Analysis of thermal decomposition behaviors with consecutive reactions by TG

Thermal decomposition behaviors of a fluororubber are observed with linear heating mode at constant rate, controlled rate mode and isothermal mode of TG/DTA, and, with isothermal mode of TG/mass-spectrometer. The results sugg est that this material decomposes with, at least, three consecutive reactio ns. From the results of TG/DTA and TGMS in isothermal mode, it is considere d that the first reaction is the first-order reaction, the second reaction is chain reaction and the last reaction is vaporization of residue. Supposi ng these three consecutive reactions, the decomposition behaviors of the ru bber is simulated. The observed curves of fraction of mass loss, alpha, aga inst time, t, are well reproduced by the simulation. The relationship betwe en d alpha/dt and alpha is reproduced also, though the differences between observed and the calculated values of d alpha/dt are slightly larger than n oise level of d alpha/dt. (C) 2000 Elsevier Science B.V, All rights reserve d.