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The dissolution properties of 2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (Keto-RDX) in dimethyl sulfoxide (DMSO) were studied by using a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. The heat effects, molar enthalpies (Δ diss H), and differential enthalpies (Δ dif H) of dissolution were determined. Furthermore, the corresponding kinetic equations describing the dissolution processes at the four experimental temperatures are dα/dt = 10−2.43 (1 − α)0.63 (T = 298.15 K), dα/dt = 10−2.41 (1 − α)0.67 (T = 303.15 K), dα/dt = 10−2.40 (1 − α)0.75 (T = 308.15 K), and dα/dt = 10−2.38 (1 − α)0.76 (T = 313.15 K). The determined values of the activation energy E and pre-exponential factor A for the dissolution process are 5.99 kJ mol−1 and 10−1.38 s−1, respectively.

6b-Nitrohexahydro-2H-1,3,5-trioxacyclopenta[cd]-pentalene-2,4,6-triyltrinitrate (NHTPN) is an energetic compound with interesting properties. Its thermal and kinetic behaviors were studied by differential scanning calorimetry (DSC), and its specific heat capacity (Cp) was determined by a continuous Cp mode of microcalorimetry (Micro-DSC III). In order to evaluate its thermal safety, the values (Te0 and Tp0) of Te and Tp corresponding to β → 0, critical temperature of thermal explosion (Tbe and Tbp), adiabatic time-to-explosion (tTIad), 50% drop height (H50) of impact sensitivity, critical temperature of hot-spot initiation (Tcr), thermal sensitivity probability density function [S(T)] vs. temperature (T) relation curves for NHTPN with radius of 1 m surrounded with ambient of 340 K, the peak temperature corresponding to the maximum value of S(T) vs. T relation curve (TS(T)max), safety degree (SD) and critical ambient temperature (Tacr) of thermal explosion of NHTPN were calculated respectively, by means of the onset temperature (Te) and maximum peak temperature (Tp) from the non-isothermal DSC curves of NHTPN at different heating rates (β), the apparent activation energy (EK and EO) and pre-exponential constant (AK) of thermal decomposition reaction obtained by Kissinger's method and Ozawa's method, Cp, density (ρ) and thermal conductivity (λ), the decomposition heat (Qd, taking half-explosion heat), Zhang–Hu–Xie–Li's formula, Smith's equation, Friedman's formula, Bruckman–Guillet's formula, Frank-Kamenetskii formula and Wang–Du's formulas.

The enthalpies of dissolution for nitroglycerin in ethanol and ethyl acetate were measured successfully at 298.15 K under atmospheric pressure by designing a special mixing device and using microcalorimetry technology. Empirical formulae for the calculation of the molar enthalpies of dissolution (∆diss H), relative partial molar enthalpies (∆diss H partial), and relative apparent molar enthalpies (∆diss H apparent) were obtained by experimental data analysis and theoretical calculation. Furthermore, the corresponding kinetic equations describing the two dissolution processes are dα/dt = 10−3.21 (1 − α)1.01 in ethyl acetate and dα/dt = 10−3.43 (1 − α)1.02 in ethanol, respectively.

The molar enthalpies of dissolution for 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) in dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K under atmospheric pressure. Empirical formulae for the calculation of the molar enthalpies of dissolution (Δdiss H), relative partial molar enthalpies (Δdiss H partial) and relative apparent molar enthalpies (Δdiss H apparent) were obtained from the experimental data of the dissolution processes of LLM-105 in DMSO or NMP. Furthermore, the corresponding kinetic equations describing the two dissolution processes were dα/dt = 10−2.37(1 − α)0.47 for the dissolution of LLM-105 in DMSO, and dα/dt = 10−2.38(1 − α)0.42 for the dissolution of LLM-105 in NMP.

The effects Fe 2 O 3 nanoparticles on the thermal decomposition of nitrocellulose (NC) have been investigated by the differential scanning calorimetry (DSC) method and the thermogravimetry with Fourier transform infrared analysis (TG-IR). DSC analysis shows that Fe 2 O 3 can be safely used with NC, and the thermal decomposition reactions of Fe 2 O 3 -NC composite and NC follow the same thermal decomposition mechanism of Avrami-Erofeev equation f(α) = 1.5(1–α)[–ln(1–α)] 1/3 in differential form. The as-prepared nanoparticles could reduce the activation energy of the decomposition reaction and the critical temperature of thermal explosion of NC. In addition, TG-IR analysis indicated that Fe 2 O 3 nanoparticles play a crucial role in promoting the O NO 2 bond cleavage and secondary autocatalytic reactions in condensed phase. This contribution suggests that introducing Fe 2 O 3 nanostructure may be a promising way to accelerate the thermal decomposition of NC.

