Comparative study of the integral TG methods used in the invariant kinetic parameter method. Application to the fire-retardant polypropylene

the computation of invariant kinetic parameters : activation energy and preexponential factor, from thermogravimetric analyses is carried out using three integral methods. It allows to test the probability of different kinetic functions. In the case of an intumescent polypropylene based formulation, eighteen degradation functions are compared. It is shown that the formation of the intumescent material cannot be described by one single mode of degradation. It is proposed that the interaction polymer matrix - additives creates a new material presenting fire-retardancy properties.