July/August 1998 | Volume 49, Issue 4
It is one of the most famous oneword lines in the history of Hollywood: “Plastics.” But however intergenerationally challenged that half-drunk friend of Dustin Huffman’s parents may have been in The Graduate , he was right about the importance of the materials revolution in the twentieth century.
It has been a curiously silent revolution, however. When we think of the scientific triumphs of this century, we think of nuclear physics, medicine, space exploration, and the computer. But all these developments would have been much impeded, in some cases impossible, without.. . plastics. And yet plastic remains, as often as not, a term of opprobrium.
Plastics are mostly synthetic materials that, because of their chemical nature, can be cast, molded, drawn out, extruded, and otherwise manipulated into an infinity of shapes. Before the 1930s almost everything people saw or handled was made of materials that had been around since ancient times: wood, stone, metal, and animal and plant fibers.
The first wholly synthetic substance with practical applications was called Bakelite, after its inventor, Leo Hendrik Baekeland, an immigrant from Belgium. As has happened again and again in the history of plastics, Baekeland was looking for one thing, in this case a substitute for shellac, and found another. Bakelite, initially marketed in 1909 (the year the word plastic was first used as a noun), is made by mixing phenol with formaldehyde (do not try this at home). Because, like most synthetic materials, it is nonconductive, Bakelite was mostly used as an electrical insulator. Its most visible use was in telephones, most of which were made of Bakelite until the 1950s.
Bakelite is what chemists call a polymer, a molecule composed of a long string of smaller molecular units, called monomers. Nature produces a host of polymers—cotton and silk, for instance—and the most famous polymer of all of course is DNA, the molecule of life.
Another natural polymer is rubber. Known since antiquity in the Americas, where the rubber tree is indigenous, rubber was first put to practical, if prosaic, use by the great eighteenthcentury chemist Joseph Priestley. He discovered that it could be used to rub off pencil marks on a piece of paper, an attribute that gave the substance its modern popular name. The Scotsman Charles Macintosh used it to make waterproof clothing. Then, in 1839, the American Charles Goodyear discovered that adding sulfur to rubber prevented it from becoming brittle at low temperatures and liquid at high ones, greatly increasing its utility. Rubber was soon indispensable in a number of industrial applications. With the arrival of the bicycle and the automobile, it became indispensable to everyday life.
But there was one big problem regarding rubber. Being native to the New World tropical rain forest, there were only a very limited number of places in the world where the trees could grow in commercial quantities on plantations. Most of these areas were part of the British Empire in Southeast Asia. So when World War I broke out, Germany faced an immediate rubber crisis. It began a frantic search for a synthetic substitute and, having the world’s most sophisticated chemical industry, soon found one, made from acetone.
As has so often happened in this century, research funded because of the necessities of war quickly led to commercially important developments in peacetime. As knowledge of the chemistry of polymers grew quickly, thanks to the search for synthetic rubber, some chemical companies began to look for other uses for polymers. Du Pont, for instance, wanted to find a substitute for silk.
The growth of the Du Pont company, too, was an artifact of war. Founded in 1802, Du Pont manufactured gunpowder and other munitions with success. But it was only one of a number of companies in a cartel of powder companies in the late nineteenth century. Then, in 1902, exactly a century after its founding, the Du Pont company came under the control of three cousins, Alfred I. du Pont, Thomas Coleman du Pont, and, especially, Pierre S. du Pont. The last transformed the firm into a thoroughly twentiethcentury enterprise. He absorbed the other companies in the cartel, reorganized the management of the company, and began a development department that conducted scientific research.
Blaise Pascal once said that “chance favors the prepared mind.” That is equally true of the prepared corporation, and Du Pont was ready when World War I erupted in 1914. Expanding, well, explosively, the company supplied the Allies with 40 percent of their munitions. The military contracts it fulfilled in the four years of that terrible conflict equaled 276 times its average annual armament business before the war and 26 times its total average business.
