2.1.4

The applet at left employs the Flory distribution to model the weight average and number average molecular weight distributions for step growth polymerizations.  It is therefore necessary to supply the values of M0, the molecular weight per repeat unit, and p, the extent of reaction where
0 ≤ p < 1, in order to view the distributions.  In addition to the distributions, the applet calculates the average molecular weight for the selected plot and also displays the polydispersity in the form <Mw> / <Mn> when both plots are selected.

Some things to investigate:

  • Are the shapes of the plots a function of M0?
  • Are the shapes of the plots a function of p?
  • What happens to the ratio <Mw> / <Mn> (ie the polydispersity) as p approaches 1 (100% completion)?
  • What is the maximum value of the polydispersity?
  • Why are the shapes of the two plots different?