- Conference date: 30–31 July 2013
- Location: Zlin, Czech Republic
The contribution discusses present state of art of modeling of the flow induced coalescence with respect to applicability of its results to the control of the phase structure evolution in flowing polymer blends. It is shown that the theory based on the switch between equations for matrix drainage between spherical or highly flattened droplets provides for probability, P c, that the collision of droplets will be followed by their fusion, similar dependences on system parameters as more complicated modeling. This theory facilitates to consider the effect of the matrix elasticity on coalescence. P c decreases with the matrix relaxation time. This decrease is small for short relaxation times but pronounced for long relaxation times. A new equation for description of the matrix drainage between flattened droplets is proposed, which is applicable for the whole range of viscosity ratios of the droplets and matrixes. Comparison of the assumptions of available theories of coalescence with characteristics of real polymer blends lead us to the conclusion that the effects of the elasticity and anisometry of droplets and their interactions in concentrated systems on coalescence need further intensive investigation. Finding of proper method of description of the coalescence in complex flow fields is needed for reliable prediction of the phase structure evolution during mixing and processing of polymer blends.
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