256
columnar- in lamellar or smectic-in lamellar arrangement with vertical alignment,
useful for manufacturing dense line spaces and contact holes or for vertical orientation of low surface energy oligodimethylsiloxane.
In the side-chain LCPs, the flexible polysiloxane backbones can improve the
decoupling of the movements of the side chain and main chain, giving rise to higher
thermal stability of the mesophases. This is further increased for the longer polysiloxane backbone, which is also associated with more ordered phase structures and
a higher T g and LC-isotropic transition temperature (T i ) (Zhang et al. 2018). Sidechain LCPs can be obtained by attaching the mesogenic group onto a polysiloxane
chain or by reacting mesogenic and siloxane dimers. Different structures containing
azobenzene moieties are exemplified in Fig. 11.6. Steglich esterification was used
by Racles et al. (2006a) to obtain side chain azo-polyesters with different
Fig. 11.6 Examples of side-chain LCPs with siloxane segments and azobenzene mesogens
C. Racles et al.
columnar- in lamellar or smectic-in lamellar arrangement with vertical alignment,
useful for manufacturing dense line spaces and contact holes or for vertical orientation of low surface energy oligodimethylsiloxane.
In the side-chain LCPs, the flexible polysiloxane backbones can improve the
decoupling of the movements of the side chain and main chain, giving rise to higher
thermal stability of the mesophases. This is further increased for the longer polysiloxane backbone, which is also associated with more ordered phase structures and
a higher T g and LC-isotropic transition temperature (T i ) (Zhang et al. 2018). Sidechain LCPs can be obtained by attaching the mesogenic group onto a polysiloxane
chain or by reacting mesogenic and siloxane dimers. Different structures containing
azobenzene moieties are exemplified in Fig. 11.6. Steglich esterification was used
by Racles et al. (2006a) to obtain side chain azo-polyesters with different
Fig. 11.6 Examples of side-chain LCPs with siloxane segments and azobenzene mesogens
C. Racles et al.