Accelerated Living Polymerization of Methacrylonitrile with Aluminum Porphyrin Initiators by Activation of Monomer or Growing Species. Controlled Synthesis and Properties of Poly(methyl methacrylate-b-methacrylonitrile)s

Abstract

Polymerization of methacrylonitrile (MAN) with methylaluminum porphyrin (1) as initiator proceeded rapidly in the presence of methyaluminum bis(2,6-di-tert-butyl-4-methylphenolate) (3). The living polymer of methyl methacrylate (MMA) with a (porphinato)aluminum enolate growing terminal (2), prepared by the polymerization of MMA with 1, also brought about the polymerization of MAN in the presence of 3, affording the corresponding block copolymer with Mw/Mn ranging from 1.1 to 1.3. The living nature of polymerization was confirmed by a delayed sequential two-stage polymerization of MAN initiated with 2 (living prepolymer of MMA on aluminum porphyrin). Pyridine instead of 3 was also effective for the rapid block copolymerization of MAN from 2 to give the block copolymer of controlled molecular weight. Copolymerization of MAN and MMA initiated with 1 proceeded more rapidly in the presence of 3 or pyridine than in the absence. In the presence of 3, the consumption of MAN was much more accelerated than that of ...