TIT# SAXS-Fiber Computer-Tomography. Method Enhancement and Analysis
     of Microfibrillar-Reinforced Composite Precursors from PEBAX and PET
AUT# Stribeck, Norbert; Nöchel, Ulrich; Fakirov, Stoyko; Feldkamp, Jan;
     Schroer, Christian; Timmann, Andreas; Kuhlmann, Marion;
SOU# Macromolecules (2008), ~, submitted 8 July
LOC# xv115
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APP#
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ABS# The nanostructure gradient along the fiber radius inside polymer
     strands is uncovered by small-angle X-ray scattering (SAXS)
     microbeam-scanning experiments and X-ray scattering fiber
     computer-tomography (XSF-CT) analysis. We notice restricted
     visibility of scattering features within the series of patterns.
     The reason is violation of local fiber symmetry (LFS) in the
     irradiated volume elements (voxels). For its theoretical
     treatment a set of elementary topologies (tangential grain,
     radial grain) is introduced. Systematic aberrations
     (ultra-reconstruction, infra-reconstruction) generated by
     tomographic reconstruction of affected series are described. A
     concept for handling and utilization of these aberrations for
     nanostructure analysis is devised. Precursors of polymer
     microfibrillar-reinforced composites (MFC) containing
     poly(ether)-block-amide (PEBA) and poly(ethylene terephthalate)
     (PET) with varying cold-draw ratio are studied. We compare
     results from a direct analysis of the smeared measured patterns
     to results obtained after tomographic reconstruction and sound
     the power of reconstruction methods. Ideas for advanced practical
     applications of the XSF-CT method are discussed.