Critical temperature(Tb) of thermal explosion for energetic materials is estimated from Semenov's thermal explosion theory and the non-isothermal kinetic equation da/dt=Aoexp(bT)[1+(T-T0)b][(a) deduced via reasonable hypotheses, where To is the initial point of the deviation from the baseline of DSC curve. The final formula is (Tb-Te0){ 1+1/[1+( Tb-T00)b]}=1. We can easily obtain the initial temperature(T0/) and onset temperature(Tci) from the non-isothermal DSC curves, the values of Too and Tc0 from the equation TOi or ei=T00 or c0+α1βi+a2βi^2+…+aL-2L-2βiL-2, i=1,2,…L, the value of b from the equation: In[β/(Tei-T0i)]=ln[A0/G(a)]+bTei, so as to calculate the value of Tb. The result obtained with this method coincides completely with the value of Tb obtained by Hu-Yang-Liang-Wu method.
A method of estimating the kinetic parameters and the critical rate of temperature rise in the thermal explosion for the autocatalytic decomposition of 3,4-bis(4'-nitrofurazan-3'-yl)-2-oxofurazan (BNFOF) with non-isothermal differential scanning calorimetry (DSC) was presented. The rate equation for the decomposition of BNFOF was cstablished, and information was obtained on the rate of temperature increase in BNFOF when the empiric-order autocatalytic decomposition was converted into thermal explosion.
The kinetic parameters of the exothermic decomposition reaction of s-Tripicryaminotrinitrobenzene under linear temperature rise condition are studied by means of DSC. The results show that the empirical kinetic model function in differential form, apparent activation energy and pre-exponential constant of the reaction are 225.4 kJ·mol-1 and 1 019.53 s-1, respectively. The critical temperature of thermal explosion of the compound is 267.36 ℃.