Solvent reorientation dynamics in Aroclor/polymer solutions
Dynamic light scattering experiments have been conducted in order to probe the orientational dynamics of the solvent Aroclor (A1248) in solutions containing either 1,2- or 1,4-polybutadiene (PB). The measurements of the orientational time correlation functions C VH(t) were carried out over the temperature range 262–233 K and polymer concentrations of up to 25%. C VH(t) is described by a unimodal distribution of solvent relaxation times near T g and the width of the distribution increases with the addition of the polymer. The solvent reorients faster in the presence of the polymeric solute. These results are described in terms of the Kohlrausch-Williams-Watts (KWW) relaxation function with exponent β=0.64 for A1248, 0.58 for a 20% 1,2-PB (M w=4300)/A1248 solution and discussed in terms of the coupling scheme of relaxation.
Key wordsSolvent modification dynamic light scattering coupling model
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