Carothers, Wallace Hume

(b. Burlington, Iowa, 27 April 1896; d Philadelphia, Pennsylvania, 29 April 1937),

chemistry.

Wallace Carothers was the eldest of the four children of Ira Hume and Mary Evelina McMullin Carothers. His early education, in Des Moines, Iowa, included a final year at Capital City Commercial College, where his father taught and later served as vice-president. In 1915 he entered Tarkio College in Tarkio, Missouri, supporting himself as a student by teaching accounting, English, and his major interest, chemistry. He received his bachelor’s degree at Tarkio in 1920 and his master’s degree at the University of Illinois in Urbana in 1921. After teaching for a year at the University of South Dakota, he returned to Urbana and in 1924 earned his doctorate, with a major in organic chemistry and a dissertation on hydrogenations with modified platinum-oxide-platinum-black catalysts, under the direction of Roger Adams. He remained there for two years as instructor in organic chemistry and in 1926 accepted a like position at Harvard University. In the period 1923–1927 he published his first four independent papers, of which the most notable—on the electronic nature of the double bond—confirmed his early promise of brilliance and originality.

A turning point in Carothers’ career came in 1928, when he joined E. I. du Pont de Nemours and Company to lead the organic group in a program of fundamental research at its central laboratories in Wilmington, Delaware. At the time this was a radical departure in industrial research, and the opportunity thus offered to undertake basic research with a group of postdoctoral associates and maximum physical support overcame Carothers’ reluctance to leave the academic world. The ensuing nine years until his premature death were extraordinarily productive, resulting not only in major contributions to theoretical organic chemistry but also in the founding of two industries, the production of synthetic rubber and of wholly synthetic fibers for textile and industrial purposes. In 1936 Carothers was elected to the National Academy of Sciences, the first organic chemist associated with industry to be so recognized.

Although he was modest to the point of shyness, Carothers’ personal warmth, generosity of spirit, and sense of humor inspired deep affection in his friends. He was married 21 February 1936 to Helen Everett Sweetman of Wilmington, Delaware, and a daughter, Jane, was born 27 November 1937. His death, by his own hand, followed a long history of intensifying mental depressions, despite the best medical advice and care.

The first area that Carothers chose for intensive investigation at Du Pont was the synthesis of polymers of high molecular weight by means of simple, well-understood reactions, such as esterification and amide formation. Using as reactants compounds that can be generalized as xAx, yBy, and xCy, where x represents hydroxyl (—OH) or amino (—NH₂) groupsand y the carboxyl (—COOH) group, his team prepared and studied in detail a great number and variety of linear polymers of general formula

xAzBz(AzBz)_nAzBy or xC(cz)_nCy.

A, B, and C represent chains of carbon atoms, and z represents an ester (—OCO—) or amide (—NHCO—)group formed by reaction of an hydroxyl or amino group with carboxyl. When the factor n attained some minimum high value, the polymers proved capable of being formed into fibers that, after being stretched to orient the chain molecules into parallel configuration, were strong, flexible, and tough. The outcome of these studies was a great advance in the understanding of the chemistry and properties of both natural and synthetic polymers and the opening of new avenues of experimentation in polymerization. A massive development program on one of these new fiber-forming polymers, based on hexamethylene diamine and adipic acid, led to the first nylon, the manufacture of which the Du Pont Company started in 1939 at Sea-ford, Delaware.

Carothers’ second major area of investigation was the chemistry of vinylacetylene and divinylacetylene, low polymers of acetylene that were available from the discoveries of Nieuwland and work in other Du Pont laboratories. These studies led to a wide range of derivatives, the most important of which was chloroprene (2-chlorobutadiene), made by adding hydrogen chloride to vinylacetylene. This compound, the chloro analogue of isoprene, was shown to convert readily to a polymer having elastic properties like those of rubber. Du Pont started manufacture of this product, called neoprene, in 1931. Alone and with collaborators, Carothers published sixty-two scientific papers and was granted sixty-nine U.S. patents, many of which were equivalent in content to scientific papers.

BIBLIOGRAPHY

Carothers’ papers were brought together in Collected Papers of Wallace H. Carothers on Polymerization, H. Mark Whitby and G. S. Whitby, eds. (New York, 1940). Roger Adams, in Biographical Memoirs. National Academy of Sciences, 20 (1939), 293–309, contains a complete list of Carothers’ scientific papers and most of his U.S. patents. See also Dictionary of American Biography, supp. 2 (New York, 1958), 96–97.

Julian W. Hill