Wallace Hume Carothers

• Born: April 27, 1896
• Birthplace: Burlington, Iowa
• Died: April 29, 1937
• Place of death: Philadelphia, Pennsylvania

American organic chemist

Carothers conducted innovative polymer chemistry research to create synthetic rubber and nylon, stronger than natural materials, which were industrially developed for widespread distribution in consumer and military products. His investigations helped professionalize polymer chemistry as a scientific field.

Primary field: Chemistry

Primary inventions: Nylon; synthetic rubber

Early Life

Wallace Hume Carothers, born on April 27, 1896, in Burlington, Iowa, was his parents’ first child. His father, Ira Hume Carothers, taught penmanship at the local Elliott’s Business College. His mother, Mary McMullin Carothers, named her son Wallace to honor her mother’s maiden surname. By the time of the 1900 U.S. Census, the Carothers were living in Mount Pleasant, Iowa, before moving to the state capital, Des Moines, when Ira was hired by Capital City Commercial College.

Carothers and his two younger sisters and brother attended United Presbyterian Church services with their parents, who were devout members of that denomination. He took classes at North High School and collected water meter data and worked in the city library’s reference section for income. Science intrigued Carothers, who read Robert Kennedy Duncan’s books discussing chemistry and built a chemistry laboratory in his bedroom.

After his 1914 high school graduation, Carothers completed the year-long business curricula at Capital City Commercial College, where his father had been promoted to vice president. Tarkio College, a four-year Presbyterian-affiliated school in northwest Missouri, sought students for its Commercial Department. Hoping to please church leaders, Carothers’s father selected Wallace and another student to travel to Tarkio in September, 1915. Carothers earned tuition money as an assistant in the Commercial and English departments and as Tarkio president Reverend J. A. Thompson’s private secretary.

Although Carothers took business courses, he sought a scientific education and within two years completed every chemistry class Tarkio offered. Department head Arthur McCay Pardee, who had been taught by Duncan, loaned Carothers his chemistry texts, which expanded Carothers’s understanding of organic chemistry and German chemical research. Carothers devoted his laboratory work to investigating carbon. Disqualified for World War I service because of his goiter, Carothers taught chemistry at Tarkio, starting in 1918 when Pardee left for war work, until 1920 when he received his bachelor of science degree.

Life’s Work

Because Carothers aspired to become a professional chemist, he traveled to Urbana, Illinois, to enroll in graduate school at the University of Illinois, which Pardee had suggested would offer Carothers a challenging organic chemistry program. Roger Adams mentored Carothers and provided professional support throughout Carothers’s career. After Carothers received his master of science degree in 1921, he taught chemistry courses at the University of South Dakota at Vermillion.

The next year, Carothers started doctoral work at the University of Illinois. In 1923, he published his first paper in the Journal of the American Chemical Society. Carothers completed his dissertation, “Platinum Oxide as a Catalyst in the Reduction of Organic Compounds,” and received his Ph.D. in 1924. He remained at the university to teach until 1926. While at Illinois, Carothers endured intense emotional despair and purchased cyanide, telling people he might kill himself with the poison.

When Harvard University sought an organic chemistry instructor, Adams endorsed Carothers for that position. At Harvard, Carothers started investigating chemistry associated with polymers and large molecules. He preferred pure, not applied, science and did not actively seek industrial or commercial use of his findings. His research, however, attracted chemists’ attention at both academic and industrial laboratories. Charles M. A. Stine, director of the chemical department at E. I. du Pont de Nemours and Company, contacted Carothers while searching for an exceptional organic chemist to develop synthetic materials for DuPont to produce. Carothers accepted, as he disliked teaching and considered focusing on research with a team of skilled chemists preferable.

Carothers moved to Wilmington, Delaware, and started his DuPont duties as research director on February 6, 1928. DuPont managers told Carothers to consider how his chemists might make synthetic rubber, needed because natural rubber was not easily obtainable, with an acetylene polymer. Intrigued by Hermann Staudinger’s polymer work in Germany, Carothers tested that chemist’s provocative 1920 hypothesis that polymers chemically consisted of long chains of large molecules.

In April, 1930, during their investigations to prove Staudinger’s theory, the DuPont chemists developed the synthetic rubber neoprene from polymerized chloroprene made from acetylenes. DuPont trademarked that synthetic rubber as Duprene and commercially manufactured it, noting its resiliency to temperature extremes. In 1931, Chemical Review printed Carothers’s paper “Polymerization,” which discussed significant publications regarding polymer chemistry and explained related terminology and information to aid other chemists to pursue investigations in that emerging field. Carothers was associate editor of the Journal of the American Chemical Society from 1929 to 1937 and also edited the annual Organic Syntheses in the early 1930’s.

After developing synthetic rubber, Carothers attempted to create synthetic polyester fibers with sebacic acid and ethylene glycol in his laboratory. When colleague Julian Hill removed a glass stick he had inserted into a polymer, some of the polymer stuck to the stick, stretching without snapping as he stepped away. The polymer threads remained pliable and strong when dried and cooled but dissolved in moisture and heat.

Carothers decided to pursue another project, creating the synthetic scent Astrotone. Elmer K. Bolton, who had succeeded Stine when he was promoted, pressured Carothers to continue his synthetic fiber investigations. In 1934, Carothers resumed research with large molecules from amines instead of glycols in an attempt to create fibers which were more durable when heated. He also explored the role of condensation in polymerization. Carothers and his chemists successfully made synthetic fibers on February 28, 1935. Fluent in German, Carothers met Staudinger at the September, 1935, Faraday Society meeting in England to discuss their work with macromolecules.

