Estimation of Critical Temperature of Thermal Explosion for Nitrosubstituted Azetidines Using Non‐isothermal DSC

Based on reasonable hypothesis, two general expressions and their six derived formulae for estimating the critical temperature ( T b ) of thermal explosion for energetic materials (EM) were derived from the Semenov's thermal explosion theory and eight non‐isothermal kinetic equations. We can easily obtain the values of the initial temperature ( T 0i ) at which DSC curve deviates from the baseline of the non‐isothermal DSC curve of EM, the onset temperature ( T ei ), the exothermic decomposition reaction kinetic parameters and the values of T 00 and T e0 from the equation T 0i or ei = T 00 or e0 + a 1 β i + a 2 β i 2 +···+ a L −2 β i L −2 , i =1, 2, ;···, L and then calculate the values of T b by the six derived formulae. The T b values for seven nitrosubstituted azetidines, 3,3‐dinitroazetidinium nitrate ( 1 ), 3,3‐dinitroazetidinium picrate ( 2 ), 3,3‐dinitroazetidinium‐3‐nitro‐1,2,4‐triazol‐5‐onate ( 3 ), 1,3‐bis(3′,3′‐dinitroazetidine group)‐2,2‐dinitropropane ( 4 ), 1‐(2′,2′,2′‐trinitroethyl)‐3,3‐dinitroazetidine ( 5 ), 3,3‐dinitroazetidinium perchlorate ( 6 ) and 1‐(3′,3′‐dinitroazetidineyl)‐2,2‐dinitropropane ( 7 ), obtained with the six derived formulae are agreeable to each other, whose differences are within 1.5%. The results indicate that the heat‐resistance stability of the seven nitrosubstituted azetidines decreases in the order 6 > 7 > 5 > 4 > 3 > 2 > 1 .