Ressenya

Stephanie Kwolek invented polyparaphenylene terephthalamide known as Kevlar, a type of plastic five times stronger than steel and fire resistant. Thanks to Kevlar, many lives have been saved, as it is used in bullet-proof waistcoats, firefighters' suits and motorcyclists' helmets.

Kwolek went on to receive 17 patents in the field of polymer materials and many awards. This made her a pioneer in a predominantly male world. She was committed to bringing science closer to young people, especially girls.

Kwolek's career as a researcher spanned four decades, and the impact of her contributions to science, as well as her support and inspiration for more women to pursue science, is still being felt today.

Activitats

Angles

• Types of plastics. Properties and applications.
  • Espanya > Tecnologia i Digitalització > 3r ESO > Procés de resolució de problemes. Materials, productes i solucions tecnològiques

Espanyol

• Tipos de plásticos. Propiedades y aplicaciones.
  • Espanya > Tecnologia i Digitalització > 3r ESO > Procés de resolució de problemes. Materials, productes i solucions tecnològiques

Justificacions

• She is considered the inventor of Kevlar.
• The plastic she discovered/invented has the characteristic of being light and up to five times stronger than steel. It is also fire resistant, which is why it is used in bulletproof vests, helmets, or firefighters' suits.

Biografia

Stephanie Kwolek was born in New Kensington, Pennsylvania, near Pittsburgh, to a family of Polish immigrants. Her father, died when she was ten years old, he was a naturalist by avocation, and Stephanie spent hours with him, exploring the natural world. She attributed her interest in science to him and her interest in fashion design to her mother, who worked as a seamstress.

Kwolek's intelligence and aptitude for the natural sciences and mathematics made him decide he wanted to become a doctor and save lives, but in order to pay for medical school he first had to work.

In 1946, she earned her Bachelor of Science degree in Chemistry from Margaret Morrison Carnegie College. The idea was to work as a chemist temporarily until she had enough money to fulfill her dream of becoming a doctor. So that same year, she went to work for the company that would change her life, DuPont. At DuPont, he found the work so interesting and challenging that he decided to abandon his plans to study medicine and make chemistry his lifelong career.

DuPont was trying to find a polymer fibre that was lighter and stronger than steel. At the same time, World War II highlighted the need for lightweight, wearable armour to protect personnel and equipment. Steel was the only armour material available, and its weight limited its use to armoured vehicles.

Kwolek’s early research focused on finding a new process to create polymers at low temperatures. At that time, the process used for creating polymers through condensation, polycondensation, only worked at high temperatures, , making it a very energy-intensive and expensive process. Ideally, the industry wanted the polycondensation process to occur between 0C and 40C.

When Kwolek was in her 40s, in 1964, the country faced the prospect of a petrol shortage, which would minimise the volume of crude materials available for manufacturing rubber. Her new research aim was to find a strong but lightweight fibre that could be incorporated into tyres to reinforce them and improve fuel efficiency. She discovered that under certain experimental conditions, the polyamide solutions that she was working with became very runny and behaved strangely. Whilst runny solutions did not normally lead to the production of strong polymer fibres, Kwolek was curious to find out what properties these polymers would have, if indeed fibres could be spun from something so runny. In a speech in 1993, she explained:

"The solution was unusually (low viscosity), turbid, stir-opalescent and buttermilk in appearance. Conventional polymer solutions are usually clear or translucent and have the viscosity of molasses, more or less. The solution that I prepared looked like a dispersion but was totally filterable through a fine pore filter. This was a liquid crystalline solution, but I did not know it at the time".

This type of cloudy solution used to be discarded. Kwolek was denied use of the fibre spinneret for his solution because it was thought that the solution would clog the machine. However, Kwolek convinced the technician operating the spinneret to try his solution. The result was impressive: the resulting fiber was much stronger than nylon (in fact, it was much stronger than steel) and also very light. Kwolek also found that heat-treating these new fibers increased their strength; the rod-shaped molecules aligned and hydrogen bonds formed between them. Kevlar was born.

