New Approaches in Polymerizations Using Transition Metal Complexes.

Abstract

New approaches to organo-transition-metal catalyzed-polymerizations of methyl methacrylate (MMA), ethylene, and 1-olefins using modified methylalumoxane (MMAO) as cocatalyst are described. Ni (acac) 2, (C5H5) Ni (η3-C3H5), [NiMe4Li2 (THF) 2] 2 coupled with MMAO showed a good catalytic activity toward the polymerization of MMA. A variety of (C5R5dP) (η3-C3H5) also showed good catalytic activities for the polymerization of MMA, while these initiators exhibited no catalysis for the polymerizations of ethylene and 1-olefins. V (1-R, 3-R'-acac) 3/MMAO systems showed a moderate catalytic activity for the polymerization of ethylene, while the polymerization using (2-dimethylaminoethyl-C5Me4) VCl2 produced high-molecular-weight polyethylenes. [6-Thiobis (2, 4-di-tert-butyl-phenolate)] VOCl2, and (N, N'-di-tert-butyl-1, l'binaphthyl-2, 2'-diamino) VOCl2 exhibited a higher catalytic activity for the polymerization of ethylene. The (Ind) CH2CH2NMe2CrCl2/MMAO system also showed a high catalytic activity. Me2Si bridged lanthanocene complexes showed high catalytic activity for both block copolymerizations of ethylene with polar monomers such as MMA or e-caprolactone and the block copolymerizations of 1-hexene with polar monomers.