热致型液晶聚合物的等温和非等温晶化动力学

LIQUID CRYSTALLIZATION AND CRYSTALLIZATION KINETICS OF THERMOTROPIC POLYESTER

利用等温和非等温方法详细研究了芳香族聚酯──热致型聚合物对，对’－联苯二甲酸二辛酯的结晶相和液晶相形成机理，并计算了相变过程中的表面自由能与温度系数，研究结果表明：从介晶相开始的结晶过程是二维异相成核、三维线性增长的，而从各向同性液相开始的液晶相形成过程则是二维异相成核二维线性增长的．对两个晶化过程的表面自由能的研究表明，该聚合物液晶相形成过程的相转变表面自由能比结晶过程小得多，预示了它将具有更大的晶化速率．研究还发现，该聚合物的液晶相形成过程具有比结晶过程大得多的温度敏感性．

The mechanism of crystallization and liquid crystallization of an aromatic thermotropic polymer-thermotropic poly (octamethylene p, p'-bibenzoate) were investigated detailedly with DSC and hot-polarized microscope and the surface fre energy and temperature coefficient of these phase transitions were determined and estimated. The results suggest that liquid crystallization process of the polymer is heterogeneous in two-dimentional nucleation and linear growth in twodimensional with a value of Avrami exponent n to be 2.7,while the crystallization process is heterogeneous in two-dimentional nucleation and linear growth in three dimensional with a value of n to be 4.2-4.5.From the analysis of surface free energy and temperature coefficient of liquid crystallization and crystallization processes, it is found that liquid crystallization process is much faster than the crystallization process, and the liquid crystallization is more temperature sensitive than the crystallization.