Results for forced Rayleigh scattering on 0.3% PEO- in a PMMA-10 matrix at selected temperatures. The extracted mean relaxation time is plotted as a function of the squared grating spacing . The solid lines indicate the fit of Eq. (4) to the data.
Zero shear viscosity as a function of temperature for PEO-1 (●) and PMMA-10 (∎). The error bars on the PEO-1 data represent standard deviations from time averaging the experimental viscosity signal.
Complex viscosity as a function of frequency of tracer blends at selected temperatures. (a)–(d) 1% PEO- PMMA-10 blend (filled symbols) and for PMMA-10 homopolymer (open symbols), (e)–(h) 1% PEO- PMMA-10 blend (filled symbols) and for PMMA-10 homopolymer (open symbols). is denoted by circles and by squares. The dotted line is equal to , which is approximately the threshold below which cannot be experimentally resolved. The insets in (c), (d), (g), and (h) plot as a function of ; the frequency range containing the relaxation process attributed to the PEO tracer is designated with arrows in the insets.
(a) Monomeric friction factor as a function of temperature for the PEO homopolymer, PMMA homopolymer, and the PEO tracers in the PMMA matrix. The error bars for the PEO-1 data are propagated from the reported error for viscosity (see Fig. 2). The error bars for the tracer rheology data points are estimated from the range of frequencies over which the tracer terminal relaxation occurs (see the insets of Fig. 3). The solid line is a fit of the WLF equation to the PEO tracer diffusion and rheology data; the fitting parameters are , , , and . To enable a direct comparison between the temperature dependences of the PEO tracer and the PMMA matrix, the WLF equation was vertically shifted by a factor of 30 (dotted line). (b) Comparison between global and segmental dynamics for the PEO homopolymer and PEO tracer in a PMMA matrix. The monomeric friction factor extracted from terminal dynamics , the apparent monomeric friction factor extracted from segmental dynamics , and the monomeric friction factor for diethyl ether are plotted as a function of temperature. The factor of 3 is an arbitrary shift factor chosen to overlay the PEO homopolymer global dynamics data (●) and the homopolymer segmental dynamics (solid line). The segmental dynamics data are from Ref. 18. The data used to calculate for diethyl ether come from Ref. 21.
Attempted time-temperature superposition for PEO tracer blends. is plotted as a function of reduced frequency for (a) the 1% PEO- PMMA-10 blend and (b) the 1% PEO- PMMA-10 blend. In both cases, a reference temperature of is used.
Diffusion coefficients for PEO- in the PMMA-10 matrix.
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