To enhance the reactivity of the terminal hydroxyl groups of cholesterol or diosgenin

the cholesteryl or diosgenin derivatives were prepared by chain extension reaction

which was used as initiators to initiate the ring-opening polymerization of trimethylene carbonate (TMC). Two kinds of main-chain polycarbonate liquid crystals with different liquid crystal motifs were prepared. The structure and properties of the obtained liquid crystal polymers were tested and characterized by means of hydrogen-1 nuclear magnetic resonance (

1

H-NMR)

differential scanning calorimetry (DSC) and polarizing microscope (POM). The results show that the introduction of cholesteric or diosgenin gives polytrimethylene carbonate a liquid crystal property

and the structure of the liquid crystal motifs has a significant influence on its liquid crystal properties.