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 18.5: Poster
Wednesday, April 4, 2001, 12:30–15:00, AT1
Determination of the binodal and spinodal decomposition temperatures in the blend system Luran/Lucryl with positron annihilation lifetime spectroscopy — •Katja Günther-Schade1, Dirk W. Schubert2, and Franz Faupel1 — 1Technische Fakultät der Universität Kiel, Kaiserstr. 2, 24143 Kiel — 2GKSS Forschungszentrum, Max-Planck-Str., 21502 Geesthacht
Luran (PαMS0,5-co-AN0,5) is a statistical copolymer made up of equal parts of αmethyl styrene and acrylonitrile. Lucryl is a PMMA with 5 wt % MA. Luran and Lucryl form a blend system with upper miscibility gap, which is a subject of the IUPAC Working Party “Structure and Properties of Commercial Polymers”.
Positron annihilation lifetime spectroscopy is sensitive to detect small changes of the free volume. Phase separation in polymer blends should be accompanied by a change in free volume. With the current methods only the binodale separation temperature can be detected. Therefore we tried to detect the separation temperatures with temperature dependent “in-situ” measurements. Characteristic changes in lifetime parameters and hence in free volume for different compositions in the blend system Luran/Lucryl could be attributed to the binodal and spinodal decompositions. Comparison to other experiments and theoretical calculations showed good agreement.