A fiber with half the density of fiberglass and five times stronger, weight for weight, than steel, Kevlar8 is now globally recognized and widely used. It is best known for its use in bulletproof and stabproof vests, where it has saved thousands of lives.
After graduating from the Carnegie Institute of Technology in 1946, American chemist Stephanie Kwoleck (b. 1923) was employed by DuPont to research high-performance chemicals. Her work on polymers yielded a number of successful discoveries. Kwoleck, who holds twenty-eight U.S. patents, specialized in developing polymers at low temperatures and in the 1960s discovered a new group called liquid crystalline polymers.
Kwoleck's invention of Kevlar fibers in 1965 stemmed from an interest in the chemicals produced during the process of polymer synthesis. These substances are sensitive to moisture and heat and easily undergo hydrolysis and self-polymerization. She discovered that, in cool conditions, these chemicals created an aramid polymer that was a cloudy liquid. Kwoleck's research team spun it out and the resulting fibers were much stiffer and .stronger than any others previously created.
The Pioneering Lab at DuPont was put to work finding a commercial use for these fibers, and now Kevlar has many important applications; it replaced asbestos brake pads, and it is used for racing sails and standing rigging on performance boats. Fiberoptic cables, spacecraft shells, radial tires, and suspension- bridge cables are now frequently made of Kevlar. It is widely used in bulletproof vests for military and police personnel. One clothing firm has even incorporated Kevlar into fabric for children's school uniforms.
