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A study of acid/base treatments of polypyrrole films using 13C n.m.r. spectroscopy

journal contribution
posted on 01.01.1995, 00:00 authored by Maria ForsythMaria Forsyth, V T Truong
Electrodeposited polypyrrole films prepared with paratoluenesulfonate (pTS), dodecylsulfate (DDS) and perchlorate anions were treated with acidic and basic solutions, and their structure was investigated by 13C solid state n.m.r. spectroscopy. This technique has confirmed that pTS is completely removed from the film in both acidic and basic solutions whilst DDS is only partially removed and tends to decompose upon treatment with H2SO4. The appearance of shoulders at 143 ppm upon treatment with 0.5 M base indicates formation of a quinoid pyrrole structure. Substitution on the β-carbon by OH cannot be confirmed from the present spectra. Stronger base causes a more dramatic change in the polypyrrole backbone with an obvious increase in the electron density on the β-carbons, consistent with the reduction of the carbon backbone. There is no indication of quinoid units in this case. Acid treatments result in considerable broadening of the main 127 ppm polypyrrole peak.

History

Journal

Polymer

Volume

36

Issue

4

Pagination

725 - 730

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.