Stephanie Kwolek

Born on 31 July 1923 in New Kensington, Pennsylvania, Stephanie Kwolek was a chemist at the DuPont Company who fabricated the class of high-strength fibers that is used in Kevlar. Growing up she developed passions for science and nature and also fashion and sewing. In 1946 Kwolek earned a bachelor’s degree in chemistry from Margaret Morrison Carnegie College, the women’s college of Carnegie Mellon University in Pittsburgh. Her initial plan was to get a job in chemistry and earn enough money to go to medical school. But she got hooked when she started researching polymers at DuPont. In the mid-1960s, with fears of impending gasoline shortages, she led a group to search for a fabric that could be used to reinforce car tires without adding much weight. The process involved dissolving polymers in solution and then spinning the molecules into strands. During one of her trials, Kwolek discovered polymer molecules that formed liquid crystals in solution. When forced through a spinneret, the fibers lined up to form a fabric that was nine times as stiff as anything she had previously developed. After several years more research, DuPont was able to introduce Kevlar in 1971. The material is used in engineering, cookware, and most notably, bulletproof vests for soldiers and police. Kwolek received the National Medal of Technology and was inducted into both the National Inventors Hall of Fame and the National Women’s Hall of Fame. She died in 2014 at age 90. (Photo credit: Chemical Heritage Foundation, CC BY-SA 3.0 )

Date in History: 31 July 1923