Novel High Performance Aromatic Polyamide Fiber(III)-Fiber Structure Formation of High Strength and Modulus Poly(4,4폴-diamino-2폴-cyanobenzanilide terephthalamide) Fiber Prepared by Dry-Jet Wet Spinning of In-situ Polymerized Anisotropic Spinning Solution-

새로운 고성능 방향족 폴리아미드 섬유(III) - 액정방사에 의한 고강도 고탄성 방향족 poly(4,4폴-diamino-2폴-cyanobenzanilide terephthalamide) 섬유의 섬유구조형성 -

Formation of fiber structure of high strength and modulus aromatic poly(4,4'-diamino-2'-cyanobenzanlllde-terephthalamide) (poly(DACYB/TPC)) fiber as a function of spin draw ratio during dry-jet wet spinning of in-situ polymerized anisotropic spinning solution was examined by X-ray diffraction, birefringence and density measurement. Wide angle X-ray diffraction and hire-fringence demonstrated that high orientation of poly(DACYB/TPC) fiber resulted from the efficient elongational flow of mesophase in the spinline rather than the shear flow within the spinneret; poly(DACYB/TPC) fiber exiting from the spinneret did not develop appreciable chain oriontation due to probably a moderate extent of die swell despite a considerable amount of shear deformation within the spinneret. The X-ray diagram at a spin draw ratio of around 2 showed intense broad equatorial scatter with well defined meridional maxima and no difference from that of a fully drawn fiber. It indicated that there was nematic structure with high degree of axial orientation of the molecules in the fibers and its irregular lateral packing was not improved by high ratio of spin draw. The presence of some sharp equatorial and off-equatorial Bragg reflections of the heat treated fiber indicated that the nematic structure of as-spun fiber transformed to three dimensional fiber structure during heat treatment.