热致性液晶共聚酯PET/PHB的相态研究(Ⅰ)

STUDIES ON THE PHASE STRUCTURE OF PET/PHB THERMOTROPIC LIQUID CRYSTAL COPOLYESTER(Ⅰ)

用 X 射线衍射仪法、广角 X 射线行射照相法,同时借助 DSC、偏光显微镜,对 PET/PHB 液晶共聚酯摩尔比为40/60体系在液晶温区中的结构作了研究。结果表明,270℃开始出现向列型液晶;280℃～300℃温区中 PHB 微晶已完全熔融,向列型液晶的局部有序区尚未产生物理形态分离,此时的取向度最高,是纺丝的较理想的温区。该体系在熔体中的 PET 以液晶的局部有序微区的介质形式存在,与液晶微区有一定的相互作用,其结构有序性与纯 PET 无定形有所不同。

The liquid crystal structure of 40:60 molar ratio for PET/PHB copolyester at different tempera-tures above the flow temperature was studied by means of x-ray diffraction in quality and in quantity,i.e.,diffraction accepted by counter and wide angle diffraction photograph,and with help of DSC andPolarizing Microscope Observation.As result the temperature at which the nematic texture of liquidcrystal began to appear was 270℃.Within the range of 280℃～300℃ the small crystal of PHB wasmelted completely and the regions of local order of nematic mesophase were not separated,when it waseasiest to develop the orientation.So such a range is regarded as best for spinnign.The amorphous re-gion in the melt of this system existed as medium,which the local order regions depended on and hadinteracts with.So its order was different from that of the pure PET amorphous.From this it was sug-gested that the amorphous region in this system behave higher order than that of pure PET.