抄録
Poly (p-phenylene terephthalamide) fibers (Kevlar 29 and 49) were thin-sectioned or treated with a mixed solvent of sulfuric-acid/water (SAW) to be observed in transmission and/or scanning electron microscopes. Microfibrillar and pleated-band morphology existed in Kevlar 29 and 49 fibers, while the skin-core structure was confirmed only in Kevlar 29 fiber. A microfibril ca. 100nm thick is composed of several tens of needle-shaped microcrystals 10_??_20nm thick, being pleated with a period of 500_??_600nm along the fiber axis. Hydrogen-bonding or crystal structure in the core region was considered to be more ordered than that in the skin region in the case of Kevlar 29 fiber. Orientation of microcrystals in each microfibril was incoherent although b-axis orientation mainly distributed around the radial direction. Such tendency is more prominent for Kevlar 29 fiber which was finally suggested to assume the hierarchical morphology of “pleated-microcrystal band”.
