastics, particularly in packaging. This has been done, in part, to avoid the theft of small objects. The use of plastics can be reduced through a better choice of container sizes and through the distribution of liquid products in more concentrated form. A concern is the proper disposal of waste plastics. Litter results from careless disposal, and decomposition rates in landfills can be extremely long. Consumers should be persuaded or required to divert these for recycling or other environmentally acceptable procedures. Marine pollution arising from disposal of plastics from ships or flow from storm sewers must be avoided. Disposal at sea is prohibited by federal regulation.
Recycling of plastics is desirable because it avoids their accumulation in landfills. While plastics constitute only about 8 percent by weight or 20 percent by volume of municipal solid waste, their low density and slowness to decompose makes them a visible pollutant of public concern. It is evident that the success of recycling is limited by the development of successful strategies for collection and separation. Recycling of scrap plastics by manufacturers has been highly successful and has proven economical, but recovering discarded plastics from consumers is more difficult. It is well recognized that separated plastics can be recycled to yield more superior products than possible for mixed ones.
Labeling plastic items with symbols has been employed, which enables consumers to identify them easily for placement in separate containers for curbside pickup. However, success depends on how conscientious consumers are in employing such standards and the ability of collectors to keep various types of plastic separate. Even a small amount of a foreign plastic in recycling feedstock can lead to the appreciable deterioration of properties, and it is difficult to achieve a high degree of purity. Manual sorting at recycling centers helps, but even trained sorters have difficulty identifying recyclables. Furthermore, manual sorting is an unattractive task and retaining labor willing to be trained for this is problematic. Automatic sorting techniques have been developed that depend on various physical, optical, or electronic properties of plastics for identification. Such methods prove difficult because of the variety of sizes, shapes, and colors of plastic objects that are encountered. Although in principle it is possible to create devices that can separate plastics with varying degrees of success, the equipment generally becomes more expensive with increasing efficiency. Technology for this continues to improve, and it is becoming possible to successfully separate mixed plastics derived from curbside pickup using such equipment.
To separate plastics, it is first necessary to identify the different types as indicated in the table. One must also distinguish between thermoplastics and thermosets. The latter, as found in tires and melamine dishes, has molecules that are interconnected by "crosslinks" and cannot be readily melted for recycling unless they are chemically reduced to low-molecular-weight species. For tires, recycling has not proved economical so disposal has involved grinding them up as asphalt additives for roads or burning in cement kilns.
Over 1.5 million pounds of plastic bottles were recycled in 2000, representing a four-fold increase in the amount of plastic recycled the previous decade. Nonetheless, the capacity to recycle bottles appreciably exceeds their supply by about 40 percent, so local governments and environmental groups need to encourage greater participation in this practice among consumers.
Profitable operations are currently in place for recycling polyethylene terephthalate (PET) from bottle sources and converting it into products such as fibers. One persistent problem, though, is obtaining clean enough feedstock to avoid the clogging of orifices in spinnerets by foreign particles. This has limited the ability to produce fine denier fibers from such sources. PET recycling is also constrained by regulations limiting its use to produce items in contact with food because there had been concern about contamination in consideration of improved recycling techniques.
A leading candidate for recycle feedstock is carpets because replacement carpets are usually installed by professionals able to identify recyclables and who serve as a ready source for recycling operations. They face the problem, however, of separating the recyclable carpet components from other parts such as jute backing and dirt. Such recycling operations have been only marginally profitable.
Polystyrene (PS) is another potentially recyclable polymer, but identifying a readily collectable source is problematic. One had been the Styrofoam "clamshells" fast-food chains use to package hamburgers. Recyclers were able to profitably collect polystyrene from such sources and produce salable products. However, largely because of public pressure, this use of polystyrene has declined, so related recycling practices have largely disappeared too. Cafeteria items from school lunchrooms are another potential, but the collection of such objects involves the development of an infrastructure, often not in place. In these cases, it is necessary to separate the polystyrene from paper and food waste, but washing and flotation techniques have been developed for this purpose.
Increasing amounts of plastic components appear in automobiles, and their recovery from junked cars is a possibility. Its success depends on the ability of a prospective "junker" to identify and separate the plastic items. Three efforts may aid in this accomplishment:
- The establishment of databases to enable junkers to learn what kinds of plastic are used in what parts of what model cars.
- A reduction in the number of different plastics used for car construction.
