Synthesis of Trimethylene Carbonates and Polycarbonates from Oxetanes and CO₂Using Bifunctional Aluminum Porphyrin Catalysts

Bifunctional aluminum porphyrins catalyzed the conversion of oxetane and CO₂into trimethylene carbonate (TMC) and poly(trimethylene carbonate) (PTMC). The catalytic activity of the bifunctional catalysts is driven mainly by the central Al³⁺ion while TMC/PTMC selectivity is controlled by the counteranions. A variety of TMCs including bis(TMC) were prepared from oxetanes with different substituents. The terpolymerization of oxetane, CO₂, and bis(TMC) or the copolymerization of TMC and bis(TMC) produced cross-linked PTMCs, one of which was successfully used for the formation of soft and thin film.