E. Chiellini et al., SYNTHESIS AND LIQUID-CRYSTALLINE PROPERTIES OF NEW THERMOTROPIC POLYURETHANES, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 243, 1994, pp. 135-147
The synthesis and liquid crystal behavior of new thermotropic polyuret
hanes derived from different mesogenic diols, alkylene (omega-hydroxya
lkyloxy-4-oxybenzoyl)oxybenzoate]s, and 2,4-toluenediiso-cyanate are r
eported. Depending upon the chemical structure of the repeat unit, the
polyurethanes formed either one or two mesophases extending over a fa
irly broad (>60 K) and accessible range of temperature (T-i < 430 K).
A cybotactic nematic mesophase was identified in each polyurethane sam
ple.