A cloudy polymer solution nearly was discarded, but Stephanie Kwolek's intuition led to the creation of Kevlar, a revolutionary material that saved countless lives.
Kwolek's unusual polymer solution
In the 1960s, at DuPont, a cloudy, strangely fluid polymer solution nearly ended up in a laboratory sink. Stephanie Kwolek, a chemist at DuPont, decided to spin this solution despite it being considered a failure according to usual criteria. Technician's hesitation and the test
Charles Smullen, the technician in charge of spinning operations, initially refused to take the risk with the unusual cloudy solution, fearing damage to his spinneret. However, Kwolek insisted, and Smullen eventually gave in and started the machine. Unexpected fiber strength
What came out then surprised everyone in the laboratory: a fine fiber of unprecedented strength. Unlike nylon, the absolute reference of the time, this new fiber did not break under tension. It bent, resisted, and absorbed the impact, where existing synthetic materials always ended up giving way. Kevlar's introduction and properties
This particular polymer gave rise to what is now known as Kevlar, marketed by DuPont in 1971. The material is commonly presented as about five times stronger than steel at equal weight, a feat that alone justifies the immediate interest generated by the discovery. Diverse applications of Kevlar
Since its commercialization, the material has found over two hundred different applications, from optical fiber cables to aerospace components, through some sports equipment. Its use in bulletproof vests has most marked people's minds and the general public. Kwolek's legacy and impact
Stephanie Kwolek remained at DuPont until her retirement, continuing to work on polymers and filing several patents throughout her career. She died in 2014 at the age of 90, leaving behind a scientific legacy whose magnitude continues to astonish, well beyond the world of chemistry.
