Regensburg 2002 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 3: Poster: Kristalline Polymere

CPP 3.5: Poster

Montag, 11. März 2002, 13:30–15:00, B

Light Scattering by Syndiotactic Polypropylene and Poly(ethylene-co-octene) during Early Stages of Crystallization — •Anke Hoffmann and Gert Strobl — Fakultät für Physik, Universität Freiburg, Herrmann-Herder-Str.3, 79104 Freiburg

We report on time resolved simultaneous HV (cross polarized) and VV (parallel polarized) light scattering experiments on poly(ethylene-co-octene) and syndiotactic polypropylene. Small angle light scattering (SALS) provides information on shape, size and internal structure of the scattering entities (eg. spherulites) as well as on the crystallinity of the sample. We are able to follow the crystallization over three orders of magnitude in crystallinity. The two materials show quite different crystallization kinetics. While polyethylene forms spherulites, whose internal structure does not change during growth, the experiments on syndiotactic polypropylene show non-spherulitic objects growing with increasing contrast, indicating that insertion crystallization takes place already at very early stages of crystallization.