In 1971, Kwolek was granted a patent for Kevlar, but transferred it to DuPont. Although he was not involved in developing practical applications for Kevlar, he continued to research its derivatives.  Her discovery generated billions of dollars in revenue for DuPont, but she never benefited directly financially.

Today, Kevlar has over two hundred applications, bulletproof vests, tennis rackets, skis, parachute lines, boats, airplanes, ropes, cables. It has been used for car tyres, firefighter boots, hockey sticks, cut-resistant gloves and armoured vehicles. It has also been used for protective construction materials, such as bomb-proof materials, hurricane safety rooms and bridge reinforcements.

Kwolek continued to work for the Dupont Company and the National Research Council of the National Academy of Sciences (NAS), her career was filled with accomplishments, including 17 patents and multiple awards.

In 1994 she was inducted into the National Inventors Hall of Fame, one of only four women out of 113 members. In 1995, DuPont awarded her with the Lavoisier Medal, awarded for outstanding technical achievement and to this day, she is the only female employee ever to be honoured in such a way. In 1996, she was awarded the National Medal of Technology, acknowledging her general contributions to the area of polymer science, and the practical applications of her research. Again, this was an award rarely given to women, much like the Perkin Medal she received in 1997 and is regarded as the highest honour that can be awarded in the US industrial chemical industry. Also in 1997, she was inducted into the Plastics Hall of Fame at the University of Massachusetts, remaining the only woman to be thus honoured until Dr Maureen Steinwall was inducted in 2015.

Kwolek appreciated the under-representation and lack of acknowledgement of women in science, and turned her hand to working with female scientists as a mentor, offering advice and guidance as their careers developed. When Kwolek died, DuPont’s chief executive Ellen Kullman described her as “a creative and determined chemist and a true pioneer for women in science”.

It's hard to estimate how many lives bulletproof vests have saved around the world, but they have made the inventor of Kevlar feel as lucky as the people those vests protect. Although she didn't study medicine, Stephanie finally fulfilled her dream of saving lives. In a 2007 interview with the Wilmington News Journal, Kwolek said, "At least I hope I am saving lives. There are very few people in their careers that have the opportunity to do something to benefit mankind".

After forty years at DuPont, where she rose to become director of the DuPont Pioneer Polymer Laboratory, and a highly successful career, Stephanie retired in 1986. Always active, she continued to work to bring science to young people, designing and writing educational experiments. In her own words, "I believe in inspiring young people to believe in themselves and not be afraid to think differently". She had a particular focus on young girls and mentored many female students and researchers. Stephanie died on 18 June 2014 at the age of 90.

Obres

Bibliografia

Uve, Sandra (2018). Supermujeres superinventoras. Ed. Planeta.

Stephanie Kwolek , en Wikipedia, (18-03-2022), <https://es.wikipedia.org/wiki/Stephanie_Kwolek> 

Stephanie Kwolek , en Wikipedia, (18-01-2025) <https://en.wikipedia.org/wiki/Stephanie_Kwolek>

López, Aitziber (07-03-2017) Vidas científicas "Stephanie Kwolek, la química que ha salvado miles de vidas" Mujeres con ciencia. Cátedra de Cultura Científica de la UPV/EHU (18/01/2015) <https://mujeresconciencia.com/2017/03/07/stephanie-kwolek-la-quimica-ha-salvado-miles-vidas/>

Stephanie (27-05-2021) "Stephanie Kwolek: inventora del Kevlar" Ada Lovelace Day (18/01/2025) <https://findingada.com/blog/2021/05/27/stephanie-kwolek-inventor-of-kevlar/ >

Enfocament Didàctic

This author can be studied in the subject of technology of 3rd of ESO, in the block of materials of technical use and plastics. She can also be used in chemistry

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