The molar enthalpies of dissolution for potassium salt of bis(dinitromethyl)difurazanyl ether [K2(BDFE)] in N-methyl-2-pyrrolidone (NMP) and water were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K under atmospheric pressure. Empirical formulae for the calculation of the molar enthalpies of dissolution (Δdiss H), relative partial molar enthalpies (Δdiss H partial), and relative apparent molar enthalpies (Δdiss H apparent) were obtained from the experimental data of the dissolution processes of K2(BDFE) in NMP or water. Furthermore, the corresponding kinetic equations describing the two dissolution processes were dα/dt = 10−4.11(1 − α)1.12 for the dissolution of K2(BDFE) in NMP and dα/dt = 10−3.76(1 − α)0.88 for the dissolution of K2(BDFE) in water.

Thermal decomposition kinetics and mechanism of the high-energetic material 5,7-diamino-4,6-dinitrobenzenfuroxan (CL-14) were determined by differential scanning calorimetry (DSC), rapid scanning Fourier transform infrared spectroscopy, and simultaneous thermogravimetric and DSC analyses, coupled with FT-IR and mass spectroscopy. To evaluate the thermal safety of 5,7-diamino-4,6-dinitrobenzenfuroxan (CL-14), its specific heat capacity (C p) was measured by DSC, and thermal conductivity (λ) was estimated. Kinetic parameters and heat of exothermic decomposition reaction of CL-14 were obtained by analysis of DSC curves. Kinetic parameters used to evaluate the thermal safety of CL-14, such as self-accelerating decomposition temperature (T SADT), critical temperature of thermal explosion (T b) and impact sensitivity (H 50), were obtained. Results showed that for CL-14, T SADT = 282.0 °C and T b = 307.9 °C, whereas H 50 = 39.79 cm, revealing that CL-14 had better thermal safety and heat resistance than HMX, RDX and GNTO.

The thermokinetics of the curing reactions between poly-(3-azidomethyl-3-methyloxetane) (PAMMO) and bispropargyl succinate (BPS) were studied using a microcalorimeter. On the basis of experimental and calculated results, three thermodynamics parameters (the activation enthalpies, the activation entropies, the activation free energies), the rate constant, three thermokinetic parameters (the activation energies, the pre-exponential constant, and the reaction order) and the enthalpies of the curing reactions between PAMMO and BPS in the temperature range of 50–65 °C were obtained, showing that the main reaction leading to a triazole structure easily took place in the studied temperature range. The linear relationship between lnk and the molar ratio of triple bonds to azide groups was found. Furthermore, the corresponding kinetic equation describing the curing reaction between PAMMO and BPS was dα/dt=10−4.48(1−α)0.962 at 333.15 K.

The dissolution properties of 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowutrzitane (TEX) in N-methyl pyrrolidone (NMP) were studied with a RD496-2000 Calvet microcalorimeter at four different temperatures. The heat effects were measured for TEX in NMP. The molar enthalpies and the differential molar enthalpies for TEX in NMP were also obtained at the same time. The corresponding kinetic equations that describe the four dissolution processes are dα/dt = 10−2.64(1−α)1.31 (T = 298.15 K), dα/dt = 10−2.58(1−α)1.31 (T = 303.15 K), dα/dt = 10−2.54(1−α)1.51 (T = 308.15 K), dα/dt = 10−2.49(1−α)1.03 (T = 313.15 K), and respectively. The values of activation energy E a and pre-exponential factor A for TEX in the dissolution process are 16.84 kJ mol−1 and 100.32 s−1.

The thermal decomposition behaviors of dihydroxylammonium 5,5′-bistetrazole-1,1′- diolate (TKX-50) were studied by using a C-500 type Calvet microcalorimeter at five heating rates. The kinetic and thermodynamic parameters of the first decomposition reaction were obtained. The specific heat capacity of TKX-50 was determined with a Micro-DSCIII calorimeter, and the specific heat capacity equation and the molar specific heat capacity at 298.15 K were also obtained. The self-accelerating decomposition temperature and the critical temperature of thermal explosion are 466.17 and 475.36 K, respectively. The adiabatic time-to-explosion is calculated to be a certain value between 112.65 and 113.93 s.

