The Development of Plastics

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The Development of Plastics

Overview

At the beginning of the twentieth century manufacturers made consumer goods and electrical insulation from natural materials like shellac, rubber, cellulose, and camphor. Leo Hendrik Baekeland's (1863-1944) invention of Bakelite in 1907 ushered in the era of chemically synthesized moldable materials called plastics.

Background

The word plastic comes from the Greek adjective plastikos, which means moldable. The first citation of plastic as a material dates from 1910, when a dictionary defined it as a substance that could be molded into shape when soft.

Alexander Parkes (1813-1890) presented the first artificial molding compound at London's Great International Exhibit of 1862. A mixture of nitrocellulose softened with camphor and castor oil, it could be molded after heating and held its shape when cooled. Parkes believed his invention would one day be a substitute for rubber, but its raw materials were expensive and its manufacturing process inefficient.

John Wesley Hyatt (1837-1920) invented celluloid in 1869, after reading about a $10,000 prize for the discovery of a substitute for ivory billiard balls. Celluloid, also made of nitrocellulose and camphor, became a cheap and durable substitute not only for ivory, but also for marble, pearl, tortoiseshell, linen, and other natural substances. It was popular for decorative items and for detachable shirt collars that could be wiped clean with a sponge, a convenience that appealed to the new class of clerical and service workers. By the end of the 1920s celluloid's own properties were exploited to make automobile parts, household goods, and photographic film.

The importance of celluloid diminished once synthetic plastics entered the market. The first was Bakelite. Leo Baekeland was familiar with experiments in which phenol and formaldehyde were heated in the presence of hydrochloric acid. The result was either a sticky mass or a rubber-like solid, often accompanied by an explosion. The growing market for shellac and rubber insulators encouraged Baekeland, a Belgian-born immigrant to the United States with a doctorate in chemistry, to find a more reliable way of combining phenol and formaldehyde. He found that heating them under pressure in an apparatus he called the Bakelizer produced a material that would not melt, burn, dissolve, crack, or break. Although Baekeland did not understand the new chemical composition of this material, he did foresee its commercial significance and patented both his process and several potential applications. He built a small pilot plant where he experimented with materials and molding techniques before licensing them to other manufacturers. After describing Bakelite in a speech to the American Chemical Society in 1909, Baekeland was deluged with inquiries and founded the General Bakelite Company.

New companies sprang up to manufacture similar compounds. After years of fighting patent infringements, Baekeland joined with his two main competitors to form the Bakelite Corporation. During the 1920s, Bakelite's sales skyrocketed to meet the needs of the new automobile and radio industries. An advertising campaign called Bakelite "the material of a thousand uses" in an effort to convince manufacturers to try it and consumers to demand it. Although the shiny black of Bakelite radios epitomized modernity in the 1920s, black was also the only color that could hide the fillers that gave Bakelite its strength. As Bakelite's patents expired, new plastics were invented.

Baekeland and other chemists created synthetic plastics through trial and error, before their molecular structure was understood. In the 1920s, Hermann Staudinger (1881-1965) showed that plastics consist of giant molecules strung together in chains called polymers. These chains slide apart when heated, allowing the material to soften but not melt, then snap back together when cooled. The interwoven polymers, like a chain link fence, give plastic its hardness and ductility. Bakelite and other plastics derived from cellulose and coal tar are thermosetting. This means that once heated and shaped, they cannot resoften. This makes them hard, heat resistant, and practically indestructible. The second wave of plastics, derived from petroleum and natural gas, are thermoplastic. This means they can be reheated and shaped in their final chemical state, making them easier to mold, more economical (waste is reused), but less durable than thermosetting plastics. Once the fundamental structure of plastics was known, research into new plastics progressed rapidly.

Wallace Hume Carothers (1896-1937) was hired from Harvard by the DuPont chemical company in 1928 to direct basic research in polymerization. His goal was to create new synthetics by building polymer chains. Not only did he further the knowledge of polymerization, he also created the first synthetic fiber, nylon. Nylon stockings, introduced with fanfare in 1939, were greeted with immediate enthusiasm. Within three years, however, nylon production was diverted to the military. The demand for nylon stockings after the war was so frenzied that riots broke out wherever they were sold.

Several other thermoplastics were invented in the 1930s. Cellulose acetate was popular because of its strength and visual appeal. Polyvinyl chloride was used for everything from shower curtains to shoes. Polystyrene had the advantages of transparency and the ability to capture the tiniest details of a mold. They were all shaped in a speedy process called injection molding. Acrylic (polymethyl methacrylate), manufactured in sheets, was sold under the trade names Plexiglas and Lucite. Despite the vastly different characteristics of the hundreds of synthetic materials available by 1940, the public tended to lump them all together under one name—plastic.

