Cellulose-Based Non-Isocyanate Polyurethane (NIPU) Foams

• Reece DeCook, Material Science, University of Delaware

• Max Curello, Chemical Engineering, Materials Science and Engineering, University of Delaware

Polyurethane (PU) foams are a widely sought after material across numerous fields due to their versatility and high insulation performance. However, the production of these foams uses isocyanates, a known carcinogen, which can have negative health effects on those exposed. Bio-based non-isocyanate polyurethane (NIPU) foams show promise of a safer and sustainable alternative. This research specifically explores functionalized cellulose nanocrystals (FCNCs) as a building block for NIPU foams. Cellulose nanocrystals (CNCs) are a naturally occurring nanomaterial which are biodegradable and demonstrate high mechanical strength. CNCs have a crystalline structure which is necessary to retain through the functionalization process as it enables FCNCs to contribute to the structure and performance of NIPU foams when incorporated. One of the biggest challenges of this work is maintaining the crystalline structure of the CNCs used. Through XRD and NMR testing, the crystalline structure and chemical functionality of the CNCs were proven to be preserved. In addition to the functionalization of CNCs, the synthesis of diglycerol dicarbonate (DGDC) was conducted to produce a key building block in creating the polymer back bone of the NIPU foam. Through synthesis of DGDC, functionalization of CNCs, and reactant preparation, NIPU foam samples were successfully produced. As the FCNC content in the foam samples increased, the foam displayed a more uniform structure, suggesting the improvement of structural consistency. The successful incorporation of FCNCs into NIPU foams shows possibility for eco-friendly alternatives to conventional PU foams.