Abstract
A method for the synthesis of phenyl phosphonic acid functionalized poly[aryloxyphosphazene] membranes is described. Membranes of polymers with total ion-exchange capacities between 1.17 and 1.43
meq.
g
−1 were cast from
N,
N-dimethyl-formamide and found to have proton conductivities between 10
−2 and 10
−1
S
cm
−1. Equilibrium water swelling values were determined to be between 11 and 32% depending on the polymer structure. Methanol diffusion coefficients for both radiation cross-linked and non-cross-linked membranes in 3
M aqueous methanol at 80
°C and 2.8
bar were found to be at least 12 times lower than for Nafion 117, and 6 times lower than for a radiation cross-linked sulfonated polyphosphazene membrane.
