reaction, vinyl groups react almost completely, whereas methacryloyl groups
remained unreacted. This weakly cross-linked network was deformed to obtain a
macroscopic alignment of the liquid crystalline phase. In the second step, locking of
this anisotropic network was done by reacting methacryloyl group. To understand
the mechanical strain effect prior to the second cross-linking process, polymer 75.1
was prepared without applying the mechanical field, whereas 75.2 was prepared
utilizing the same methodology. The polymers 76.1–76.5 were synthesized by
RO
O
RO
OR
OR
OR
6
R = C 5 H 11
O
O
9
9
O
4
O
O
O
O
6
O
RO
O
RO
O
OR
OR
6
R = C 5 H 11
6
71
72
73
74
Elastomer 75
(71) + (72) + (73)
(71) + (74)
Si O
H
x
Si O
H
x
Elastomer 76
Scheme 15 Synthesis of triphenylene-based discotic elastomers (redrawn from Bengs et al. 1993;
Disch et al. 1995)
Table 14 Phase behavior of triphenylene-based discotic elastomers (Ref 29: Bengs et al. 1993;
Ref 30: Disch et al. 1995)
Mesogen
Phase behavior
Ref
75.1
g À 50 Col 28 I
29
75.2
g À 50 Col 28 I
29
76.1
g À 50 Col 106 I
30
76.2
g À 49 Col 94 I
30
76.3
g À 50 Col 94 I
30
76.4
g À 45 Col 78 I
30
76.5
g À 44 Col 76 I
30
3 Liquid Crystalline Polymers Derived from Disc-Shaped Molecules
85