World War II transformed the plastic industry and changed its public image. As Life magazine proclaimed, "War Makes Gimcrack Industry into Sober Producer of Prime Materials." The urgent need for military supplies forced the industry to develop new materials and processes. In the interest of patriotism manufacturers worked together, and the U.S. output of synthetic resins almost quadrupled between 1939 and 1945.

Many wartime materials and fabrication techniques found peacetime uses. The resinbonded plywood that had formed curved airplane wings and fuselages was shaped into furniture and prefabricated housing. Fiberglass, developed for radar housings because it did not interfere with transmissions, was molded into small boats. Polyethylene, a thermoplastic used for electrical insulation during the war, was injection-molded into cups by Tupper Plastics and into fishing lures by Loma Plastics, two companies that became giants in the 1950s.

Some people believed the return to peacetime would be a return to a totally plastic world, with a plastic house and a plastic car for every family. Predictions about the potential of plastics became so unrealistic that the Society of the Plastics Industry began a campaign to "deglamorize" it by offering more balanced information to the public, manufacturers, and retailers. The risk to the industry was that disappointed customers would reject all plastics.

Manufacturers tried to transform plastic's modernistic image by designing traditional, wood-grained furniture made of Formica with leather-like upholstery made of vinyl. House Beautiful magazine devoted an entire issue to decorating with plastic. The characteristic of plastic that received the highest praise was neither appearance nor cost, but ease of cleaning. As another publication promised, all homemakers had to do was "swoosh and smile."

Impact

One hundred years after the invention of Bakelite, life without plastics is unimaginable. Almost every manufactured object in homes, schools, offices, and shopping mall would either cease to exist or look entirely different. At the beginning of the twenty-first century, the word "plastic" resonates with meaning, both positive and negative. It conjures up both control—the dominance of science over nature—and loss of control—the fear of plastics burying the planet. People depend on the convenience, strength, versatility, and low cost of plastics, but at the same time worry about dependence on a material they see as phony, polluting, and even dangerous.

Early in its history, plastics were promoted as a social equalizer. No longer would only the rich be able to own brightly colored jewelry, silk stockings, and ivory comb and brush sets. Cast phenol, nylon, and celluloid made these luxuries available to everyone. Plastics, created from seemingly endless supplies of coal and petroleum, bridged the gap between the demands of an increasing population and the fixed supply of natural materials.

In doing so, the plastics industry transformed the economy of the industrialized world. Not only did the chemical companies that made plastic resins flourish, so did the large and small manufacturers that produced finished products. The number of molders and fabricators jumped from 60 in 1929 to 170 in 1939 to 370 in 1946, most of them small businesses. After the war, although the major chemical companies continued to control the supply of resins, manufacturing entrepreneurs flourished. In fact, plastics became synonymous with opportunity, as ironically illustrated in the movie The Graduate, when a family friend advises the recent college graduate, "I just want to say one word to you...Plastics....There's a great future in plastics."

Twentieth-century design is inextricably linked with plastics, alternately capitalizing on and rejecting their unnaturalness. The physical characteristics of early plastics elicited a style called modernism characterized by streamlined shapes and simple lines. Rounded molds were cheaper to create than molds with sharp edges, and molten plastic flowed through them more easily, making certain styles economically as well as esthetically appealing. Industrial designers in the 1930s and again in the 1960s recommended that new materials be treated "on their own terms" instead of as imitations of natural materials.

The first seeds of anxiety about plastics were planted as early as the 1920s when people started to question the wisdom of defying the natural order by creating new materials. Twenty years later, rumors spread that nylon stockings were made of decayed corpses and caused rashes or even cancer. Although these particular concerns evaporated over time, the underlying anxiety about plastics did not. It reappeared when babies were suffocated by dry-cleaning bags in the 1950s, when fears spread about the safety of Teflon coatings in the 1960s, and when statistics showed higher-than-average cancer rates among workers in the plastic industry in the 1970s.

The discovery of plastic was motivated by the need to save scarce natural resources. By the time of the first Earth Day in 1970, plastics were accused of harming the environment by overloading landfills, creating pollution, and depleting fossil fuels. The plastic industry has responded by promoting resource conservation through recycling, reuse, and the efficient use of resources.

LINDSAY EVANS