290
M. Hong
O
O
400
O
O
400
O
O
400
O
O
400
O
O
400
O
O
400
O
O
400
O
O
400
O
O
400
O
O
400
a Decablock PMMA
O
O
400
O
O
100
O
O
100
O
O
100
O
O
100
b Nonacosablock PMMA
7
O
O
400
O
O
400
O
O
400
O
O
400
O
O
O
O
400
c Pentablock Copolymer
O
O
400
O
O
100
O
O
100
O
O
100
O
O
O
O
100
d Pentacosablock Copolymer
6
O
O
400
O
O
50
O
O
50
O
O
50
O
O
O
O
50 13
e Tripentacontablock Copolymer
Scheme 8.3 Structures of multiblock copolymers with different monomer types, block numbers,
and the degrees of polymerization per block
accomplish full conversion for the former copolymerization, while the latter one
only required 28 min (30 s per block). Accordingly, a pentacosablock with a high M n
of 225 kg/mol and a low Ð of 1.23 as well as a tripentacontablock copolymer with
a high M n of 310 kg/mol and a low Ð of 1.22 (Scheme 8.3d, e) can be successfully
synthesized, thus affording an unparalleled opportunity for the facile preparation
of DHDM multiblock copolymers without the addition of extra initiator/catalyst
or time-consuming/complex synthetic procedure which was indispensable in the
previous synthetic strategies. Meanwhile, (BHT)Al
i Bu 2 /IAP-1 FLP also have the
ability to incorporate random block into multiblock copolymers, affording random
heteropolymers with tailored properties [MMA 400 -b-EEMA 400 -b-(MMA 360 -rEEMA 40 )-b-(MMA 40 -r-EEMA 360 ), MMA 400 -b-(MMA 360 -r-EEMA 40 )-b-(MMA 40 -
r-EEMA 360 )-b-EEMA 400 , and MMA 400 -b-(MMA 360 -r-EEMA 40 )-b-(MMA 280 -
r-EEMA 120 )-b-(MMA 200 -r-EEMA 200 )-b-(MMA 120 -r-EEMA 280 )-b-(MMA 40 -rEEMA 360 )-b-EEMA 400 ].
In 2019, Zhang and co-workers found that MeAl(BHT) 2 /NHO-5–7 (Scheme 8.4)
CLAs are also capable of promoting living polymerization of MMA at a low