PMPCS (side chain) and poly(vinylbenzyl azide) (backbone), as shown in Scheme 12
(Ma et al. 2012). However, the comb polymer did not exhibit liquid crystallinity owing
to the confinement of the comb architecture.
Supramolecular Approaches
In addition to chemical reactions, supramolecular strategies have also been
employed to obtain MJLCPs. Supramolecular jacketed polymers showing SmA or
Col n LC phases were prepared via hydrogen bonding (Xu et al. 2012). Poly
(2-vinylbenzene-1,4-dioic acid) was synthesized and used as the hydrogen-bonding
donor, while five series of pyridine derivatives were designed and synthesized as
hydrogen-bonding acceptors (Scheme 13). Because the starting polymer is the same,
mixing the polymeric hydrogen-bonding donor and acceptors leads to complexes
with the same DP and polydispersity, which is advantageous in studying the
structure-property relationships of MJLCPs. The structures of the pyridine derivatives, including the rigidity, and the hydrogen-bonding strength are vitally important
in determining the LC behaviors of the complexes obtained. The disadvantage of this
method lies in the uncertainty of the chemical structures of the complexes, compared
to regular MJLCPs synthesized using covalent bonds.
Two mesogen-jacketed liquid crystalline polyelectrolytes (MJPEs), poly{sodium
2,5-bis[(4-sulfophenyl)aminocarbonyl]styrene} (PSPAS) and poly{sodium 2.5-bis
[(4-sulfophenyl)oxycarbonyl]-styrene} (PSPCS), with sulfonate groups on the two
ends of the side chains were synthesized by conventional radical polymerization.
Then, cationic lipids of different lengths and shapes were chosen to complex with
these two MJPEs (Scheme 14), leading to comb-shaped nonstoichiometric polymersurfactant complexes (Cheng et al. 2011b). The length and shape of the lipids
Cl
TEMPO-Cl
Cl
x
NaN 3
DMF
N 3
x
O
Br
O
CuBr, PDMAEMA
y
Click reaction
y
y
y
y
=
O
O
O
O
H 3 CO
OCH 3
Scheme 12 Synthesis routine of comb polymers with a semirigid MJLCP as side chains (Ma et al.
2012)
2 Mesogen-Jacketed Liquid Crystalline Polymers: Molecular Design and. . .
53
(Ma et al. 2012). However, the comb polymer did not exhibit liquid crystallinity owing
to the confinement of the comb architecture.
Supramolecular Approaches
In addition to chemical reactions, supramolecular strategies have also been
employed to obtain MJLCPs. Supramolecular jacketed polymers showing SmA or
Col n LC phases were prepared via hydrogen bonding (Xu et al. 2012). Poly
(2-vinylbenzene-1,4-dioic acid) was synthesized and used as the hydrogen-bonding
donor, while five series of pyridine derivatives were designed and synthesized as
hydrogen-bonding acceptors (Scheme 13). Because the starting polymer is the same,
mixing the polymeric hydrogen-bonding donor and acceptors leads to complexes
with the same DP and polydispersity, which is advantageous in studying the
structure-property relationships of MJLCPs. The structures of the pyridine derivatives, including the rigidity, and the hydrogen-bonding strength are vitally important
in determining the LC behaviors of the complexes obtained. The disadvantage of this
method lies in the uncertainty of the chemical structures of the complexes, compared
to regular MJLCPs synthesized using covalent bonds.
Two mesogen-jacketed liquid crystalline polyelectrolytes (MJPEs), poly{sodium
2,5-bis[(4-sulfophenyl)aminocarbonyl]styrene} (PSPAS) and poly{sodium 2.5-bis
[(4-sulfophenyl)oxycarbonyl]-styrene} (PSPCS), with sulfonate groups on the two
ends of the side chains were synthesized by conventional radical polymerization.
Then, cationic lipids of different lengths and shapes were chosen to complex with
these two MJPEs (Scheme 14), leading to comb-shaped nonstoichiometric polymersurfactant complexes (Cheng et al. 2011b). The length and shape of the lipids
Cl
TEMPO-Cl
Cl
x
NaN 3
DMF
N 3
x
O
Br
O
CuBr, PDMAEMA
y
Click reaction
y
y
y
y
=
O
O
O
O
H 3 CO
OCH 3
Scheme 12 Synthesis routine of comb polymers with a semirigid MJLCP as side chains (Ma et al.
2012)
2 Mesogen-Jacketed Liquid Crystalline Polymers: Molecular Design and. . .
53