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Efficient Preparation of Cyclic Olefin Copolymers with Unreacted Double Bonds by Using Thermal Stable Non‐Metallocene Vanadium Catalytic System
Author(s) -
Liu Yi,
Xiang HongXia,
Wang KaiTi,
Wu Gang,
Li YouBing
Publication year - 2019
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.201900008
Subject(s) - norbornene , copolymer , ethylene , polymer chemistry , dicyclopentadiene , monomer , vanadium , catalysis , metallocene , chemistry , post metallocene catalyst , polymerization , materials science , organic chemistry , polymer
Five β‐ketoimine vanadium(III) catalysts with promising thermal stability are employed to promote efficient ethylene/dicyclopentadiene (DCPD), ethylene/5‐ethylidene‐2‐norbornene (ENB), and ethylene/5‐vinyl‐2‐norbornene (VNB) copolymerizations, respectively. These vanadium catalysts show high activities toward ethylene/DCPD and ethylene/ENB copolymerization, producing copolymers with high molecular weight and co‐monomer incorporations. By contrast, they exhibit moderate activities toward ethylene/VNB copolymerization and afford copolymers with much lower molecular weight and co‐monomer incorporation. This can be ascribed to less steric hindrance around the pendant vinyl group in VNB. All of the selected catalysts exhibit a single‐site catalytic behavior during the copolymerization. These dienes enchained by vinyl‐type addition via the intra cyclic CC bonds of norbornene and the extra CC bonds are totally maintained as unreacted. Besides, the conversion rates of the monomer, as well as the molecular weight and co‐monomer contents of the copolymers can be effectively regulated by varying the structure of catalysts and the processing parameters.