Copolymerization of THF with Propylene Oxide

The copolymerization of THF with PO has partially been described in the section devoted to the reactive oligomers based on poly THF (Chapter 6.5). 

Reversibility of THF homopropagation leads to an additional difficulty in its copolymerization. This reversibility was neglected, however, by several groups and, therefore, erroneous values of rt and r2 resulted (cf. Chapter 6.5). 

The scheme including reversibility is shown by the following set of equations  

In studies of THF/PO copolymerization, except in the cited-above paper28), no attempts were made to consider reversibility of THF homopropagation. 

Below we describe in more detail a reversible copolymerization with the THF/ oxetane pair. 

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Stable trityl salts, which might lead to systems devoid of side reactions, do not however initiate polymerization of the majority of heterocyclic monomers by direct addition The only reported exception is the copolymerization of THF with propylene oxide ... 

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