The enthalpies of dissolution for dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) in dimethyl sulfoxide were measured using a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. Differential enthalpies (Δdif H) and molar enthalpies (Δdiss H) of dissolution were determined. Furthermore, the corresponding kinetic equations describing the dissolution processes at the four experimental temperatures are dα/dt = 10−2.60(1 − α)1.01 (T = 298.15 K), dα/dt = 10−2.59(1 − α)0.93 (T = 303.15 K), dα/dt = 10−2.58(1 − α)1.36 (T = 308.15 K), dα/dt = 10−2.57(1 − α)1.21 (T = 313.15 K). The determined values of the activation energy E and pre-exponential factor A for the dissolution process are 3.24 kJ mol−1 and 10−2.03 s−1, respectively.

The thermal decomposition behaviors of 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowutrzitane (TEX) were studied by using a C-500 type Calvet microcalorimeter at five heating rates. The kinetic and thermodynamic parameters of exothermic decomposition reaction were obtained. The specific heat capacity of TEX was determined with a Micro-DSC III calorimeter, the specific heat capacity equation and the molar specific heat capacity were also obtained. The self-accelerating decomposition temperature, adiabatic decomposition temperature rise, and critical temperature of thermal explosion are 512.69, 7115.59, and 527.42 K, respectively. The adiabatic time-to-explosion is calculated to be a certain value between 53.69 and 54.05 s.

The effects of nano-CuO particles on thermal decomposition behavior of the copolymer of 3,3′-bis(azidomethy) oxetane and glycidyl azide polymer (BAMO–GAP) were investigated by employing DSC–TG–FTIR–MS coupling technique. The results showed that, when the nano-CuO was dispersed into the BAMO–GAP copolymer, the thermal decomposition temperatures of copolymer was decreased, the apparent activation energy was decreased by 11.2 kJ mol −1 and the apparent decomposition heat increased by maximum 12%. The major gaseous products of BAMO–GAP copolymer and BAMO–GAP/CuO were identified. It was suggested that nano-CuO enhanced the N N bond breaking in azido groups and more N 2 was released. Namely, nano-CuO is a marked kind of catalyst, which has a crucial effect on thermal decomposition of BAMO–GAP copolymer.

An exothermic reaction between aluminum hydride (AlH3) and water was observed in our laboratory. The reaction process of AlH3 and water was studied using a microcalorimeter. The results show that the reaction enthalpies of AlH3 with water and the enthalpies of formation of AlH3 at T = (313.15, 318.15, 323.15, 328.15) K are (−405.10, −405.56, −406.02 and −406.48) kJ mol−1, and (−10.81, −10.59, −10.36, −10.13) kJ mol−1, respectively. The standard enthalpy of formation and standard molar heat capacity of AlH3 obtained by an extrapolation method are −11.49 kJ mol−1 and 45.22 J mol−1 K−1, respectively. The values of activation energy E, pre-exponential factor A and the reaction order n for the reaction of AlH3 and water over the temperature range from 313.15 to 328.15 K are 69.41 kJ mol−1, 108.46 s−1 and about 1.033, respectively.

The enthalpy of dissolution of NNHT in N,N-dimethyl formamide (DMF) was measured by means of a DC08 Calvet microcalorimeter at 298.15 K. Empirical formulae for the calculation of the enthalpy of dissolution (ΔdissH), relative partial molar enthalpy (ΔdissHpartial), and relative apparent molar enthalpy (ΔdissHapparent) were obtained from the experimental data of the enthalpies of dissolution of NNHT in DMF. The kinetic equation that describes the dissolution process of NNHT in DMF at 298.15 K is determined as \( \frac{{{{\rm d}}\alpha }}{{{{\rm d}}t}} = 2.86 \times 10^{ - 3} (1 - \alpha )^{0.94} \).

The thermochemical properties of 2,4-dinitroanisole (DNAN) in N-methy pyrrolidone (NMP) and dimethyl sulfoxide(DMSO) were studied using a RD496-2000 Calvet microcalorimeter at four different temperatures. The heat effects were measured for DNAN dissolved in NMP and DMSO and the relationships between the heat effects and the amounts of the substance were determined. The molar enthalpies and the differential molar enthalpies of dissolution processes were also obtained from the experimental data. The corresponding kinetic equations describing the two dissolution processes at different temperatures were discussed.

The dissolution properties of ammonium dinitramide (ADN) in N-methyl pyrrolidone (NMP) were studied with a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. The heat effects were determined for ADN in NMP. The molar enthalpies and the differential molar enthalpies for ADN in NMP were also obtained at the same time. The corresponding kinetic equations that describe the four dissolution processes are discussed.

