Mesogen-Dominated Columnar Phase-Forming Polymers
In this type of polymers, the columns form as the result of self-assembly of
mesogens, most commonly discotics. These mesogens could attach to the polymer
backbone as side-groups, be a part of polymer main-chain or in the form of network.
Side-Chain Mesogenic Columnar Phase-Forming Polymers
Triphenylene-Based Side-Chain Columnar LC Phase-Forming Polymers
Triphenylene (TP) is the mostly commonly studied discotic mesogen for side-chain
columnar phase-forming polymers. The first side-chain TP polymers, PTPSiO as
shown in Chart 7, were reported in 1983, showing a distorted Col h phase (Kreuder
and Ringsdorf 1983; Werth and Spiess 1993). The early study concerning the effect
of the polymer main-chain and spacer length on the columnar LC phase suggested
CTA-m
PAS-n
PcPSiO
N
N
N
N
R1
R2
R1
R2
R1
R2
R2
R1
Si
N
N
N
N
R1
R2
R1
R2
R1
R2
R2
R1
Si
N
N
N
N
R1
R2
R1
R2
R1
R2
R2
R1
Si
O
O
O
O
Chart 6 Structures of rigid-rod columnar LC phase-forming polymers
132
S. Jin