Foam from old mattresses and sponges can now be safely recycled without toxic chemicals

Researchers at the University of Twente have developed a method to recycle polyurethane foam from mattresses and furniture and also household sponges. They did this safely, without using toxic chemicals. The discovery offers a circular solution for millions of tons of hard-to-recycle waste.

Polyurethane (PUR), the foam found in mattresses, furniture, and countless other products, typically ends up in landfills or is incinerated after use because it is rarely reusable. Until now, only parts of the foam could be recovered, or a highly toxic substance was needed to recover the building blocks.

“For a long time, the use of phosgene, a lethal substance, was the only way to break apart this foam,” says Jurriaan Huskens, project leader of the study. “That is simply unacceptable if you really want to use recycling on a large scale.”

The paper is published in the journal Green Chemistry.

From mattresses to sports insoles

The Twente researchers have now found a way to completely disassemble the foam into the original building blocks, without dangerous chemicals. With a relatively safe and environmentally friendly compound, the foam is efficiently broken down into usable raw materials, which in turn can serve as the basis for new foam.

“We show that you can recover both the soft part and the hard part of the foam,” adds Jean-Paul Lange. “This makes it possible for the first time to make PUR truly circular.”

The method has been found to work on various types of foam, from mattresses and furniture to sports insoles and medical applications. This broad applicability increases the chance that the technology will be quickly adopted by industry. “That’s what makes this finding so powerful,” says Ph.D. student Ege Hosgor, first author of the study. “We did not use artificially pure foam in the lab, but just foam as it is found in real-world products.”

Towards a circular future

This approach is a great step towards a circular economy for plastics and will significantly reduce waste. The researchers now want to further develop and scale up the method so that recycling on an industrial scale becomes possible.

“The great thing is that this process is not only safer, but also offers a real solution for the millions of tons of foam that are thrown away worldwide,” says Huskens.