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Controlled Ethylene Polymerization Catalyzed by Cp $\rm{{_{2}^{\ast}}}$ ZrBu 2 /[Ph 3 C] [B(C 6 F 5 ) 4 ]/ i Bu 4 Al 2 O above Room Temperature
Author(s) -
Mathis Déborah,
Rouholahnejad Fereshteh,
Chen Peter
Publication year - 2010
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200900225
Subject(s) - chemistry , polymerization , ethylene , polyethylene , chain transfer , polymer chemistry , branching (polymer chemistry) , hydride , polymer , dispersity , catalysis , ternary operation , crystallography , organic chemistry , radical polymerization , hydrogen , computer science , programming language
The ternary system composed of Cp $\rm{{_{2}^{\ast}}}$ ZrBu 2 (Cp*=Me 5 Cp), [CPh 3 ][B(C 6 F 5 ) 4 ], and tetraisobutyldialuminoxane (TIBAO) catalyzed the polymerization of ethylene in a controlled fashion at temperatures up to 60 °C. The consumption of ethylene remained constant during the polymerization process, the molecular weight of the polyethylene increased linearly with time, and polydispersity indexes down to 1.3 were obtained. Characterization of the polyethylene by 13 C‐NMR and FT‐IR spectroscopy did not indicate any branching or CC linkages, even for polymer produced at 40 °C or above. The linear and saturated polymer structure is due to the absence of β ‐hydride transfer, β ‐hydride elimination and chain walking during the polymerization. The absence of termination reactions is consistent with the system's demonstrated controlled polymerization.