Rate Distribution and Averages of Bimodal Polymer

Rate constants A mixture of two narrow PS (Mw/Mn 1.03) with molar masses of Mw 1 = 48 kg/mol and Mw2 = 556 kg/mol at equal concentrations (c0 1 = c0 2 0.0029 j, dissolved in ethylacetate, has been used as a simple model system for a broad molar mass distribution [37]. To investigate the influence of exposure time, an exposure series with 0.025 s 2 s has been recorded, and the re- 

The main part of Fig. 13 shows the average rate (77, which closely follows the theoretical curve with the asymptotic values (r)c in the short and (r)c/r in the long exposure limit. There are no free parameters for the theoretical curve since the individual diffusion rates were obtained from the independently determined scaling relation for the diffusion coefficient, D = 2.76 X 10 4 cm2s x M° 525. 

The two modes could be recovered for all values of xp. Despite the exposure time dependent average rate (T) in Fig. 13, the two rates and F2 are almost independent of Xp, and there is a good agreement between the measured values and the ones calculated from the scaling relation, as shown in Fig. 15. 

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