TY - JOUR
T1 - Homogeneous α-olefin polymerizations over racemic Ethylene-bridged ansa-Bis(2-(tert-butyldimethylsiloxy)-1-indenyl) and ansa-Bis(2-tert-butyldimethylsiloxy)-4,5,6,7-tetrahydro-1-indenyl metallocene dichlorides
AU - Leino, Reko
AU - Luttikhedde, Hendrik J G
AU - Lehmus, Petri
AU - Wilén, Carl-Eric
AU - Sjöholm, Rainer
AU - Lehtonen, Ari
AU - Seppälä, Jukka V.
AU - Näsman, Jan H.
PY - 1997/6/16
Y1 - 1997/6/16
N2 - Ethylene and propylene were polymerized over the siloxy-substituted bis(indenyl) ansametallocenes, rac-[ethylenebis(2-(tert-butyldimethylsiloxy)indenyl)]zirconium dichloride (1), rac-[ethylenebis(2-(tert-butyldimethylsiloxy)-4,5,6,7-tetrahydroindenyl)] zirconium dichloride (2), and rac-[ethylenebis(2-(tert-butyldimethylsiloxy)indenyl)]hafnium dichloride (3), using methylaluminoxane (MAO) and trityl tetrakis(pentafluorophenyl)borate as cocatalysts. Especially complex 1 forms a highly active catalyst precursor for the polymerization of α-olefins. Synthesis and characterization of 2 and 3 are described. The 1/MAO and 3/MAO catalyst systems show high polymerization activities at exceptionally low [Al]: [Zr] ratios [(100-250):1]. For both catalysts, extensive chain transfer to aluminum is observed as the predominant chain-transfer mechanism. Preliminary results from copolymerization of ethylene with 1-hexene and 1-hexadecene over 1/MAO indicate a good comonomer response.
AB - Ethylene and propylene were polymerized over the siloxy-substituted bis(indenyl) ansametallocenes, rac-[ethylenebis(2-(tert-butyldimethylsiloxy)indenyl)]zirconium dichloride (1), rac-[ethylenebis(2-(tert-butyldimethylsiloxy)-4,5,6,7-tetrahydroindenyl)] zirconium dichloride (2), and rac-[ethylenebis(2-(tert-butyldimethylsiloxy)indenyl)]hafnium dichloride (3), using methylaluminoxane (MAO) and trityl tetrakis(pentafluorophenyl)borate as cocatalysts. Especially complex 1 forms a highly active catalyst precursor for the polymerization of α-olefins. Synthesis and characterization of 2 and 3 are described. The 1/MAO and 3/MAO catalyst systems show high polymerization activities at exceptionally low [Al]: [Zr] ratios [(100-250):1]. For both catalysts, extensive chain transfer to aluminum is observed as the predominant chain-transfer mechanism. Preliminary results from copolymerization of ethylene with 1-hexene and 1-hexadecene over 1/MAO indicate a good comonomer response.
KW - activated metallocene catalysts
KW - ethylene/alpha-olefin copolymerization
KW - ethylene/propylene copolymerization
KW - methylaluminoxane cocatalyst
KW - siloxy-substituted metallocene
KW - activated metallocene catalysts
KW - ethylene/alpha-olefin copolymerization
KW - ethylene/propylene copolymerization
KW - methylaluminoxane cocatalyst
KW - siloxy-substituted metallocene
KW - activated metallocene catalysts
KW - ethylene/alpha-olefin copolymerization
KW - ethylene/propylene copolymerization
KW - methylaluminoxane cocatalyst
KW - siloxy-substituted metallocene
UR - http://www.scopus.com/inward/record.url?scp=0031168809&partnerID=8YFLogxK
U2 - 10.1021/ma970041o
DO - 10.1021/ma970041o
M3 - Article
AN - SCOPUS:0031168809
SN - 0024-9297
VL - 30
SP - 3477
EP - 3483
JO - Macromolecules
JF - Macromolecules
IS - 12
ER -