Effects of nitro substituents on the properties of a ferroelectric liquid crystalline side chain polysiloxane

The syntheses of chiral liquid crystalline side chain polysiloxanes with lateral nitro substituents in the mesogenic core are described. The influence of the substituents and substituent positions on phase behaviour and electro-optical properties are investigated and compared. The lateral nitro groups strongly affect the phase behaviour of the side chain precursors as well as the liquid crystalline polymers. Properties in smectic A and C* phases are discussed with respect to substituent position. One side chain precursor exhibits very large spontaneous polarization of similar to 700 nC cm(-2).