A series of mixed-substituent poly(organophosphazenes) with ethyleneoxy side groups has been synthesized. These polymers possess multiple electron-donor coordination sites that can form complexes with metal salts and generate "solid electrolyte" behavior. The polymers were characterized by 31 P, 1 H, and 13 C NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and elemental analysis. All the mixed-substituent polymers have low glass transition temperatures, from -70 to -56 °C, as well as at least one melting transition. Several polymer-lithium triflate complexes were examined by impedance analysis. The maximum conductivities for these polymers ranged from 1.6 × 10 -6 to 3.9 × 10 -5 S cm -1 .
The synthesis of new hybrid polyphosphazene−siloxane
polymers is described. These
polymers contain a polyphosphazene backbone and
[(N-methylamino)propyl]siloxane side groups,
−N(Me)(CH2)3SiMe2OSiMe3
or
−N(Me)(CH2)3SiMe2OSiMe2OSiMe3,
in ratios of 1:1 and 1:3 with trifluoroethoxy,
2-(2-methoxyethoxy)ethoxy, or p-methylphenoxy
cosubstituents. The synthetic method utilized allows
the polymer properties to be tuned by variations in the cosubstituent
ratios. The polymers were
characterized by 31P, 13C, and 1H
NMR, differential scanning calorimetry (DSC), gel
permeation
chromatography (GPC), and elemental analysis. The percent loading
of siloxane-containing side groups
and the nature of the cosubstituents were correlated to the glass
transition temperatures. The glass
transition temperatures ranged from −83 to −22 °C. The
longer, trisiloxane-containing units generated
lower glass transition temperatures than did the analogous polymers
with disiloxane-containing side
groups. Several polymers were further characterized by dynamic
mechanical analysis (DMA). In addition
to glass transition temperatures, other transitions attributed to the
siloxane side groups were detected
at approximately −124 °C.
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