Wallace Carothers

Inventor of Nylon

Carothers was born on April 27, 1896, in Burlington, Iowa. As a child he gained a deep appreciation for music from his mother and a sense of the importance of education from his father, a teacher. Recognized as an outstanding student at Tarkio College, Missouri, he was appointed to replace the director of the chemistry department during Word War I. He completed a bachelor’s degree in 1920 and continued at the University of Illinois, earning a Ph.D. in chemistry in 1924.

Carothers accepted a position at Harvard University in 1926. In addition to teaching chemistry, he researched the properties of large polymers, molecules consisting of numerous repeating sequences of atoms strung together.

In 1928 Carothers joined the Experimental Station of the Du Pont Company in Delaware as director of a new program aimed at investigating the emerging field of synthetic materials. Beginning with molecules in the acetylene family, he devised experimental methods based on the work of Belgian­born American chemist and botanist Julius Arthur Nieuwland. This research yielded a rubber­like substance formed from the combination of vinylacetylene and chlorine compounds. In 1931 the synthetic substance was marketed as neoprene.

Carothers then focused on the creation of synthetic fibers with properties similar to those of silk and cotton. The task called for a chemical reaction that would cause certain groups of chemicals to bind together into a polymer. Working with families of compounds called diamines and dicarboxylic acids, Carothers developed a theory explaining the factors involved in the polymerization (the process of polymer formation) of these chemicals. About 1935 this work culminated in the creation of the first synthetic fiber, later called nylon; it was similar to silk but stronger and more elastic.

In January 1937 the death of his sister Isobel plunged Carothers into despair. Having long suffered fits of severe depression, he committed suicide on April 29, 1937, in Philadelphia, Pennsylvania.

Wallace Carothers’s Legacy

Carothers’s work laid the foundation for the commercial polymer industry.

Neoprene, Carothers’s first marketable invention, replaced natural rubber to a large extent. At the beginning of the twentieth century the automobile industry was rapidly expanding, increasing the demand for rubber for tires. One of Du Pont’s research aims was to prevent a future shortage of rubber by supplying a synthetic alternative. Although not ideal for tires, neoprene was, and still is, used for making wire, cable, hose, machinery belts, molded goods, soles, heels, and adhesives.

The Du Pont Company started marketing nylon in 1940; it met with immediate success in the production of toothbrushes and stockings. Toothbrush bristles had previously been made from the stiff hair of animals such as hogs, horses, and badgers. Nylon was softer, cheaper, and resistant to the growth of bacteria. Synthetic toothbrushes made effective tooth­ cleaning devices available to more people, ushering in the modern era of dental care.

Prior to the fabrication of nylon stockings, most stockings were made from silk. The debut of nylon stockings in 1940 caused great excitement in the United States following a campaign that advertised the synthetic stockings as virtually indestructible. Within a few years delicate silk stockings were obsolete. Today nylon is used in some fashion in nearly all industries.

Carothers’s success with neoprene and nylon followed the introduction of the first plastics and launched the development of other synthetic polymers. Celluloid and Bakelite, in regular use by the early 1920s, were followed by cellophane, acetate, vinyl, plexiglass, acrylic, styrene, formica, and polyester. In 1945 Du Pont chemist Earl Tupper produced polyethylene (soon commercialized as Tupperware), one of the most versatile synthetic polymers. Modern synthetic polymers, the result of more than a half century of industrial experimentation, include various combinations of chemicals engineered to produce products with specific properties.

Convenient, lightweight, airtight, cheap, and durable, synthetic polymers revolutionized modern life and helped conserve some natural resources. However they also yielded a mass of commercial waste, created by the continuous production of disposable but non­degradable items.

Wallace Carothers – 1896-­1937