UC Berkeley

Polyurethane foam (PUF) was synthesized from commercial polyether polyol and methylene diphenyl diisocyanate (MDI) to provide a representative model polyurethane for chemical upcycling. Due to its crosslinked solid structure, PUF was first liquefied via aminolysis with monoethanolamine (MEA) at 150 °C. Density functional theory (DFT) calculations provided additional insight into the differences in aminolysis observed under nitrogen and air. Excess MEA was subsequently removed by evaporation at 170 °C, and the remaining solution was aged overnight, yielding phase separation into a polyol-rich fraction (PRF) and 4,4′-methylenedianiline (MDA) rich phase. While the MDA-rich phase is typically treated as a byproduct, it can serve as a precursor for MDI. The PRF was then catalytically cracked over zeolite catalysts to produce value-added chemicals. A novel one-dimensional (1D) shaped H-MFI zeolite nanorod with enhanced external surface area and mesoporosity may contribute to interactions between polymers and catalysts. Compared to commercial H-ZSM-5, 1D-H-MFI exhibited higher selectivity toward propionaldehyde (61.8 wt% vs. 50.3 wt%) with 50% lower catalyst loading. This two-step strategy demonstrates the potential to upcycle commercial PUF into valuable chemicals.