Molecular weight theoretical predictions

Another sampling effect which deserves mention is that since the molecular weight distribution shifl towards higher molecular weights with conversion, a slice will not in general contain proportionate amounts of polymer from all conversions. This dufting can be accounted for in the theoretical predictions by incorporating it into cumulation of the instantaneous property distributions (e.g. Equation 8). 

Many QSPR models rely on some sort of idealized theoretical model for the transport of a molecule through the skin barrier. The descriptors necessary for predicting skin permeability—usually molecular weight and the octanol-water... 

Fig. 14. Data (points) for G (co) and G (co) for a range of compositions of a blend of two polyisoprene stars of molecular weights 28 and 144 kg mol The fractions of the bigger star are in order 0.0,0.2,0.5,0.8 and 1.0. Curves are theoretical predictions of the tube model with co-operative constraint release treated by dynamic dilution [56]. The choice of 2.0 rather than 7/3 for the dilution exponent p is compensated for by taking M = 5500 kg mol" ...

This theoretical model allows to predict the variation of complexation degree 6 and the molecular weight of the complex versus PAA concentration, molecular weight of the primary chains (PAA, polybase), concentration ratio r - [polybase]/[PAA], acrylate ratio p, and the minimvim chain length 1 (27). The theoretical predictions about the evolution of the system are confirmed by experimental results. For instance, in figure 12 (DP ). - which is the num-... 

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