Rational Design of Silicon-Bridged Fluorenyl−Phenoxy Group 4 Metal Complexes as Catalysts for Producing High Molecular Weight Copolymers of Ethylene and 1-Hexene at Elevated Temperature

2010 ◽  
Vol 43 (5) ◽  
pp. 2299-2306 ◽  
Author(s):  
Taichi Senda ◽  
Hidenori Hanaoka ◽  
Shinya Nakahara ◽  
Yoshiaki Oda ◽  
Hayato Tsurugi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Elevated Temperature ◽  
Metal Complexes ◽  
High Molecular Weight ◽  
Rational Design ◽  
Phenoxy Group ◽  
Group 4 ◽  
Group 4 Metal

Chemical synthesis of poly(β-hydroxybutyrate) by the polymerization of (R,S)-β-butyrolactone with aluminoxane catalysts

1995 ◽  
Vol 41 (13) ◽  
pp. 274-281 ◽  
Author(s):  
Robert W. Lenz ◽  
John Yang ◽  
Bin Wu ◽  
C. Jeff Harlan ◽  
Andrew R. Barron
Keyword(s):  
Molecular Weight ◽  
Chemical Synthesis ◽  
Physical Properties ◽  
High Molecular Weight ◽  
Crystalline Polymers ◽  
Group 4 ◽  
Catalyst Systems

Racemic β-butyrolactone can be polymerized to crystalline polymers of reasonably high molecular weight by the use of aluminoxane catalysts. Investigations in this and other laboratories have shown that these polymers can be fairly highly isotactic, and in that form they are closely related in structure and physical properties to a reserve polyester produced by many bacteria: poly(β-hydroxybutyrate). In the present investigation, Ziegler–Natta type aluminoxane catalyst systems and a new aluminoxane derivative, tert-butylaluminoxane, were evaluated in attempts to polymerize racemic β-butyrolactone in higher yields to polymers of higher molecular weight and higher stereoregularity. The addition of group 4 metallocenes as cocatalysts for both methylaluminoxane and iso-butylaluminoxane catalysts gave higher yields of the isotactic polymer than those obtained with these catalysts alone, but surprisingly, the tert-butylaluminoxane catalysts produced predominantly syndiotactic rather than isotactic polymers.Key words: poly(β-hydroxybutyrate), β-butyrolactone, aluminoxane catalysts, isotactic poly(β-hydroxybutyrate), syndiotactic poly(β-hydroxybutyrate).

NSSN-Type Group 4 Metal Complexes in the Ring-Opening Polymerization of l-Lactide

2021 ◽  
Author(s):  
Salvatore Impemba ◽  
Giuseppina Roviello ◽  
Stefano Milione ◽  
Carmine Capacchione
Keyword(s):  
Metal Complexes ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Type Group ◽  
Group 4 ◽  
Group 4 Metal

Tridentate [N,N,O] Schiff-base group 4 metal complexes: Synthesis, structural characterization and reactivity in olefin polymerization

2006 ◽  
Vol 258 (1-2) ◽  
pp. 275-283 ◽  
Author(s):  
Gino Paolucci ◽  
Alessandra Zanella ◽  
Laura Sperni ◽  
Valerio Bertolasi ◽  
Mina Mazzeo ◽  
...  
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Structural Characterization ◽  
Olefin Polymerization ◽  
Group 4 ◽  
Group 4 Metal ◽  
Base Group

scholarly journals Allylsilylcyclopentadienyl Group 4 metal complexes: synthesis, structure and reactivity

2003 ◽  
Vol 345 ◽  
pp. 15-26 ◽  
Author(s):  
Jesús Cano ◽  
Pilar Gómez-Sal ◽  
Georg Heinz ◽  
Gema Martı́nez ◽  
Pascual Royo
Keyword(s):  
Metal Complexes ◽  
Group 4 ◽  
Group 4 Metal
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