Copolymerization of styrene and butadiene with nickel compounds-methylaluminoxane catalysts

Abstract

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 Bd induced with NiX2–MAO catalysts (X = acac, OCOC6H5, OCOC18H35, Cl, Cp) gave copolymers with high cis-1,4 contents of Bd units. The St and cis-1,4 units of the Bd 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 Bd with the Ni(acac)2–MAO catalyst were seen the microstructure of Bd units in the copolymer. © 2001 Society of Chemical Industry