Despite Carothers’s achievements, including approximately fifty DuPont patents identifying him as inventor and an invitation to head the University of Chicago’s Chemistry Department, he perceived himself as inept, agonized that his synthetic fiber was useless, and doubted his capabilities. Carothers’s intense work ethic, a failed romance, and alcoholism conflicted with his emotional stability. His ever-present cyanide vial and erratic actions alarmed DuPont managers and coworkers, who tried to reassure the fragile Carothers regarding his scientific merits and reduced his workload. In the summer of 1934, Carothers received psychiatric treatment at a Baltimore hospital.

On February 21, 1936, Carothers married Helen Everett Sweetman, a DuPont chemist who worked in the Patent Department. Four months after their wedding, she arranged for him to be admitted to a Philadelphia mental institution for several weeks. That year, the National Academy of Sciences chose Carothers as that group’s first organic chemist member who researched for an industrial employer.

On April 9, 1937, Carothers filed a patent for DuPont describing his synthetic fiber. His depression had deepened when a sister died in January, 1937, and his wife revealed she was pregnant despite Carothers’s insistence they not have children because of his mental instability. In late April, 1937, Carothers retreated to a Philadelphia hotel room, where authorities found his cyanide-poisoned body.

Impact

Carothers died without knowing how significant his synthetic fiber invention would become. His chemical innovations initiated industrial activity specifically devoted to manufacturing and selling nylon and neoprene. His inventions assisted economic recovery as the Depression ended and injected millions of dollars, then billions in later decades, into the U.S. and global economies, as well as increasing domestic and foreign trade as synthetics were incorporated in more products. DuPont employees, executives, and stockholders profited from Carothers’s inventions; many became wealthy, and DuPont was able to invest in additional research while seeking a similar extraordinary invention as nylon.

In addition to enhancing economic conditions, Carothers’s inventions and investigations advanced professional recognition of polymer research as an emerging branch of industrial chemistry. His successful work with macromolecules caused many chemists to reconsider their previous rejection of Staudinger’s theories and pursue similar research. Industries sought chemists to investigate how to create synthetics with polymers to meet specific manufacturing and consumer needs and demands, escalating production. Staudinger noted that Carothers’s successes with polymers and macromolecules contributed to acceptance of his research, which won him the 1953 Nobel Prize in Chemistry. Carothers’s DuPont colleague Paul John Flory was awarded a Nobel Prize in 1974 for macromolecular research. If Carothers had lived longer, he might have also received a Nobel Prize for his groundbreaking work.

Although Carothers did not attain public fame during his lifetime, his inventions, primarily nylon, earned him posthumous acclaim. Nine years after Carothers’s suicide, his DuPont colleagues named a nylon research laboratory located at Wilmington in his honor. The National Inventors Hall of Fame selected Carothers for induction in 1984. The Wall Street Journal profiled Carothers in May, 1989, as a significant figure in the history of U.S. commerce. In 1990, Life magazine listed Carothers among notable twentieth century Americans. In August, 1998, U.S. News & World Report declared that Carothers and nylon represented outstanding twentieth century innovation. The American Chemical Society and Chemical Heritage Foundation commemorated a Carothers centennial in April, 1996, and the laboratory where Carothers invented nylon was declared a historical chemical landmark four years later.

Bibliography

Furukawa, Yasu. Inventing Polymer Science: Staudinger, Carothers, and the Emergence of Macromolecular Chemistry. Philadelphia: University of Pennsylvania Press, 1998. Places polymer research developments in context with scientific and public perception of chemistry’s role during World War I and the interwar period and analyzes Carothers’s influence on academic and industrial chemistry.

Handley, Susannah. Nylon: The Story of a Fashion Revolution—A Celebration of Design from Art Silk to Nylon to Thinking Fibres. Baltimore: The Johns Hopkins University Press, 1999. Textile scholar summarizes Carothers’s research and DuPont’s production and distribution of nylon, examining how consumers responded to nylon and how synthetics transformed the clothing industry.

Hermes, Matthew E. Enough for One Lifetime: Wallace Carothers, Inventor of Nylon. Washington, D.C.: American Chemical Society and the Chemical Heritage Foundation, 1996. Former DuPont researcher Hermes consulted archival records and Carothers’s family, coworkers, and associates for this detailed account. Includes appendix of chemical formulas associated with Carothers’s research and photographs from Carothers’s relatives and friends.

Hounshell, David A., and John Kenley Smith, Jr. Science and Corporate Strategy: DuPont R&D, 1902-1980. Cambridge, England: Cambridge University Press, 1988. Discusses Carothers’s career at DuPont during the 1930’s and how management controlled his pure research interests by insisting he focus on such goals as producing marketable synthetics.

Kinnane, Adrian. DuPont: From the Banks of the Brandywine to Miracles of Science. Wilmington, Del.: E. I. du Pont de Nemours and Company, 2002. Comprehensive illustrated corporate history notes the impact of the Depression on DuPont’s research, particularly the emphasis on commercial applications, and Carothers’s reactions to this policy.

Raber, Linda R. “Landmark Honors Carothers’ Work.” Chemical and Engineering News 79, no. 4 (January 22, 2001): 108-109. Quotes text of plaque placed at Carothers’s DuPont laboratory when the American Chemical Society named it a historic chemical site in 2000, providing a list of speakers at the unveiling and a synopsis of Carothers’s work.