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In this study, an Al/Co@RDX composite was meticulously prepared through a combination of planetary high-energy ball-milling and a spray-drying technique. The thermal reactivity of these Al/Co@RDX composites was comprehensively investigated and compared using the TG/DSC technique. It is shown that the initial decomposition temperature of RDX in the DSC curve was decreased by 26.3 °C in the presence of Al/Co, which could be attributed to the nano-sized Co transition metal catalyzing the decomposition reaction of nitrogen oxides in RDX decomposition products. The decomposition peak temperature of RDX and the heat released by the thermal decomposition of RDX in the Al/Co@RDX composite were decreased by 26.3 °C and increased by 74.5 J·g−1, respectively, in comparison with those of pure RDX. The types of major gaseous products released from Al/Co@RDX were found to be identical to those of pure RDX, encompassing N2O, CH2O, CO2 and HCN. However, the concentrations of those gaseous products for Al/Co@RDX were higher than those observed for pure RDX, which may owe to the fact that the Al/Co composite can interact with the –CH2 and –NO2 within RDX molecules, which leads to the weakening of the C-N and N-N bonds. In addition, the decomposition of RDX in the Al/Co@RDX composite was observed as a one-step process with an apparent activation energy (Ea) of 115.6 kJ·cm−3. The decomposition mechanism of the RDX in the Al/Co@RDX composite was identified to follow the chain scission model (L2), whereas the two-step decomposition physical models observed for pure RDX were found to closely resemble the L2 and autocatalytic models. [ABSTRACT FROM AUTHOR]

In order to improve the energy efficiency of composite nano-metal materials, the energetic intermolecular complexes Si@PVDF/CL-20 with different silicon content (20%, 30% and 40%)were prepared by electrostatic spray method. The heat of combustion of PVDF/CL-20 composites with different ratios was obtained by bomb calorimeter. The morphology of PVDF/CL-20 composite was clarified by using SEM. The effect of Si content on the morphology of Si@PVDF/CL-20 composite particles was also analyzed. The thermal behavior of energetic compounds with different silicon content was studied by DSC-TG, and the kinetic paramters of thermal decomposition were calculated. The thermal analyses indicate that when the PVDF/ CL-20 mass ratio is 1-6, the heat of combustion reaches a maximum value, which can be used as the optimal ratio incoating of nano-Si powder. The SEM results show that when the silicon content is 30%, the composite particles (Si-30% ©PVDF/CL-20) exhibite the best sphericity. The DSC results show that when the silicon content is 20%, a runaway chemical reaction was likely occurred. The effect of Si powder on the decomposition of PVDF/CL-20 composite plays less significant role with the increase of content. The apparent activation energies of Si@PVDF/CL-20 composites calculated by Friedman method are 470. 6, 182.1, 91.7kJ/mol, respectively. The complex decomposition process of Si-20% @PVDF/CL-20 cannot be described by a single kinetic model, whereas those of Si-30% ©PVDF/CL-20 and Si-40% ©PVDF/CL-20 can be well described by a nuclea-tion and growth model. [ABSTRACT FROM AUTHOR]

Graphical abstract The Diaminotriazole group has great effect on the physical models and activation energies of the initial decomposition of tetrazine derivatives. Highlights • The heat flow behaviour of three insensitive and thermostable s -tetrazine derivatives was evaluated. • The mass loss properties of these compounds were compared with DSC results. • Their decomposition kinetic parameters and physical models were determined. • The gaseous products were analyzed with proposed initial thermolysis mechanisms. Abstract The thermal behaviour, decomposition kinetics and mechanisms of three diaminotriazole-substituted tetrazine compounds have been investigated using simultaneous DSC-TG and TG/MS techniques. It has been found that TBDM-2NB is much more stable than TBDM-NB and TBDM, where the latter decomposes in two steps with different kinetic parameters. The TBDM decomposes with peak temperature of 379.0 °C, while it is 355.6 °C and 386.5 °C for TBDM-NB and TBDM-2NB, respectively. The activation energy of the first step of TBDM is much higher (176.2 kJ mol−1) than the second step (102.3 kJ mol−1). The decomposition of TBDM-NB follows 2-d diffusion model, while it is a first order reaction model for TBDM and nucleation growth model for TBDM-2NB. The rearrangement of s-tetrazine ring is typical for thermal decomposition of the title compounds, which may undergo a homo-scission to produce N 2 and followed by production of NH 3. [ABSTRACT FROM AUTHOR]

