Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 7: POSTER: INTERNAL SYMPOSIUM Scattering Experiments
CPP 7.28: Poster
Montag, 26. März 2007, 16:00–18:00, Poster B
Nanostructure evolution during melting and oriented crystallization of polypropylene studied by in-situ SAXS — •Ulrich Nöchel1, Armando Almendárez Camarillo1, Norbert Stribeck1, and Stephan Volkher Roth2 — 1University of Hamburg, Institute TMC, Hamburg, Germany — 2HASYLAB at DESY, Hamburg, Germany
Polypropylene film with high uniaxial orientation and lamellar structure is melt-annealed at temperatures between 168°C and 175°C followed by different cooling programs during which 2D SAXS patterns are continuously taken in order to identify the mechanisms of crystallization. Peculiar "cross-patterns" observed during the early stages of crystallisation clearly demonstrate the mechanism of "building of lamellae from blocks" as proposed by Strobl. The evolution of the patterns under quiescent conditions shows that the complementary model of a "cross-hatched structure" cannot be applied. 2D SAXS data from various crystallization series[1] are evaluated by means of the CDF method[2] for a quantitative description of the crystallization mechanisms.
[1] Fibr. Text. EE (2005), 13(5), 27-29
[2] J. Appl. Cryst. (2001), 34(4), 496-503