TIT# The Equatorial Small-Angle Scattering During the Straining of
     Poly(ether ester) and its Analysis
AUT# Stribeck, N.
SOU# J. Polym. Sci., Part B: Polym. Phys. (1999), 37, 975-981
LOC# xv033 @selbst.ftx
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ABS# A method for the quantitative analysis of two-dimensional (2D)
     small-angle X-ray scattering (SAXS) patterns with fiber symmetry
     by successive information filtering is proposed and applied to a series
     of images recorded durig a straining experiment of a two-phase polymer
     sample at a synchrotron beamline. The studied equatorial scattering is
     similar to the frequently discussed void scattering, but originates from
     an ensemble of rodlike soft domains (needles) in the sample, orientated
     in the direction of strain. The intensity is extracted and projected onto
     the equatorial plane, the ideal two-phase structure is extracted, and the
     2D chord distribution is computed. This curve describes a 2D two-phase
     morphology made from needle cross-sections embedded in matrix material.
     Because interparticular correlation is found to be weak in the chord
     distribution, pure particle scattering is assumed. Modeling the needle
     cross-sections by circular disks leads to a simple theory, which allows
     the deconvolution of a disk diameter distribution from the chord
     distribution. It is shown hwo parameters of the disk diameter distribution
     can be computed without deconvolution. For the selected poly(ether ester)
     thermoplastic elastomer the study of the soft domain needles indicates
     strain-induced hardening. While for low elongation $\epsilon$ the soft
     needles are more compressible than the microfibrillar matrix, saturation
     is observed for $\epsilon > 2.5$.