Reprocessing Postconsumer Polyurethane Foam Using Carbamate Exchange Catalysis and Twin-Screw Extrusion

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Cross-linked polyurethane (PU) is a widely used thermoset foam.
• Effective methods for reprocessing commercial PU foam waste into high-value materials are lacking.

Purpose of the Study:

• To develop a direct reprocessing method for cross-linked PU foam waste.
• To enable the creation of PU materials with tunable mechanical properties from waste.

Main Methods:

• Introducing dibutyltin dilaurate (DBTDL) catalyst into cross-linked PU foams and films.
• Utilizing dynamic carbamate exchange reactions at elevated temperatures.
• Employing twin-screw extrusion for continuous reprocessing of PU waste.

Main Results:

• Successfully reprocessed both model and commercial cross-linked PU foams.
• Produced PU filaments and films with elastomeric or rigid thermoset properties.
• Demonstrated efficient reprocessing with properties of microcompounded PU matching synthesized PU.

Conclusions:

• The developed method enables bulk reprocessing of commercial thermoset PU waste.
• This approach facilitates the creation of materials with thermoset mechanical properties from waste.
• The findings inspire further reprocessing methods for other thermosets and material compatibilization.