Preliminary investigations on polymerization catalysts composed of lanthanocene and methylaluminoxane

Summary

The polymerization of butadiene(Bd), isoprene(Ip) and styrene(St) has been examined using the six catalyst systems composed of lanthanocene, (C₅H₉Cp)₂NdCl(I), (C₅H₉Cp)₂SmCl(II), (MeCp)₂Sm OAr'(III), (Ind)₂NdCl(IV), Me₂Si(Ind)₂NdCl(V) and (Flu)₂NdCl(VI), and methylaluminoxane(MAO) respectively.

All of them can be used to form the polyisoprene with molecular weights of 1 to 10 thousand and cis-1,4-unit contents of 41 to 47%. (I), (II) and (III) of them can be also used to form the polybutadiene with molecular weights of 10 to 20 thousand and cis-1,4-unit contents of 62 to 78%. In addition, the catalysts from (II) to (V) are still active for St polymerization and (II) of them gives a syndio -rich random polystyrene. It is noteworthy that (II) and (III) are active for homopolymerization of Bd, Ip and St in the same polymerization condition.