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Polymerization of 1,3‐butadiene, 4‐methyl‐1,3‐pentadiene and styrene with catalyst systems based on biscyclopentadienyl derivatives of titanium
Author(s) -
Ricci Giovanni,
Bosisio Carlo,
Porri Lido
Publication year - 1996
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.1996.030171105
Subject(s) - methylaluminoxane , styrene , polymerization , stereospecificity , polymer chemistry , polystyrene , catalysis , polybutadiene , chemistry , titanium , tacticity , materials science , copolymer , metallocene , organic chemistry , polymer
Abstract 1,3‐Butadiene, 4‐methyl‐1,3‐pentadiene and styrene were polymerized with dicyclopentadienyltitanium dichloride/methylaluminoxane (Cp 2 TiCl 2 /MAO) and dicyclopentadienyltitanium chloride/MAO (Cp 2 TiCl/MAO). These systems are less active than cyclopentadienyltitanium trichloride/MAO (CpTiCl 3 /MAO), but show the same stereospecificity as the latter; they give predominantly cis‐1,4‐polybutadiene, 1,2‐syndiotactic poly(4‐methyl‐1,3‐pentadiene) and syndiotactic polystyrene. Cp 2 TiCl/MAO is much more active than Cp 2 TiCl 2 /MAO; this is probably due to the fact that in the reaction of Cp 2 TiCl 2 with MAO, only a small amount of Ti(IV) is reduced to Ti(III), which is the active species in the polymerization of styrene and 1,3‐dienes. An interpretation of the structure of the active species in Cp 2 TiCl/MAO is reported.