%A HU Rong-Zu, ZHAO Feng-Qi, GAO Hong-Xu, YAO Er-Gang, ZHANG Hai, WANG Yao, Chang Xiang-Yu, ZHAO Hong-An
%T Method to Determine the Kinetic Parameters of the Autocatalytic Decomposition Reaction and Critical Rate of Temperature Rise of Thermal Explosion of Energetic Materials from DSC Curves
%0 Journal Article
%D 2013
%J Acta Phys. -Chim. Sin.
%R 10.3866/PKU.WHXB201305282
%P 1623-1631
%V 29
%N 08
%U {http://www.whxb.pku.edu.cn/CN/abstract/article_28493.shtml}
%8 2013-07-09
%X To evaluate the thermal safety of energetic materials (EMs) using the critical rate of temperature rise of thermal explosion (d*T*/d*t*)_{Tb} and obtain basic data used to calculate (d*T*/d*t*)_{Tb}, nine expressions to calculate (d*T*/d*t*)_{Tb} for EMs were derived from Semenov thermal explosion theory and nine autocatalytic reaction rate equations, d*α*/d*t*=*A*exp(-*E*/*RT*)*α*(1-*α*) (I), d*α*/d*t*=*A*exp(-*E*/*RT*)(1-*α*)^{n}(1+*K*_{cat}*α*) (II), d*α*/d*t*=*A*exp(-*E*/*RT*)[*α*^{a}-(1-*α*)^{n}] (III), d*α*/d*t*=*A*_{1}exp(-*E*_{a1}/*RT*)(1-*α*)*+A*_{2}exp(-*E*_{a2}/*RT*)*α*(1-*α*) (IV), d*α*/d*t*=*A*_{1}exp(-*E*_{a1}/*RT*)(1-*α*)^{m}+A_{2}exp(-*E*_{a2}/*RT*)*α*^{n}(1-*α*)^{p} (V), d*α*/d*t*=*A*exp(-*E*/*RT*)(1-*α*) (VI), d*α*/d*t*=*A*exp(-*E*/*RT*)(1-*α*)^{n} (VII), d*α*/d*t*=*A*_{1}exp(-*E*_{a1}/*RT*)*+A*_{2}exp(-*E*_{a2}/*RT*)(1-*α*) (VII) and d*α*/d*t*=*A*_{1}exp(-*E*_{a1}/*RT*)*+A*_{2}exp(-*E*_{a2}/*RT*)*α*(1-*α*) (IX), using reasonable hypotheses. A method to determine the kinetic parameters in the nine autocatalytic decomposition reaction rate equations and (d*T*/d*t*)_{Tb} of EMs when autocatalytic decomposition converts into thermal explosion from difference scanning calorimetry (DSC) curves at different heating rates (*β*) was presented. The onset temperature (*T*_{e0}) corresponding to heating rate *β*→0, the critical temperature of thermal explosion (*T*_{b}) and the conversion degree (*α*_{b}) corresponding to *T*_{b} used in the calculation of (d*T*/d*t*)_{Tb} were obtained from analysis of DSC curves. The kinetic parameters of the autocatalytic decomposition reactions in Eqs.(I) and (VI), and Eqs.(II)-(V), (VII)-(IX) were estimated by the linear least-squares method and trust region approach, respectively. The values of (d*T*/d*t*)_{Tb} for EMs were obtained from basic DSC data. Results show that (1) under non-isothermal DSC conditions, the autocatalytic decomposition reaction of nitrocotton (NC) (13.54% N) can be described by the apparent empiric-order equation d*α*/d*t*=10^{15.82}exp(-170020/*RT*)(1-*α*)^{1.11}+10^{15.82}exp(-157140/*RT*)*α*^{1.51}(1-*α*)^{2.51}; (2)The value of for NC (13.54% N) when autocatalytic decomposition converts into thermal explosion is 0.103 K·s^{-1}.