POLYANILINE SYNTHESIZED IN PROPYLENE CARBONATE MEDIUM IN THE PRESENCEOF DI-CHLOROACETIC AND TRI-CHLOROACETIC ACIDS - PART I - POLYMER GROWTH-STUDIES

In this work the electrochemical synthesis of polyanilne (PAni) in pro pylene carbonate (PC) medium in the presence of lithium perchlorate an d di- (DCA) and tri-chloroacetic (TCA) acids was studied. In order to determine the best experimental conditions to grow an electroactive fi lm of PAni by cyclic voltammetry, the effects of the supporting electr olyte and acid concentration were analysed. These experiments allowed us to conclude that although the degradation processes associated with the polymer are always present for both acids they are much stronger for DCA, probably due to its dimerization capability. In the presence of TCA a maximum ratio between polymer growth and polymer degradation was achieved. For aniline concentrations of 0.25 M and 0.5 M LiClO4, t he electroactive PAni growth occurs only for acid concentrations highe r than 1 M and 2 M, respectively for TCA and DCA. (C) 1997 Elsevier Sc ience Ltd.