Look through your closet and you’d be hard-pressed to find a fabric that is not a blend of multiple fibers. The most common is a cotton-polyester blend: a soft comfortable material that is cheap to boot. Which is why it has become the darling of the fast fashion industry.
The downside of this modern fashion is that blended fabrics are difficult to recycle. Over 99% of the over 113 million tons of textiles the world produces today ends up burned or landfilled.
But researchers at the University of Amsterdam have now developed a viable process to recycle waste polycotton textiles. The method offers a simple way to fully separate the cotton from polyester and recycle both materials.
“Proper recycling is necessary for the textile sector to transition into a true circular and low-carbon industry,” the researchers write in the journal Nature Communications. But separating polyester and cotton fibers in blended textiles is difficult. So besides disposal, they are typically downcycled into low-value materials such as furniture stuffing or carpet padding.
In the past, researchers have devised ways to break down the cotton fibers in polycotton blends in order to separate the two materials. But most of these efforts have used a low acid concentration at high temperature or a multistep process with different acid concentrations.
The Dutch researchers wanted to develop a simple, room temperature process. They turned to a technique developed by their collaborators at Avantium to break down woody plant mass into its components.
The method involves soaking the textiles in a concentrated solution of 43% hydrochloric acid for 1 to 4 days at room temperature while being continually stirred. At the end of the chemical process, the cotton breaks down into its building block molecule, glucose, which can be used to make renewable plastics.
What’s left behind in the reactor is the intact polyester part of the fabric. The team uses an advanced chemical recycling technique to break down the polyester into its molecular building block, which can then be reformed into the polyester, creating a closed-loop recycling process.
The researchers said in a press release that this work lays the foundation for industrial-scale recycling of polycotton textiles and the first commercial availability of non-food glucose. “Many parties are trying to get either of these things done but no one has succeeded yet,” said Gert-Jan Gruter, a professor of molecular sciences at the University and chief technology officer at Avantium. “Our techno-economic analysis looks rather favorable. Our ambition is to advance this technology to the next phase of commercialization, together with partners.”
Source: Nienke Leenders et al. Polycotton waste textile recycling by sequential hydrolysis and glycolysis. Nature Communications, 2025.
Image by hartono subagio from Pixabay
