NEW YORK — Half a century ago, working quietly in a New Orleans laboratory, Ruth Benerito helped smooth the fabric of modern life. In so doing, she helped liberate people from hours of household drudgery.
A chemist long affiliated with the US Department of Agriculture, Ms. Benerito helped perfect modern wrinkle-free cotton, colloquially known as permanent press, in work that she and her colleagues began in the late 1950s.
Widely available since the mid-1960s, wrinkle-free cotton is considered one of the most significant technological developments of the 20th century. For her role, Ms. Benerito was inducted into the National Inventors Hall of Fame in 2008.
Ms. Benerito died Saturday at 97. The death, at her home in Metairie, La., was confirmed by Rini Paiva, the hall of fame’s executive director.
Many news articles described Ms. Benerito as the sole inventor of wrinkle-free cotton, a distinction she repeatedly disavowed. Her demurrals, in polite Southern tones, were widely ascribed to modesty.
In reality, wrinkle-free cotton first appeared in the 19th century, developed by a Shaker community in Maine. Many scientists contributed incrementally to the problem of persuading cotton, constitutionally crease-prone, to lie down and behave.
Ms. Benerito’s accomplishments are no less noteworthy for that. As unusual as it was for a woman of her time to earn a doctorate in the hard sciences, it was rarer still for one to go into textile science, then a world of clangorous mills and swaggering men.
She more than held her own and came to hold more than 50 patents, many, but by no means all, in cotton chemistry.
Ruth Mary Rogan was born in New Orleans. At 15, she entered H. Sophie Newcomb Memorial College, then the women’s college of Tulane University. She received a bachelor’s degree in chemistry there in 1935, followed by a master’s in the field from Tulane. She taught at Randolph-Macon Woman’s College in Lynchburg, Va., and at Newcomb and Tulane, before earning a doctorate in chemistry from the University of Chicago.
In 1953, she joined the USDA’s Southern Regional Research Center in New Orleans, where she remained until her retirement in 1986. Her early work was in the center’s intravenous fat program, where she helped develop a fat emulsion, originally designed for wounded soldiers in the Korean War, with which long-term hospital patients could be fed. In 1958, she became the leader of the center’s cotton chemical reactions laboratory.
Cotton’s penchant for wrinkling is inscribed in its DNA. Cotton is a cellulose fiber, and cellulose is a polymer. Like all polymers, cellulose has a chainlike structure, comprising long strands of glucose molecules. Hydrogen bonds tie the glucose together.
These hydrogen bonds are weak and easily broken. (Washing breaks them handily.) When the bonds break, the structure of the chains is no longer secure, causing the molecules within them to shift and the fabric to wrinkle.
True permanent press — the term properly describes cloth that is a blend of cotton and synthetic fibers — was invented in the mid-20th century, but for textile makers, a no-iron, 100-percent cotton fabric was a long-sought grail. A few such fabrics had been developed, but they still needed touch-ups with an iron on emerging from the dryer.
Ms. Benerito refined these earlier fabrics by attacking cotton’s weakest link. With her colleagues, she developed a process called cross-linking, which replaced the ineffectual hydrogen bonds with stronger ones. The new chemical bonds act like the sturdy rungs of a ladder, snapping the polymer chains back to crisp, unwrinkled attention.
Treated this way, the resulting fabric (also known by names like durable press and wash-and-wear) needed little or no ironing. Cross-linking, which lets a range of chemicals be affixed to polymer chains, also made possible later developments including stain-resistant and flame-retardant cotton.
After retiring from the USDA, Ms. Benerito joined the faculty of the University of New Orleans, teaching there until she was 81.
Her husband, Frank Benerito, whom she married in 1950, died in 1970. She leaves no immediate family members.
Her other honors include a Lemelson-MIT Award for Invention and Innovation.
In a 2004 video interview produced by the USDA, Ms. Benerito reiterated that wrinkle-free cotton, like so much else in science, was the product of many hands over time.
“I don’t like it to be said that I invented wash-wear, because there were any number of people working on it, and there are various processes by which you give cotton those properties,” she said. “No one person discovered it or was responsible for it. But I contributed to new processes of doing it.”