Background
Polyurethane (PU) is a widely used plastic material that has excellent physical and mechanical properties. However, PU is difficult to recycle due to its complex chemical structure, making the effective disposal of PU waste a pressing issue. Current methods for PU disposal include incineration, which can release harmful toxins into the environment, or placing in landfills, where it takes a long time to decompose.
Crosslinked PU is formed by chemically linking PU chains together, which can further improve the mechanical properties of the compound. However, crosslinked PU waste is even more difficult to effectively recycle due to its even more complex structure than standalone PU. The main method for disposal currently is depolymerization, which involves breaking the urethane bonds. However, this process typically requires use of a solvent, which can be toxic, and currently operates with relatively slow kinetics. It also requires intensive separations to occur to harvest end products of the reaction, which can be time-consuming and expensive.
Invention Description
Researchers at Arizona State University have developed method of functional upcycling of crosslinked polyurethane (PU) waste through small-molecule carbamate-assisted decrosslinking extrusion. This process produces high-value end products including adhesives, photoreactive resins, and stimuli-responsive materials, while reducing waste.
Potential Applications:
- Upcycling of crosslinked polyurethane (PU) for use in:
- Adhesives (e.g., packaging, construction, electronics)
- Photoreactive resins (e.g., 3D printing, dentistry)
- Stimuli-responsive materials (e.g., drug delivery, smart textiles, sensors)
Benefits and Advantages:
- Effective – produces high-value end products
- Sustainable – reduces waste from recycling process
- Non-toxic – does not require use of solvent
- Faster process – improved reaction kinetics
- Simple – does not require separation for end products