Polymer thermogravimetric analysis: effects of chain-end and reversible random scission

A new approach to polymer pyrolysis kinetics is based on moments of a popul ation balance equation describing chain-end and random scission and repolym erization. Two equations for the zero and first moments (moles and mass) ar e solved for isothermal and nonisothermal (linear T increase) thermogravime tric analysis. The isothermal case is shown to have a simple relationship t o an empirical acceleratory model, thus revealing its limitations and appro ximations. With realistic values of prefactors and activation energies, the new theory compares well with experimental data for polyether-ether-ketone pyrolysis. (C) 2001 Elsevier Science Ltd. All rights reserved.