shown that triphenylene containing polymethacrylates can form columnar phases
(Boden et al. 1998). The low glass transition at 2
C and a mesophase to isotropic
phase transition at 45
C shown by polymer 51.3 was attributed to high polydispersity (Stewart et al. 1998).
Si O
RO
RO
OR
OR
OR
O
9
n
RO
RO
OR
OR
OR
O
RO
RO
OR
OR
OR
O
Z
x
H
C
O
RO
RO
OR
OR
OR
O
Z
x
C
O
RO
RO
OR
OR
OR
O
O
x
H
C
O
D
D
D
D
D
D
Si O n
O
x
48
49
50
51
52 ; R = C 5 H 11
H 2
C
H 2
C
H 2
C
H 2
C
H
C
O
O
OH
n
n
n
n'
These acrylate functionalized triphenylene monomers were mixed with
2-hydroxyethyl acrylate or methyl acrylate functionalized triphenylene monomers
to produce copolymers 52. Copolymer made up of triphenylene and 2-hydroxyethyl
acrylate exhibited mesophase to isotropic transitions between 104
C and 165
C
depending upon their composition (Talroze et al. 2000). However, copolymer made
of triphenylene-based acrylate and methyl acrylate was found to be non-liquid
crystalline.
Catry et al. (1993) have reported the synthesis of triphenylene-based side-chain
polyesters 54 and 55. The malonate-terminated triphenylene-based monomer 53 was
condensed with α,ω-diols to produce these polymers. It has been observed that
polymer 54 is non-mesomorphic with a glass transition at À10
C, whereas polyester
55 showed liquid crystalline behavior. The isophthalate-terminated triphenylenebased monomer was condensed with polyethylene glycol (PEG 300) by Imrie et al.
(2004) to furnish the polymer 56, which exhibited liquid crystalline behavior.
80
S. Setia et al.