Making Various Degradable Polymers from Epoxides Using a Versatile Dinuclear Chromium Catalyst

The environmental impact of industrially important plastics can be minimized by using renewable feedstocks and preparing biodegradable polymers. A significantly more meaningful strategy is the utilization of alternating copolymerization of epoxides and cyclic anhydrides or lactone or CO2 to provide degradable polyesters or polycarbonates. Herein, we report a versatile and efficient catalyst system based on dinuclear chromium complex bearing biphenol linking bridge for copolymerizing epoxides with cyclic anhydrides or CO2 or dihydrocoumarin (DHC), affording various degradable copolymers with perfectly alternating structure and narrow molecular weight distribution. Most of the polyesters from DHC are typical semicrystalline materials, being beneficial to the potential application of aliphatic polyesters as structural materials. Notably, this dinuclear chromium catalyst system was also discovered to be very efficient in the one-pot terpolymerization of cyclohexene oxide/phthalic anhydride/CO2, cyclohexene ox...