Wallace Carothers

Wallace Hume Carothers (April 27, 1896 – April 29, 1937) was an American chemist, inventor and the leader of organic chemistry at DuPont, credited with the invention of Nylon.^[1]

Carothers was a group leader in DuPont’s Experimental Station laboratory, near Wilmington, Delaware, where most polymer research was done.^[2] Carothers was a brilliant organic chemist who, in addition to first developing nylon, also helped lay the groundwork for Neoprene. After receiving his Ph.D, he taught at several universities before he was hired by the DuPont Company to work on fundamental research.

He married the former Helen Sweetman on February 21, 1936. Wallace Carothers had been troubled by periods of mental depression since his youth. Despite his success with Nylon, he felt that he had not accomplished much and had run out of ideas. His unhappiness was compounded by the death of his favorite sister, and on April 29, 1937, he checked into a Philadelphia hotel room and died after drinking a cocktail of lemon juice laced with potassium cyanide.^[3] His daughter, Jane, was born seven months later on November 27, 1937.

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Childhood and education

Carothers was born on April 27, 1896 in Burlington to Wallace and Helen. He was the oldest of four children. He had one brother and two sisters: John, Isobel, and Mary. As a youth Carothers was fascinated by tools and mechanical devices and spent many hours experimenting. He attended public school in Des Moines, Iowa, where he was known as a conscientious student. After graduation he enrolled in the Capital City Commercial College in Des Moines, where his father, Ira, was Vice-President, completing the accountancy and secretarial curriculum in July 1915.

In September 1915, he entered Tarkio College in Missouri. Carothers excelled in chemistry so much, that even before his graduation he was made a chemistry instructor.^[4] He graduated from Tarkio in 1920 at the age of 24 with a bachelor of science degree. Then he went to the University of Illinois for his master of arts degree, which he received in 1921.

During the 1921–22 school year, Carothers held a one-year appointment as a chemistry instructor at the University of South Dakota. It was at the University of South Dakota that he began his independent research, which resulted in an article accepted by the Journal of the American Chemical Society.

He went back to the University of Illinois to study for his Ph.D under Dr. Roger Adams. His degree was awarded in 1924. He specialized in organic chemistry and minored in physical chemistry and mathematics. He worked as a research assistant during 1922–1923 and received the Carr Fellowship for 1923–24. This was the most prestigious award offered by the university at that time.

Career

After receiving his Ph.D, Carothers stayed at the University of Illinois for two years as an instructor in organic chemistry.

In 1926 Carothers moved to Harvard. Again he was an instructor in organic chemistry. James B. Conant, who became President of Harvard College in 1933, said of Carothers: "In his research, Dr. Carothers showed even at this time the high degree of originality which marked his later work. He was never content to follow the beaten path or to accept the usual interpretations of organic reactions. His first thinking about polymerization and the structure of substances of high molecular weight began while he was at Harvard."^[5]

In 1927, the DuPont Company decided to fund fundamental, pure research: research not deliberately aimed at the development of a money-making product. Wallace Carothers traveled to Wilmington, Delaware to discuss the possibility of being in charge of organic chemistry at the new DuPont laboratory for fundamental research.

DuPont

The decision to leave academia was difficult for Carothers. At first he refused DuPont's offer of employment, explaining that "I suffer from neurotic spells of diminished capacity which might constitute a much more serious handicap there than here."^[6] In spite of this admission, a DuPont executive, Hamilton Bradshaw, traveled to Harvard and convinced Carothers to change his mind. His beginning salary was $500 a month.

Later in a letter to Wilko Machetanz, his Tarkio roommate, Carothers expanded on his feelings of depression: "I find myself, even now, accepting incalculable benefits proffered out of sheer magnanimity and good will and failing to make even such trivial return as circumstances permit and human feeling and decency demand, out of obtuseness or fear or selfishness or mere indifference and complete lack of feeling."^[7]

Neoprene

Carothers started working at the DuPont Experimental Station on February 6, 1928. The synthesis of a polymer with a molecular weight of more than 4,200, the mass achieved by Dr. Emil Fischer, was his primary goal.

By the summer of 1928, Carothers boasted a small staff of Ph.D chemists and two consultants: Dr. Roger Adams, his thesis advisor, and Dr. Carl Marvel, his instructor of organic chemistry at the University of Illinois. The laboratory where these top scientists worked became known as "Purity Hall." It was discouraging that by the middle of 1929, "Purity Hall" had not produced a polymer with a weight of much over 4,000.

In January 1930, Dr. Elmer K. Bolton became assistant chemical director in the chemical department, and thus, Carothers' immediate boss. Bolton wanted practical results in 1930, and his wish was fulfilled. Bolton asked Carothers to examine the chemistry of an acetylene polymer with the goal of creating synthetic rubber. In April 1930 one of Carothers' staff, Dr. Arnold M. Collins, isolated chloroprene, a liquid which polymerized to produce a solid material that resembled rubber. This product was the first synthetic rubber and is known today as Neoprene.

In the same year, Dr. Julian Hill, another member of the Carothers team, started work again on attempting to produce a polyester with a molecular weight of above 4,000. His efforts were soon met with great success when he produced a synthetic polymer with a molecular weight of about 12,000. The high molecular weight allowed the melted polymer to be stretched out into strings of fiber. Thus was created the first synthetic silk, described by the chemists as a superpolyester. Hill also produced a synthetic fiber that was elastic and strong by combining glycols and acids under reduced pressure in a molecular still. Unfortunately the fiber produced could not be commercialized because it reverted back to a sticky mass when placed in hot water. Carothers dropped his research on polymers for several years.

