Synthesis of cyclolinear phosphazene-containing polymers via ADMET polymerization

We report here a new method for the synthesis of cyclolinear organic-inorganic polymers with phosphazene rings in the main chain structure by the use of ADMET polymerization. In this work, cyclic phosphazene trimers bearing two nongeminal alkene chains were prepared. Both of the alkene chains have a terminal double bond that together form the diene structure required for ADMET polymerizations. The remaining four substituents were varied to include phenoxy, benzyloxyphenoxy, methoxyethoxyethoxy, and dimethylamino groups. The resultant polymers are well-defined, low-polydispersity materials with phosphazene cyclic trimers uniformly incorporated into the backbone structure. The variation of substituents on the phosphazene ring affects both the polymerization and the properties of the resultant polymers.