全芳香族共聚酯纤维轴向压缩变形结构的研究

INVESTIGATION ON BANDED STRUCTURE OF AXIALLY COMPRESSED WHOLLY AROMATIC COPOLYESIER FIBERS

借助偏光显微镜、扫描电子显微镜及Ｘ射线衍射等方法研究了全芳族共聚酯（ＷＡＰＥＴ）纤维轴压缩变形行为。在变形初期，因局部晶面滑移而形成与纤维轴约呈６０～６５°角的变形带。变形带内链分子受剪切作用而折断或挫屈。随着变形程度增加，变形带堆积厚度增大，并且在原有变形带周围还产生许多新的较小的变形带，表明在这些区域出现应力集中。最后，微原纤间的滑移导致大分子发生剧烈侧向位移，使纤维轴向长度明显缩短，纤维破坏。

Deformation behaviour of wholly aromatic copolyester(WAPET)fiber during axial compression was examined by means of polarizing optical microscopy,scanning eletron microscopy and X-ray diffraction. In the initial stage of compression,kink bands are formed on the surface of WAPET fiber at an angle of ca.60～65°to fiber axis.It can be predicated that local crystalline slip systems are responsible for the formation of the kink band.The all molecular chains within the band were broken or bent,suggesting that all the chains in the band were sheared with respect to each other along their molecular axes.With progressive compression,new kink bands were formed near the kink bands that were formed in the initial stage of compression,indicating that compressional stress is concentrated at regions near the kink bands.In the final stage of compression,massive lateral displacement occurred from place to place along fiber axis and the fiber was almost sqeezed out of shape. It can be assumed that intermicrofibrillar slip plays an important role at the final state of compression.