利用 WAXD,DSC和 FTIR等方法研究了 PET在升温过程中的晶体结构变化 .X射线衍射分析表明 :在升温过程中 ,双轴拉伸薄膜只有 10 0晶面衍射峰 ,等温结晶和自然冷却样品有 110和 10 0两个晶面衍射峰 ,而淬火样品无衍射峰 .淬火后加热再自然冷却样品有 0 10 ,110和 10 0三个晶面衍射峰 .在 DSC曲线中淬火样品有冷结晶峰 ,而其它样品没有 .红外光谱图中的 5 0 0 cm- 1 ,195 0 cm- 1和 2 96 0 cm- 1谱带波数的位移表明了冷结晶的发生 The crystal structure of PET during heating was studied by means of WAXD, DSC and FTIR.The X-ray diffraction analysis showed that the biaxially stretched film had only 10 × crystal diffraction peaks, isothermal crystallization and naturally cooled samples There are two crystal diffraction peaks at 110 and 10 0, while the quenched sample has no diffraction peaks.After quenching and heating, the samples with natural cooling have 0 10, 110 and 10 0 crystal diffraction peaks.The quenched samples in DSC curve have cold crystallization Peak, while the other samples did not.The shift of the wavenumber of bands of 500 cm-1, 195 0 cm-1 and 2 96 0 cm-1 in the infrared spectrum indicated the occurrence of cold crystallization