Polymerization termination by disproportionation

The theoretical molecular weight distributions for cationic chain polymerizations (see Problem 8.30) are the same as those described in Chapter 6 for radical chain polymerizations terminating by disproportionation, i.e., where each propagating chain yields one dead polymer molecule. The poly-dispersity index (PDI = DP /DPn) has a limit of 2. Many cationic polymerizations proceed with rapid initiation, which narrows the molecular weight distribution (MDI). In the extreme case where termination and transfer reactions are very slow or nonexistent, this would yield a very narrow MDI with PDI close to one (p. 681). 

The theoretical molecular weight distributions for cationic chain polymerizations (see Problem 8.25) are the same as those described in Chapter 6 for radical chain polymerizations terminating by disproportionation, i.e., where each propagating... 

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