Synthesis and characterization of novel ferroelectric liquid crystals and copolymers containing biphenyl azobenzene and / or phenyl biphenyl carboxylate mesogenic groups

Abstract

Two new ferroelectric liquid crystals, 4-[(S)-1-(ethoxycarbonyl)]ethyl 4-[4-(9-decenyloxy)biphenyl]azobenzoate (10) and its ester analogue 4-[(S)-1-(ethoxycarbonyl)]ethyl {[4-(9-decenyloxy)]biphenyl-4'-yl}carbonyloxybenzoate (17), and side chain polysiloxane copolymers and terpolymers containing various amounts of 10 and 17 as mesogenic side groups have been synthesized. Their mesomorphic and physical properties have been characterized. Both 10 and 17 exhibit isotropic, SmA*, SmC*, and Sm(I or F)* phases. The copolymer with 17 as the mesogenic group and terpolymers having low content of the azo compound 10 show a SmC* phase over a large temperature range down to room temperature. The copolymer with the azo compound 10 as the mesogenic group is amorphous.