THERMODYNAMIC AND STRUCTURAL CHARACTERISTICS OF CHOLESTERIC COPOLYESTERS

The mesomorphous properties of copolymers based on 4,4'-dihydroxybiphe nyl and a mixture of aliphatic dicarboxylic acids, one being L-camphor amic acid and the other, azelaic or sebacic acid, were studied by X-ra y diffraction, calorimetry, and polarization microscopy. It is demonst rated that introduction of a chiral component into linear LC polyester s at an amount below 50% leads to the formation of a cholesteric mesop hase in the melt and extends the temperature interval of existence of the mesophase as compared to that in homopolymers based on 4,4'-dihydr oxybiphenyl and azelaic or sebacic acid. Increasing the content of the chiral component above 50 mol % deprives the polyester of the mesomor phism manifestations.