Synthesis and Characterization of Low Co-monomer Content Ethylene-Norbornene Copolymer Using Pentafluorophenol Modified MAO

Copolymers of ethylene and norbornene were synthesized using rac-ethylene bis(indenyl) zirconium dichloride/ pentafluorophenol modified MAO system at low Al/Zr ratio. Results showed higher co-monomer incorporation (ca. 20% improvement) and catalyst activity in presence of modifier as a result of more strongly interaction of pentafuorophenol modified MAO with cationic metal center of metallocene. By comparison of NMR spectra of copolymers it was concluded presence of modified MAO results in more alternating and dyad norbornene units together with alternating isotactic sequences