Copolymerizations of ethylene with 1-decene over various ansa-metallocene complexes combined with Al(i-Bu)_3/[CPh_3][B(C_6F_5)_4]cocatalyst

摘要

Copolymerizations of ethylene with 1-decene were carried out with a series of stereospecific metallocene compounds,rac-(EBI)Zr(NMe_2)_2[1,EBI=ethylene-1,2-bis(l-indenyl)],rao(EBI)Hf(NMe_2)_2(2),rac-Me_2Si(l-C_5H_2-2-Me-4-~tBu)_2Zr(NMe_2)_2(3),ethylidene(cyclopentadienyl)(9-fluorenyl)ZrMe_2[4,Et(Flu)(Cp)ZrMe_2]and iso-propylidene(cyclopentadienyl)(9-fluorenyl)ZrMe_2[5,iPr(Flu)(Cp)ZrMe_2],combined with Al(/-Bu)_3/[CPh_3][B(C_6F_5)_4]cocatalyst.All catalyst systems showed very high copolymerization rates and the 1-decene reactivity decreased in the order of 2>5>1~4>3.The reactivity product of ethylene and 1-decene(r_Exr_D)was below 1 except 3 catalyst,corresponding to random copolymer structures with an alternating character.The melting point(T_m),crystallinity(X_c),intrinsic viscosity([eta]and density of the 1-decene/ethylene copolymers decreased markedly with an increase in the 1-decene content,regardless of the type of catalytic system.