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

Recent results from melt spinning of several polymers (nylon 6, polyethylen e:, poly(vinylidene fluoride) using in-situ simultaneous synchrotron small- and wide-angle X-ray scattering (SWAXS) techniques are summarized. Here, m echanisms of early stages of structural and morphological development durin g crystallization under melt flow are probed. We find that a model consisti ng of the formation of defective shish-like structures, followed by the for mation of kebab crystals is most consistent with our results. We have furth er verified that the defective shish structure cannot be detected by the wi de-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.