Stephanie Kwolek

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Stephanie Kwolek
Stephanie Kwolek 1986.TIF
Born (1923-07-31) July 31, 1923 (age 90)
New Kensington, Pennsylvania, U.S.
Residence Wilmington, Delaware
Nationality American
Fields Organic chemistry
Institutions DuPont
Known for Kevlar
Notable awards National Medal of Technology
Perkin Medal
Howard N. Potts Medal

Stephanie Louise Kwolek (born July 31, 1923) is an American chemist who invented poly-paraphenylene terephthalamide—better known as Kevlar.[1] She was born in the Pittsburgh suburb of New Kensington, Pennsylvania. Kwolek has won numerous awards for her work in polymer chemistry.

Early life and education[edit]

External video
Stephanie Kwolek at Spinning Elements by Harry Kalish.TIF
Women in Chemistry - Stephanie Kwolek, Chemical Heritage Foundation[2]

Stephanie L. Kwolek was born as a daughter of Polish immigrants in New Kensington, Pennsylvania, in 1923.[3] Her father, John Kwolek[3] (Polish: Jan Chwałek), died when she was ten years old.[4] He was a naturalist by avocation, and Kwolek spent hours with him, as a child, exploring the natural world. [5] Kwolek attributes her interest in science to him and an interest in fashion to her mother, Nellie Zajdel Kwolek.[3][4] In 1946, Kwolek earned a degree in Chemistry from Margaret Morrison Carnegie College of Carnegie Mellon University.[4] Kwolek had planned on becoming a doctor and hoped that she could earn enough money from a temporary job in a chemistry-related field to go to medical school.[4]

DuPont career[edit]

In 1946, Hale Charch, a future mentor to Kwolek, offered her a position at DuPont's Buffalo, New York facility[6] because after telling Kwolek he would get back in touch within two weeks, Stephanie asked Charch if he could make a decision faster because she had to answer another job offer. Charch called in his secretary and had them draft an offer letter on the spot.[4] Though Kwolek initially only intended to work for DuPont temporarily, she found the work interesting enough to stay and not pursue a medical career. Kwolek moved to Wilmington, Delaware in 1950 to continue to work for DuPont.[6] In 1959, she won a publication award from the American Chemical Society (ACS).[7]


While working for DuPont, Kwolek invented Kevlar.[4] In 1964, in anticipation of a gasoline shortage, her group began searching for a lightweight yet strong fiber to be used in tires.[4] The polymers she had been working with at the time, poly-p-Phenylene-terephthalate and polybenzamide,[8] formed liquid crystal while in solution that at the time had to be melt spun at over 200 degrees Celsius which produced weaker and less stiff fibers. Something unique to her new projects and melt condensation polymerization process was to reduce those temperatures to between 0-40 degrees Celsius.[4] The solution was "cloudy, opalescent upon being stirred, and of low viscosity" and usually was thrown away. However, Kwolek persuaded technician Charles Smullen, who ran the spinneret, to test her solution. She was amazed to find that the new fiber would not break when nylon typically would. Not only was it stronger than nylon; Kevlar was ounce for ounce five times stronger than steel. Both her supervisor and the laboratory director understood the significance of her discovery and a new field of polymer chemistry quickly arose. By 1971, modern Kevlar was introduced.[4] However, Kwolek was not very involved in developing the applications of Kevlar.[9]


In 1986, Kwolek retired as a research associate for DuPont. However, she still consults for DuPont, and also serves on both the National Research Council and the National Academy of Sciences.[6] During her 40 years as a research scientist, she filed and received either 17[9] or 28 patents.[10] In 1995,[6][10] she became the fourth woman to be added to the National Inventors Hall of Fame.[11] In 1996, she received the National Medal of Technology, and in 2003, she was added to the National Women's Hall of Fame.[3] She received the 1997 Perkin Medal from the American Chemical Society,[12] and a 1980 award from the ACS for "Creative Invention".[8]


  1. ^ Wholly Aromatic Carbocyclic Polycarbonamide Fiber Original Kevlar patent awarded in 1974 to Stephanie Kwolek
  2. ^ "Women in Chemistry - Stephanie Kwolek". Chemical Heritage Foundation. Retrieved June 13, 2013. 
  3. ^ a b c d "Stephanie Kwolek". Soylent Communications. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 
  4. ^ a b c d e f g h i "Inventing Modern America: Insight — Stephanie Kwolek:". Lemelson-MIT program. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 
  5. ^ "Stephanie L. Kwolek". Chemical Heritage Foundation. Retrieved September 19, 2013. 
  6. ^ a b c d "Invent Now". National Inventors Hall of Fame. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 
  7. ^ Rossiter, Margaret W. (1998). Women Scientists in America. Baltimore, Maryland: Johns Hopkins University Press. p. 267. ISBN 0-8018-5711-2. Retrieved May 24, 2009. 
  8. ^ a b "Stephanie Louise Kwolek Biography". Bookrags. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 
  9. ^ a b Quinn, Jim. "I was able to be Creative and work as hard as I wanted.". American Heritage Publishing. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 
  10. ^ a b "The History of Kevlar — Stephanie Kwolek:". The New York Times Company. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 
  11. ^ "Citation conferring an Honorary Doctor of Science degree on Stephanie Louise Kwolek:". University of Delaware. UDaily. May 31, 2008. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 
  12. ^ "JCE Online: Biographical Snapshots: Snapshot". American Chemical Society. Journal of Chemical Education. Archived from the original on May 24, 2009. Retrieved May 24, 2009. 

External links[edit]