Stephanie Louise Kwolek

DOVER, Del. (AP) — Police Lt. David Spicer took four .45-caliber slugs to the chest and arms at point-blank range and lived to tell about it. Like thousands of other police officers and soldiers shot in the line of duty, he owes his life to a woman in Delaware by the name of Stephanie Kwolek.

Kwolek, who died Wednesday at 90, was a DuPont Co. chemist who in 1965 invented Kevlar, the lightweight, stronger-than-steel fiber used in bulletproof vests and other body armor around the world.

A pioneer as a woman in a heavily male field, Kwolek made the breakthrough while working on specialty fibers at a DuPont laboratory in Wilmington. At the time, DuPont was looking for strong, lightweight fibers that could replace steel in automobile tires and improve fuel economy.

"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 explained. "This was way stronger than any of those types of fibers."

Spicer and more than 3,100 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.

"Rest in peace, Stephanie Kwolek. Thank you for inventing Kevlar and saving Soldiers' lives," the U.S. Army tweeted Friday evening.

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.

RANDALL CHASE, Associated Press


Copyright © 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.