聚对苯二甲酸乙二醇酯的DSC研究

用 DSC、动态力学方法和密度测量等手段对经不同条件热处理或拉伸的PET试样进行了研究,结果表明:DSC曲线上放热峰的位置明显地依赖于样品的结晶和取向程度。由放热峰面积算出的结晶过程的热量与试样密度无单值的依赖关系,而线性地依赖于 70℃时的力学损耗值 tanδ,后者为试样中非晶区部分多少的量度。在这一结晶阶段生成不完善的晶区并伴有密度剧增现象。

THE DSC STUDIES OF POLYETHYLENE TEREPHTHALATE

DSC, dynamic mechanical properties and density measurement have been performed for PET samples heat treated or stretched at different conditions. It was found that the position of the exothermal peak is obviously dependent on the degree of crystallization and orientation of the samples. The amount of heat calculated from the exothermal peak is not uniquely determined by the density of the sample, but is linearly dependent on tan 6 at 70℃, which can be used as a measure of the amount of amorphous state within a sample. At this stage of crystallization imperfect crystalline regions are formed and an abrupt increase of density is observed.