Dresden 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

CPP: Chemische Physik und Polymerphysik

CPP 20: POSTER A

CPP 20.32: Poster

Montag, 24. März 2003, 19:00–21:00, ZEU/250

Interpenetrating Spherulitic Crystallization in Poly (Vinylidene Fluoride)/Poly-3-Hydroxybutyrate Blends — •Jieping Liu and Bernd-J Jungnickel — Deutsches Kunststoff-Institut,Schlossgartenstrasse,6,64289,Darmstadt

Interpenetrating Crystallization in PVDF/PHB Blends

Jieping Liu, Bernd-J. Jungnickel

The PVDF/PHB blend forms a homogeneous melt where both components crystallize individually. We report on step crystallization and anisothermal crystallization by light microscopy and time resolved synchrotron X-ray diffraction. Upon step crystallization, the PVDF crystallizes first at Tc(1), and amorphous PHB can be incorporated into the spherulites of PVDF or rejected from them depending on composition and Tc(1). That PHB crystallizes at Tc(2), starting from a defined site in the interfibrillar regions if the PVDF formed volume filling dendrites. It such formed dendritic spherulites too which include a large number of those of the PVDF. For blends where the PVDF dendrites were not volume filling, PHB formed at first regular spherulites. Their growth started from outside the PVDF dendrites but could later interpenetrate them, turning their own morphology to dendritic. Upon gradual cooling the melt, the resulting morphology is very complex. The amount of amorphous PHB in the PVDF crystals decreases and the long period increases with increasing cooling rate.