Copolymerization of ethylene with 2,5-norbornadiene using a homogeneous metallocene/MAO catalyst system

Copolymerization of ethylene with a symmetrical diene, namely, 2,5-norborna diene was studied using a homogeneous metallocene/MAO catalyst system. Copo lymerizations were found to occur exclusively through one of the two equall y reactive endocyclic double bonds with Cp2ZrCl2, (buCp)(2)ZrCl2 and Et(Ind )(2)ZrCl2 catalysts. Both double bonds are involved in the polymerization w hen Me2SiCp2ZrCl2 is used as the catalyst. In the case of Et(Ind)(2)ZrCl2, the incorporation of the diene was found to increase with time. The extent of incorporation of the diene, molecular weight and copolymerization activi ty were found to depend on the nature of the catalyst.