- The design of cars such that plastic parts may be removed easily (this would require special types of fasteners).
This illustrates a general need—the design of plastic-containing products with the ability to recycle in mind. As a consequence of public concern about the environmental problems arising from plastic use, industry is responding to these needs. The effort continues to use fewer different kinds of plastics and to adopt designs that allow for easier recycling but still retain desirable properties.
There are, however, some worthwhile products that can be produced from mixed plastic, such as "plastic lumber" used for picnic benches and marine applications such as docks and bulkheads that successfully replace wooden lumber which often contains toxic preservatives and arsenic. But, the market for such a product is limited, so efforts to obtain separated plastics are preferred.
Discarded plastics are hard to eliminate from the environment because they do not degrade and have been designed to last a long time. It is possible to design polymers containing monomer species that may be attacked by chemical, biological, or photochemical action so that degradation by such means will occur over a predetermined period of time. Such polymers can be made by chemical synthesis (as with polylactic acid) or through bacterial or agricultural processes (as with the polyalkonates). Although such processes are often more expensive than conventional ones, cost would undoubtedly drop with increased production volume. One success story was the introduction of carbonyl groups into polyethylene by mixing carbon monoxide with ethylene during synthesis. These carbonyl groups are chomophores that lead to chain breaking upon the absorption of ultraviolet light. The polymer is then broken down into small enough units that are subject to bacterial attack. This approach has been successful, for example, in promoting the disappearance of rings from beverage cans, which are potentially harmful to wildlife.
A problem with the degradation of plastics is that it is probably undesirable in landfills because of the leachants produced that may contaminate water supplies. It is better in these instances to ship the plastics to composting facilities. This requires the separation of degradable plastics from other materials and the availability of such facilities. In most cases, the infrastructure needed for such an approach is not in place. This has discouraged its use for disposable diapers that are said to constitute 1 to 2 percent of landfill volume.
Degradable polymers may have limited use in the reduction of litter and production of flushable plastics, for example, feminine hygiene products, but it seems unlikely that the use of such materials will be a viable means of disposal for large amounts of plastic products. Degradation leads to the loss of most of the potential energy content of plastics that might be recovered by trash-to-energy procedures.
Trash to Energy
A method of plastic disposal with more positive environmental implications is burning and recovering the energy for power generation or heating. Plastics contain much of the energy potential of the petroleum from which they are made, and they, in a sense, are just borrowing this energy that may be recovered when the plastic is burned. Environmentalists and the public have objected to this procedure, leading to legislative restrictions. This has arisen, in part, because of the image of "old-fashioned" incinerators polluting the air with toxic fumes and ash. However, it is possible to construct a "high-tech" incinerator designed to operate at appropriate temperatures and with sufficient air supply that these problems are minimized. Remaining toxic substances in fumes may be removed by scrubbing, and studies have shown that no significant air pollution results. Toxic ash, for the most part, does not arise from the polymer components of the feedstock, but rather from other materials mixed with the polymers as well as from fillers, catalyst content, and pigments associated with the polymers. Proper design of the polymers and crude separation of the incinerator feedstock can reduce this problem. Furthermore, if the feedstock was not incinerated but placed in landfills, contaminants would ultimately enter the environment in an uncontrolled way. Incineration reduces the volume, so that the ash, which may contain them, can be disposed of under more controlled conditions. Also, it is possible to insolublize the ash by converting it into a cementlike material that will not readily dissolve.
Facilities for converting trash to energy in an environmentally acceptable way are expensive and at present not cost-effective when considering short-range funding. However, in the long run, they are environmentally desirable and reduce the need for alternative means for plastic waste disposal. It is imperative that legislators and taxpayers soon adopt this long-range perspective.
see also Endocrine Disruption; Recycling; Solid Waste; Waste.
American Plastics Council. (2001). "2000 National Post Consumer Plastics Recycling Report." Arlington, VA: Author.
Gerngross, T.U., and Slater, S.C. (2000). "How Green Are Green Plastics." Scientific American August.
Hocking, M.B. (1991). "Paper vs. Polystyrene, a Complex Choice." Science 251.
Limbach, B.M. (1990). Plastics and the Environment, Progress and Commitment. Washington, D.C.: Society of the Plastics Industry.
Piaecki, B.; Rainry, D.; and Fletcher, K. (1998). "Is Combustion of Plastics Desirable?" American Scientist 86: 364.
