LIQUID-CRYSTAL COMB-SHAPED POLYMERS WITH MESOGENIC GROUPS CONTAINING POLAR 2-(P-CYANOPHENYL)PYRIMIDINE FRAGMENTS

New comb-shaped polymers (polysiloxanes, polyacrylates and polymethacr ylates) containing polar 2-(p-cyanophenyl)pyrimidine fragments in the side chains were synthesized. Structural identification of the phases formed by these polymers Was carried out, and the temperatures and hea ts of the phase transitions were determined. Comparison of the propert ies of the synthesized polymers with those of structurally similar pol ymers containing 4-cyanobiphenyl groups revealed that incorporation of cyanophenylpyrimidine fragments into the macromolecules raises the gl ass transition temperature, enhances the tendency of the resultant pol ymers to crystallize and form ordered smectic phases, and increases th e thermal stability of LC phases.