In this paper, the thermal degradation properties of Viton A and Fluorel are investigated by both isoconversional and combined kinetic analysis methods using non-isothermal thermogravimetry technique. It has been found that the heating rate has little affect on the degradation residue of Fluorel and Viton A, where around 1.3% char was formed for Fluorel and 3.5% for Viton A. Different from the literature, the decomposition of Viton A should be considered as an overlapped dehydrofluorination and carbon chain scission process, with activation energy of 214 ± 11 and 268 ± 13 kJ mol, respectively. The effect of dehydrofluorination on degradation of Fluorel is not so significant due to low content of H, and hence, it could be considered as a single-step mechanism with average activation energy of 264 ± 14 kJ mol. The thermal stability of Fluorel is much better than that of Viton A, and the predicted half-life is around 218 min for Fluorel and 49 min for Viton A at 420 °C, which are consistent with experimental values. If using a single-step model as in the literature for Viton A, its half-life at 420 °C would be underestimated for >20%. [ABSTRACT FROM AUTHOR]

The RDX, HMX, and AP are currently the most widely used energetic ingredients in composite solid propellants, since the newly developed energetic compounds are still unable to replace them due to various bottleneck technical problems. In order to improve their combustion efficiency and performance, a common alternative way is to utilize novel nano-sized energetic additives. There are a great many nanomaterials that have been developed in the past decades, which include nanometal particles, metal oxides, metal salts, metallic composites, organometallic compounds, energetic nanocatalysts, and carbon nanomaterials. These additives could increase both the decomposition and the burning rate as well as enhance the combustion efficiency of the corresponding solid propellants by changing the thermal conductivity, energy barrier of thermolysis, heat of reaction, and gas-phase reaction mechanisms of the main ingredients such as RDX, HMX, and AP. This review paper discusses and summarizes the effects of abovementioned nano additives on decomposition kinetics, reaction models, decomposition mechanisms and burning rates, pressure exponents, combustion wave structures, and flame propagation of RDX-, HMX-, and AP-based energetic compositions. The catalytic mechanisms associated with different types of nanomaterials are explained and clarified. Owing to their extremely large specific surface areas, nano-sized energetic additives have significant catalytic effects in both condensed and gas phases during decomposition and subsequent combustion via activation of the reactants and acceleration of their transition state formations. The flame structures of AP-based composite propellants under the effect of some nanoadditives are presented showing the enhanced burning characteristics and stabilized combustion process. [ABSTRACT FROM AUTHOR]

Erythritol tetranitrate (butane-1,2,3,4-tetrayl tetranitrate, ETN) has become one of the most synthesized improvised explosives nowadays as it can be found on public internet discussion boards. However, the low melting point, nitrocellulose gelling ability, high energy content, and availability of its precursor make the substance potentially useful in industry as an energetic component or additive in certain gun propellants. Mixtures of ETN with other high explosives are also frequently discussed on web pages dealing with improvised explosives. This article describes thermal behavior and decomposition kinetics of pure ETN and its mixtures with pentaerythritol tetranitrate and cyclonite (1,3,5-trinitro-1,3,5-triazinane, RDX). The thermal behavior and decomposition kinetics of such mixtures are described using non-isothermal DSC and TG techniques. Kissinger method, Soviet manometric method, and modified Kissinger-Akahira-Sunose method were used for data evaluation. [ABSTRACT FROM AUTHOR]

