硝酸法PAN原丝及其预氧化纤维微细结构的X射线研究

X-RAY STUDIES ON THE FINE STRUCTURE OF THE HNO_3 WET-SPUN PAN FIBER AND ITS PREOXIDATIVE FIBER

用广角X射线衍射(WAXD)和小角X射线散射(SAXS)技术,探讨了批量生产的聚丙烯腈(PAN)原丝及其预氧化纤维的结构特征。同时,定量地估计出它们的相对取向度分别为83％和70.89％。PAN原丝的结晶度和微晶尺寸分别为36.82％和8.83nm。预氧化纤维的芳构化指数为0.54和该试样在2θ=30min时,SAXS的弱峰强度的最大值为5.48×10^(-3)nm^(-1),长周期为17.65nm。

The structural characteristics of the HNO3 wet-spun polyacrylonitrile (PAN) fiber and its preoxidative fiber were studied by using wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) techniques. The degree of relative preferred orientation for the samples of PAN fiber and its preoxidative fiber was quantitatively calculated to be 83% and 70. 89% respectively. The crystallinity and the crystallite sizes of the sample of PAN fiber amounted to 36. 82% and 8. 83nm respectively. The 'aromatization index' values of the sample of PAN-based preoxidative fiber was 0. 5-1 and a very weak maximum at 2θ=30min as well as an apparent long period were found.