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Cyclopolymerization of 1,7‐octadiene with metallocene/methylaluminoxane
Author(s) -
Naga Naofumi,
Shiono Takeshi,
Ikeda Tomiki
Publication year - 1999
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/(sici)1521-3935(19990601)200:6<1466::aid-macp1466>3.0.co;2-n
Subject(s) - methylaluminoxane , metallocene , cyclopentadienyl complex , zirconium , monomer , polymerization , polymer chemistry , selectivity , chemistry , materials science , catalysis , organic chemistry , polymer
Polymerization of 1,7‐octadiene was conducted with isospecific rac ‐dimethylsilylenebis(indenyl)zirconium dichloride ( 1 ), syndiospecific diphenylmethylene(cyclopentadienyl)(9‐fluorenyl)zirconium dichloride ( 2 ) and aspecific bis(cyclopentadienyl)zirconium dichloride ( 3 ) metallocene catalysts combined with methylaluminoxane. The microstructure of the poly(1,7‐octadiene)s produced was characterized by means of 1 H NMR, 13 C NMR and DEPT (distortionless enhancement by polarization transfer) spectroscopy. A portion of monomeric units in poly(1,7‐octadiene)s is saturated as a result of cycloaddition. The fraction of the saturated units (cyclization selectivity) decreases in the following order: 1 > 3 > 2 . The effect of polymerization temperature was studied, and the cyclization selectivity was found to decrease with lowering the polymerization temperature. The monomer concentration affects the microstructure of poly(1,7‐octadiene), and the cyclization selectivity is drastically decreased with increasing monomer concentration.