SYNTHESIS AND STRUCTURE-PROPERTY RELATIONSHIPS OF PROCESSABLE LIQUID-CRYSTALLINE POLYMERS WITH ARYLENEVINYLENE SEGMENTS IN THE MAIN-CHAIN FOR LIGHT-EMITTING APPLICATIONS

Polymers were synthesized with modified trans-bis(styryl)benzene segme nts in the main polycondensation of OH-functionalized oligo(arylenevin ylenes) and aliphatic diacid chlorides. Most of the visible light emit ting polymers were soluble at room temperature and fusible below the r ange of decomposition. The formation of a smectic A phase was observed in the melt state. Isotropization temperatures of polymers with pheny l-substituted arylenvinylene segments were detected below 200 degrees C. A remarkable thermal stability in the melt state with respect to cr oss-linking was observed for polymers containing CF3-substituted aryle nevinylene segments. The polymers were investigated by spectroscopic m ethods, thermogravimetrical analysis, differential scanning calorimetr y, polarizing microscopy, wide angle X-ray scattering, small angle X-r ay scattering, dielectric relaxation spectroscopy, and by stress-strai n experiments.