Stein, R.S. (2002). "Plastics Can Be Good for the Environment." NEACT Journal 21: 10–12.
Vesilind, P.A. (1997). Introduction to Environmental Engineering. Boston, MA: PWS Publishing.
Richard S. Stein
The term "plastic" can be broadly defined as any inherently formless material that can be molded or modeled under heat and/or pressure. It is derived from the Greek word plastikos, meaning a shaped or molded substance.
The term "plastics" first included only natural polymers—usually animal proteins (horn and tortoise shell), tree resins, or insect secretions called shellac—that were subsequently mixed with fillers such as wood flour to yield substances having better molding properties. (A polymer, from the Greek word poly, meaning "many," and mer meaning "unit," is a molecule with an extremely high molecular weight.)
The use of natural polymers to make plastic products started as early as 1760, when Enoch Noyes opened a business making combs out of keratin and albuminoid organic proteins derived from animal horns and horse hoofs. However, the first commercially successful plastic material, celluloid, would not come about for another hundred years.
In the 1840s German chemist Christian Schönbein developed cellulose nitrate from a mixture of cotton, nitric acid, and sulfuric acid. Cellulose nitrate is a highly flammable doughlike substance primarily used in the manufacture of explosives. Schönbein's innovation represents the beginning of the modification of natural polymers by chemists so as to increase their processibility and functionality. Cellulose nitrate's properties as a molding substance interested other scientists of the time, and in 1855 an Englishman named Alexander Parkes developed a form of cellulose nitrate he named Parkesine. From this material, Parkes manufactured a number of buttons, pens, medallions, and combs. In 1862 he displayed this material officially at the Great International Exhibit in London. Parkes made small commercial gains with Parkesine and eventually sold the rights to Daniel Spill, who subsequently began production of the substance under the names Xylonite and Ivoride, around 1865. Spill received British patents for Xylonite and Ivoride in 1867 and 1869, respectively.
At around the same time in the United States, a billiard ball company advertised a $10,000 reward for the discovery of an alternate material to ivory. John Wesley Hyatt developed collodion, a mixture of cellulose nitrate and alcohol. Like cellulose nitrate, collodion was highly flammable and would produce a small explosion upon agitation. Hyatt reported: "[W]e had a letter from a billiard saloon proprietor in Colorado mentioning this fact … saying he did not care so much about it, but that instantly every man in the room pulled a gun." To avoid melee, camphor, a derivative of the laurel tree, was added, and in 1870 Hyatt received a U.S. patent for celluloid. In 1871 Hyatt and his brother Isaiah formed the American Celluloid Company, which is today the Plastics Division of the Celanese Corporation.
HERMAN MARK (1895–1992)
The influence of Herman Mark, the so-called father of polymer science, on the plastics industry still echoes today in a legacy of education and research. His work in the 1920s on the structure of cellulose opened the door for the development of synthetic fibers such as acrylic, nylon, polyester, polystyrene, and PVC.
A more common perception of plastic is that it is a synthetic or man-made material, with highly engineered properties and product designs. Dr. Leo Baekeland engineered the first totally synthetic plastic in 1907. Patented in 1909 and named Bakelite after its inventor, the material was the first thermoset plastic. The term "thermoset" refers to a plastic that under initial heat and pressure can be molded into form. After cooling, the material sets and cannot be remelted or re-formed. This setting is due to the cross-linking of polymer chains, wherein strong covalent bonds form between separate oligomers, short chains of polymer units called monomers. The most common thermoset resin is vulcanized rubber, created by Charles Goodyear in the United States in 1839. Vulcanized rubber utilizes natural hevea rubber made from the gutta percha tree, and therefore is not totally synthetic (like Bakelite). Ironically, the first use of Bakelite was as a replacement for natural rubber in electrical insulations. Bakelite is formed via the reaction of phenol and formaldehyde under high heat. Initially, formaldehyde is added to the reaction mixture in small amounts (forming a resin); the mixture is then poured into a mold, into which more formaldehyde is added; and pressure is applied to create the final product.
Over the next several decades, many varieties of synthetic thermoplastic materials would be developed in Germany, England, and the United States. Thermoplastic materials such as vinyls, nylons, and acrylics are polymers that can be molded or formed under heat and pressure, and if necessary can be reheated and re-formed (and will retain most of their original mechanical properties).
