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Vinylic polymerization by homogeneous chromium(III) catalysts
Author(s) -
Peucker Uwe,
Heitz Walter
Publication year - 1998
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/(sici)1521-3927(19980301)19:3<159::aid-marc159>3.0.co;2-g
Subject(s) - norbornene , chromium , catalysis , polymerization , copolymer , polymer chemistry , homogeneous , polyethylene , ligand (biochemistry) , polymer , crystallinity , materials science , olefin fiber , homogeneous catalysis , chemistry , organic chemistry , composite material , physics , biochemistry , thermodynamics , receptor
A new class of homogeneous chromium(III)‐based catalysts of the type [Cp*CrMeCl] 2 /MAO with different kinds of Cp ligands has been synthesized. The influence of the electronic nature and the sterical demand of the catalysts were explored with regard to the vinylic polymerization of norbornene. The catalyst activity could be increased by intensifying the electron‐donating character of the Cp ligand, whereas the sterical demand of the Cp ligand affects the crystallinity of the obtained polynorbornene. In order to improve their processability, copolymers of norbornene with ethene were made using the [Cp*CrMeCl] 2 /MAO catalyst, which led to copolymers with a high α‐olefin content. Furthermore, highly linear, ultra‐high molecular weight polyethylene was obtained using the new class of chromium(III)‐based catalysts.