Mourned by arms dealers everywhere

Stephanie Kwolek, the American chemist who invented the super-strong fibre Kevlar used in bullet-proof vests, has died at age 90. 

Kwolek, who worked for the DuPont chemical company for four decades starting in 1946, died in Delaware after a short illness. 

The company confirmed her death."We are all saddened at the passing of DuPont scientist Stephanie Kwolek, a creative and determined chemist and a true pioneer for women in science," DuPont chief executive Ellen Kullman said in a statement. "Her synthesis of the first liquid crystal polymer and the invention of DuPont Kevlar highlighted a distinguished career." 

Kwolek was working to find a fibre to strengthen radial tyres when she came across a thin, milky solution of polymers that showed real promise. 

She told the News Journal newspaper in Wilmington, Delaware, in 2007 that it was not exactly a "eureka moment." 

But it led to the development of Kevlar, now a critical part of bulletproof vests, helmets and other body armor components as well as a range of other applications like tires, firefighter suits, boat hulls, fibre optic cables, fuel hoses, airplane and spacecraft parts and skis. 

Kevlar is lightweight but extremely strong - five times tougher than steel. 

"At least, I'm hoping I'm saving lives," Kwolek told the newspaper. "There are very few people in their careers that have the opportunity to do something to benefit mankind."