Synthesis and characterization of novel chiral smectic C(Sc*) phase shish-kebab type liquid crystalline block copolymers

A new series of chiral shish-kebab type liquid crystal block copolymers tha t form the smectic C(Sc*) phase was synthesized by solution polycondensatio n. The copolymers were characterized by GPC, DSC, TG, POM, X-ray diffractio n and polarimeter. The copolymers 7 entered into liquid crystal phase whin they were heated to their melting temperatures (T-m) and the copolymers 8 w ere in liquid crystal phase at room temperature with low viscosities. The s mectic sanded texture or focal-conic texture were observed on POM. All the chiral block copolymers showed high optical activity. No racemization has h appened. Temperature-variable X-ray diffraction study together with POM and polarimetric analysis realized that they are chiral smectic C(Sc*) phase. Thus we offer in this report the first example of shish-kebab type liquid c rystal block copolymers that form a chiral smectic C(Sc*) phase. The variat ion of melting and isotropization temperatures with molecular structure was also discussed.