Highlights: [•] The thermal behavior of Fluorel bonded explosives (PBXs) containing cyclic nitramines have been investigated. [•] Their decomposition kinetics parameters have been calculated by modified Kissinger–Akahira–Sunose (KAS) method. [•] It has been found that Fluorel matrix has a significant effect on the activation energy distribution of cyclic nitramines. [•] The Fluoropolymer is chemical incompatible cyclic nitramines with crowded molecule such as BCHMX. [Copyright &y& Elsevier]

Highlights: [•] The effects of Viton A binder on the thermal behavior of cyclic nitramines have been investigated by using non-isothermal techniques. [•] The decomposition kinetics parameters have been calculated by modified Kissinger-Akahira-Sunose method. [•] As a thermostable polymer, Viton A could inhibit the initial autocatalysis effect of cyclic nitramines. [•] It would improve the thermal stability of corresponding PBXs containing RDX, β-HMX and ε-CL-20. [Copyright &y& Elsevier]

The zero-order reaction rates (specific rate constants) for isothermal decomposition at 120 °C of plastic bonded explosives (PBXs) were measured by means of the Czech vacuum stability test, STABIL. The PBXs are based on 1,3,5-trinitro-1,3,5-triazinane (RDX), β-1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX), cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5- d] imidazole (BCHMX), and ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-HNIW, ε-CL-20) with 9 wt.% of the C4 type matrix, i.e., a matrix containing 25 wt.% of polyisobutylene, 59 wt.% of dioctyl sebacate and 16 wt.% of the oil HM46. Dependencies were found between the specific rate constants mentioned and the detonation velocities of the PBXs, and consequently between these constants and the impact of pure explosive fillers, i.e., RDX, β-HMX, ε-HNIW, RS-ε-HNIW, and BCHMX and, at the same time, the corresponding PBXs. The results obtained are compared with those from a recent analogous study of PBXs using an SBR (Formex P1) binder which could increase the PBXs' reactivity in comparison with C4 matrix. These results also help to dispel a widely held view about HNIW being a relatively sensitive explosive. [ABSTRACT FROM AUTHOR]

The critical temperature and mechanism functions for thermal decomposition of ε-CL-20, RS-ε-CL-20, α-CL-20, ε-CL-20/C4, and RS-ε-CL-20/C4 were evaluated based on non-isothermal TG data. A two-step mechanism has been found for thermal decomposition of α-CL-20, ε-CL-20/C4, and RS-ε-CL-20/C4, where the initial step is partly controlled by crystal structure of CL-20. The more reasonable mean activation energies could be obtained after peak separation for each individual steps. In fact, the activation energy for the post integrated process is almost equivalent with that of the second step, indicating that the total activation energy at the main decomposition process is dominated by thermolysis of CL-20 molecular. Besides, it has been found that the decomposition of C4 matrix does not affect the decomposition of normal ε-CL-20, resulting in identical activation energy and reaction model. However, the interaction between the C4 matrix and RS-ε-CL-20 is significant especially at the initial stage, where the activation energy of RS-ε-CL-20/C4 was overestimated before peak separation, while the activation energy for the second step due to thermolysis of CL-20 molecular is underestimated. The first decomposition step for α-CL-20, ε-CL-20/C4, and RS-ε-CL-20/C4 could be considered as autocatalytic process (AC model), whereas the second as JMA model, which is also applicable to that of pure ε-CL-20 and RS-ε-CL-20. Moreover, The critical temperatures of thermal explosion ( T) are obtained as 205.6, 205.5, 209.4, 214.4, and 227.5 °C for α-CL-20, ε-CL-20, RS-ε-CL-20, ε-CL-20/C4, and RS-ε-CL-20/C4, respectively. It proves that the C4 matrix could stabilize ε-CL-20 while the crystal form of CL-20 has little effect on its thermal stability. [ABSTRACT FROM AUTHOR]

