Ethylene/dicyclopentadiene copolymers and functionalized derivatives thereof

Disclosed is a selected type of copolymer composition comprising copolymers having units derived from ethylene and dicyclopentadiene (DCPD) co-monomers. Such copolymer compositions: a) have a DCPD-derived comonomer unit content of from about 25 mole % to about 45 mole %; b) have a Weight Average Molecular Weight, Mw, of greater than about 170,000; c) comprise amorphous material and have glass transition temperatures, Tg, of from about 8° C. to about 129° C., which also fit the equation Tg (in ° C.)>=[(mole % DCPDx 3.142 )-4.67]; and d) comprise no significant amount of crystalline polyethylene homopolymer or crystallizable polyethylene segments within the ethylene-dicylopentadiene copolymers. Such copolymers can be readily derivatized by hydrogention and/or epoxidation to provide polymeric materials suitable for use as engineering thermoplastics. Also disclosed are processes for preparing and optionally further derivatizing ethylene/dicyclopentadiene copolymers having the characteristics hereinbefore described. Such processes comprise: a) contacting ethylene with a polymerization mixture comprising greater than about 4.0 molar dicyclopentadiene, in the presence of a selected activated cyclopentadienyl-fluorenyl metallocene catalyst bearing a substituent, preferably a methyl substituent, at the 3-position of the cyclopentadienyl ring, under specific polymerization conditions including relatively high ethylene pressures to thereby form the desired ethylene-dicyclopentadiene copolymers within the polymerization mixture. Such copolymers are then recovered and/or further hydrogenated or functionalized.