Eugen Baumann created today's most common vinyl, polyvinyl chloride (PVC), in 1872. However, Friedrich Heinrich August Klatte did not patent it until 1913. At that time PVC was not well received, as illustrated by Waldo Semon's comment, "People thought of PVC as worthless back then; they would throw it in the trash." Semon was responsible for creating plasticized PVC. He had been attempting to dehydrohalogenate PVC in a high boiling solvent when he realized that the molten material was exhibiting greater flexibility and elasticity. The exposure of PVC to a boiling solvent introduced a plasticizer, or low molecular weight molecule, to the PVC matrix. Today plasticizers are commonly added to polymers (especially PVC) to enhance flexibility, prevent stress cracking, and enhance processability. This has enabled the use of PVC in diverse commercial applications, including the manufacture of rigid tubing and flexible car seats.
In 1920 German scientist Hermann Staudinger published his theories on polyaddition polymerization, the formation of long-chain molecules. (Previously, the manner in which long-chain molecules were formed was unexplained.) Nine years later, in a publication that detailed the polymerization of styrene, this method of chain formation would be laid out. During this time period Staudinger developed polystyrene into a commercial product. A division of the German chemical company IG Farben, known as Badische Anilin-und Soda-Fabrik, or BASF, produced polystyrene in 1930. The Dow Chemical Company introduced the American public to polystyrene in 1937.
In 1928 directors at E. I. du Pont de Nemours & Company (Du Pont) placed Dr. Wallace H. Carothers in charge of fundamental research into what are now classic studies on the formation of polymer chains. During his years at Du Pont, Carothers published his theory on polycondensation, and discovered both neoprene and nylon.
Nylon, not publicly announced until 1938, was first used for bristles on combs, but made headlines in 1939 when nylon stockings debuted at the World's Fair in New York City. Nylon is known by its chemical name, poly(hexamethylene) adipamide, but more often simply as nylon. The first nylon manufacturing plant went into production at Seaford, Delaware, in 1940. Commercial production of nylon 6 by IG Farben in Germany began in 1941. These two plants would go on to produce millions of pounds of nylon annually. This mass production was essential to the World War II effort, as nylon was used for everything from belts, ropes, and straps to tents and parachutes.
Another polymer that came into use during World War II was polytetrafluoroethylene (PTFE), which received the trademark Teflon. Dr. Roy J. Plunkett and his assistant Jack Rebock at Du Pont discovered PTFE accidentally on April 6, 1938. They had been conducting research on alternate refrigeration methods when they discovered the polymerization of tetrafluoroethylene. Plunkett received a patent for PTFE in 1941. It was found that the material was resistant to corrosion by all the solvents, acids, and bases that were available for testing at that time. This led to the U.S. military's interest in PTFE, and its subsequent use as a cover for proximity fuses on the nose cones of artillery shells. It was not until the material was declassified in 1946 that the public learned of the material Du Pont had named Teflon two years earlier. Teflon has since become a household name; its best-known use being its contribution to nonstick surfaces on pots and pans.
Today's most widely produced and perhaps most versatile plastic, polyethylene, was discovered at the Imperial Chemical Industries (ICI) in England in 1933. E. W. Fawcett and R. O. Gibson set off a reaction between ethylene and benzaldehyde under 2,000 atmospheres of pressure, resulting in the polymerization of ethylene and the birth of polyethylene. By 1936, ICI had developed a larger volume compressor that made the production of useful quantities of polyethylene possible. Among polyethylene's first applications were its uses as underwater cable coatings and as insulation for radar during World War II.
In 1943, Karl Ziegler began work that would drastically alter the production of polyethylene. Ziegler used organometallic compounds, which have both metallic and organic components, as catalysts. At very modest pressures, these catalysts generated a linear, more rigid, high molecular weight polyethylene, and the innovation increased the number of the polymer's applications. Today polyethylene is used in the production of detergent bottles and children's toys, and is even replacing Kevlar as a bulletproof material.
In 1957, at the Montecatini Laboratories in Italy, Giulio Natta continued the work of Ziegler and used what is now termed Ziegler–Natta polymerization to create polypropylene. When Natta reported the polymerization of ethylene with a titanocene catalyst, it became clear that polymer chains with specific tacticities, or specific ordered structures, were possible. Polypropylene rose to become a substitute for polyethylene in products in which slightly higher temperature stability was necessary, for example, dishwasher-safe cups and plates.
