The kinetic analysis of the thermogravimetric curves for the thermal decomp
osition processes of polyaniline in undoped and doped state (udpan and dpan
) was performed. Various forms of non-isothermal methods of analysis for de
termining the kinetic parameters were used. The results show that the appar
ent activation energies for both udpan and dpan in static air are 126.5 and
78.5 kJ mol(-1), and those in N-2 are 45.2 and 36.6 kJ mol(-1), respective
ly. The mean reaction orders obtained from integral method for udpan and dp
an in static air are 2.1 and 2.0, and those in N-2 are 1.9 and 2.1, respect
ively. Therefore the reaction function f(alpha) = (1 - alpha)(2) for the th
ermal decomposition of both udpan and dpan is reasonable. The thermal decom
position processes for udpan and dpan in N-2 may be a random degradation of
polymer chain, whereas in air it should be an oxidation degradation involv
ing the participation of oxygen. Thus the maximum of reaction rate in nitro
gen is only 20-26% of those in air and the apparent activation energies for
them are only 1/2-1/3 of those in air. But the temperatures corresponding
to the maximum reaction rate are higher by about 230-320 K than those in ai
r. (C) 2000 Elsevier Science B.V. All rights reserved.