Measured SAXS

4 Thermoplastic Polyurethane Elastomers Under Uniaxial Deformation 

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The measured SAXS curve of the calibration sample must have been pre-processed in the usual way (cf. Sects. 7.3 - 7.6). Therefore it is important to have calibration samples with a well-defined thickness27. Because synchrotron beamlines can be adjusted to a fairly wide range of radiation power, it is important to have thin calibration samples for a high-power adjustment (e.g., common SAXS with wide slit openings) and thick calibration samples for low-power adjustments (e.g., USAXS with microbeam). For calibration samples from synthetic polymers, thicknesses ranging between 0.2 mm and 3 mm are reasonable. It appears worth to be noted that not only polymers, but as well glassy carbon [88] can be used as a solid secondary standard for the calibration to absolute intensity. 

All measured SAXS data were analyzed by the generalized indirect Fourier transformation (GIFT) technique with the Boltzmann simplex simulated annealing (BSSA) algorithm [34, 35]. The GIFT calculation is based on the analytical or numerical solution of the Ornstein-Zernike (OZ) equation that describes the interplay between the total (h(r)) and direct (c(r)) correlation functions ... 

SAXS - measurements. SAXS curves were measured using a home-made KRM-1 diffractometer with a slit scheme for the primary beam collimation (CuKa-line, Ni filter, scintillation detector). The scattering coordinate was measured in terms of the scattering vector modulus s = 47t sinO/X, where 0 is the difraction angle, and X = 0.1542 nm is the radiation wavelength. The scattering intensity was measured in the range of s = 0.07 to 4.26 nm The experimental data were processed as described in 17-18). 

In the present study, we have measured SAXS and SANS in dilute solutions of CsPFO and analyzed observed scattering curves to elucidate whether two-dimensional micellar growth occurs or not. 

Fig. 4.5 TPU 205. Measured SAXS intensity during the tensile test. The pseudo-color fiber patterns /( 12. 3) show the region —0.2nm < ii2,. S3 < 0.2nm. Pattern intensities on a logarithmic scale. Cross-head speed is 2 mm/s. Straining direction is vertical...

Figure 17 shows some of the measured SAXS curves of unstrained, isotropic films. The curves for water-swollen samples are indicated by dashed lines. Most of them exhibit a long period reflection, which is characteristic of correlation among domains in a multiphase system. Water-swollen materials show a more pronounced long period peak. A considerable shift of the peak position is observed only with the 57PEO/PA6 material. 

Proposed molecular packing in the fiber. Reprinted with permission from Ref [54]. Copyright 1994 American Chemical Society, (c) Comparison of the measured SAXS data... 

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