Thermal lifetime evaluation of polymeric materials exhibiting a compensation effect and dependence of activation energy on the degree of conversion

It is shown that the estimation of thermal lifetime of polymeric materials from In t vs (1/T) straight line plots is not justified theoretically. It is considered that the thermal lifetime can be estimated by using a kinetic equation derived from the degradation rate equation given by Dakin and considering that the material shows a compensation effect and an activation energy dependent on the degree of degradation. The conclusions derived from the theoretical considerations are checked for the thermal degradation of polychloroprene rubber.