Ionic polymerization triple ions

One of the first examples of Intramolecular Interactions In anionic polymerization was encountered In the propagation of two-ended polystyrylceslum In THF (28). Intramolecular triple ions are formed which Increase the Ionic conductance but lower the propagation rate. Reactive free anions associate with ion Pairs on the same chain to form less reactive triple Ions. 

If the solutions contain ion pairs and free ions, the slope should be —0.5 (29). If triple ions coexist with these. ionic species, the slope value shifts toward +0.5. From this, it is suggested that triple ions contribute to the polymerization in these particular solvent systems. 

In ionic polymerizations the non-terminated end-groups may exist in a variety of interchangeable states such as of free ions, various ion-paus, triple ions, quadrupoles, etc. Each polymeric end-group exists in each accessible state for some time and in that period it contributes to propagation as required by its momentary character. Hence, the observed propagation constant kp is given by... 

These condensation reactions are not restricted to the C==C double bond systems but seem to be quite general for C=C triple bonds, C—O double bonds, and C=N double bonds. In only some cases, however, is the long-chain product found quite frequently double molecules or small rings are produced instead. Studies of the details of these polymerizations, as we vshall now refer to them, show that there are two mechanisms which can usually be distinguished from one another. One of these is an ionic mechanism which may proceed by the addition of an ion to one end of the double bond and so lead to the formation of an ion which can now add to the double bond of another molecule to start a chain ... 

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