Carothers was a group leader in DuPont’s Experimental Station laboratory, near Wilmington, Delaware, where most polymer research was done. 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. His daughter, Jane, was born seven months later on November 27, 1937.
In September 1915, he entered Tarkio College in Missouri. Carothers so excelled in chemistry that even before his graduation he was made a chemistry instructor. 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.
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.
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.
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.
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.
Polyesters and polyamides are examples of condensation polymers formed by step-growth polymerization. Carothers worked out the theory of step-growth polymerization and derived the Carothers equation which relates the average degree of polymerization to the fractional conversion (or yield) of monomer into polymer. This equation shows that for a high molecular weight, a very high fractional conversion is needed (for step-growth polymers only).
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.
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.
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. 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.
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.
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, knowing that the ingestion of cyanide in an acidic solution would greatly intensify the speed and effect of the poison. He left no note.