Structural development during the early stages of polymer melt spinning by in-situ synchrotron X-ray techniques

Recent results from melt spinning of several polymers (nylon 6, polyethylene:, poly(vinylidene fluoride) using in-situ simultaneous synchrotron small- and wide-angle X-ray scattering (SWAXS) techniques are summarized. Here, mechanisms of early stages of structural and morphological development during crystallization under melt flow are probed. We find that a model consisting of the formation of defective shish-like structures, followed by the formation of kebab crystals is most consistent with our results. We have further verified that the defective shish structure cannot be detected by the wide-angle X-ray scattering (WAXS) technique, but is visible by small-angle X-ray scattering (SAXS). This model has been proposed by Keller et al., for structural development during elongational flow. (C) 2000 Elsevier Science Ltd. All rights reserved.