Stephanie Kwolek: Curiosity and the Discovery of Kevlar

Stephanie Kwolek: Curiosity and the Discovery of Kevlar

Film transcript

Transcription from video completed in August 2012, using pre-recorded footage of Stephanie Kwolek from 2007 and original interview with Neil Gussman from February 2012. Learn more about Stephanie Kwolek and additional resources connected to the film.


The thing that impressed me most was I loved learning. And I loved learning new things and making discoveries.


Chapter 1. Stephanie Kwolek: Curiosity and the Discovery of Kevlar


Stephanie Kwolek was born in 1923 near Pittsburgh to Nellie and John Kwolek.


When I was a child, I was a very creative child. I watched my mother sewing and making patterns. I imitated, actually, what she did, except that I had all these paper dolls; and I remember, uh, just lying on the floor and drawing, making costumes for these paper dolls. And, of course, when I was slightly older, then I made actual clothes from fabric.

I used her sewing machine when she wasn’t around; it was fun, and it was creative, and it gave me a great deal of satisfaction.


While her mother encouraged creativity and even a future in fashion design, her father was a naturalist and inspired Stephanie’s curiosity about the outdoors.


I had a father who was very much interested in plants and trees. He and I spent a lot of time just roaming through the woods looking for animals and snakes and leaves and wild plants, and I put all these things in a scrapbook.

I, of course, got help from him as to names for all these things. And I watched him. We grew vegetables and flowers and so forth; so it was almost like living on a farm. I remember seeing my father when he would come home from work sit and read the newspaper and books and so forth.

I spent four years, in grades one to four, in a public school, and it was a small school in the country. A lot of the classes were a combination of two classes.

That was quite an experience (laughs) because if you spoke out of turn, as I did once upon a time, you could make a lot of boys very angry, especially if you knew the answer to a math problem—and you spoke up.

What you really did was you learned two grades at one time. I really found it an advantage.

You know, I did much more reading than was intended for someone in my years. In addition, I had an excellent memory, and I could remember everything I read for several pages at a time (laughs) so that I was very fortunate that way.

I was different from a lot of the students there. This probably made me what I am today.


Chapter 2. Where Creativity Meets Chemistry


In 1942 Stephanie enrolled in the Carnegie Institute of Technology—now Carnegie Mellon University—as a chemistry major.


I think when I was in college that I was greatly influenced by a woman professor that I had who taught me chemistry—Dr. Clara Miller. You know, it was not an easy time for women then.

It surprised me that, uh, she was as enthusiastic as she was. And she also was very bright. She had a great deal of influence over me—more so than the men teachers did. (laughs)


In fact, during her first year working at the University of Pittsburgh the faculty there invited her to join a panel and present her current work, an appointment that pleasantly surprised the young chemist.


I considered myself very green, but they were asking a number of people there to give a talk. And it really surprised me that they asked me to give a talk on my work. So I thought to myself, “You know, I must be pretty good.” (laughs)

I was interested in a number of careers, and I thought that I might be a designer, a dress designer. Then I thought I might be a teacher. Then I thought I might be an M.D. doctor. But I didn’t have the money to become a doctor.


In 1946 she graduated a Margaret Morrison chemistry major with a bachelor’s degree and got directly to work earning her way closer to her dream.


And I thought, “Well, I’ll go out and work, save my money, and then I’ll go to medical school.”

When I entered the workforce in 1946, not many women were being hired, but the few that were, were hired because there were so few men available. They were at war or just coming back from war.

So, uh, women were being made offers, and many women did not stay very long; and particularly women with Ph.D.s in chemistry—they left after about two years and went into teaching.

I was stubborn, and I decided that I was gonna stick it out and see what happened.

When I graduated from college, I had a choice. I could work for Gulf Research, or I could work for DuPont. I thought if I was gonna work, I wanted to do research, and I thought DuPont had greater potential, even though I didn’t expect to spend the rest of my life there.


At DuPont, Stephanie joined a team of chemists called the Pioneering Research Laboratory, just a few years after DuPont’s monumental creation of the world’s first synthetic fiber: nylon.


I started out immediately doing research, of course under a supervisor. And I, uh, still intended to go to medical school. But, uh, eventually the work became so interesting, and I had the opportunity to make discoveries.

I made up my mind then that I would stay with the work that I was doing, particularly since I found it very satisfying.

Well, I would say that I discovered that chemistry was the field I wanted to be in when I actually started working for DuPont.

I was very fortunate that I worked under men who were very much interested in making discoveries and inventions. They were very much interested in what they were doing, and they left me alone (laughs). And I was able to experiment on my own, and I found this very stimulating. It appealed to the creative person in me.


Chapter 3. “I seem to see things that other people do not see.”