Polycarbonate, a popular plastic used originally to make eyeglass lenses, was first discovered by A. Einhorn in 1898. But it would be more than fifty years before further research was performed on the material. In the 1950s Dr. Herman Schnell, working at Bayer, a division of IG Farben, along with Daniel Fox of General Electric's Corporate Laboratory in Schenectady, New York, conducted concurrent research on the synthesis of polycarbonate. Schnell and Fox each achieved a polymerization that produced polycarbonate via different methods, and received patents in 1954 and 1955, respectively. Upon his achievement of polymerization, Fox described his attempts to remove the newly formed polymer from the reaction vessel: "The remnants of the glass were broken away to yield a hemispherical, glass fragment embedded, glob of plastic on the end of a steel stirrer shaft. The glob was pounded on the cement floor and struck with a hammer in abortive attempts to remove the remaining glass, and/or, shatter the plastic. The pseudo plastic mallet was even used to drive nails into wood." That glob would eventually be developed into bulletproof glass and provide General Electric and Bayer with billions of dollars in revenue.
Means to improve the material properties of plastics have been sought for decades. Improvement has sometimes come in the form of compounds such as mineral fillers, antioxidants, and flame-retardants. One of the first searches for an improved material was centered on cellulose nitrate. Cellulose nitrate is colorless and transparent, which enabled it to be used as photographic film. However, it is extremely flammable, and its early use in motion picture film and concomitant exposure to hot lights led to numerous fires. In 1900, Henri Dreyfus substituted acetic acid for nitric acid in the synthesis of cellulose nitrate, and created instead a less flammable material, cellulose acetate. Today, polymers are often halogenated in order to achieve flame-retardation.
Plastics have been designed to be chemically resistant, stable compounds, and have been extremely successful in these regards. In fact, they have been so successful that an environmental problem has been created. Plastic products discarded in landfills decay slowly. They sometimes contain heavy metal additives. In addition, the millions of pounds of plastic discarded annually have engendered a crisis over landfill space. In the early 1980s plastic recycling programs began to spring up across the United States in response to the large number of polyethylene terephthalate (PET or PETE) bottles being discarded. In 1989, 235 million pounds of PET bottles were recycled. The number rose to 1.5 billion pounds in 1999.
Most plastics can be recycled. Even mixed plastic waste can be recycled into artificial lumber or particleboard. Plastic "wood" is easy to saw, and it has better resistance to adverse weather and insects than real wood.
see also Baekeland, Leo; Carothers, Wallace; Goodyear, Charles; Staudinger, Hermann; Nylon; Polymers, Synthetic.
Paul E. Koch
DiNoto, Andrea (1984). Art Plastic Designed for Living. New York: Abbeville Press.
Morawetz, Herbert (1985). Polymers: The Origins and Growth of a Science. New York: John Wiley.
Seymour, Raymond B. (1986). High Performance Polymers: Their Origin and Development. New York: Elsevier Science.
plastic, any organic material with the ability to flow into a desired shape when heat and pressure are applied to it and to retain the shape when they are withdrawn.
Composition and Types of Plastic
A plastic is made up principally of a binder together with plasticizers, fillers, pigments, and other additives. The binder gives a plastic its main characteristics and usually its name. Thus, polyvinyl chloride is both the name of a binder and the name of a plastic into which it is made. Binders may be natural materials, e.g., cellulose derivatives, casein, or milk protein, but are more commonly synthetic resins. In either case, the binder materials consist of very long chainlike molecules called polymers. Cellulose derivatives are made from cellulose, a naturally occurring polymer; casein is also a naturally occurring polymer. Synthetic resins are polymerized, or built up, from small simple molecules called monomers. Plasticizers are added to a binder to increase flexibility and toughness. Fillers are added to improve particular properties, e.g., hardness or resistance to shock. Pigments are used to impart various colors. Virtually any desired color or shape and many combinations of the properties of hardness, durability, elasticity, and resistance to heat, cold, and acid can be obtained in a plastic.
There are two basic types of plastic: thermosetting, which cannot be resoftened after being subjected to heat and pressure; and thermoplastic, which can be repeatedly softened and remolded by heat and pressure. When heat and pressure are applied to a thermoplastic binder, the chainlike polymers slide past each other, giving the material "plasticity." However, when heat and pressure are initially applied to a thermosetting binder, the molecular chains become cross-linked, thus preventing any slippage if heat and pressure are reapplied.
