Stephanie Kwolek

Stephanie Kwolek was an American chemist at the DuPont Company who invented Kevlar in 1965. Working in DuPont's Wilmington, Delaware laboratory on long chain polyamide molecules at low temperature, she produced an unexpectedly thin, opalescent liquid crystalline polymer solution that other chemists of the time would have discarded as a failed batch; when she insisted it be spun anyway, the resulting fiber proved five times stronger than steel by weight. She held a Bachelor of Science in chemistry from the Carnegie Institute of Technology (now Carnegie Mellon University), joined DuPont in 1946 intending the position as a stepping stone toward medical school, and remained there for her entire 40 year career, eventually leading polymer research at DuPont's pioneering research laboratory. She retired in 1986 but continued consulting for DuPont and serving on National Academy of Sciences and National Research Council committees, and held 17 U.S. patents over her career.