USE OF SMALL-ANGLE LIGHT-SCATTERING (SALS) TO EXAMINE THE STRUCTURE OF FIBERS

The small-angle light-scattering (SALS) patterns of a wide range of polypropylene, nylon 6, and polyethylene ter ephthalate (PET) fibers have been examined so as to investigate the level of superstructural (>500 nm) ordering present within them. Many samples that were highly-disordered at a microstructural level, as evidenced by their wide-angle x-ray scattering (WAXS) patterns, showed evidence of extensive superstructural ordering. For example, a rapidly- quenched polypropylene fiber, which exhibited a smectic WAXS pattern, had a SALS pattern characteristic of spheru lites about 6 μm in diameter. Brief annealing of this sample produced the conventional monoclinic polypropylene WAXS pattern but did not noticeably change the size or shape of the SALS pattern. The usefulness and limitations of SALS for examining sheath-core effects and for demonstrating the existence of distorted spherulites is also discussed. © 1979, Sage Publications. All rights reserved.