Depression

In 1931, Carothers moved into a house in Wilmington, which became known as Whiskey Acres, with three other DuPont scientists. Therefore, he was no recluse, but his depressive moods often prevented him from enjoying all the activities in which his roommates took part. In a letter to a close friend, Frances Spencer, he says, "There doesn't seem to be much to report concerning my experiences outside of chemistry. I'm living out in the country now with three other bachelors, and they being socially inclined have all gone out in tall hats and white ties, while I after my ancient custom sit sullenly at home."^[8] From now on, Carothers always kept a capsule of cyanide attached to his watch chain.

Carothers hated the public speaking that was necessary to maintain his high profile. In a letter to a friend, Wilko Machetanz, in January 1932, he says, "I did go up to New Haven during the holidays and made a speech at the organic symposium. It was pretty well received but the prospect of having to make it ruined the preceding weeks and it was necessary to resort to considerable amounts of alcohol to quiet my nerves for the occasion. … My nervousness, moroseness and vacillation get worse as time goes on, and the frequent resort to drinking doesn't bring about any permanent improvement. 1932 looks pretty black to me just now."^[9]

In 1932, the agreement under which Carothers was hired was modified by Dr. Bolton. "Purity Hall" would now focus on "effecting a closer relationship between the ultimate objectives of our work and the interests of the company."^[10] Essentially this meant that funds were shifted from pure research to practical research. Carothers did not see himself as a skilled commercial researcher. He proposed that fundamental work be limited to two or three proposals, which would be consistent with DuPont's interests.

Personal life

Carothers's personal life during this time was busy. He was having an affair with a married woman, Sylvia Moore, who, with her husband filed for divorce in 1933. At the same time, he worried about the financial problems of his parents and planned to bring them to Wilmington. With no thought of the possible emotional ramifications of this move, he bought a house in Arden about ten miles from the Experimental Station and moved into it with his parents. He was 37 at the time. Interactons with his parents soon became tense. Carothers was still seeing Sylvia Moore, who was now single. Of course, his parents highly disapproved of this relationship. Finding the tension in the household too wearing, his parents returned to Des Moines in the spring of 1934.

Polyamides

In 1934, Carothers turned his attention to fibers again. Now the team substituted amines for glycols to produce a type of polymer called a polyamide. These substances were much more stable than the polyesters formed by using the glycols. The ability of the polyamide to form crystalline domains through hydrogen bonding gives them the increase in mechanical properties. Therefore they might produce a synthetic silk that would be practical for everyday use. His research resulted in the invention of a number of new polyamides. The labwork for this project was conducted by Dr. W.R. Peterson and Dr. Coffman. Later Dr. Gerard Berchet was assigned to this research.

It was during this productive period of research, in the summer of 1934, prior to the eventual invention of Nylon, that Carothers disappeared. He did not come into work, and no one knew where he was. He was found in a small psychiatric clinic, Phipps Clinic, associated with Johns Hopkins in Baltimore. Apparently, he had become so depressed, he drove to Baltimore to consult a psychiatrist, who put him in the clinic.

Nylon

Shortly after his release from the clinic, Carothers returned to DuPont. Bolton instructed Carothers to work on polyamides that might lead to a viable fiber. Berchet became the lab man for this job. On February 28, 1935, he produced a half-ounce of a polymer, which was labeled polyamide 6-6. This was the substance that would eventually become Nylon. It was difficult to work with because of its high melting point, but Bolton chose this polyamide as the one to develop commercially. He selected Dr. George Graves to work with Carothers on the project. Eventually Graves supplanted Carothers as the leader of the polyamide project. In addition, dozens of chemists and engineers worked on refining polyamide 6-6 into a viable commercial product.

Marriage and decline

On February 21, 1936, Carothers married Helen Sweetman, whom he had been dating since 1934. Sweetman worked for duPont on the preparation of patent applications. She had a bachelors degree in Chemistry.

Soon after, on April 30, 1936, Carothers was elected to the National Academy of Sciences, a very high honor. Carothers was the first industrial organic chemist to receive this honor. Yet by June 1936, in spite of this honor which validated his contributions to science, Carothers could not shake his depression, which prevented him from working. In early June he was admitted involuntarily to the Philadelphia Institute of the Pennsylvania Hospital, a prestigious mental hospital, where his psychiatrist was Dr. Kenneth Appel. One month later he was given permission to leave the institute to go hiking in the Tyrolean Alps with friends. The plan was for him to day hike with Dr. Roger Adams and Dr. John Flack for two weeks. After they left, he stayed on, hiking by himself, without sending word to anyone, even his wife. On September 14, he suddenly appeared at her desk at the Experimental Station. From now on Carothers was not expected to perform any real work at the Experimental Station. He would often go in and visit. He began living in Whiskey Acres again, at the request of his wife, who did not feel emotionally strong enough to handle his problems.

On January 8, 1937, Carothers' beloved sister Isobel died of pneumonia. Wallace and Helen traveled to Chicago to attend her funeral and then to Des Moines to view her burial. He still traveled to Philadelphia to visit his psychiatrist, Dr. Appel, who told a friend of Carothers that he thought suicide was the likely outcome of Carothers' case.

On April 28, 1937, Carothers went to the Experimental Station to work. The following day he committed suicide in a lonely hotel room in Philadelphia by taking cyanide dissolved in lemon juice. He left no note.

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