Aluminum nanopowders coated with oleic acid (nmAl+OA), perfluorotetradecanoic acid (nmAl+PA) and nickel acetylacetonate (nmAl+NA) were prepared. The combustion characteristics of hydroxyl terminated polybutadiene (HTPB) composite solid propellants containing different coated aluminum nanpowders were investigated. The result shows that the burning rate of the propellant sample containing nmAl+NA is the highest at different pressure, the maximum burning rate is up to 26.13 mm·s-1at 15 MPa. The burning rates of propellant samples containing nmAl+OA and nmAl+PA are almost the same at different pressures, and higher than the propellant samples containing untreated aluminum nanopowders only at the pressure range of 10 ~ 15 MPa. The flame brightness of different propellants under different pressure is not the same. The flame brightness is increased with the pressure increasing. The flame center zone brightness of the propellant containing nmAl+PA and nmAl+NA is brighter under 4 MPa, and the brightness of nmAl+NA is the brightest. The surface coating of aluminum nanopowder has little effect on the combustion flame temperature of solid propellant. The burning surface temperature increases with the pressure increasing.

The thermal behavior of N-2′,4′-dinitrophenyl-3,3-dinitroazetidine (DNPDNAZ) was studied under a non-isothermal conditions by DSC and TG/DTG methods. The apparent activation energy (Ea) and pre-exponential factor (A) of the intense exothermic decomposition reaction of DNPDNAZ were 172.26 kJ · mol−1 and 1013.15 s−1, respectively. The specific molar heat capacity (Cp,m) of DNPDNAZ was determined by a continuous Cp mode of microcalorimetry and theoretical calculation. The detonation velocity (D) and pressure (P) of DNPDNAZ were estimated using the nitrogen equivalent equation according to the experimental density. The free radical signals of DNPDNAZ and 1,3,3-trinitroazetidine (TNAZ) were detected by electron spin resonance (ESR) technique, which is used to estimate their sensitivity.

The expressions to calculate the critical rate of temperature rise of thermal explosion $$ ({\text{d}}T / {\text{d}}t)_{{\text{T}_{\text{b}} }} $$ for energetic materials (EMs) were derived from the Semenov’s thermal explosion theory and autocatalytic reaction rate equation of nth order, CnB, Bna, first-order, apparent empiric-order, simple first-order, Au, apparent empiric-order of m = 0, n = 0, p = 1 and m = 0, n = 1, p = 1, using reasonable hypotheses. A method to determine the kinetic parameters in the autocatalytic-decomposing reaction rate equations and the $$ ({\text{d}}T / {\text{d}}t)_{{\text{T}_{\text{b}} }} $$ in EMs when autocatalytic decomposition converts into thermal explosion from data of DSC curves at different heating rate was presented. Results show that (1) under non-isothermal DSC conditions, the autocatalytic-decomposing reaction of NC (12.97 % N) can be described by the first-order autocatalytic reaction rate equation dα/dt = 1016.00exp(−174520/RT)(1 − α) + 1016.00exp(−163510/RT)α(1 − α); (2) the value of $$ ({\text{d}}T / {\text{d}}t)_{{\text{T}_{\text{b}} }} $$ for NC (12.97 % N) when autocatalytic decomposition converts into thermal explosion is 0.354 K s−1.

The thermal behavior of 3,3-dinitroazetidinium hydrochloride (DNAZ·HCl) was studied at a nonisothermal condition by differential scanning calorimetric and thermogravimetric/differential thermogravimetric methods. The results show that there is only one intense exothermic decomposition process. Its kinetic parameters of the intense exothermic decomposition process are obtained from analysis of the DSC curves. The apparent activation energy (Ea), pre-exponential factor (A), and the mechanism function (f(α)) are 155.72 kJ·mol–1, 1015.84 s–1 and 3α2/3, respectively. The specific heat capacity (Cp) of DNAZ·HCl was determined with a continuous Cp mode of microcalorimeter. The specific molar heat capacity (Cp,m) of DNAZ·HCl was 205.10 J·mol–1·K–1 at 298.15 K. The self-accelerating decomposition temperature (TSADT), thermal ignition temperature (TTIT), and critical temperatures of thermal explosion (Tb) were obtained to evaluate the thermal stability and safety of DNAZ·HCl. The detonation velocity (D) and detonat...

