"I knew that I had made a discovery," Kwolek said in an interview several years ago that was included in the Chemical Heritage Foundation's "Women in Chemistry" series. "I didn't shout 'Eureka,' but I was very excited, as was the whole laboratory excited, and management was excited because we were looking for something new, something different, and this was it."
Spicer was wearing a Kevlar vest when he was shot by a drug suspect in 2001. Two rounds shattered his left arm, ripping open an artery. A third was deflected by his badge. The last one hit his nametag, bending it into a horseshoe shape, before burrowing into his vest, leaving a 10-inch tear.
"If that round would have entered my body, I wouldn't be talking to you right now," the Dover police officer said.
While recovering from his wounds, Spicer spoke briefly by telephone with Kwolek and thanked her.
"She was a tremendous woman," he said.
In a statement, DuPont CEO and chairwoman Ellen Kullman described Kwolek, who retired in 1986, as "a creative and determined chemist and a true pioneer for women in science."
Kwolek is the only female employee of DuPont to be awarded the company's Lavoisier Medal for outstanding technical achievement. She was recognized as a "persistent experimentalist and role model."
"She leaves a wonderful legacy of thousands of lives saved and countless injuries prevented by products made possible by her discovery," Kullman said.
During the "Women in Chemistry" interview, Kwolek recounted the development of Kevlar. She said she found a solvent that was able to dissolve long-chain polymers into a solution that was much thinner and more watery than other polymer solutions. She persuaded a skeptical colleague to put the solution into a spinneret, which turns liquid polymers into fibers.
"We spun it and it spun beautifully," she recalled. "It was very strong and very stiff, unlike anything we had made before."
The exceptionally tough fibers she produced were several times stronger by weight than steel. So strong, according to friend and former colleague Rita Vasta, that DuPont had to get new equipment to test the tensile strength.
"DuPont was big in Nylon, Dacron," Vasta said. "This was way stronger than any of those types of fibers."
Spicer and more than 3,1000 other police officers are members of a "Survivors Club" formed by DuPont and the International Association of Chiefs of Police to promote the wearing of body armor.
While Kevlar has become synonymous with protective vests and helmets, it has become a component material in products ranging from airplanes and armored military vehicles to cellphones and sailboats.
Sen. Chris Coons, D-Del., said in a statement that Kwolek had made the world safer.
Vasta said Kwolek had been ill about a week, although she didn't know the cause of death. Vasta said a Catholic funeral Mass is scheduled June 28.