Abstract
A series of anilido⁻imine chromium complexes have been used as precursors to catalyze homo- and copolymerization of ethylene and norbornene. The chromium complexes activated with methylalumoxane (MAO) exhibit good activities for homopolymerization of ethylene (E) to produce linear polyethylene and moderate activities for norbornene (N) polymerization to afford vinyl-type polynorbornene. Ethylene⁻norbornene copolymers with high incorporation of norbornene can be also produced by these catalysts. (13)C NMR and differential scanning calorimetry (DSC) analyses show that the copolymers are random products, and ⁻NNN⁻ and ⁻EEE⁻ units can be observed in the microstructure of the copolymers.