In his time at DuPont Carothers invented nylon, discovered the first practical synthetic rubber, and the first synthetic musks. But he and his reasearch group let a few breakthroughs slip through their grasp.
Nylon 6
Before making nylon 6-6, Carothers had tried to make a simpler material. He instructed one of
his scientists named Jim Kirby to try to make a
polymer
from caprolactam.
The scientists of "Purity Hall" had trouble with this reaction and never did make a
polyamide
from caprolactam. This led Carothers to hstily write that it could not be done.1
Meanwhile scientists in Germany were hard at work, not knowing what Carothers had written. Paul Schlak of I.G. Farben made the polyamide Carothers had sought, and patented it. It was marketed under the name "Perlon", but it is now generally known as "nylon 6".
Had Carothers not written that caprolactam could not be
polymerized,
DuPont may have had some claim that they had done important work toward inventing nylon 6, and
thus would have had a claim to patent rights for the material. But with this one statement
Carothers made, DuPont relinquished any claim to have participated in the invention of nylon 6.
A Better Polyester
Polyesters are another field where Carothers might have
made a breakthrough, but didn't. Long
before they ever made nylon, the world's first linear polyester, polyester 3-16, was made by
Julian Hill in 1930.
As an offshoot of this,
they investigated cyclic by-products that
form during the making of polyesters. In 1934,
Edgar W. Spanagel was
trying to make some cyclic by-products when he reacted ethylene glycol and terephthalic acid.
"I could not make a ring out of it. I had the polymer out on the desk, and Carothers came in and looked at it. Then he got up and walked away, and he never talked about it again."- Edgar W. Spanagel3 |
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That's too bad, because this polyester was an excellent fiber. PET would have to be reinvented in 1940 by scientists in England. It was marketed under the name Terylene¨. So it happened that J.R. Whinfield and J.T. Dickson, not Edgar Spanagel and Wallace Carothers, would go down in history as the inventors of PET, the polyester now used in everything from clothing to soft drink bottles.
References
1. Carothers, Wallace and Berchet, Gerard. Journal of the American Chemical Society, 1930, 52, 5289.2. Hermes, Matthew. Enough for One Lifetime: Wallace Carothers, Inventor of Nylon. Washington, D.C.: American Chemical Society; Philadelphia: Chemical Heritage Foundation, 1996, pp 133-4.
3. Labovsky, Joseph. Oral history by John K. Smith, 24 July 1996. Philadelphia: Chemical Heritage Foundation.
4. Spanagel, Edgar W. Oral history by John K. Smith, 9 May 1997. Philadelphia: Chemical Heritage Foundation.