Due to the complex character of the thermal degradation of polymers as a solid-gas chain reaction, an unequivocal kinetic
characteirzation is possible only for stationary states of both radical concentration and reaction mechanism. These conditions
are hardly realizable in non-isothermal thermogravimetry. Additional the weight losses are depedent on the volatility of the
reaction products. That is not always certain in polymer degradation. As a consequence the deduced ‘kinetic parameters’ are
not unequivocal. They are conversion and heating rate dependent and may be influenced by sample shape and size. Thus the ‘kinetic
parameters’ are in fact from the point of view of mathematics the fitting parameters of a ‘rate equation’ like relation, specific
for the used reaction conditions only. From the point of view of chemical kinetics they are neither attributable to a determined
reaction mechanism nor can they be used for predictions.