Prediction of Polydispersity Indexes

Shroff and Mavridis [56] examined the simpler problem of inferring a single polydispersity parameter from various types of rheological data. They considered several parameters in addition to the polydispersity index MJMJ, including the polydispersity index of relaxation times originally defined by Graessley [57]. This is the ratio of average relaxation times defined by Eqs. 4.56 and 4.57. 

It is useful to group the various methods into three categories. 

A) Models based on an empirical transformation from rheological material function to molecular weight distribution (viscosity models and modulus models) 

B) Models based on double reptation without taking into account other relaxation mechanisms. (Mead, Wasserman) 

C) Models including Rouse relaxation (L onardi etal. Carrot and Guillet, Ruymbeke etal.) 

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