3,5-Dinitrobenzoic acid of 3,5-diamino-1,2,4-triazole (DAT) salt (DAT·DNBA) was synthesized and its structure was characterized by element analysis, IR and single-crystal X-ray diffraction analysis. The thermal behavior was investigated with the methods of differential scanning calorimetry (DSC) and rapid scan Fourier transform infrared spectroscopy (in situ thermolysis/RSFTIR), and the thermal decomposition reaction kinetics was obtained by means of DSC technique at the different heating rate. The results show that there are two mass loss stages at the thermal decomposition process, and the apparent activation energy and pre-exponential factor of the exothermic decomposition reaction of DAT·DNBA obtained by five integral methods (General integral, MacCallum–Tanner, Satava–Sestak, Agrawal, Flynn–Wall–Ozawa) and one differential method (Kissinger) are 226.37 kJ mol−1 and 1014.51 s−1 in the second decomposition stage. According to the change of the bond intensities, it can be deduced that hydronitrogen, oxynitride, and carbonitride should appear in the gaseous products breaking away from the condensed phase of DAT·DNBA. The groups of nitryl, amido and carboxyl have main contribution to some properties of the compound from the result of the quantum chemical calculation. The self-accelerating decomposition temperature (TSADT), thermal ignition temperature (TTIT) and the critical temperatures of thermal explosion (Tb) and the adiabatic time-to-explosion (tTIAD) is obtained as 660.25 K, 677.16 K, 691.70 K and 236 s, respectively. The detonation velocity (D) and pressure (p) were also estimated as 8358.86 m s−1 and 30.19 GPa. The above-mentioned information is quite useful for analysis and evaluating the stability and thermal safety of DAT·DNBA.

1,3-Bis(4-aminophenoxy)benzene (TPER) and poly(amic acid) based on TPER and pyromellitic dianhydride (PMDA) were synthesized. After imidization of the poly(amic acid), polyimide based on TPER and PMDA was obtained. The melting process and the specific heat capacity (C p) of TPER were examined by DSC and microcalorimetry, respectively. The melting enthalpy, the melting entropy, and the C p for TPER were obtained. The enthalpy change, the entropy change, and the Gibbs free energy change for TPER were obtained within 283 and 353 K. The thermal decomposition reaction mechanism of the polyimide is classified from the TG–DTG experimental data, and the thermokinetic parameters of the thermal decomposition reaction are E a = 296.87 kJ mol−1and log (A/s−1) = 14.41.

The thermal hazard of 2,4-dinitroanisole (2,4-DNAN) was evaluated by microcalorimetry methods. The specific heat capacity, melting enthalpy, and the solidification heat of 2,4-DNAN were determined with a Micro-DSCIII calorimeter. The thermal decomposition behavior of 2,4-DNAN at four different heating rates was studied by using a C-500 type calvet microcalorimeter. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow data. The critical temperature of thermal explosion (Tb) and the initial decomposition temperature (Tp0) were determined to distinctly evaluate the thermal hazard of 2,4-DNAN.

The thermal decomposition behavior of composite modified double-base propellant containing hexanitrohexaazaisowurtzitane (CL-20/CMDB propellant) was studied by microcalorimetry. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow curves. The effect of different proportion of CL-20 to the thermal decomposition behavior, kinetics, and thermal hazard was investigated at the same time. The critical temperature of thermal explosion (T b), the self acceleration decomposition temperature (T SADT), and the adiabatic decomposition temperature rise (ΔT ad) were calculated to evaluate the thermal hazard of the CL-20/CMDB propellant. It shows that the CMDB propellant with 38% CL-20 has relative lower values of E and lgA, and with 18% CL-20 has the highest potential hazard.

A method for estimating the critical temperature of thermal explosion for energetic materials using differential scanning calorimetry (DSC) measurement is derived from the Semenov’s thermal explosion theory and the non-isothermal kinetic equation based on Harcourt-Esson’s kinetic equation. The result obtained from this method coincides completely with that of the Hu-Yang-Liang-Wu method.

The properties of dissolution in different solvents, the specific heat capacity and thermal decomposition process under the non-isothermal conditions for energetic triazole ionic salts 1,2,4-triazolium nitrate (1a), 1,2,3-triazolium nitrate (1b), 3,4,5-triamino-1,2,4-triazolium nitrate (2a), 3,4,5-triamino-1,2,4-triazolium dinitramide (2b) were precisely measured using a Calvet Microcalorimeter. The thermochemical equation, differential enthalpies of dissolution (Δdif H m Θ ), standard molar enthalpies of dissolution (Δdif H m Θ ), apparent activation energy (E), pre-exponential constant (A), kinetic equation, linear relationship of specific heat capacity with temperature over the temperature range from 283 to 353 K, standard molar heat capacity (C p,m Θ ) and enthalpy, entropy and Gibbs free energy at 283–353 K, taking 298.15 K as the benchmark for 1a, 1b, 2a and 2b were obtained with treating experimental data and theoretical calculation method. The kinetic and thermodynamic parameters of thermal decomposition reaction, critical temperature of thermal explosion (T b), self-accelerating decomposition temperature (T SADT) and adiabatic time-to-explosion (t) of 1a, 1b, 2a and 2b were calculated. Their heat-resistance abilities were evaluated. Information was obtained on the relation between molecular structures and properties of 1a, 1b, 2a and 2b.

