Copolymerization of ethylene with 5-vinyl-2-norbornene in the presence of the Ph2C(Flu)(Cp)ZrCl2/MAO catalyst

Cycloolefin copolymer, poly[(ethylene)-co-(5-vinyl-2-norborene)], was synth etized using the MAO activated ansa-metallocene Ph2C(Flu)(Cp)ZrCl2 as a cat alyst; Formation of mostly isolated 5-vinyl-2-norbornene sequences was conf irmed by NMR analysis. Comonomer incorporated selectively via cyclic double bond. No selectivity towards the reactivity of the particular isomer of 5- vinyl-2-norbornene (5-endo:5-exo) was observed. The molar mass was found to decrease when the comonomer concentration in product increased. At low com onomer incorporation levels copolymers were insoluble, crosslinked elastome rs. With high comonomer concentration in reaction medium copolymers were am orphous determined by means of DSC and X-ray diffraction and the vinyl grou p of the comonomer remained unreacted for further modification.