LEWIS ACID-ASSISTED ANIONIC RING-OPENING POLYMERIZATION OF EPOXIDE BY THE ALUMINUM COMPLEXES OF PORPHYRIN, PHTHALOCYANINE, TETRAAZAANNULENE, AND SCHIFF-BASE AS INITIATORS

Polymerization of 1,2-epoxypropane (PO) with aluminum porphyrin (2) was substantially accelerated (460 times) by the addition of an organoaluminum compound such as methylaluminum bis(2,4,6-tri-tert-butylphenolate) (8). The molecular weight of the produced polyether increased linearly with the amount of PO reacted, while the molecular weight distribution (MWD) was invariably narrow throughout the polymerization. SequentiaI polymerizations of PO and 1,2-epoxybutane (BO) with the aluminum porphyrin-8 system afforded the corresponding block copolymer with a narrow MWD. In the presence of methylaluminum bis(2,6-di-tert-butyl-4-methylphenolate) (9) as Lewis acid, aluminum complexes of phthalocyanine (3), tetraazaannulene (4), and Schiff bases (5-7) with very low reactivities brought about the polymerization of 1,2-epoxypropane fairly rapidly at room temperature.