The microstructure of stabilized fibers

The morphology and microstructure of a stabilized fiber, nonburning fiber, has been investigated under optical and electron microscopes, and a model for the structure of the stabilized fiber is presented. Skin-core morphology was found in the cross section of the stabilized fiber. The proposed model is consistent with the lamellar-plate-like structure, measuring about 400-700 Å in thickness, 500-4000 Å in breadth and 0.1-0.5 m in length along the fiber axis, which is composed of microfibrils. The structure has some circumferential distribution in the outer zone, while the inner zone has a radical distribution. Evidence for the lamellar-plate structure, including two chemical structures and having two different crystalline phases, which are the original AN units and the ladder polymer, were obtained from electron microscopy, wide-angle X-ray, and electron diffraction analyses.