Abstract: In this paper we report nine polysiloxanes with azobenzene or azoxybenzene mesogens in the side chains.Polysiloxanes Ⅲ_a-f were synthesized by reacting poly (3-chlorocarbonylpropyl)methyl-siloxane-co-dimethylsiloxane with 4-(4'-substituted phenylazo)phenol or 3-methyl-4 (4'-substituted phenylazo)phenol in 74%-81% yields.By the oxidation of Ⅲ_a-c,polysiloxanes Ⅲ_a-c were further prepared.The chemical structures of these polysiloxanes obtained were confirmed by IR,¹H NMRand elemental analysis.Their phase behavior were investigated using differential scanning calorimeter (DSC) and polarizing microscope.Six of them, Ⅲ_a-c and Ⅲ_a-c,show liquid crystalline properties.

Key words: Liquid crystalline polymer, Polysiloxane, Azobenzene mesogen, Azoxybenzene mesogen