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

• Published in: Macromolecules 1999-11, Vol.32 (24), p.8121-8132
• Main Authors: Samon, Joshua M, Schultz, Jerold M, Hsiao, Benjamin S, Seifert, Sönke, Stribeck, Norbert, Gurke, Inga, Saw, CollinsCheng
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Machinery and processing; Plastics; Polymer industry, paints, wood; Spinning; Technology of polymers
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma9906332

In the present study, the structural and morphological development during melt spinning of polyethylene and poly(vinylidene fluoride) fibers was studied using simultaneous in-situ synchrotron small- 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 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 kebob crystals. The defective shish-kebob 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.