Norbornadiene homopolymerization and norbornene/norbornadiene/1-octene terpolymerization by ansa -fluorenylamidotitanium-based catalysts

ansa -Fluorenylamidotitanium complexes Me 2 Si(Flu)(N t Bu)TiMe 2 ( 1 ) and Me 2 Si(2,7- t Bu 2 Flu)(N t Bu)TiMe 2 ( 2 ) were used as precatalysts for the homopolymerization of norbornadiene (NBD) and the terpolymerization of NBD, norbornene (NB), and 1-octene (OC). In the NBD homopolymerization, ca...

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Bibliographic Details
Published in:Polymer chemistry 2020-11, Vol.11 (42), p.6803-6810
Main Authors: Suo, Hongyi, Yuan, Haobo, Tanaka, Ryo, Nakayama, Yuushou, Sun, Wen-Hua, Shiono, Takeshi
Format: Article
Language:English
Subjects:
Catalysts
Conversion
Crosslinking
Molecular weight
NMR
Nuclear magnetic resonance
Octenes
Polymer chemistry
Polymerization
Terpolymerization
Terpolymers
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Summary:ansa -Fluorenylamidotitanium complexes Me 2 Si(Flu)(N t Bu)TiMe 2 ( 1 ) and Me 2 Si(2,7- t Bu 2 Flu)(N t Bu)TiMe 2 ( 2 ) were used as precatalysts for the homopolymerization of norbornadiene (NBD) and the terpolymerization of NBD, norbornene (NB), and 1-octene (OC). In the NBD homopolymerization, catalyst 2 showed double the conversion and yielded a polymer having more than double the molecular weight compared with catalyst 1 when activated by modified methylaluminoxane (MMAO). The conversion and molecular weight were significantly increased by changing the cocatalyst from MMAO to [Ph 3 C][B(C 6 F 5 ) 4 ]. The conversion levels after 10 min polymerization using 2 -[Ph 3 C][B(C 6 F 5 ) 4 ] at 25 and 0 °C were 52% and 62%, respectively. The conversion reached 82% at 0 °C after 1 h, and soluble polyNBD with a number-average molecular weight ( M n ) of 34 100 was obtained. The 2 -[Ph 3 C][B(C 6 F 5 ) 4 ] catalytic system also showed the best performance for NBD/NB/OC terpolymerization among the four combinations of precatalyst/cocatalyst and gave the terpolymer with M n of 66 300 containing 13 mol% of NBD at 64% conversion after 10 min polymerization at 0 °C. All resulting polymers possessed good solubility, indicating that crosslinking via the NB unit derived from NBD was negligible.
ISSN:1759-9954
1759-9962
DOI:10.1039/D0PY01180K