不同形状中间相沥青炭纤维的横断面结构(英文)

CROSS-SECTIONAL TEXTURES OF MESOPHASE PITCH-BASED CARBON FIBERS WITH DIFFERENT SHAPES

在场发射扫描电子显微镜（ＦＥ－ＳＥＭ）下观察了圆形、中空、条形和Ｙ－形中间相沥青炭纤维的横断面结构。用流变学理论分析了纺丝过程中几种炭纤维结构的形成，提出中空纤维纺制时沥青流体的最大流速线在喷丝孔中心线的内侧，并根据中空炭纤维横断面的显微照片对此加以证实，用催化缩聚中 间相沥青制备的条形炭纤维显示出的特殊弧形对称结构，起因于中间相沥青的流变性质和条形喷丝孔的形状设计，非圆形中间相沥青炭纤维趋向于以线形为中心的放射状横断面结构，因而在热处理过程中能避免应力集中和裂纹产生，有利于提高炭纤维的抗压强度。

The textures of circular, hollow, ribbon-shaped and Y-shaped mesophase pitch-based carbon fibers were observed on the broken cross-section by using a field emission scanning electron microscope (FE-SEM ). The formation process of the textures during the spinning was analyzed with the theory of rheology. It was inferred for the hollow fibers that the largest flow-rate line of pitch fluid should be at the position inside the center line of the spinneret, which had been proved based on the photographs of the fibers. The special texture of the ribbonshaped carbon fibers prepared from the catalytically condensed mesophase pitch was caused by the rheological property of the mesophase pitch and the arc ends of the ribbon-shaped spinneret. Noncircular mesophase pitch-based carbon fibers were found tending to be line-origin textures, which could avoid stress-concentrating and cracking during heat-treatment and be helpful for carbon fibers to improve their compressive strength.