Throwback Thursday: Stephanie Kwolek

Stephanie Louise Kwolek’s research in 1971 resulted in an important discovery, in the form of a liquid crystalline polymer solution. The unusual strength and stiffness of this solution led to the invention of Kevlar®, a synthetic material five times stronger than steel and resistant to wear, corrosion, and flame. That’s why Kevlar is the main component of modern bulletproof vests, which have become invaluable to legions of servicepeople. Not restricted to just this use, Kevlar is used in several other products like skis, safety helmets, hiking and camping gear, and suspension bridge cables.


The famous woman inventor and scientist Stephanie Kwolek was born in New Kensington, Pennsylvania in 1923. Her father was a foundry worker and a keen naturalist who instilled in her a love for science. Her mother was a seamstress, giving her an interest in fabrics and design. While growing up, Kwolek wanted to study medicine, and that desire persisted as she studied for a B.A. in chemistry at Carnegie Mellon University. After finishing her degree, Kwolek took a temporary research position with DuPont to earn money and get herself into a medical school. But her work at DuPont turned out to be so interesting, she decided to stay on, working there until her retirement in 1986.

In the 1960s, Kwolek took up work on synthetic fibers as a part of a team at DuPont’s research laboratory in Wilmington, Delaware that was trying to develop a lightweight yet strong fiber to be used in tires. The research involved manipulating strings of carbon-based molecules to produce larger molecules known as polymers. Kwolek was specifically working with poly-p-phenylene terephthalate and polybenzamide. She struggled with the polymers she was working with and was not able to get the results the way she wanted. Conventional polymer solutions are usually translucent, but the one she created looked like a dispersion. When she performed some tests on her solution, it gave amazing results. The fibers spun from these polymers displayed unusual stiffness.

Tests performed on these fibers revealed strength five times that of steel, and fire resistance. Kwolek’s seniors at DuPont recognized the commercial potential of the newly developed fiber and so, after some more work, in early 1970s it was launched in the market as Kevlar. Kwolek was not very involved in developing the practical applications of Kevlar. 

Even after making such an important discovery, Kwolek remained modest and humble. When asked about her achievements, she said, “I hope I’m saving lives. There are very few people in their careers that have the opportunity to do something to benefit mankind.”

Kwolek never married, and dedicated her entire life to her profession. She received several awards and acknowledgments for her discoveries, and lived a long and fruitful life. She died June 18, 2014, at the age of 90

For the younger generations, she had this message: “I tell young people to reach for the stars. And I can’t think of a greater high than you could possibly get than by inventing something.”

If you know other legendary women in manufacturing we should feature next, let us know.

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