Ns. Murthy et Wj. Orts, HYDRATION IN SEMICRYSTALLINE POLYMERS - SMALL-ANGLE NEUTRON-SCATTERING STUDIES OF THE EFFECT OF DRAWING IN NYLON-6 FIBERS, Journal of polymer science. Part B, Polymer physics, 32(16), 1994, pp. 2695-2703
Water absorbed by nylons appears to be partitioned into interlamellar
and interfibrillar spaces. The amount of water in the interfibrillar r
egion remains essentially unchanged with increasing draw ratio, wherea
s that in the interlamellar regions decreases with draw ratio; the lat
ter accounts for the decrease in the water uptake in the drawn fibers.
These results suggest that the amount of the amorphous material in th
e interfibrillar regions remains unchanged during drawing, and the inc
rease in the crystallinity during drawing results from the incorporati
on of the amorphous chain segments in the interlamellar regions into t
he crystalline lamellae. Further, the interfibrillar water is more tig
htly bound than the interlamellar water. The length of the longitudina
l channels into which water diffuses is about the same as that of the
fibrils, and increases from ca. 1500 to 2000 Angstrom upon drawing. Th
e longitudinal channels are highly oriented even in undrawn fibers, an
d their misorientation increases from 5 degrees to 15 degrees upon dra
wing. These channels can be described as surface fractals of dimension
3.4-3.6. (C) 1994 John Wiley and Sons, Inc.