See epoxy resins; polyacrylics; polycarbonates; polyethylene; polyolefins; polypropylene; polystyrene; polyurethanes; polyvinyl chloride; vinyl plastics.
Molding of Plastic
Plastics are available in the form of bars, tubes, sheets, coils, and blocks, and these can be fabricated to specification. However, plastic articles are commonly manufactured from plastic powders in which desired shapes are fashioned by compression, transfer, injection, or extrusion molding. In compression molding, materials are generally placed immediately in mold cavities, where the application of heat and pressure makes them first plastic, then hard. The transfer method, in which the compound is plasticized by outside heating and then poured into a mold to harden, is used for designs with intricate shapes and great variations in wall thickness. Injection-molding machinery dissolves the plastic powder in a heating chamber and by plunger action forces it into cold molds, where the product sets. The operations take place at rigidly controlled temperatures and intervals. Extrusion molding employs a heating cylinder, pressure, and an extrusion die through which the molten plastic is sent and from which it exits in continuous form to be cut in lengths or coiled.
Plastics are so durable that they will not rot or decay as do natural products such as those made of wood. As a result great amounts of discarded plastic products accumulate in the environment as waste. It has been suggested that plastics could be made to decompose slowly when exposed to sunlight by adding certain chemicals to them. Plastics present the additional problem of being difficult to burn. When placed in an incinerator, they tend to melt quickly and flow downward, clogging the incinerator's grate. They also emit harmful fumes; e.g., burning polyvinyl chloride gives off hydrogen chloride gas.
Development of Plastics
The first important plastic, celluloid, was discovered (c.1869) by the American inventor John W. Hyatt and manufactured by him in 1872; it is a mixture of cellulose nitrate, camphor, and alcohol and is thermoplastic. However, plastics did not come into modern industrial use until after the production (1909) of Bakelite by the American chemist L. H. Baekeland. Bakelite, made by the polymerization of phenol and formaldehyde, is thermosetting. New uses for plastics are continually being discovered. Following World War II optical lenses, artificial eyes, and dentures of acrylic plastics, splints that X rays may pierce, nylon fibers, machine gears, fabric coatings, wall surfacing, and plastic lamination were developed. More recently a hydrophilic, or water-attracting, plastic suitable for use in non-irritating contact lenses has been developed. Among the trade names by which many plastic products are widely known are Plexiglas, Lucite, Polaroid, Cellophane, Vinylite, and Koroseal. Plastics reinforced with fiberglass are used for boats, automobile bodies, furniture, and building panels.
See L. K. Arnold, Introduction to Plastics (1968); J. H. DuBois, Plastics History, U.S.A. (1972); H. D. Junge, Dictionary of Plastics Technology (1987); A. W. Birley et al., Plastics Materials: Properties and Applications (1988).
Plastic is a synthetic material made out of petroleum products that can be shaped and molded into an infinite variety of shapes without breaking. Few other products have influenced American culture as much as plastic. In the early twentieth century, plastic proved that it could be used as a substitute for all kinds of natural materials. It soon began to appear in all kinds of products that Americans used. Americans' use of plastic as a cheap imitation of natural substances led some to call American culture a "plastic" or artificial culture, focused on cheap imitations rather than on items of genuine quality. Whether or not that was true, plastics became a part of most Americans' daily lives.
Plastic began as a search for a man-made alternative to natural materials such as marble, ivory, and bone. Those items were used in all kinds of consumer goods in the 1800s and earlier, but depending on the substance they could be somewhat rare and expensive. The first plastic-like substance was celluloid, invented in 1869 by John Wesley Hyatt (1837–1912) as a substitute for ivory. That discovery led to later innovations, including the development of chemically synthetic plastics in the early twentieth century. The invention of other plastic forms such as nylon (see entry under 1930s—Fashion in volume 2), rayon, polyvinyl chloride, vinyl, lucite, plexiglas, and teflon followed.
