Regensburg 2002 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 12: Poster: Polymere Netzwerke, Blends und Blockcopolymere

CPP 12.3: Poster

Wednesday, March 13, 2002, 16:30–18:00, B

Modelling compatibilized polymer blends in elongational flow — •Ulrich A. Handge — ETH Zürich, Dept. Werkstoffe, Institut für Polymere, 8092 Zürich, Schweiz

The rheology of blends of immiscible polymers is strongly influenced by the addition of compatibilizers. In the present paper it is shown that the behaviour of compatibilized polymer blends in uniaxial elongational flow can be described using the Cahn-Hilliard theory [1]. A newly introduced additional term in the free energy of the blend system describes the interaction of the compatibilizers with the other two components of the blend. The additional term in the free energy causes a diffusion of the compatibilizers to the interface between the two phases and therefore leads to a local reduction of the interfacial tension. Results of simulations of polymer blends without and with compatibilizers are presented. The analysis of the simulations shows that the deformation of droplets in polymer blends without compatibilizers can be described by Taylor’s theory [2]. If compatibilized polymer blends are exposed to a uniaxial elongational flow, the compatibilizers are swept to the poles leading to a non-uniform distribution of compatibilizers at the interface. The relaxation behaviour of compatibilized polymer blends is also discussed.

[1] J.W. Cahn and J.E. Hilliard, J. Chem. Phys. 28, 258 (1958).

[2] G.I. Taylor, Proc. Roy. Soc. London Ser. A 146, 501 (1934).