06/21/2025
She was told to throw away her ‘useless’ experiment. Instead, it stopped bullets.
In 1965, chemist Stephanie Kwolek was working at DuPont. Her team sought a lightweight, durable fiber for car tires, anticipating a gasoline shortage.
Kwolek synthesized a peculiar, buttermilk-like liquid crystalline polymer solution. Some colleagues, and initially Kwolek herself, thought it might be waste due to its cloudy appearance, different from the clear solutions usually sought.
With persistence and the crucial help of technician Charles Smullen who ran the spinneret, she convinced her colleagues to test it. The resulting fibers were exceptionally strong, five times stronger than steel by weight.
This material became Kevlar. Its first commercial application was in tires during the 1970s.
Later, Kevlar became renowned for its use in bulletproof vests. Its applications also expanded significantly to aerospace components, sports equipment, and other protective gear.
Stephanie Kwolek was one of the few female chemists at DuPont during the 1940s–1960s. Her invention has saved countless lives and advanced numerous technologies.
