Polymerization-inactive complexes of ions

Coordination of molecules to some part of an ionic active centre may increase its activity or it may lead to its complete deactivation. The detailed structure and properties of these C and C complexes are not suf- 

Already the equilibrium (77) has described the loss of the polymerization activity of a certain part of the centres by interaction of growing ends of equal basicity. Therefore we have called this reaction Usobasic termination . An addition of alkali metal hydroxides to the initiator (potassium hydroxide) 

Which themselves initiate polymerization of cyclic siloxanes. 

Much more stable complexes are formed from silanolate active centres and oxides, hydroxides or partly dehydrated hydroxides of amphoteric metals [106]. A polymer whose centres have been complexed in this way is completely resistant to depolymerization even at 523 K. This situation is illustrated in Fig. 10. 

The transformation of reactive centres to stable complexes may be of considerable practical importance. The expensive washing out of initiator residues can be substituted by their complexation. Suitable procedures and agents will also be sought for other ionic and coordination polymerizations. 

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