December 18, 2013

Solving practical problems with basic physical chemistry: Ruth Benerito

by Bonnie Denmark

Ruth Benerito, © The Telegraph

This fall, science lost one of its great inventors, Ruth Benerito (January 12, 1916 – October 5, 2013), chemist at USDA’s Southern Regional Research Center in New Orleans. Benerito held more than 50 patents, but she is best known for inventing wrinkle-resistant cotton, also known as wash-and-wear.

Wrinkle-resistant cotton is considered one of the most significant scientific developments of the 20th century, earning Benerito a place in the National Inventors Hall of Fame. This advance in chemistry took some of the drudgery out of daily chores and resurrected America’s faltering cotton industry. In fact, Benerito is hailed as the savior of the U.S. cotton industry, which had suffered mightily as synthetic materials like nylon and polyester became hugely popular due to their easy-care properties, edging out high-maintenance cotton.

Cotton, a cellulose fiber, wrinkles by nature because of its molecular structure. Cellulose consists of multiple strands of a polymer, seen in the Figure below. In cotton, those single polymer strands are linked together by hydrogen bonds, which are easily broken during washing, resulting in rumpled fabric.

Structure of Cellulose

Cross-linking of cellulose

Benerito and her team developed “cross-linking,” a process that joins chemicals to the polymer chains to replace the weak hydrogen bonds with strong new chemical bonds. In the process for treating cotton, ring-shaped organic compounds are inserted between the cellulose chains to prevent adjacent polymers from breaking apart, and thus to stop the fabric from wrinkling. (You can learn more about basic organic compounds in our Carbon Chemistry module.)

Fabric treated this way needs virtually no ironing after it’s washed and is more durable over the long run. This technology also paved the way for other scientific breakthroughs, such as stain-resistant and flame-retardant fabric and treatments for wood and film.

A 2004 USDA “Conversations from the Hall of Fame” interview with Ruth Benerito gives insight into this remarkable scientist’s life, along with some valuable takeaways:

  • She believed in the importance of teamwork and diversity.

I think you need a team effort. No two people are alike, but you can use the talents of the people that you are working with, each one contributing to what he knows and what he can do.

  • She persevered when confronted with obstacles until she achieved her educational goal, even though she had to pursue it little by little as circumstances permitted.

It was depression days and it was almost impossible for a woman to get a job…so I did social work for a year. Finally I did high school teaching and then I got into college. So all during the war and for 13 years I was a professor at Tulane University and would teach there all year long. …My father moved to Chicago. He was with the Illinois Central Railroad, so by chance I could go to Chicago every summer and they had the quarter system. And that’s how I got my degree, by going to Chicago in the summer.

  • She knew her worth and advocated for herself, which is how she came to be a full-time USDA chemist.

[I] did more than the men did…but the men got increases in salary and I didn’t. So I said I wanted an increase in salary. They got a new dean. He said, ‘Well, we’ll have to wait awhile to get to know you better ‘cause I don’t know you.’ So I said, ‘Well, I’ve been here 13 years. If you don’t know me now, you’ll never know me.’  So I quit.

Scientists had been trying to wrinkle-proof cotton for more than 100 years before the advances made by Benerito’s team but without much success. Benerito acknowledged that scientific discoveries are not made in isolation and saw her role as fitting into the larger process of science: “I don’t like it to be said that I invented wash-wear because any number of people worked on it and the various processes by which you give cotton those properties. No one person discovered it or is responsible for it, but I contributed to new processes of doing it” (Conversations from the Hall of Fame, USDA, 2004). For more about how science builds, see our “Theories, Hypotheses, and Laws” module.

Benerito felt that her greatest accomplishment was “the application of basic physical chemistry to solve practical problems.” A practical problem, indeed. Unlocking the secret to wrinkle-free cotton changed lives and reinvigorated a dying national industry.

 

LEARN MORE

Read our Carbon Chemistry and Chemical Bonding modules to learn more.

To learn more about the history of wrinkle-free fabrics, read this article from Chemical & Engineering News.

Watch a video on Ruth Benerito and her work.

Written by

Bonnie Denmark holds an MA in linguistics and teacher certification in English, ESL, and Spanish. She has devoted her professional life to educational and accessibility issues as a computational linguist, multimedia curriculum developer, educator, and writer. She has also worked nationally and internationally as a language instructor, educational technology consultant, and teacher trainer. Bonnie joined the Visionlearning team as a literacy specialist in 2011, assisting the project by developing comprehension aids for science modules and creating other STEM learning materials.

The views expressed above do not necessarily represent those of Visionlearning or our funding agencies.