Three different polynorbornenes (PNB) with pendent cyclotriphosphazene side units that bear different short-chain oligoethyleneoxy side groups were synthesized via ring-opening metathesis polymerization (ROMP). Polymers with methoxyethoxy (−OCH2CH2) n OCH3 (n = 1), di(ethylene glycol) methyl ether (n = 2), and tri(ethylene glycol) methyl ether (n = 3) were synthesized and characterized by multinuclear NMR, GPC, DSC, and elemental analysis. The solid polymers were complexed with LiSO3CF3 and LiN(SO2CF3)2 (10−60% molar ratios), and the ionic conductivities were measured by impedance analysis as a function of temperature. The polymers with methoxyethoxy side units showed no detectable ambient temperature conductivities within the limitations of the impedance analyzer. The conductivities of the other polymer electrolytes increased as the concentration of salt was increased, with similar maximum conductivities found for the di(ethylene glycol) and tri(ethylene glycol) systems (2.1 × 10-5 S/cm at 30 °C with the use of 40 mol % LiN(SO2CF3)2 in both cases). The conductivities showed non-Arrhenius temperature dependence. No melting or crystallization transitions were detected at temperatures above 25 °C for any of polymer−salt complexes tested. Modification of one polymer with −O(CH2CH2O)3CH3 side chains was carried out by epoxidation of the backbone CC bonds.

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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.

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The synthesis of well-defined cyclolinear phosphazene polymers via acyclic diene metathesis (ADMET) has been demonstrated. This work extends the range of properties achievable in cyclolinear phosphazenes synthesized via ADMET and provides an assessment of the synthetic limitations. A series of tetraphenoxy and tetramethoxyethoxyethoxy functionalized phosphazene trimers have been synthesized that bear two alkene side chains, which together form the diene structure necessary for ADMET. The alkene chains vary in length from three carbons to 11 carbons. This has allowed the influence of the negative neighboring group effect to be examined as well as steric factors as they apply to the metathesis of phosphazene monomers. Moreover, the role of different catalysts is discussed together with the influence of the nonolefinic phosphazene substituents on the reactivity of the monomers. The influence on bulk polymer properties of the incorporation of different amounts of cyclic phosphazene per average polymer chain, through copolymerization studies with decadiene, is also discussed.