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CPP: Chemische Physik und Polymerphysik
CPP 3: SYMPOSIUM: Dynamics of multi-component fluids III
CPP 3.1: Hauptvortrag
Freitag, 4. März 2005, 14:00–14:30, TU C243
Rheology and morphology of multiphase polymer blends — •Martin Laun1, Marian Mours1, Inge Vinckier2, Filip Osterlink2, and Paula Moldenaers2 — 1BASF Aktiengesellschaft, Ludwigshafen/Rhein — 2KU Leuven, Belgium
The rheology and processing behaviour of multiphase polymer blends strongly depend on their phase morphology. The latter is affected by the rheological properties of the polymer components, their interfacial characteristics as well as by the flow conditions during blending/processing. Intelligent blend processing and material selection requires insight in the interrelations between material parameters, process variables and resulting morphology. The interplay between rheology and morphology in simple shear flow is demonstrated on LCST technical model blends of PαMSAN and PMMA, which allow the creation of various morphologies for a given composition. Phase separation and coarsening as monitored by oscillatory shear, can quantitatively be described by the Palierne model (droplet matrix morphology) and the Doi-Ohta theory (co-continuous structures. Droplet deformation, break-up and coalescence in steady shear were monitored by the transient normal stress and subsequent oscillatory shear measurements. More complex and processing related flows like filament extension, extrusion through a capillary or squeezing flow were investigated on immiscible model blends of PMMA and PS. Droplet morphology development after elongation is significantly affected by the viscoelasticity of the disperse phase. Thin fibrils may be obtained due to a suppression of the Rayleigh instability during elongational flow.