Tuesday, 13 April 2021

K is for... Kwolek... n ... Knockout


Stephanie Kwolek (July 31, 1923 - June 18, 1914) was a renowned, much awarded American scientist who invented a polyamide fibre, known secretively as Fibre B in its initial years. It came to be renamed Kevlar (happily for me!). So that’s a double K entry here, read one and get one free – a knockout bargain!

Stephanie was born in Pennsylvania to Polish immigrant parents. Her father died when she was still a child, but from him she inherited a love of science and nature. Her mother was a seamstress and passed onto her an interest in textiles. But the lady told Stephanie she was too much of a perfectionist to be successful in the fashion industry. Stephanie initially wanted to be a doctor, but that was not how things panned out. She completed her bachelor's in chemistry and was looking for a stopgap job to fund her medical school studies. She ended up taking on a position in DuPont where she continued working for the next 40 years.  In retrospect, it seems perfectly fitting that she should have become a textile chemist, doesn't it?

In the mid-60s, DuPont anticipated a fuel shortage soon and their engineers thought that lighter tyres could improve mileage on cars. The idea was to develop light, strong, rigid fibres to replace the steel in tyres. At the time, the materials DuPont was working with had to be heated to very high temperatures to be melted and spun, and that did not work well as a steel substitute at all, because it made them limp. Stephanie was given the task of finding something that would work at lower temperatures and would not go floppy. The work was basically to dissolve long chains of a group of molecules called polyamides and then running the resulting solution through a machine that spun them into fibre. 

A particular batch Stephanie worked yielded, to her surprise and mild disappointment, a cloudy, runny liquid instead of the nice clear, viscous syrupy thing she had expected. But instead of just chucking the lot, she chose to run it through the machine and hey presto! it produced the strongest man made fibre in the world. Five times as strong as steel, as light as fibreglass, impenetrable to bullets. Kwolek had found exactly the wonder material her bosses had tasked her with.

Initially the uptake was slow, it did find its way into radials for racing. But over the last 50 years, it has been used for bulletproof vests and body armour, firefighter shoes, protective gloves for chefs, spacecraft parts, skis, tennis racquets, surfboards, canoes, cell phone casings - anywhere where strength and lightweight attributes are important.  Read an article from the 70's here for insights into Kevlar's markets then.

And what happened to Kwolek? DuPont made her in-charge of polymer research at its lab. She spent the next 20 years working there and retired in 1986. But she continued to consult for DuPont in her later years. She was awarded the Lavoisier Medal by DuPont, the only woman to have been so honoured till she died in 2014. She also received the Chemical Pioneer Award, the Perkin Medal, and a string of other awards/honours and was inducted into the National Inventors Hall of Fame and the National Women's Hall of Fame.  She also devised and wrote about several classroom demonstrations which continue to be used in schools today.  The Royal Society of Chemistry has instituted the Stephanie L Kwolek Award to recognise exceptional contributions from non-UK scientists. Kwolek served on committees in the National Academy of Sciences and National Research Council. A pioneer in the sciences and an inspirational  role model.

A-Z Challenge 2021  


  1. Hari OM
    well, thank you for increasing my Knowledge today! I had of course heard of Kevlar, but kne nothing of its origins... I am glad to read that this lady was suitably lauded during her active time; that itself is quite the Knockout, given how so many women were lost to history for equal efforts, only to be 'unearthed' in recent times. YAM xx

  2. Thank you. Like YAM I knew of kevlar but nothing about its inventor. How wonderful that her work was recognised. And how equally wonderful that her passion/skill/triumph drew on her inheritance from both parents.

  3. Knockout post. You are killing it on the A to Z challenge. Very cook to have a female scientist with such success. Growing up in PA and my sister now lives in Delaware, the DuPont name and money are a huge influence. Winterthur home, Longwood Gardens, the list is infinite of donations - no doubt thanks to Kevlar profits and many other products bearing the DuPont name.

    1. not "cook" - cool. I did not proofread first, but too lazy to delete and repost.

  4. Hi Nila - as the others have said I knew about Kevlar ... but not how and where it came about - reminds me of Penicillin - also an 'accident', as too Paul Nurse's identification of 'fission yeast' - an essential in today's development of vaccines - also an afterthought ... strange but true in life.

    Kevlar has so many applications today ... Wonderful lady - she looks delightful too (Stephanie Kwolek). Thanks for this info - Hilary