Journal of Applied Polymer Science, Vol.80, No.12, 2335-2340, 2001
Synthesis and characterization of chiral smectic side-chain liquid crystalline polysiloxanes and ionomers containing sulfonic acid groups
The synthesis of new chiral smectic A (S-A) side-chain liquid crystalline polysiloxanes (LCPs) and ionomers (LCIs) containing 4-allyloxy-benzoyl-4-(S-2-ethylhexanoyl) p-benzenediol his ate (ABB) as mesogenic units and 4-[[4-(2-propenyloxy)phenyl] azo]benzensulfonic acid (AABS) as nonmesogenic units is presented. The chemical structures of the monomers and polymers are confirmed by FTIR spectroscopy or H-1-NMR. Differential scanning calorimetry (DSC), optical polarizing microscopy, and X-ray diffraction measurements reveal that all the polymers P-I-P-IV and ionomers P-V-P-VI exhibit S-A texture. The results seem to demonstrate that the tendency toward the S-A-phase region increases with increasing sulfonic acid concentration, and the thermal stability of the S-A phase is determined by the flexibility of the polymer backbones and the interactions of sulfonic acid groups.
Keywords:chiral;smectic;polysiloxane;liquid crystalline ionomer;sulfonic acid;4-allyloxybenzoyl-4-(S-2-ethylhexanoyl) p-benzenediol bisate