jp500183y_si_001.pdf (181.04 kB)
Ion and Chain Mobility in a Tetrazole Proton-Conducting Polymer
journal contribution
posted on 2014-04-03, 00:00 authored by R. Casalini, B. L. Chaloux, C. M. Roland, H. L. Ricks-LaskoskiThe morphology, relaxation properties,
and conductivity of the statistical copolymer polystyrenic (alkoxy
1H-tetrazole-co-alkoxy nitrile),
an anhydrous proton conductor, were measured. The material phase-separates
into hard and soft domains, the latter corresponding to a phase richer
in the pendant tetrazole groups. Using dielectric and mechanical spectroscopies,
two relaxation processes were observed, the slower associated with
local segmental dynamics of the backbone and the higher-frequency
process involving motion of the tetrazole moieties. The latter is
coupled to the ionic conductivity, which means that below the principal
glass transition of the material (∼313 K) the conductive mechanism
remains active. Thus, the usual compromise in proton exchange membranes
between mechanical stability and ion conductivity can be avoided.