HIGH-SPEED LIVING RING-OPENING POLYMERIZATION BY A NEW CATALYST BASED ON METALLOPORPHYRIN

Polymerization of epsilon-caprolactone and delta-valerolactone initiated with aluminum porphyrin (1) was much accelerated by the addition of methylaluminum diphenoxide with bulky substituents 2, to give polymers with narrow molecular weight distribution. The polymerization of beta-butyrolactone was also accelerated by to different extents depending on the mode of ring scission. 2 also accelerated the living polymerization of propylene sulfide initiated with zinc porphyrin (3). The effect of 2 is due to the coordinative activation of monomer.