Journal Article

FZJ-2013-00648

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Composition and long-range Density Fluctuations in PEO/PMMA Polymer Blends - a Result of asymmetric Component Mobility

Schwahn, D. (Corresponding author)FZJ* ; Pipich, V.FZJ* ; Richter, D.FZJ*

2012
Soc. Washington, DC

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Please use a persistent id in citations: doi:10.1021/ma2019123

Abstract: Fluctuations of density and composition were observed in the disordered regime of a symmetric poly(ethylene oxide) (PEO) and a poly(methyl methacrylate) (PMMA) polymer blend. This blend is of particular interest as the glass transition (TG) of both polymers happens at very different temperatures thereby inducing a dynamic asymmetry in the molecular dynamics. Small-angle neutron scattering and oscillatory shear rheology were the principle experimental tools. Composition fluctuations determined the Flory–Huggins parameter as well as glass and gelation temperature (TA). The density fluctuations are of long-range and show a mass fractal dimension whose strength enlarges below the glass transition. A fairly constant TA about 40 K above TG separates two regions of distinctively different fluctuation behavior. A comparison of viscoelastic plateau modulus and high frequency modulus determined from rheology and SANS show that the relaxation modes in the regime between TG and TA are determined by the freezing segmental modes of PMMA.

Keyword(s): Basic research (1st) ; Others (1st) ; Soft Matter, Macromolecules, Complex fluids, Biophysics (1st) ; Soft Condensed Matter (2nd)

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Contributing Institute(s):

1. Neutronenstreuung (Neutronenstreuung ; JCNS-1)
2. JCNS-FRM-II (JCNS (München) ; Jülich Centre for Neutron Science JCNS (München) ; JCNS-FRM-II)
3. Neutronenstreuung (ICS-1)

Research Program(s):

1. 451 - Soft Matter Composites (POF2-451) (POF2-451)
2. 54G - JCNS (POF2-54G24) (POF2-54G24)
3. 544 - In-house Research with PNI (POF2-544) (POF2-544)

Experiment(s):

1. KWS-1: Small angle scattering diffractometer (NL3b)
2. KWS-2: Small angle scattering diffractometer (NL3ao)

Appears in the scientific report 2012

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Database coverage:
; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection ; Zoological Record

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