Who Invented Kevlar?
Stephanie Louise Kwolek, a Polish-American chemist, patented Kevlar in 1966. She found the new materials while working for DuPont, an American chemical company. Kevlar is mainly used in bullet proof jackets. The term ‘bullet proof’ originated in the 15th century England. ‘Pistol proof’ was also in use, although only for a short time. It is five times stronger than steel and it is lightweight. The substance doesn’t rust like iron; therefore it wasn’t long before it was established in the market.
Stephanie Kwolek was born in 1923 in the United States. She graduated in 1946 from the Carnegie Institute of Technology. She then began working as a chemist at DuPont. There are 28 patents in her name and she is also a member of the National Inventors Hall of Fame.
Kevlar is a polymer, which means it is made up of smaller molecules, which attach themselves to one another to form a larger molecule. The smaller molecules are known as monomers. The monomers of Kevlar are 1, 4-phenylene-diamine and terephthaloyl chloride. The chemical reaction is a condensation reaction – two molecules of hydrochloric acid are released each time the monomers get combined.
Kevlar comes in three types or grades:
(1) Kevlar,
(2) Kevlar 29,
(3) Kevlar 49
They are put to use differently because of the difference in strength and other properties. Kevlar is used in tyres and simple mechanical goods. Kevlar 29 is used in brake linings. Kevlar 49 is the strongest of all and it is used in boat hulls, airplanes and bicycles.
Category: Technology