Randomly Functionalized Polyethylenes: In Quest of
Avoiding Catalyst Deactivation
Miloud Bouyahyi
Younes Turki
Akhilesh Tanwar
Lidia Jasinska-Walc
Rob Duchateau
10.1021/acscatal.9b01174.s001
https://acs.figshare.com/articles/journal_contribution/Randomly_Functionalized_Polyethylenes_In_Quest_of_Avoiding_Catalyst_Deactivation/9170786
Well-defined
randomly functionalized polyolefins produced by catalysis
form an interesting class of polymers with great potential for various
applications. One of the major challenges for the production of these
materials forms the incompatibility of the commonly used electrophilic
group 4 metal based catalysts and the desired nucleophilic, especially
protic functionalities like hydroxyl and carboxylic acid groups. Although
pacification of the protic functionality remains necessary, it was
found that lowering the oxidation state of a constrained geometry
type of catalyst from Ti(IV) to Ti(III) turned the catalyst unexpectedly
tolerant to a wide variety of aluminum alkyl pacified, hydroxyl-functionalized
olefin comonomers. The catalyst’s tendency to undergo chain
transfer to aluminum, which was found to be intensified by the presence
of aluminum alkyl pacified, hydroxyl-functionalized comonomers, can
be efficiently suppressed by the addition of a sterically hindered
phenol such as 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT). Surprisingly,
the addition of BHT also increases the catalyst’s affinity
to incorporate these functionalized comonomers.
2019-07-30 14:46:25
protic
hydroxyl-functionalized olefin comonomers
Ti
Randomly Functionalized Polyethylenes
aluminum alkyl
catalyst
electrophilic group 4 metal
Catalyst Deactivation Well-defined
BHT
carboxylic acid groups