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Enhanced thermal properties and morphology of ion-exchanged polypyrrole films

journal contribution
posted on 01.05.1995, 00:00 authored by V T Truong, B Ennis, Maria ForsythMaria Forsyth
The thermal stability of electrochemically prepared polypyrrole (PPy) films with p-toluenesulfonate (pTS) or perchlorate (ClO4) counterion (PPy/pTS and PPy/ClO4) is improved by simple treatment with aqueous sulfuric acid, sodium sulfate or sodium bisulfate. The degree of stabilization achieved depends on the solution, temperature and duration of treatment. Although the mechanism for improved stability is not yet clear, it is apparent that the level of ion exchange and the original polymer microstructure are important. A model for the conductivity decay as a function of thickness has been proposed. The early stages of ion exchange are not symmetrical, and diffusion is facilitated at the electrode side of the film. Furthermore, X-ray diffraction shows no evidence of morphological change after treatment of PPy/pTS (43 μm), but in PPy/pTS (12 μm) and PPy/ClO4 (41 μm) films an additional peak is indicative of more ordered structure following treatment. The glass transition temperature, Tg, of PPy/pTS and PPy/ClO4 films obtained by modulated differential scanning calorimetry is approximately 155°C.

History

Journal

Polymer

Volume

36

Issue

10

Pagination

1933 - 1940

Publisher

Elsevier Ltd.

Location

Oxford, England

ISSN

0032-3861

eISSN

1873-2291

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1995, Elsevier Science Ltd.