Invariant , crystal SAXS data

Figure 5.13 Comparison of vibrational spectroscopic data with SAXS data collected for (a) LLDPE (2) and (b) DHDPE samples in the isothermal crystallization process from the melt. Q. invariant, d) lamellar thickness, Li and I(Li) the long period and the corresponding SAXS peak intensity of lamellar stacking structure LI for 800 A period and L2 for 400 A period.

The invariant Q, long period L, crystal lamelar thickness /< and interlamelar amorphous thickness were calculated from the SAXS data using the correlation function method s which are shown in Figures 6 (a) and (b) for the S2 and S3 samples... 

Figure 5.14 Time dependence of the various structural parameters estimated in the isothermal crystallization process of isotactic polypropylene. The FTIR data show the growth of regular helical segments. The Rg, and L are the radius of gyroid of the higher-density domains, the correlation distance between the neighboring domains, and the long period of the stacked lamellae, respectively, revealed by the SAXS data analysis. The Q is the invariant and is approximately proportional to the degree of crystallinity Xc, which was evaluated also using the WAXD data [67].

Fig. 18. SAXSAVAXS experiment on the isothermal crystallization of iPP. The saxs invariant and the crystallinity derived from the integrated intensity of the crystalline waxs peaks are coplotted with an arbitrary vertical axis. In this data set, the rise of the invariant precedes the rise of the crystallinity, which can indicate a spinodal-like crystallization mechanism. To base theories regarding crystallization solely on the outcome of such an experiment is dangerous since the results could be influenced by both instrumentation shortcomings and the physics behind the diffraction phenomena. —A— saxs invariant — — waxs crystallinity.

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