Berlin 2001 – scientific programme
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CPP: Chemische Physik und Polymerphysik
CPP 18: Poster: Polymer Blends, Heterogeneous Systems, Colloids and Nanoparticles, Interfaces, Polyelectrolytes
CPP 18.4: Poster
Wednesday, April 4, 2001, 12:30–15:00, AT1
The dynamics of a ternary homopolymer/diblock copolymer melt in the bicontinuous microemulsion phase — •C.M. Papadakis1, F. Rittig2, S. Gröger1, J. Kärger1, K. Almdal3, and P. Stepanek4 — 1Fakultät für Physik, Universität Leipzig, D-04103 Leipzig — 2Air Products and Chemicals, Inc., Allentown, PA 18195, USA — 3Condensed Matter Physics and Chemistry Department, Risø National Laboratory, DK-4000 Roskilde, Denmark — 4Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, CZ-16206 Prague
The most important application of diblock copolymers is the stabilization of homopolymer blends. Ternary blends of composition homopolymer A/B and diblock copolymer A-B display complex phase behavior similar to that of amphiphilic systems. A key factor for the compatibilizing effect is the dynamics of the diblock copolymers at the interfaces. We have studied the dynamics in the bicontinuous microemulsion phase of the poly(ethyl ethylene)/poly(dimethylsiloxane) (PEE/PDMS) system. Using dynamic light scattering, several dynamic processes were observed [1], but not all of them are fully understood. As an additional technique for studying the diffusional processes we have used pulsed field gradient NMR. By comparison with the diffusivities of the parent homo- and diblock copolymers, we have found that the diffusion of PDMS homopolymer and of the PEE-PDMS diblock copolymer through the melt are at the origin of the two fast and weak processes observed in dynamic light scattering.
[1] T.L. Morkved et al., Faraday Disc. 112(1999)335.