Co2O3 and MnO2 as inexpensive catalysts for the ring-opening polymerization of cyclic esters

The cheaper and easy to handle catalysts are particularly important for catalytic studies. Herein, inexpensive Co2O3 and MnO2 were used as catalysts for the ring-opening polymerization (ROP) of rac-lactide (rac-LA) and epsilon-caprolactone (epsilon-CL). The polymerization proceeded in a controlled manner with the formation of high molecular weight (M-n) and narrow dispersity (D). Heterotactically enriched (P-r up to 0.7) poly(lactic acid) (PLA) was formed during the polymerization process. MALDI-TOF and H-1 NMR analyses of low M-n oligomer from rac-LA indicated that the polymerization followed an activated monomer mechanism. The data on the polymerization kinetics showed that the polymerization followed first order kinetics.

Automated summary

The study employed inexpensive and easy to handle catalysts for the ring-opening polymerization of rac-lactide and epsilon-caprolactone, resulting in high molecular weight polymers with narrow dispersity and heterotactically enriched poly(lactic acid). The polymerization followed an activated monomer mechanism and exhibited first-order kinetics based on the data from MALDI-TOF and H-1 NMR analyses.