On thermal decomposition kinetics of poly(ethylene-alt- tetrafluoroethylene) using an autocatalytic model

The thermal decomposition of a commercial poly(ethylene-alt-tetrafluomethylene) (ETFE) Fluon (R) C-88AXP, in nitrogen atmosphere has been carried out using thermogravimetric analysis (TG) with dynamic method at different heating rates. The widely used Kissinger equation, Friedman's and Ozawa analysis are used to estimate the activation energy of the degradation reaction. Method of fitting the dynamic derivative thermogram (DTG) data directly using isothermal kinetic model is adopted and the model parameters have been obtained which could not be acquired by using the conventional methods. The TG data of Fluon (R) C-88AXP could not be described properly using n-order kinetic model but the autocatalytic Kamal model fits the data perfectly. The standard deviations of the calculated mass loss rates from the experimental results decrease from 1.497 x 10(-6) to 0.138 x 10(-6), with a decrease of 91 %, when Kamal model was used instead of n-order kinetics. This indicates that the thermal decomposition of ETFE in nitrogen atmosphere obeys an autocatalytic kinetics.