Polyurethane is one of the most widely used plastics in the world.
It appears in everything from furniture foam and insulation to coatings, adhesives, and medical devices.
Yet making it has long required a dangerous step.
Manufacturers rely on isocyanates—highly toxic chemicals that can cause severe allergies, asthma, and other health problems if people are exposed during production.
Even though the finished plastic contains no isocyanates, strict safety rules are needed to protect workers.
Now, researchers from the Fraunhofer-Gesellschaft have achieved a major breakthrough. For the first time, they have successfully produced polyurethane without using isocyanates at all.
The work was carried out as part of the CO₂NIPU project, which focuses on making non-isocyanate polyurethanes, also known as NIPUs.
The research team, led by Christoph Herfurth at the Fraunhofer Institute for Applied Polymer Research IAP, replaced toxic isocyanates with a harmless compound called dicarbamate. This simple switch makes the entire production process safer and easier.
Workers no longer need specialized training or protective measures to handle hazardous substances, greatly reducing health risks on the factory floor.
The new approach also brings environmental benefits. The dicarbamate used in the process is made using carbon dioxide, helping reduce greenhouse gas emissions.
At the same time, the project includes methods for recycling old polyurethane materials, such as foam waste, and turning them back into new products. This supports the idea of a circular economy, where materials are reused instead of discarded.
Several Fraunhofer institutes collaborated on the project, including those focused on chemical technologies, manufacturing materials, and environmental safety. Together, they designed a process that works not just in the lab but also at an industrial scale.
One important advantage of the new material is that it behaves just like conventional polyurethane.
According to Herfurth, the molecular structure of polyurethane made from dicarbamates is identical to that of polyurethane made with isocyanates. This means manufacturers can rely on existing knowledge and experience to achieve the same strength, flexibility, or adhesive properties they already use in products today.
The production process itself is carefully controlled. Different ingredients are mixed in precise ratios to tailor the final material. Polymer diols soften the plastic, chain extenders help link molecules together, and dicarbamate replaces isocyanate as the key reactive component.
The mixture is heated to around 180 to 190 degrees Celsius, then cooled and tested for properties like elasticity and tensile strength.
Unlike isocyanates, which react very quickly and can make polyurethane in minutes, dicarbamates react more slowly. While the process takes several hours, this slower reaction makes it easier to control, reducing waste and improving product quality.
The technology has already moved beyond the laboratory. The team can now produce several kilograms of isocyanate-free polyurethane in a pilot plant, with plans to scale up to hundreds of kilograms. One of the first planned uses is in medical applications, such as biocompatible catheter tubes and specialized adhesives.
By removing toxic chemicals from polyurethane production, this new method could make plastics safer for workers, better for the environment, and ready for a more sustainable future.
