TIT# Small-angle X-ray scattering investigations of styrene-butadiene-styrene
     block copolymers during stretching
AUT# Polizzi, S.; Bösecke, P.; Stribeck, N.; Zachmann, H. G.; Zietz, R.;
     Bordeianu, R.
SOU# Polymer (1990), 31, 638-645
LOC# xv009  @selbst.ftx
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ABS# A small-angle X-ray scattering study on styrene-butadiene-styrene block
     copolymers during stretching is reported. Measurements have been performed
     at the Hamburg Synchrotron Radiation Laboratory at DESY using a
     two-dimensional position-sensitive detector. A pattern of layer lines
     perpendicular to the stretching direction with ellipsoidal envelope is
     obtained. This indicates a good orientation of cylindrical polystyrene
     domains along the stretching direction. The diameter-to-length ratio of
     the cylinders was found to be 0.6, the length being approximately 39 nm.
     The long period of the undrawn sample is about 47 nm. Upon stretching,
     initially this value increases almost affinely, while for $\lambda > 3$
     it tends to reach a constant value. The extension at which the curve bends
     coincides with the inflection point in the stress-strain curve; at higher
     values of extension, most of the polybutadiene chains are probably
     completely stretched and further extension is achieved partly by
     disruption of the polybutadiene matrix.