Synthesis and characterization of cholesteric liquid crystalline copolysiloxanes containing 4-biphenyl 4-allyloxybenzoate and [S]-1-(2-naphthyl)ethyl 6-[4-(10-undecen-1-yloxy) biphenyl-4 '-carbonyloxy]-2-naphthoate side groups

Abstract

A series of side-chain liquid crystalline copolysiloxanes containing 4-biphenyl 4-allyloxybenzoate and [S]-1-(2-naphthyl)ethyl 6-[4-(10-undecen-1-yloxy) biphenyl-4'-carbonyloxy]-2-naphthoate side groups was synthesized and characterized. Differential scanning calorimetry and optical polarizing microscopy measurements reveal a cholesteric mesophase for all copolysiloxanes. The effect of the monomer feeding ratio on the mesomorphic temperature range of copolysiloxanes is discussed. These copolysiloxanes were used as stationary phases in gas chromatography capillary columns. They show very unique, chiral separating properties for various racemic compounds.