The development of plastic as a scientific story is important, but, like many scientific inventions, its use by ordinary people is what made plastic such an important part of everyday American life. As the twentieth century progressed, plastics crept into American life in more and more unique ways. For instance, celluloid, the first plastic substance, revolutionized photography, enabling film to be used easily in portable cameras by all kinds of people. No longer did one need to be a professional photographer to take pictures. Celluloid was also crucial to the development of motion pictures. All the classic images Americans enjoy on the screens of their local movie theaters are due to plastic celluloid. Cellophane, a close relative of celluloid, was used as plastic wraps to help keep food fresh and in such products as "Scotch" tape. Plastics found their way into clothing in the form of nylon stockings (see entry under 1930s—Fashion in volume 2), or nylons, for women's legs; in rayon dresses that simulated natural, and therefore more expensive, silk; and in polyester (see entry under 1970s—Fashion in volume 4) suits for men.
Plastics also entered the home in increasing numbers. People spoke into new, one-piece plastic telephone receivers and sat on Naugahyde (artificial leather) recliners. Plastics were especially popular in the kitchen. Vinyl flooring stood up to lots of rough treatment and spills wiped up easily from its surface. Plastic Tupperware, kitchen bowls made out of plastic, proved very popular in the 1940s and after. Plastic could form all kinds of convenient shapes for bowls, glasses, and containers. Plastic kitchenware could be dropped without breaking, and it was inexpensive to buy. Teflon proved it could be used as a nonstick cooking surface. As a result of these innovations, homeowners loved plastic. Plastic was also found elsewhere in the home—in children's toys, such as LEGO (see entry under 1950s—Sports and Games in volume 3) blocks and Fisher-Price toys (see entry under 1930s—Commerce in volume 2); in teenagers' bedrooms, with vinyl rock-and-roll records; in plastic swimming pools in the backyard; and in plastic doormats that resembled green grass.
By the 1960s, plastics were an inescapable part of American life. The substance was even immortalized in the 1967 film The Graduate (see entry under 1960s—Film and Theater in volume 4), starring Dustin Hoffman, when an older neighbor tells Hoffman's character that he could describe a bright future for him in one word: "plastics." By that time, however, although millions of people were using plastic in their everyday lives, some people became disturbed by the American tendency to replace natural things with synthetic plastics. Even as early as the 1920s, plastic was used as a negative word for artificial. Living in a "plastic society" meant living in an artificial world cut off from nature. Indeed, plastics had been phenomenally successful in replicating natural materials. But by the 1970s, the costs of this material were slowly becoming known. Plastics, it turned out, caused cancer in many workers who breathed in fumes during its manufacture. It also proved a big environmental problem. Plastic made possible a throwaway culture centered around convenience. Many items, like styrofoam cups, were used once and then thrown away, piling up along roadsides as litter and taking up precious space in landfills. Plastics also do not degrade into their base materials as natural substances do, so the plastic cup someone threw away in 1955 still exists today, sitting in a landfill somewhere. These problems even led some people to boycott styrofoam cups and to urge people to reconsider their use of plastic.
By the end of the twentieth century, plastics were an inescapable part of American life. Plastics helped make life easier in a multitude of ways but also proved that few, if any, innovations come without some cost to society.
For More Information
Fenichell, Stephen. Plastic: The Making of a Synthetic Century. New York: HarperBusiness, 1996.
Katz, Sylvia. Plastics: Common Objects, Classic Designs. New York: Harry N. Abrams, 1984.
Meikle, Jeffrey L. American Plastic: A Cultural History. New Brunswick, NJ: Rutgers University Press, 1995.
M. Foster (ed.) (1982);
T. Newman (1972);
Skeist (ed.) (1996);
Jane Turner (1996)
plas·tic / ˈplastik/ • n. a synthetic material made from a wide range of organic polymers such as polyethylene, PVC, nylon, etc., that can be molded into shape while soft and then set into a rigid or slightly elastic form. ∎ inf. credit cards or other types of plastic card that can be used as money: he pays with cash instead of with plastic. • adj. 1. made of plastic: plastic bags. ∎ looking or tasting artificial: long-distance flights with their plastic food she smiled a little plastic smile. 2. (of substances or materials) easily shaped or molded: rendering the material more plastic. ∎ (in art) of or relating to molding or modeling in three dimensions, or producing three-dimensional effects. ∎ (in science and technology) of or relating to the permanent deformation of a solid without fracture by the temporary application of force. ∎ offering scope for creativity: the writer is drawn to words as a plastic medium. ∎ Biol. exhibiting adaptability to change or variety in the environment. DERIVATIVES: plas·ti·cal·ly / -(ə)lē/ adv.