A Highly Proton-Tolerant Multicenter Borane/Phosphazene Catalytic System for Efficient PO/CO2 Copolymerization toward CO2-Based Poly(carbonate-ether) Polyols
Year: 2026
Type: preprint
Abstract: Low-molecular-weight CO2-based poly(carbonate-ether) polyols from ring-opening copolymerization (ROCOP) of propylene oxide (PO) with CO2 are highly desired as soft blocks to synthesize sustainable polyurethanes. However, such process remains great challenges because of the demanding of highly proton-tolerant catalysts. Herein, we report a binary organocatalysis system based on a nanoscopic multicenter borane Lewis acid (POSS-B8) combined with various organobases for the tunable ROCOP of PO and CO2. The confined POSS-B8 framework not only endows excellent tolerance to proton but enables cooperative activation of PO and CO2, thereby facilitating PO/CO2 ROCOP while effectively suppressing the formation of cyclic propene carbonate (cPC). Remarkably, the binary system can tolerate high loadings of chain-transfer agents (up to 400 equivalents), affording low-molecular-weight polycarbonate polyols (0.6 kDa) with narrow dispersity (Ð = 1.16). By tuning POSS-B8 loading and CO2 pressure, both the carbonate content (19-64 mol%) and glass transition temperature (-58.6 to 4.7 °C) of resulting polymers can be modulated. This metal-free and tunable platform offers a versatile strategy for the preparation of CO2-based poly(carbonate-ether) polyols with controlled structure and strong potential for industrial applications.
Source: ChemRxiv
Language: English
Subfield: Process Chemistry and Technology
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7220854040