Organocatalytic Ring-Opening Alternating Copolymerization of Epoxides and Cyclic Anhydrides by a Simple Organobase/Urea Binary Catalyst

Although several organocatalysts have been reported for the efficient ring-opening alternating copolymerization (ROAC) of epoxides and cyclic anhydrides, the low catalytic activity still remains as a problem. Thus, there is still a motivation to develop new simple and high active organocatalysts. In this contribution, an organic cyclic trimeric phosphazene base (CTPB) is used as catalyst in combination with different ureas for the ROAC of phthalic anhydride with a variety of epoxides. The CTPB/urea binary catalysts exhibit high catalytic activities, producing perfectly alternating polyesters without formation of ether linkages. Polyesters with diverse structures, well-defined chain-ends, as well as low dispersities are successfully obtained.

Automated summary

In this research, an organic cyclic trimeric phosphazene base (CTPB) in combination with different ureas was utilized as a binary catalyst, showing high catalytic activities in the ring-opening alternating copolymerization (ROAC) of epoxides and cyclic anhydrides. The resulting polyesters exhibited diverse structures, well-defined chain-ends, and low dispersities.