In 1965 there was talk of a gasoline shortage. So DuPont issued its researchers a challenge: look for the next-generation high-performance fiber to take the place of steel wire in tires because lighter tires would ensure better fuel economy.


I was assigned to look for this super-strong, super-stiff, but lightweight fiber. In the course of that work I made a discovery.

I was working with these very long-chain, extended, uh, they’re called extended-chain polymers, where you had a lot of benzene rings in them.

They were difficult to dissolve, and I found a solvent, uh, to dissolve them in—and the solution was very peculiar. It was not the typical polymer solution, which is sort of like syrup. But instead, this was a very thin solution; it was very watery. Not only was it watery, but it was opalescent.


Transforming a polymer solution from a liquid to a fiber requires a process called spinning. A spinneret forces the liquid through tiny holes to create strands, then spins them—similar to the way cotton candy is made—to build the fibrous material.


The fellow who does the spinning looked at it and said, “This solution is too thin; it’s too watery; furthermore, it has particles in it, and it’s gonna plug up my equipment.” And actually what it was doing was interpreting the opalescence there as particles.

I filtered this solution, and I knew there were no particles in it, and he still refused to spin it. So I think eventually after a few days—he had a guilty conscience or something (smiles)—and he came and said he would spin that thing. We spun it, and it spun beautifully.

It was very strong and very stiff—unlike anything we had made before. I knew that I had made a discovery. I didn’t shout “Eureka!” (laughs) 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.



DuPont Kevlar fiber makes hundreds of household and industrial items safe and cut resistant. It’s lightweight and extraordinarily strong—five times as strong as steel.

Best known for its use in ballistic and stab-resistant body armor, Kevlar has heroically helped to save the lives of thousands of people around the world.

From vehicles and industrial clothing to fiber optics and city roads, Stephanie’s persistence in the lab back in 1965 has led us to a new world by inspiring unimaginable possibilities.


I really did not think of the bulletproof vest. We had Dr. Joe Rivers who at that time was already looking for fibers to use to, uh, in making bulletproof vests.

And I remember the very first time that I spun the 1-4B that he came over and he said, “If you can possibly spare a tiny bit of that fiber, I would like to test it and see if it’ll be useful in a bulletproof vest.”

It’s the vest, you know, it’s made up of many layers. It isn’t just a single layer of cloth.


I’m Sergeant Neil Gussman of the Second of the 104th Aviation, Fort Indiantown Gap, Pennsylvania.

In 2009 our unit deployed to Iraq. Before we went everybody got a Kevlar vest and a Kevlar helmet because they’re our primary personal protection.

No matter where we are we have to have our helmet and vest with us and our weapon. It’s not full protection, but it’s way better than what we used to have.

I first enlisted in 1972, and back then they didn’t have Kevlar vests and they had steel helmets. And while the steel helmets had some advantages, compared to a Kevlar helmet they just didn’t work as well at stopping shrapnel.


In fact, four-pound helmets lined with Kevlar are up to 40% more resistant to shrapnel than old steel helmets.

Today’s ground troops—as well as most journalists—must wear helmets and vests lined with Kevlar for vital body protection.

Essentially, the weave of the fabric has a bit of give and absorbs the blow of a high-velocity object, distributing its force across the other fibers instead of being pierced by it.


A lot of what happens in Iraq or any other war is fragments. I mean, there’s explosions, and both fragments from the explosive itself and anything that’s blown up in an explosion gets thrown around.

So if a car explodes, uh, pieces of the car, pieces of the engine become shrapnel, and Kevlar is great at stopping these flying chunks of metal. And a Kevlar vest and helmet cover most of your upper body and your head. But it protects your vital organs from damage.

STEPHANIE (voiceover)
When a bullet hits this vest, it’s slowed down and finally stopped as it meets the fabric made of Kevlar.


A low-velocity bullet like a pistol, or for pieces of metal flying through the air, it’ll bend but not break. And that means that the fragment doesn’t get through. You get bruised, but you don’t have a piece of metal going through you, which is a huge difference.

And you can more confidently go places, you know, dangerous places, both as any kind of first responder, police officer, firefighter, or in a war zone because you know that you and your buddies are protected.

STEPHANIE (voiceover)

When I look back on my career, I’m inspired most by the fact that I was fortunate enough to do something that would be of benefit to mankind. It’s been an extremely satisfying discovery.

I don’t think there’s anything like saving someone’s life to bring you satisfaction and happiness.



Stephanie was the only chemist at DuPont to do this kind of work without a Ph.D. She worked with a bachelor’s degree throughout her career.

In 1995 Stephanie was inducted into the National Inventors Hall of Fame, only the fourth woman to earn this prestigious honor.

Stephanie has retired from chemistry and currently lives in Delaware.

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