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Metallocene Catalysts for 1‐Butene Polymerization
Author(s) -
Resconi Luigi,
Camurati Isabella,
Malizia Federica
Publication year - 2006
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/macp.200600307
Subject(s) - tacticity , 1 butene , polymerization , metallocene , polymer chemistry , materials science , catalysis , melting point , coordination polymerization , ligand (biochemistry) , chemistry , polymer , organic chemistry , radical polymerization , composite material , biochemistry , receptor
Summary: Isotactic polybutenes of variable isotacticity and melting points of form I in the range 100–125 °C have been prepared with both C 2 ‐ and C 1 ‐symmetric zirconocenes. The C 1 ‐symmetric zirconocenes bearing the bilateral symmetric 2,5‐dimethyl‐7 H ‐cyclopenta[1,2‐b:4,3‐b′]dithiophene ligand connected by a dimethylsilandiyl bridge to a substituted indenyl ligand produce iPB with higher molecular mass, up to 400 000 at polymerization temperature of 70 °C in liquid butene. The degree of isotacticity depends on the substitution pattern of the indenyl ligand. The correlations between microstructure and melting points of the crystalline forms I and II of iPB have been defined. Some relevant differences in catalyst selectivity between propylene and 1‐butene polymerizations have been identified.Linear correlation of melting points of form I and form II in isotactic poly(1‐butene)s of different chain regularities.