Bullet Proof Ms
With the sad news of the death of Stephanie Kwolek, erectile the inventor of Kevlar, ambulance reproduced here is the short piece written by Michael Williams about her, vcialis 40mg from the final edition of HerStoria Magazine.
Stephanie Kwolek, born in Pennsylvania in 1923, originally set out to be a doctor. However, after graduating in science in 1946, she realised that she had insufficient funds to finance expensive medical studies. Instead she took a job in chemistry with a view to saving enough to money to start training in medicine. Such jobs had only become available to women recently after the end of World War Two and women chemists were still rare. Nonetheless, the story goes that Kwolek was appointed on the spot after interviewing for a job at the pioneering research facility DuPont (pioneering in more ways than one!).
In 1964, rumours of a severe petrol shortage in America led scientists at DuPont to think of creative ways to address the problem. One idea was to design a new, light weight fibre and use it to make tyres; vehicles fitted with these new tyres would be lighter and therefore use less petrol.
During the course of this research, Kwolek made a discovery. Under certain conditions, a chemical polymer would manifest straight molecules instead of bendy ones, but it would still form liquid crystals in a solution – something never seen before. To find out more about this ‘special’ polymer, Kwolek sent the solution off to be ‘spun’ (a type of testing used in chemistry to identify a fibre’s attributes). After persuading the company to allow her to spin the polymer (they thought the chemical might block their machines) Kwolek was excited by the results. The substance was nine times as strong as any existing polymer in use at the time. Shocked, Kwolek was ‘very hesitant about telling anyone’ and reportedly returned the fibre for testing several times more before believing her discovery. The chemical’s name is Poly-paraphenylene terephthalamide, branded as Kevlar.
Kevlar is remarkably lightweight yet strong—five times stronger than the same weight of steel—and does not corrode or rust. It is used in suspension bridge cables, for a range of other building construction purposes, and in the manufacture of items from canoes to audio equipment. But the main use of Kevlar is in the production of bullet proof vests. Kwolek has often been approached by police officers and others wanting to express their gratitude to the woman who invented the vest that saved their life – and even wanting her autograph.
In response Kwolek, now in her late eighties, has simply remarked ‘I love doing chemistry. And I love making discoveries’.
Stephanie Kwolek – HerStoria’s first First Lady of Invention.