In four years E. I. Du Pont de Nemours and Company went from being a relatively modest enterprise to an industrial giant. Not wanting to be wholly dependent on a business in which governments inevitably would be the dominant customers, Du Pont had been increasingly investing in the chemical industry. In 1928 it hired Wallace Carothers to head its new laboratory for organic chemistry at its Experimental Station in Wilmington, Delaware.
Carothers was born in Iowa on April 27,1896, the son of a teacher. He studied at the Capital City Commercial College, where his father taught, and his first degree was in accounting. But he soon gravitated to chemistry, and he earned his Ph.D. at the University of Illinois in 1924, a year after he had published his first scientific paper. As a mark of his promise, Carothers was offered a position at Harvard in 1926. But two years later he gave up the prestige of that appointment for the then much less prestigious work of a corporate laboratory.
He did so because the new position suited him far better. Intensely shy, Carothers loved research but dreaded the lectures that professors had to give. At the Du Pont laboratory he could immerse himself wholly in chemistry, especially the chemistry of polymers and the technology of turning them into new products.
The lab that Carothers headed was state-of-the-art, not only in equipment but in personnel, for Du Pont spared no expense to have the best of everything. The result, over the next nine years, would be one of those incandescent periods of human creativity that change the world.
Carothers and his team did much basic research into exactly how polymers form and what is needed for that formation. They developed a whole chemical vocabulary to describe the processes involved. They worked on acetylene, especially on two derivative forms of it with the jawbreaking names of vinylacetylene and divinylacetylene. Acetylene, a gas at room temperatures, had been discovered in the middle of the nineteenth century and was used mostly in welding.
But Carothers discovered that by adding a chlorine atom, he could produce a synthetic rubber that was actually superior to natural rubber in some ways, especially in heat resistance. The new rubber did not have much commercial use as long as natural rubber was cheap and available. But when the Japanese seized the Malaya rubber plantations in 1941, neoprene, as the substance was called, proved indispensable to Allied victory.
Even more important was Carothers’s investigation into silk. He thoroughly analyzed the natural substance and then began looking for compounds that would duplicate it. One day an assistant, Julian Hill, noticed that when he stuck a glass stirring rod into a gooey mass at the bottom of a beaker the researchers had been investigating, he could draw out threads from it, the polymers forming spontaneously as he pulled. When Carothers was absent one day, Hill and his colleagues decided to see how far they could go with pulling threads out of goo by having one man hold the beaker while another ran down the hall with the glass rod. A very long and very silklike thread was produced.
When Carothers returned to the lab, he was told of the results of this “experiment,” and a major research project was launched. Seven years, and twenty-seven million dollars later, the lab had a thread that was tough, elastic, and heat- and water-resistant and could be woven into fabric inexpensively. Carothers walked into his boss’s office and said, “Here is your synthetic textile fabric.” It was nylon.
On September 21, 1938, Du Pont opened a plant in Seaford, New Jersey, to produce nylon, and the product was an instant commercial success. Nylon stockings proved so superior to the old silk hose that there were near riots at lingerie counters. The new fiber was soon being used to make everything from shower curtains to toothbrush bristles to fishing tackle. Nylon and the multitude of other synthetic fibers that followed were quickly built into a multibillion-dollar industry.
There is no doubt whatever that Wallace Carothers would have won the Nobel Prize in Chemistry for his work on nylon and neoprene. But Nobels go only to living recipients, and Carothers was dead. In the nine years he headed the organic chemistry lab at Du Font’s Experimental Station, he and his colleagues turned out more than fifty scientific papers and got an equal number of patents that are the foundation of modern polymer chemistry. But Carothers had few outlets other than work—mainly reading and listening to music—and the strain of such sustained production finally proved too much. Two days after his forty-first birthday, on April 29, 1937, he took cyanide in a Philadelphia hotel room and ended his life.
Genius can be a frightful burden.