Invention Of Kevlar®

As a female scientist working for a large corporation in the 1950s, Stephanie Kwolek encountered cynicism and mysogyny from many of her male colleagues - until she invented Kevlar, a synthetic fibre with almost miraculous properties.


Kevlar sounds simply too good to be true. Invented in 1963 by scientist Stephanie Kwolek (USA) as part of her research into synthetic textile fibres for chemical company DuPont (USA), it is an extremely strong, lightweight, fire-resistant fibre that has found its way into everything from bullet-proof vests and bridge cables to racing cars, lifeboats and fishing lines.

Kwolek, who already had a degree in chemistry, began working for DuPont part time in order to fund her way through medical school. But she found her work at DuPont so interesting that instead of becoming a doctor she decided to stay on, joining the company's Pioneering Research Laboratory full time in 1950 and researching the manufacture of very strong fibres from long chains of molecules. Kevlar originated not as the planned result of an experiment, but because Kwolek was inquiring enough to investigate the unexpected. She was researching an improved means of joining certain simple molecules (monomers) into longer chains (polymers) by fusing them at low temperatures, but the result was an opaque solution, not the clear liquid she was expecting. Instead of ditching the solution and starting again, Kwolek tried spinning it into fibres and found that she had created an entirely new type of synthetic material, described in her patent as "crystalline, linear condensation polyamides."

Analysis showed that the fibre she had created was five times as strong as steel of the same weight, and that when woven into a textile or fabricated into a composite material, it could absorb energy and prevent cracks from spreading from the point of impact. The process has been described as being like that of a spider's web, in that the fibres at the point of impact stretch rather than break, dissipating energy by causing other fibres beyond the impact to stretch as well - properties so remarkable that Kwolek has been described as a modern alchemist for conjuring up Kevlar.

Source - The Book Of Inventions by Ian Harrison