Synthesis and Liquid Crystalline Properties of New Thermotropic Polyurethanes
摘要:
The synthesis and liquid crystal behavior of new thermotropic polyurethanes derived from different mesogenic diols, alkylene di[4-(omega-hydroxyalkyloxy-4-oxybenzoyl)oxybenzoate]s, and 2,4-toluenediiso-cyanate are reported. Depending upon the chemical structure of the repeat unit, the polyurethanes formed either one or two mesophases extending over a fairly broad (>60 K) and accessible range of temperature (T-i < 430 K). A cybotactic nematic mesophase was identified in each polyurethane sample.