Abstract: The thermal behavior and decomposition kinetics of C4-bonded PBXs based on some attractive cyclic nitramines were investigated by means of nonisothermal TG and DSC techniques. It has been shown that only a single decomposition process has been observed for RDX-C4 while an obvious two-step process for mixture of BCHMX-C4 CL-20-C4, and HMX-C4. The onset temperature of the exotherms were observed at 216.3, 238.7, 279.2 and 236.7°C with the peak temperatures of 235.1, 279.0, 231.2 and 233.7°C for RDX-C4, BCHMX-C4, HMX-C4 and CL-20-C4, respectively. Their corresponding exothermic decompostion processes were covered by energy changes of 1749, 1938, 1213 and 2639Jg−1, which are lower than that of their pure cyclic nitramines. It was also proved that C4 matrix has significant effect on the activation energy distribution of RDX, BCHMX and CL-20, whose initial autocatalysis effect was inhibited or weakened. With regard to HMX-C4, the activation energy of its initial step is much lower than that of the second step. [Copyright &y& Elsevier]

Thermal behavior and decomposition kinetics of Formex-bonded PBXs based on some attractive cyclic nitramines, such as 1,3,5-trinitro-1,3,5-triazinane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). Actually, cis-1,3,4,6-tetranitrooctahy droimidazo-[4,5-d]imidazole (BCHMX) and 2,4,6,8,10,12-hexanitro-2,4,6,8,10, 12-hexaazaisowurtzitane (CL-20), was investigated by means of nonisothermal thermogravimetry (TG) and differential scanning calorimetry (DSC). It was found that the mass loss rate of PBXs involved in this research depends greatly on heating rate and the residue of the decomposition of these PBXs decreases with the heating rate. The onset of the exotherms was noticed at 215.4, 278.7, 231.2 and 233.7 °C with the peak maximum at 235.1, 279.0, 231.2 and 233.7 °C for RDX-Formex, HMX-Formex, CL-20-Formex, and BCHMX-Formex, respectively. Their corresponding exothermic changes were 1788, 1237, 691, and 1583 J g. It was also observed that the dependence on the heating rate for onset temperatures of HMX- and BCHMX-based PBXs was almost the same due to their similar molecular structure. In addition, based on nonisothermal TG data, the kinetic parameters for thermal decomposition of these PBXs were calculated by isoconversional methods. It was shown that the Formex base has great effects on the activation energy distribution of nitramines. It was further found that the kinetic compensation effects occurred during the thermal decomposition of nitramine-based PBXs, and they almost have the same compensation effects due to similar decomposition mechanism. [ABSTRACT FROM AUTHOR]

The zero-order reaction rates (specific rate constants) of isothermal decomposition at 120 °C of plastic bonded explosives (PBXs) were measured by means of the Czech vacuum stability test, STABIL. The PBXs are based on 1,3,5-trinitro-1,3,5-triazinane (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX), cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5- d]imidazole (BCHMX), and ε 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-HNIW, ε-CL-20) with 13 wt% of the Formex P1 type matrix, i.e., a matrix of the explosive with pentaerythritol tetranitrate (PETN) bound by 13 wt% of a mixture of 25 wt% of styrene-butadiene rubber and 75 wt% of an oily material. Dependencies were found between the specific rate constants mentioned and the detonation velocities of PBXs, and consequently between these constants and the impact and electric spark sensitivities of pure explosive fillers, i.e., RDX, HMX, HNIW, BCHMX, and PETN. It is stated that the higher impact or electric spark sensitivity of their pure explosive fillers corresponds to the higher thermal reactivity of the given PBXs. [ABSTRACT FROM AUTHOR]

Abstract: As an attractive new energetic material, cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole (BCHMX) and its polymer bonded explosive (PBX) with styrene-butadiene rubber (SBR) binder (Formex type) have been investigated with regard to its thermal decomposition kinetics and reaction models by using DSC, TG and SEM techniques. It was found that the decomposition of BCHMX in dynamic nitrogen could be divided into two steps, while there is only one step for its Formex bonded explosive. The activation energy for decomposition of BCHMX/Formex was obtained to be 221.7±4.99kJmol−1 by modified KAS method, while the mean activation energies for pure BCHMX are calculated as 233.0±2.1kJmol−1 for first step and 186.0±0.92kJmol−1 for the second step. It was further proved that the first decomposition step of BCHMX is autocatalytic, during which the crystal of BCHMX could dissolve in the liquid phase of its thermolysis products on the surface. Besides, the JMA and AC models were found to be appropriate to interpret the two-step decomposition of pure BCHMX and JMA model for BCHMX/Formex, the parameterized reaction models for BCHMX could be established as f(α)= α 0.45(1− α)1.51 and f(α)=2.33×(1− α)[−ln(1− α)]0.57, while for BCHMX/Formex as f(α)=2×(1− α)[−ln(1− α)]1/2. [Copyright &y& Elsevier]

