1. Phase Transition and Transition Kinetics of a Thermotropic Poly(amide-imide) Derived from 70% Pyromellitic Dianhydride, 30% Terephthaloyl Chloride, and 1,3-Bis[4-(4’-aminophenoxy)cumyl]benzene
作者：S. Liu, T. Chung,* J. X. Geng, E. Zhou, S. Tamai
關鍵字：Phase Transition and Transition Kinetics
論文來源：期刊
具體來源：Macromolecules 2001, 34, 8710-8719
發(fā)表時間：2001年
The phase transition and transition kinetics of a liquid crystalline copoly(amide-imide) (PAI37), which was synthesized from 70 mol % pyromellitic dianhydride, 30 mol % terephthaloyl chloride, and 1,3-bis[4-(4￠-aminophenoxy)cumyl]benzene, was characterized by differential scanning calorimetry, polarized light microscopy, X-ray diffraction, and rheology. PAI37 exhibits a glass transition temperature at 182 °C followed by multiple phase transitions. The crystalline phase starts to melt at 220 °C and forms smectic C (SC) phase. The SC phase transforms into smectic A (SA) phase when the temperature is above 237 °C. The SC to SA transition spans a broad temperature range in which the SA phase vanishes and forms isotropic melt. The WAXD fiber pattern of PAI37 pulled from the anisotropic melt revealed an anomalous chain orientation, which was characterized by its layer normal perpendicular to the fiber direction. The transition kinetics for the mesophase and crystalline phase formation was also studied.