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Copolymerization of ethylene/α‐olefins over (2‐MeInd) 2 ZrCl 2 /MAO and (2‐BzInd) 2 ZrCl 2 /MAO systems
Author(s) -
Yoon JinSan,
Lee DongHo,
Park EunSoo,
Lee IkMo,
Park DuckKyung,
Jung SungOuk
Publication year - 2000
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(20000214)75:7<928::aid-app9>3.0.co;2-p
Subject(s) - comonomer , ethylene , copolymer , polymer chemistry , metallocene , monomer , reactivity (psychology) , polymerization , 1 hexene , crystallinity , olefin fiber , chemistry , catalysis , materials science , organic chemistry , polymer , crystallography , medicine , alternative medicine , pathology
Ethylene homopolymerization and ethylene/α‐olefin copolymerization were carried out using unbridged and 2‐alkyl substituted bis(indenyl)zirconium dichloride complexes such as (2‐MeInd) 2 ZrCl 2 and (2‐BzInd) 2 ZrCl 2 . Various concentrations of 1‐hexene, 1‐dodecene, and 1‐octadecene were used in order to find the effect of chain length of α‐olefins on the copolymerization behavior. In ethylene homopolymerization, catalytic activity increased at higher polymerization temperature, and (2‐MeInd) 2 ZrCl 2 showed higher activity than (2‐BzInd) 2 ZrCl 2 . The increase of catalytic activity with addition of comonomer (the synergistic effect) was not observed except in the case of ethylene/1‐hexene copolymerization at 40°C. The monomer reactivity ratios of ethylene increased with the decrease of polymerization temperature, while those of α‐olefin showed the reverse trend. The two catalysts showed similar copolymerization reactivity ratios. (2‐MeInd) 2 ZrCl 2 produced the copolymer with higher M w than (2‐BzInd) 2 ZrCl 2 . The melting temperature and the crystallinity decreased drastically with the increase of the α‐olefin content but T m as a function of weight fraction of the α‐olefins showed similar decreasing behavior. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 928–937, 2000