Kevlar

Stephanie Kwolek died a couple of weeks ago of good age (she was born in Pittsburg in 1923) and I sewed up my chain-saw trousers in honour of the event. ?! Her father Jan Chwałek was a Polish foundry-worker in the steel town but loved to fossick about in the natural world and took his daughter with him as soon as she was old enough.  This curiosity translated into an interest in science but her Dad died when she was only 10 and she saw her mother Nellie Zajdel step up to the plate as a single parent and working seamstress. Stephanie also had a girl's interest in fashion and spent time making clothes for her dolls and herself.  At one point she suggested that she might become a fashion-designer but her mother said she'd starve at that because her standards edged towards perfectionism and you have to be able to say that something is good enough.  After graduating with a degree in chemistry she thought she'd go on to medical school.  Becoming a doctor is a delusion common in young people because they only know about the dozen careers that appear in children's books. We used to meet a lot of youngsters in the TCD & UCD genetics and biochemistry degree programmes because they hadn't obtained enough points on the Leaving Certificate for Medical School.  The Gaffer used to tell them, particularly the women, that becoming a scientist was much more rewarding and challenging than being a doctor and was certainly not a fall-back or second-best option.

In 1946, young Stephanie rocked up to DuPont in Buffalo, NY looking for work to help pay for medical school.  She was interviewed by Hale Charch, a huge cheese in DuPont's chemical division, who had invented a process for moisture-proofing cellophane so that it could be used as a food wrap.  He must have been awash with youngsters wanting to work in DuPont. A case could be made that Nylon (a DuPont product) had won the war for the allies. Then again, a case could be made that DuPont almost lost the war for the allies by supplying the technology for leaded petroleum to IG Farben in das Drittes Reich. At the end of the interview Charch said he would "let her know in two weeks" but Stephanie replied that she had to know sooner than that because she had another job offer and needed to let them know.  Charch called his secretary in and dictated his letter-of-offer there and then. He recognised that assertiveness-training worked in the work-place.

As it turned out, Kwolek [L with a cartoon of Kevlar below] shelved her ideas about medical school because she was a 'good pair of hands': the perfectionism that her mother has recognised morphed into a painstaking carefulness in the laboratory.  But she was much more than a technician: she had ideas and a creative spark as well. In 1965, she was assigned to make novel polymers to replace the rubber in tyres. She had developed a way of creating nylon polymers at room-temperature which had an immediate effect on the cost of production (no fuel bills) and in the course of experimentation came up with some gloop the colour and consistency of buttermilk which everyone knew would never make a polymer fibre because their precursors were usually clear and viscous.  But she persuaded the process technician to run the stuff through his spinnerets and found that the resultant fibres were stronger than nylon: heck - they were stronger than steel and lighter and fire-resistant and water-proof. Needless to say she didn't believe her instruments and repeated the experiment numerous times "I didn’t want to be embarrassed" before kicking her lab-book upstairs to her line-manager.  The DuPont management took the principle and gave it to a team of boys to work on and develop because, like Sugru, they knew they were onto a good thing but didn't know quite where to product-place it.  It was ten years before the first Kevlar bullet-proof vests came off the production line, but in her life-time a million of them were produced.  Kevlar generated a $billion$ revenue stream for the company.

After she retired she spent 20 years mentoring young women in science.

Chain-saw pants need to be thorn- and bramble-proof but more importantly need to do something clever when you slip in the woods and the teeth lurch towards your leg. Underneath the thorn-proof outer layer is a mix of ballistic nylon and Kevlar which explodes into a fibrous tangle when disturbed by steel teeth travelling at 20 m/s, this strangles the drive-sprocket and writes off the pants but usually saves the ould leg.  The outer layer on mine has been steadily ripping down from the crotch and that's what I've just sewn up again.  It doesn't look like it would do me favours at a job-interview, but 'tis enough 'twill serve.

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