Based on the analysis of the authors' own experimental data on the che
mical oxidative polymerization of aniline (ANI), as well as on the res
ults of other authors on the electrochemical oxidation of ANI and the
electrochemical response of the polyaniline (PANI) film obtained, the
conclusion has been drawn that the polymerization of ANI can be consid
ered both as a cationic polymerization and as a normal redox process.
Summarizing, the conditions of initiation, propagation and termination
of the chains can be expressed by the value of the electrochemical po
tential (EP) of the system. When the EP is kept at a value higher than
c. 0.55V, the polymerization can be regarded as a living cationic pol
ymerization. In this case, PANI with an oxidation state (OS) higher th
an emeraldine is obtained. Thermodynamically reversible termination ta
kes place when the EP of the system drops to a value less than c. 0.5V
. In this case, the oxidative polymerization of ANI can be regarded as
a quasi-living cationic polymerization, and PANI of emeraldine OS is
obtained.