| Abstract: | Homogeneous chromium(III) catalysts of the type [Cp′CrMeCl]2/MAO (Cp′ = cyclopentadienyl, pentamethylcyclopentadienyl, indenyl, fluorenyl) have been synthesized to investigate the influence of the electronic nature and the sterical demand of different Cp′‐ligands on the polymerization and copolymerization of norbornene and ethene. In the case of norbornene polymerization the catalyst activity is increased by intensifying the electron donating character of the Cp′‐ligand whereas the sterical demand affects the crystallinity of polynorbornene. The use of the [Cp*CrMeCl]2 /MAO and the [FluCrMeCl]2 /MAO catalyst for norbornene‐ethene copolymerization under various polymerization conditions led to the formation of norbornene‐ethene copolymers with different microstructures ranging from statistical norbornene‐ethene copolymers over vinyl‐terminated norbornene macromonomers to norbornene‐ethene block copolymers. Furthermore highly linear, ultra high molecular polyethylene can be obtained using the [FluCrMeCl]2/MAO catalyst. |
