Some inventors have made their mark in material science; some became well-known, while others remained unnoticed despite their worthy contributions. Stephanie Kwolek, a chemist whose work has been hugely important but largely unknown by name, falls into the latter category. The present article explores her life and work.
In 1964, Stephanie Kwolek worked at DuPont’s Experimental Station in Wilmington, Delaware. That year, she began a project that would lead to an incredible breakthrough in materials science.
She was born in 1923 in New Kensington, Pennsylvania, to Polish immigrant parents. Her father, an amateur in nature study, had brought up the habit of taking long walks in the woods with his daughter. She became interested in science as she walked. An interview quoted from Kwolek: “I was always asking why.”
Kwolek joined DuPont after graduating with a degree in chemistry in 1946 from Margaret Morrison Carnegie College, now part of Carnegie Mellon University. She never intended to stay on for the rest of her life; Kwolek had taken the job to get some money so she could go to medical school and had resolved not to stay any longer than necessary. She became interested in polymer chemistry, which became the focus of her career.
In 1964, DuPont was looking for a fiber that could replace steel in the tires—a light but strong fiber—because of the looming gasoline shortage. The task of creating such a fiber fell to Kwolek. In one of her experiments on aromatic polyamides, she chanced upon something odd.
Her solution was unlike standard polymer solutions: instead of being clear, it was cloudy and opalescent, like a liquid crystal. When spun, it gave fibers that were extremely strong and stiff. At first, Kwolek did not entirely trust her results. “I didn’t believe it, but the numbers were there,” she recalled.
Her colleagues shared her skepticism. Initially, the lab’s spinneret operator resisted running a test on the concoction, sure it would muck up the equipment. But Kwolek was undaunted—and with excellent reason. This early experiment’s fiber was phenomenally strong—five times as strong as steel, weight for weight.
DuPont discovered the commercial potential of Kwolek’s invention. They named the substance Kevlar and patented it in 1966. In 1971, Kevlar made its commercial debut and quickly found numerous applications across various industries.
Now, Kevlar appears in countless products. It is a critical component of both bulletproof vests and military helmets, not to mention police protective gear. It’s found in sports helmets and bicycle tires. It finds use in smartphones, airplanes, and even bridge construction.
Kevlar is also significant due to its far-reaching effects. It is a prime example of how scientific research can yield surprising and important results. Kwolek’s discovery was not serendipity; it was the product of years of diligent work and the readiness to explore such surprising findings.
Kwolek retired from DuPont in 1986, by which time she had already accumulated 17 patents over the course of her career. In retirement, she most recently dedicated herself to science education, especially encouraging young women to consider and enter careers in scientific fields.
The science community acknowledged Kwolek with multiple awards. The National Inventors Hall of Fame inducted her and she won the National Medal of Technology and the Perkin Medal. Despite such acknowledgment, few people outside the scientific community know who Stephanie Kwolek is.
Stephanie Kwolek died in 2014 at the age of 90. Her work has endured, touched many fields, and probably saved lives through the gears she created. Her career stands as a long-lasting example of how scientific research can affect so many spheres. A story of Kwolek’s is a reminder that behind many a commonplace item, there stands a scientist or researcher whose work has shaped our world. Whenever we use something with Kevlar in it, from smartphones to safety gear, we benefit from Kwolek’s curiosity, perseverance, and careful observation that have brought about a discovery.
