Premium
The roles of oxidation state, Lewis acid cocatalyst and solvent polarity in activating titanium compounds for olefin polymerization
Author(s) -
Eisch John J.,
Pombrik Sofya I.,
Shi Xian,
Wu ShuChing
Publication year - 1995
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19950890122
Subject(s) - polarity (international relations) , olefin fiber , polymerization , titanium , solvent polarity , lewis acids and bases , olefin polymerization , solvent , polymer chemistry , chemistry , materials science , organic chemistry , catalysis , polymer , biochemistry , cell
The polymerization activity of the following three catalyst systems towards ethylene has been investigated and compared: 1) methyltitanocene chloride‐Me 2 AlCl 2) η 3 ‐allyltitanocene‐Me 2 AlCl and 3) titanium dichloride tetrahydrofuranate‐Me 2 AlCl. The first two catalysts formed homogeneous phases and produced linear polymer; the last catalyst functioned in a heterogeneous medium and formed crosslinked polymer. The titanium(IV) catalyst was about 30 times more active than the titanium(III) system and the titanium(II) catalyst on MgCl 2 could be made 8 times more active than the titanium(IV) system. A novel mechanism is proposed to explain the behavior and activity of the titanium(II) system.