Fluorine- and trimethylsilyl-containing phenoxy--imine Ti complex for highly syndiotactic living polypropylenes with extremely high melting temperatures.
A fluorine- and trimethylsilyl-containing phenoxy-imine titanium complex was synthesized and the structure was determined by an X-ray analysis. The complex on activation with MAO initiates highly controlled syndiospecific living propylene polymerization to form extremely high Tm syndiotactic polypropylenes (Mw/Mn = 1.05-1.08, Tm = 156-152 degrees C) at 0 or 25 degrees C. Moreover, at 50 degrees C, the complex afforded monodisperse syndiotactic polypropylene with very high Tm's of 149, 150 degrees C. In contrast, complexes having a t-Bu group instead of the silyl group provided lower tacticity polymers with much lower Tm's. In addition, we revealed the substituent effect that plays a key role for the highly controlled syndiospecific polymerization displayed by the catalyst.
Mitani
Makoto
M
R & D Center, Mitsui Chemicals, Inc., 580-32 Nagaura, Sodegaura, Chiba, 299-0265, Japan.
Furuyama
Rieko
R
Mohri
Jun-ichi
J
Saito
Junji
J
Ishii
Seiichi
S
Terao
Hiroshi
H
Kashiwa
Norio
N
Fujita
Terunori
T