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Introduction to Polymers 7

proposal and gave him $25,000 a month for the venture, which allowed him to hire 25 chemists
for the task. The initial hiring was difficult because academic chemists did not trust DuPont to

allow them to do basic research. A year later he was able to make his central hiring, Wallace Hume
Carothers.
Wallace Hume Carothers is the father of synthetic polymer science. History is often measured by
the change in the fl ow of grains of sand in the hour glass of existence. Carothers is a granite boul-
der in this hourglass. Carothers was born, raised, and educated in the Midwest of the United States.
In 1920, he left Tarkio College with his BS degree and entered the University of Illinois where he
received his MA in 1921. He then taught at the University of South Dakota where he published his

first paper. He returned to receive his PhD under Roger Adams in 1924. In 1926, he became an
instructor in organic chemistry at Harvard.
In 1927, the DuPont Company reached a decision to begin a program of fundamental research
“without any regard or reference to commercial objectives.” This was a radical departure since the
bottom line was previously products marketed and not papers published.
Charles Stine, director of DuPont’s chemical department, was interested in pursuing fundamen-
tal research in the areas of colloid chemistry, catalysis, organic synthesis, and polymer formation
and convinced the Board to hire the best chemists in each field to lead this research. Stine visited

many in the academic community, including the then president of Harvard, one of the author’s dis-
tant uncles, J. B. Conant, an outstanding chemist himself, who told him about Carothers. Carothers
was persuaded to join the DuPont group and was attracted with a generous research budget and an
approximate doubling of his academic salary to $6,000. This was the birth of the Experimental
Station at Wilmington, Delaware.
Up to this point, it was considered that universities were where discoveries were made and indus-
try was where they were put to some practical use. This separation between basic and applied work
was quite prominent at this juncture and continues in many areas even today in some fi elds of
work, though the difference has decreased. But in polymers, most of the basic research was done
in industry having as its inception the decision by DuPont to bridge this “unnatural” gap between
fundamental knowledge and application. In truth, they can be considered as the two hands of an
individual, and to do manual work both hands are important.
Staudinger believed that large molecules were based on the jointing, through covalent bonding, of
large numbers of atoms. Essentially he and fellow scientists like Karl Freudenberg, Herman Mark,
Michael Polanyi, and Kurt Myer looked at already existing natural polymers. Carothers, however,
looked at the construction of these giant molecules from small molecules forming synthetic poly-
mers. His intention was to prepare molecules of known structure through the use of known organic
chemistry and to “investigate how the properties of these substances depended on constitution.”
Early work included the study of polyester formation through reaction of diacids, with diols form-
ing polyesters. But he could not achieve molecular weights greater than about 4,000 below the size
where many of the interesting so-called polymeric properties appear.
DuPont was looking for a synthetic rubber. Carothers assigned Arnold Collins to this task.
Collin’s initial task was to produce pure divinylacetylene. While performing the distillation
of an acetylene reaction, in 1930, he obtained a small amount of an unknown liquid that he
set aside in a test tube. After several days the liquid turned to a solid. The solid bounced and
eventually was shown to be a synthetic rubber polychloroprene whose properties were similar
to those of vulcanized rubber but it was superior in its resistance to ozone, ordinary oxidation,
and to most organic liquids. It was sold under its generic name “neoprene” and the trade name
“Duprene.”
Also in 1930, Carothers and Julian Hill designed a process to remove water that was formed
during the esterification reaction. Essentially they simply froze the water as it was removed using

another recent invention called a molecular still (basically a heating plate coupled to vacuum) allow-
ing the formation of longer chains. In April, Hill synthesized a polyester using this approach and
touched a glass stirring rod to the hot mass and then pulled the rod away, effectively forming strong

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