Abstract: In this paper, several fundamental investigations published over the past decades with regard to the thermal analysis of polymer-based explosives (PBXs) have been briefly reviewed. A number of explosive fillers and polymer bases that were used as their main ingredients of PBXs are summarized herein. In addition, the calculation methods for their decomposition kinetics and thermal stability parameters are also introduced in detail. It was concluded that only PBXs based on HMX, RDX and TATB have been widely investigated, and that some other PBXs containing innovative fillers, such as CL-20, TNAZ, NTO and BCHMX are at the design stage. The isoconversional methods and model fitting procedures are usually used to analyze the discrete thermolysis processes of PBXs. In addition, their thermal stability parameters such as shelf life, explosion delay, critical temperature, thermostability threshold, 500-day cookoff temperature and approximate time to explosion could be calculated easily from the kinetic data. [Copyright &y& Elsevier]

The zero-order reaction rates (specific rate constants) of isothermal decomposition at 120 °C of plastic bonded explosives (PBXs) in the first six hours of decomposition were measured by means of the Czech vacuum stability test, STABIL. The PBXs were filled by RDX (1,3,5-trinitro-1,3,5-triazinane), β−HMX (β−1,3,5,7-tetranitro-1,3,5,7-tetrazocane), BCHMX and ϵ-CL20 (ϵ-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, ϵ-HNIW) and, in one case, on a mixture of BCHMX and 3-nitro-1,2,4-triazol-5-one (NTO), in a 1:1 wt. ratio. These nitramines were bonded by 9% by wt. of softened polyisobutylene matrix, 13% by wt. of softened polystyrene-butadiene matrix, 18% by wt. of crosslinked hydroxyl-terminated polybutadiene, 12% by wt. of polydimethylsiloxane and by 40% of TNT. The relationships of specific rate constants with experimental detonation velocities, impact and friction sensitivities of these PBXs are shown and discussed. It is postulated that this approach provides results which are applicable to studies of initiation reactivity of energetic materials and which are fully comparable with those of other methods of investigation in this area. [ABSTRACT FROM AUTHOR]

• Various qy-HMX crystal models have been constructed with different TAGP contents. • The stabilization mechanisms of TAGP on hybrid qy-HMX crystals have been proposed. • The decomposition mechanisms of qy-HMX and the mutual interactions between HMX and TAGP have been clarified. • The theoretical results agree well with experimental results. The two-dimensional high nitrogen insensitive triaminoguanidine glyoxal energetic polymer (TAGP) has been used as intercalating material for HMX crystals, resulting in novel hybrid energetic crystals (so called qy-HMX) with better stability and higher density. In this paper, the molecular dynamic simulations based on a reactive force field (ReaxFF) have been implemented to illustrate the stabilization and decomposition mechanisms of TAGP on HMX crystals, which were verified by TG-DSC and Pyro-GC/MS experiments. Six types of qy-HMX models with different TAGP contents have been constructed. The results suggest that the conformation of HMX molecule could be changed under the strong constraint of TAGP layers, which could hinder the decomposition of qy-HMX under lower temperature due to enhanced intramolecular interactions, resulting in more complete solid-state decomposition reactions than β-HMX. The TAGP and HMX would decompose simultaneously if the TAGP content is low enough, whereas the TAGP decomposes earlier than HMX molecules, if its mass content reaches over 50%. The isothermal decomposition activation energies also prove that the qy-HMX crystal is more stable and decomposes faster that raw β-HMX. Besides, the Pyro-GC/MS experiments show that there is little change for the major decomposition pathways for HMX under the effect of TAGP, but there has been strong interaction between the intermediate of their thermolysis products. The gaseous products differ only in relative content, depending on the pyrolysis temperature. Some products such as the HCN, H 2 O and NH 3 are more dominant under temperature of 350 °C, whereas the CO 2 , HNO and NO 2 , are much less than β-HMX. which agree well with the simulated results. [ABSTRACT FROM AUTHOR]

