Determination of Degradation Apparent Activation Energy Values of Polymers Regression of kinetic parameters derived from TG Data

The isothermal degradation of three aromatic polyetherketones was studied in an inert environment at various temperatures in the range 683-803 K. In the first degradation stage (mass loss D20%) a linear increase of D as a function of heating time (t) was observed and the corresponding kinetic D=Do+t equations at various temperatures were directly drawn by smoothing the experimental TG data. The values, which represent the mass loss rates during degradation, increased as a function of temperature according to Arrhenius-type equations, from which degradation Ea values were determined, which appear in agreement with those from literature methods. Some differences observed were discussed and interpreted.