Propylene oxide end-capping route to primary hydroxyl group dominated CO2-polyol

In the past decade, poly(carbonate ether)polyols, or CO 2 -polyols, have been synthesized by the copolymerization of CO 2 and propylene oxide (PO) with a double metal cyanide (DMC) catalyst in the presence of various chain transfer agents. CO 2 -polyols show great potential use as substitutes for polyols derived from fossil feedstock in the polyurethane industry. Brookfield viscosity tests have revealed the importance of primary hydroxyl (1° OH) content in the reactivity of CO 2 -polyols; in particular, the low 1° OH content of CO 2 -polyols severely limits their application in foam materials . Incorporation of more carbonate linkages has proven to be only moderately efficient for preparing CO 2 -polyols with high 1° OH content, e.g., 19 F NMR spectroscopy indicates that the 1° OH content of a CO 2 -polyol can increase from 13% to 39% when the carbonate content in the CO 2 -polyol is increased from 26.1% to 80.0%. In this study, the PO end-capping route was developed using a strong Lewis acid, such as tris(pentafluorophenyl)borane (FAB) as a catalyst, and a CO 2 -polyol with 1° OH content of 60% was synthesized.