Copolymerization of styrene and butadiene with nickel compounds-methylaluminoxane catalysts

Copolymerization of styrene (St) and butadiene (Bd) with nickel(II) compound (NiX2) in combination with methylaluminoxane (MAO) was investigated at the monomer feed ratio of 1:1. Copolymerization of St and Ed induced with NiX2-MAO catalysts (X = acac, OCOC6H5, OCOC18H35, Cl, Cp) gave copolymers with high cis-1,4 contents of Ed units. The St and cis-1,4 units of the Ed units in the copolymer were not significantly affected by the X group of NiX2, although the copolymer yields depended on the substituent. The copolymer yields depended on the solvent used for the copolymerization with the Ni(acac)(2)-MAO catalyst; an aromatic hydrocarbon was more favourable than a non-aromatic hydrocarbon. The effects of triphenylphosphine (TPP) and trifluoroacetic acid (TFA) on copolymerization of St and Ed with the Ni(acac)(2)-MAO catalyst were seen the microstructure of Ed units in the copolymer. (C) 2001 Society of Chemical Industry.