Synthesis,characterization, and mesomorphic behavior of side-chain liquid crystalline copolysiloxane polymers I. with an oligo (ethylene oxide) unit and a cyano unit in the side chain

The syntheses and characterizations of poly [4-allyloxy-benzoic acid [4-(2-methoxy) ethoxy] biphenyl]-4-yl ester-co-4-allyloxy-[(4-cyano)-4-phenyl] carboxyl benzoate ester (poly [(MS3BDBE1)-co-(MCN)]_x/y) (where x/y represents the molar ratio of the two structural units on the side chain) were performed in this study. The molar compositions of the structural units on the copolymers side chain were characterized by¹H NMR. The transition temperatures, mesophase texture, and layer spacing (dl) of the polysiloxane polymers and copolymers were determined by differential scanning calorimetry (DSC), polarized optical microscopy, and X-ray diffraction patterns. The effects of the molar composition in the copolymers on the mesophase texture, transition temperatures, enthalpy/entropy change of mesophase/isotropic transition, dl of these copolymers were also discussed.