Über den einfluß der aufheizgeschwindigkeit auf die kinetik des thermogravimetrischen abbaues von polymeren

An explanation for the observed influence of the heating rate on the activation energy of thernimogravimetric polymer destruction is presented in this work. Thereby it is shown, that for complex reactions (thus also for depolymerisations) the known displacement of the domain of destruction temperatures with the heating rate may not remain parallel, if there exists an influence of the conversion degree on the activation energy. Because the impossibility of stationarity in thermogravimetric conditions, complex reactions will show every-time such influences. However, a modification of the slope of the conversion curves for various heating rates determines a modification of the temperature coefficient and thus of the activation energy. The thermogravimetric method becomes in this way an useful one to distinguish between elementary and complex reactions, because elementary processes will not show a conversion dependence of the activation energy and therefore in this case neither the displaced conversion curves, are showing an variation of the slope, nor the activation energy a modification with heating rate.