Copolymerization of ethylene with 1 octene is reported based on metallocene

rac-C2H4(Ind)2Hf(NMe2)2 (1) (Ind=η5-indenyl) and (CH3)2C(Fluo)(Cp)ZrMe2 (2) (Cp=η5-cyclopentadienyl

Fluo=η5-fluorienyl).The result shows that the copolymerization rate increases with the increase of comonomer molar ratio ([O]/[E]).Further increase of [O]/[E] reduces copolymerization rate.The activity of 1/Al(iBu)2/[Ph3C][B(C6F5)4](3) is much higher than that of 2/MAO.System 1/Al(iBu)2/[Ph3C][B(C6F5)4](3) is much higher than that of 2/MAO.System 1/Al(iBu)2/3 also shows higher incorporation ability of 1-octene into copolymer than that of 2/MAO.The values of the product rE×rOare below 1for all the resulting copolymer

which correspond to random copolymer structures with a more alternating structure.The melting point(Tm)

crystallinity (Xc)

intrinsic viscosity ([η]) and density (D) of the type of catalytic system. High comonomer contents of the products show clearly amorphous behavior.All the copolymers show melting within a broad temperature range

duplicate peaks or with shoulder.The copolymers produced by 1/Al(iBu)2H/3 have much higher molecular weight than that of 2/MAO

and have a wider range of density rfom 0.965 to 0.84g/cm3.