中文摘要：

采用X射线二维衍射图像和面扫描法对PAN碳化纤维制备过程中各阶段纤维进行了结构表征,揭示了干喷湿纺原丝在预氧化和碳化阶段各纤维晶区取向和晶态结构的差异。结果表明,利用赤道方向二维衍射图,可直观地观察到各纤维在不同阶段取向度以及结晶度的演变规律。与原丝相比,205℃预氧化纤维的取向度、晶粒尺寸以及结晶度都增大,晶面间距无明显变化。235℃预氧化纤维的取向度、晶粒尺寸以及结晶度都减小,晶面间距增大。与原丝以及预氧化纤维相比,碳化阶段纤维的取向度、晶粒尺寸、结晶度以及晶面间距都明显减小。

英文摘要：

Structural features of fibers during the preparation of PAN carbonized fiber were investigated by X-ray diffraction including both two-dimensional and plane scanning examinations. The differences of crystalline structures and crystalline orientation of dry-jet-wet spinning precursor fibers during pre-oxidation and carboniza- tion were revealed. The results show that the evolutional laws of orientation and crystallinity of fibers in the different stages are observed intuitively by the two-dimensional diffraction patterns in the equatorial direction. Compared with the precursor fiber, the orientation, crystalline size and crystallinity are increased and the inter- planar spacing has no obvious change for 205~C pre-oxidized fibers. While, for 235~Cpre-oxidized fibers, the o- rientation, crystalline size and crystallinity are decreased and the interplanar spacing was increased. Compared with the precursor fiber and pre-oxidized fibers, the orientation, crystalline size, crystallinity and interplanar spacing of fibers are decreased obviously during the carbonization.