SYNTHESIS AND PROPERTIES OF COMB-SHAPED L IQUID-CRYSTALLINE POLY(PHENYLBENZOATE METHYLSILOXANE)S

Poly(phenylbenzoate methylsiloxane)s with alkyl spacer groups of diffe rent length (4, 6, and 11 carbon atoms) were synthesized, studied, and compared with the corresponding low-molecular-mass compounds that mod el the side chains of macromolecules. The temperatures of phase transi tions to the LC state were determined. It was shown that in a dilute s olution under applied sinusoidal electric field, the polymers behave a s flexible-chain polymers with each mesogenic unit oriented independen tly of the other units. In a mechanical shear field, the Maxwell const ant changes its sign from positive in the monomer solution to negative for the polymer. This evidences that the entire macromolecule orients in the hydrodynamic field so that the main axes of mesogens are predo minantly oriented normal to the axis of macromolecule.