The enthalpies of dissolution of 1,2,4-triazole nitrate in N-methyl pyrrolidone (NMP) were measured using a RD496−2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. Differential enthalpies (ΔdifH) and molar enthalpies (ΔdissH) were determined for 1,2,4-triazole nitrate in NMP. The corresponding kinetic equations that describe the four dissolution processes are discussed.

A novel energetic material, 4,5-dihydroxyl-2-(dinitromethylene)-imidazolidine (DDNI), was synthesized by the reaction of FOX-7 and glyoxal in water at 70 °C. Thermal behavior of DDNI was studied with DSC and TG-DTG methods, and presents only an intense exothermic decomposition process. The apparent activation energy and pre-exponential factor of the decomposition reaction were 286.0 kJ mol−1 and 1031.16 s−1, respectively. The critical temperature of thermal explosion of DDNI is 183.78 °C. Specific heat capacity of DDNI was studied with micro-DSC method and theoretical calculation method, and the molar heat capacity is 217.76 J mol−1 K−1 at 298.15 K. The adiabatic time-to-explosion was also calculated to be a certain value between 14.54 and 16.34 s. DDNI presents lower thermal stability, for its two ortho-hydroxyl groups, and its thermal decomposition process becomes quite intense.

The high-pressure thermal properties and their correlation with burning rates of the composite modified double base (CMDB) propellants containing 3,6-bis (1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz), a substitute of hexogen (RDX), were investigated using the high-pressure differential scanning calorimetry (PDSC). The results show that there is a main exothermal decomposition process with the heating of each propellant. High pressure can restrain the volatilization of NG, accelerate the main decomposition reaction, and make the reaction occur easily. High pressure can change the main decomposition reaction mechanism function and kinetics, and the control process obeys the rule of Avrami–Erofeev equation at high pressure and chemical reaction at normal pressure. However, the mechanism function can not be changed by the ballistic modifier. The correlation between PDSC characteristic values and burning rates was carried out and found that u and $$ \left( {p \, \Updelta H_{\text{d}} { / }\Updelta T} \right)^{ 1 / 2} $$ keep a good linear relation, k u keeps a similar changing trend with u, and it can be used to study the effect of the ballistic modifier or the other component on the burning rates.

The thermal decomposition behaviors of 1,2,3-triazole nitrate were studied using a Calvet Microcalorimeter at four different heating rates. Its apparent activation energy and pre-exponential factor of exothermic decomposition reaction are 133.77 kJ mol−1 and 1014.58 s−1, respectively. The critical temperature of thermal explosion is 374.97 K. The entropy of activation (ΔS≠), the enthalpy of activation (ΔH≠), and the free energy of activation (ΔG≠) of the decomposition reaction are 23.88 J mol−1 K−1, 130.62 kJ mol−1, and 121.55 kJ mol−1, respectively. The self-accelerating decomposition temperature (TSADT) is 368.65 K. The specific heat capacity was determined by a Micro-DSC method and a theoretical calculation method. Specific heat capacity equation is \( C_{\text{p}} \left( {{\text{J mol}}^{ - 1} {\text{ K}}^{ - 1} } \right) = - 42.6218 + 0.6807T \) (283.1 K < T < 353.2 K). The adiabatic time-to-explosion is calculated to be a certain value between 98.82 and 100.00 s. The critical temperature of hot-spot initiation is 637.14 K, and the characteristic drop height of impact sensitivity (H50) is 9.16 cm.

The thermal decomposition behaviors of 3,4,5-triamino-1,2,4-triazole nitrate were studied using a C-500 type Calvet Micro-calorimeter at four different heating rates. Its apparent activation energy and pre-exponential factor of exothermic decomposition reaction are 137.16 kJ mol−1 and 1010.03 s−1. The critical temperature of thermal explosion is 441.37 K. The entropy of activation (ΔS≠), enthalpy of activation (ΔH≠), and free energy of activation (ΔG≠) of the decomposition reaction are −65.65 J mol−1 K−1, 132.97 kJ mol−1 and 166.35 kJ mol−1, respectively. The self-accelerating decomposition temperature (TSADT) is 429.56 K. The specific heat capacity was determined with a Micro-DSC method and a theoretical calculation method. Specific heat capacity (J g−1 K−1) equation is Cp = 0.356 + 2.957 × 10−3T (283.1 K

The thermal decomposition behavior of double-base rocket propellant SQ-2 was studied by a Calvet microcalorimeter at four different heating rates. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow curves. The critical temperature of thermal explosion (Tb), the self acceleration decomposition temperature (TSADT), the adiabatic decomposition temperature rise (ΔTad), the time-to-explosion of adiabatic system (t), critical temperature of hot-spot initiation (Tcr), critical thermal explosion ambient temperature (Tacr), safety degree (SD) and thermal explosive probability (PTE) were presented to evaluate the thermal hazard of SQ-2.

