Stephanie Kwolek was the chemist who developed the polymer fibre Kevlar, used in bulletproof vests and body armour. Her invetion saved thousands of lives. She has died at the age of 90.
Stephanie Louise Kwolek, chemist.
Born 31 July 1923; died 18 June 2014.
When she invented Kevlar, Stephanie Kwolek, had no idea her invention would become quietly ubiquitous in modern life.
At the time, she was working for DuPont, the chemical company, trying to find a petroleum-based polymer fibre that would be lighter and harder-wearing than steel in radial tyres. The substance she created, lightweight, flexible, strong and heat-resistant, would prove to have hundreds of applications, in everything from space capsules to skis, fibre-optic cables to suspension bridges, firefighting suits to oven gloves.
Kwolek was born in New Kensington, Pennsylvania, the daughter of immigrants from Poland. Her father, who died when she was 10, was a foundry worker and keen naturalist who instilled in her a love of science.
From her mother, a seamstress, she inherited an interest in fabric and design. But following her mother's advice that she was too much of a perfectionist to go into fashion, Kwolek decided to become a doctor.
She studied chemistry in Pittsburgh at Margaret Morrison Carnegie College, the women's college of Carnegie Tech, which is now Carnegie Mellon University.
She was interviewed for a post in textile chemistry with DuPont by William Hale Charch, the man who invented the process to make cellophane waterproof. When Charch told her she would hear in a few weeks whether she had a job, she told him she had another offer and could he make a decision sooner. Impressed, Charch called in his secretary and dictated a letter offering her the job on the spot.
Taken with chemical research, she moved to DuPont's main facility in Wilmington, Delaware.
Nylon was generally spun from polymer crystals at over 200C. In 1964, working with condensation of those crystals at room temperature, Kwolek produced a thin, buttermilk-like liquid different from the clear viscous fluids that usually resulted. She was curious and, ignoring advice that the polymer would not work as a fibre, persuaded the lab scientists to let her pass it through the spinners.
They feared it would clog the finely engineered tubes. She discovered that once spun, the polymer's molecules lined up in parallel, and as they cooled produced a fire-resistant fibre of stiff toughness.
In a 2007 interview with the Wilmington News Journal, she spoke modestly of her legacy, saying "At least I hope I'm saving lives. There are very few people in their careers that have the opportunity to do something to benefit mankind."
A Catholic funeral Mass is scheduled June 28.
Read full article: Stephanie Kwolek obituary (The Guardian)