TIT# Structure Development during the Melt Spinning of Polyethylene and
     Poly(vinylidene fluoride) Fibers by in Situ Synchrotron Small- and
     Wide-Angle X-ray Scattering Techniques
AUT# Samon, Joshua M.; Schultz, Jerold M.; Hsiao, Benjamin S.; Seifert, Sönke;
     Stribeck, Norbert; Gurke, Inga; Collins, George; Saw, Cheng;
SOU# Macromolecules (1999), 32(24), 8121-32
LOC# xv053
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ABS# In the present study, the structural and morphological development during
     melt spinning of polyethylene and poly (vinylidene fluoride) (PVDF)  fibers
     was studied using simultaneous in-situ synchrotron small-angle and
     wide-angle X-ray scattering (SWAXS) techniques. The spinning apparatus
     consisted of a single screw extruder, which was mounted on a horizontal
     platform that could be translated in the vertical direction allowing
     different spinneret distances to be sampled with the X-ray beam. Effects
     of the take-up speed ($10.6 - 61.0$mpm) and spinneret distance
     ($30 - 87.5$cm) on crystallinity and morphological parameters were
     investigated. A suggested model of structural development during
     crystallization details the formation of defective shish crystals,
     followed by the formation of kebab crystals. The defective shish-kebab
     structure eventually transforms into a well-defined lamellar structure.
     This model is consistent with the qualitative appearance of the
     two-dimensional SAXS and WAXS patterns, as well as the quantitative
     analysis of the SAXS/WAXS data using position-sensitive wire detectors.