3,3-Dinitroazetidinium picrate (DNAZ⋅PA) was synthesized by adding 3,3-dinitroazetidine (DNAZ) to picric acid (PA) in methanol, the single crystals suitable for X-ray measurement were obtained by recrystallization at room temperature. The compound crystallises orthorhombic with space group P212121 and crystal parameters of a = 0.7655(1) nm, b = 0.8962(2) nm, c = 2.0507(4) nm, V = 1.4069(5) nm3, Dc = 1.776 g cm−3, Z = 4, F(0 0 0) = 768 and μ = 0.166 mm−1. The thermal behavior of DNAZ⋅PA was studied under a non-isothermal condition by DSC and TG–DTG methods. The kinetic parameters of the first exothermic thermal decomposition process were obtained from analysis of the DSC and TG curves by Kissinger method, Ozawa method and the integral method. The specific heat capacity of DNAZ⋅PA was determined with a continuous Cp mode of micro-calorimeter and the standard mole specific heat capacity was 436.56 J mol−1 K−1 at 298.15 K. Using the relationship of Cp with T and the thermal decomposition parameters, the time of the thermal decomposition from initialization to thermal explosion (adiabatic time-to-explosion) was evaluated to be 40.7 s. The free radical signals of DNAZ⋅PA and 1,3,3-trinitroazetidine (TNAZ) were detected by electron spin resonance (ESR) technique to estimate its sensitivity.

The thermal behavior and kinetic parameters of the decomposition reaction of triethylene glycol dinitrate (TEGDN) in a temperature-programmed mode at different pressures (0.1, 2, 4 and 6 MPa) have been investigated by means of DSC and TG-DTG. The results show that the properties of the thermal decomposition of TEGDN are affected by the change of pressure, and the kinetic model function, the apparent activation energy Ea. and pre-exponential factor A of this reaction are 2(1−α)[−ln(1−α)]1/2, 106.54 kJ·mol−1 and 109.17s−1 at 0.1 MPa, and 120.82 kJ·mol−1 and 1010.56 s−1 at 2 MPa, respectively. The critical temperature of thermal explosion of TEGDN obtained by the values Teo and Tpo of the onset temperature Te and the peak temperature Tp when the heating rate tends to zero are 191.05, 209.86 °C at 0.1 MPa, 207.59 and 221.65 °C at 2 MPa, respectively.

The enthalpy change of reaction of zinc chloride with L-α-histidine in the temperature range of 25-50 °C has been determined by a microcalorimeter. On the basis of experimental and calculated results, three thermodynamics parameters (the activation enthalpy, the activation entropy, the activation free energy), the rate constant and three kinetic parameters (the activation energy, the pre-exponential constant and the reaction order) of the reaction, and the standard enthalpy of formation of Zn(His)2+ (aq.) are obtained. The results showed that the title reaction easily took place at the studied temperature.

The complex of Zn(AcO)2·2H2O and threonine was prepared in the mixture solvent of water-acetone, the composition of which was identified as Zn(Thr)(AcO)2·2H2O by chemical and elemental analyses. The complex was investigated by XRD, JR, TG-DTG and DSC methods. The result of TG-DTG shows that the thermal decomposition processes of the complex can be divided into three stages, which were dehydration (I), partial decomposition (II) and complete decomposition into ZnO (III). Dehydration enthalpy was 126.89 kj·mol−1, decomposition enthalpy of the stage (II) was 79.50 kJ·mol−1. The study of non-isothermal kinetics shows that the mechanism of the dehydration stage was Maple Power of n=3/2, the apparent activation energy E was 145.32 kJ·mol−1 and the pre-exponential factor A was 1.4125×1017 s−1, and that of ligand-losting process was nucleation and growth mechanism (Avrami-Erofeev equation n=1/2), its E was 189.33 kJ·mol−1, and A was 3.4674×s−1. The empirical kinetics model equations of the investigated processes were proposed.

