Structures of polyethylene and copolymers of ethylene with 1-octene and oligoethylene produced with the Cp(2)ZrCl(2) and [(C(5)Me(4))SiMe(2)N(t-Bu)]TiCl2 catalysts

Polymerization of ethylene and copolymerizations of ethylene with 1-octene and oligoethylene having a vinyl end group were conducted with Cp(2)ZrCl(2) and [(C(5)Me(4))Si-Me(2)N(t-Bu)]TiCl2a) as catalysts, and the structures of the resulting polymers were analyzed in detail. The Cp(2)ZrCl(2) catalyst combined with methylalumoxane (MAO) gives polyethylene with vinyl, vinylidene and trans-vinylene groups. The use of Al(iC(4)H(9))(3)/(C6H5)(3)C . B(C6F5)(4) as cocatalyst produces polyethylene predominantly containing trans-vinylene groups. Polyethylene with vinyl end groups was obtained selectively with [(C(5)Me(4))SiMe(2)N(t-Bu)]TiCl2-MAO as catalyst. The types and contents of C=C double bonds in polyethylene markedly depend upon the metallocene compound as well as as the cocatalyst. In the copolymerizations the [(C(5)Me(4))SiMe(2)N(t-Bu)]TiCl2-MAO catalyst system, on the other hand, gives poly[ethylene-co-(1-octene)] with a high content of 1-octene and a polyethylene containing an appreciable amount of long-side-chain oligo-ethylene.