Organometallic compounds as catalysts in the alternating copolymerization of acrylonitirle with butadiene

The catalytic activity of various organometallic compounds of the Lewis acid type R_mMX_n(M = Zn, Cd, B, Al; R = CH₃,C₂H₅, i-C₄H₉, C₆H₅CH₂, C₆H₅C₂H₄; X = Cl, OCH₃) in the alternating copolymerization of acrylonitrile with butadiene in bulk and in toluene solution has been studied. The activity of the catalyst was found to depend on its acidity, the strength of its M? R bond, and on the type of substituent R. The results obtained have been discussed in terms of the copolymerizability of the acrylonitrile complexed by R_mMX_n and in terms of the effect of the R_mMX_n structure on the initiation rate of the copolymerization.