The ternary solid complex has been synthesized with sodium diethyldithiocarbamate (NaEt2dtc·3H2O), 1,10-phenanthroline (o-phen·H2O) and hydrated neodymium chloride in absolute ethanol. The title complex was identified as the general formula of Nd(Et2dtc)3(phen) by chemical and elemental analyses. IR spectrum of the complex showed that the Nd3+ coordinated with six sulfur atoms of three NaEt2dtc and two nitrogen atoms of o-phen. It was assumed that the coordination number of Nd3+ is eight. The enthalpy change of liquid-phase reaction of formation, ΔrH (1), was determined as (-12.274±0.050) kJ·mol−1 at 298.15 K by a microcalorimeter, the enthalpy change of the solid-phase reaction of formation, ΔrH (s), was calculated as (149.069±0.314) kJ·mol−1 on the basis of a thermochemical cycle. The thermodynamics of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex, ΔcU, was determined as (-18674.22±8.33) kI·mol−1 by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, ΔcH, and standard enthalpy of formation, ΔfH, were calculated as (-18693.43 ± 8.33) kJ·mol−1 and (-47.03 ± 9.17) kJ·mol−1, respectively.

The kinetic parameters of the exothermic decomposition reaction of the title compound in a temperature-programmed mode have been studied by means of DSC. The empirical kinetic model function in differential form, apparent activation energy (Ea) and pre-exponential factor (A) of this reaction are (1−α)0.222, 225.8 kJ·mol−1 and 1020.21 s−1, respectively. The critical temperature of thermal explosion of the compound is 224.9°C.

The thermal behavior, mechanism and kinetic parameters of the exothermic decomposition reaction of 3,3-bis(azidomethyl)oxetane/tetrahydrofuran (BAMO/THF) copolymer in a temperature-programmed mode have been investigated by means of DSC, TG-DTG, fast and lower thermolysis/FTIR and TG-MS. The reaction mechanism was proposed. The apparent activation energy and pre-exponential constant of exothermic decomposition reaction of the compound at 0.1 MPa are 167.04 kJ*mol−1 and 1014.41 s−1, respectively. The corresponding critical temperatures of thermal explosion obtained from the onset temperature Tc, and the peak temperature Tp are 223.20 and 245.78°C, respectively. The kinetic equation of the exothermic decomposition process of BAMO/THF at 0.1 MPa could be expressed as: .

The thermal decomposition behavior and kinetic parameters of the exothermic decomposition reactions of the title compound in a temperature-programmed mode have been investigated by means of DSC, TG-DTG and lower rate Thermolysis/FTIR. The possible reaction mechanism was proposed. The critical temperature of thermal explosion was calculated. The influence of the title compound on the combustion characteristic of composite modified double base propellant containing RDX has been explored with the strand burner. The results show that the kinetic model function in differential form, apparent activation energy Ea and pre-exponential factor A of the major exothermic decomposition reaction are 1-a,207.98 kJ*mol−1 and 1015.64 s−1, respectively. The critical temperature of thermal explosion of the compound is 312.87 C. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as: dα/dT=1016.42 (1–α)e-2.502×104/T As an auxiliary catalyst, the title compound can help the main catalyst lead salt of 4-hydroxy-3,5dinitropyridine oxide to enhance the burning rate and reduce the pressure exponent of RDX-CMDB propellant.

The thermal behavior, mechanism and kinetic parameters of the exothermic first-stage decomposition reaction of the title compound in a temperature-programmed mode have been investigated by means of DSC, TG-DTG and IR. The reaction mechanism was proposed. The empirical kinetic model functions in differential form, apparent activation energy (Ea) and pre-exponential factor (A) of this reaction are (1 - α) −1.119, 211.3 kj/mol and 1020.2 s−1, respectively. The critical temperature of thermal explosion of the compound is 202.2 °C. The values of ΔS≠, ΔH≠ and CΔG≠ of this reaction are 143.8 J.mol−1.K−1, 208.7 kj/mol and 141.7 kj/mol, respectively.

The kinetics of the first order autocatalytic decomposition reaction of nitrocellulose (NC, 13.86% N) was studied by using DSC. The results show that the DSC curve for the initial 508 of conversion degree of NC can be described by the first order autocatalytic equation and that for the latter 50% conversion degree of NC described by the reaction equations .

The crystal growth process of Zn(Met)(AcO)2·H2O from the mixed solution of water and acetone has been investigated using a Calvet microcalorimeter. The heat produced and the rate of heat production during the crystal growth process at 298.15, 301.15, 304.15, 307.15 and 310.15 K have been measured. On the basis of experimental and calculated results, the thermodynamics parameters (the apparent activation enthalpy, the activation entropy, and the activation free energy), the rate constant and the kinetic parameters (the activation energy, the pre-exponential factor) during the crystal growth process have been obtained. The results show that the crystal growth proceeds in accordance with the Burton-Cabrera-Frank dislocation theory.