Accession Number:

ADA242259

Title:

Electrochemically Initiated Chain Polymerization of Pyrrole in Aqueous Media

Descriptive Note:

Technical rept. 1 Jun-30 Sep 91,

Corporate Author:

TEXAS UNIV AT ARLINGTON CENTER FOR ADVANCED POLYMER RESEARCH

Personal Author(s):

Report Date:

1991-10-21

Pagination or Media Count:

34.0

Abstract:

The electrochemical quartz crystal microbalance has been employed to investigate the electropolymerization of pyrrole in a variety of aqueous electrolytes. In contrast to the generally accepted cation-radical coupling process for the electropolymerization of pyrrole, an electrochemically initiated chain polymerization, featuring a high polymerization rate and involving little charge transport, was found under specific conditions in the presence of ClO4- BF4-, and PF6- electrolytes. The more typical cation-radical coupling mechanism, characterized by a constant polymerization charge to mass deposited ratio, is observed in the presence of Cl-, NO3-, dodecyl sulfate, copper phthalocyanine tetrasulfonate, Beta-cyclodextrin tetradecasulfate, and polystyrene sulfonate. Electrochemical characterizations of polypyrrole films prepared in aqueous ClO4- electrolytes reveal that the polymer formed via chain polymerization exhibits the ability to transport both cations and anions during electrochemical switching between redox states, while the polymer synthesized through cation- radical coupling is only capable of transporting a single ionic species.

Subject Categories:

  • Polymer Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE