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Immobilized Me 2 Si(C 5 Me 4 )( N ‐ t Bu)TiCl 2 /( n BuCp) 2 ZrCl 2 hybrid metallocene catalyst system for the production of poly(ethylene‐ co ‐hexene) with pseudo‐bimodal molecular weight and inverse comonomer distribution
Author(s) -
Hong Sung Chul,
Mihan Shahram,
Lilge Dieter,
Delux Lourant,
Rief Ursula
Publication year - 2007
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.20682
Subject(s) - comonomer , ethylene , polymerization , catalysis , polymer chemistry , molar mass distribution , polymer , materials science , copolymer , isobutane , nuclear chemistry , chemistry , organic chemistry , composite material
Me 2 Si(C 5 Me 4 )( N ‐ t Bu)TiCl 2 , ( n BuCp) 2 ZrCl 2 , and Me 2 Si(C 5 Me 4 )( N ‐ t Bu)TiCl 2 /( n BuCp) 2 ZrCl 2 catalyst systems were successfully immobilized on silica and applied to ethylene/hexene copolymerization. In the presence of 20 mL of hexene and 25 mg of butyloctyl magnesium in 400 mL of isobutane at 40 bar of ethylene, Me 2 Si(C 5 Me 4 )( N ‐ t Bu)TiCl 2 immobilized catalyst afforded poly(ethylene‐ co ‐hexene) with high molecular weight ([η] = 12.41) and high comonomer content (%C 6 = 2.8%), while ( n BuCp) 2 ZrCl 2 ‐immobilized catalyst afforded polymers with relatively low molecular weight ([η] = 2.58) with low comonomer content (%C 6 = 0.9%). Immobilized Me 2 Si(C 5 Me 4 )( N ‐ t Bu)TiCl 2 /( n BuCp) 2 ZrCl 2 hybrid catalyst exhibited high and stable polymerization activity with time, affording polymers with pseudo‐bimodal molecular weight distribution and clear inverse comonomer distribution (low comonomer content for low molecular weight polymer fraction and vice versa). The polymerization characteristics and rate profiles suggest that individual catalysts in the hybrid catalyst system are independent of each other. POLYM. ENG. SCI., 47:131–139, 2007. © 2007 Society of Plastics Engineers