• Core-shell structured AP@Al/TMs reactive composites have been prepared. • Al/Ni and Al/Co improved the heat release of thermal decomposition of AP by 84.8% and 42.1%, respectively. • The physical models for AP thermal decomposition reaction under the effect of Al/TMs have been proposed. A series of AP reactive composites modified by Al/TMs bi-metal compounds including Al/Ti, Al/Ni and Al/Co have been successfully prepared by acoustic resonance mixing. Various analysis techniques have been utilized and results indicate that the Al/Co exhibits the strongest thermal interaction effect on the thermal decomposition of ammonium perchlorate (AP) by merging reaction steps with enhanced thermal reactivity. In comparison to the pure AP, the peak temperatures of high temperature decomposition (HTD) of AP in the presence of Al/Ti, Al/Ni and Al/Co are significantly decreased by 60.3 °C, 76.9 °C and 100.2 °C, respectively. Moreover, the apparent activation energies obtained for AP@Al/Ti, AP@Al/Ni and AP@Al/Co composites are 96.5 kJ·mol−1, 103.5 kJ·mol−1 and 53.6 kJ·mol−1, respectively. The thermolysis physical models of AP in composites of AP@Al/Ti, AP@Al/Ni and AP@Al/Co appear to follow three-dimensional random nucleation and nucleus growth (A3), whereas the A3, chain scission and phase boundary-controlled reaction are found to be the most appropriate models to represent the three-step thermal decomposition of pure AP. Owing to the high thermal interaction activity, as great bi-metal fuels, Al/TMs can also be considered as outstanding additives for AP thermal decomposition. [ABSTRACT FROM AUTHOR]

Preparation of highly reactive core-shell Al/Co@AP composite and their physical models for the thermal decomposition of AP and the intermetallic reactions under the mutual interaction. [Display omitted] • Core-shell structured Al/Co@AP composite has been prepared. • Al/Co improved the heat release of the thermal decomposition of AP by 52.6%. • AP enhanced the heat release of the intermetallic reaction between Al and Co by 67.7%. • The physical models for the AP thermal decomposition reaction and Al/Co intermetallic reaction have been proposed. In this paper, a group of novel intermetallic metastable composites Al/Co@AP has been designed, and three methods including ultrasonic dispersion, mechanical grinding and spray-drying have been attempted for their preparation. The latter one has demonstrated to be the most appropriate means, by which the core–shell structured Al/Co@AP with desired properties could be successfully obtained. The thermal reactivity of Al/Co/AP composites prepared differently has been investigated and compared by TG/DSC technique. It has been shown that the heat release rate of AP in DSC curve was largely increased in the presence of Al/Co when spray-drying technique was used, which may be attributed to the increased nuclear site by the intimate contact. The initial reaction temperature of AP in Al/Co@AP was decreased by 7.8 °C and the heat releases by the thermal decomposition of AP and the intermetallic reaction between Al and Co were enhanced by 52.6 % and 67.7% in comparison with that of pure AP and Al/Co. The types of major gaseous products of Al/Co@AP are almost identical to that of pure AP, which include HCl, H 2 O, N 2 O and NO 2. However, the concentrations of NO 2 and N 2 O in gaseous products for Al/Co@AP are lower than that observed for pure AP, which may be due to the partial consumption of N element by the reaction of Al with acidic substance (HNO 3) decomposed from AP. In addition, the AP in Al/Co@AP composite decomposes in one-step with the apparent activation energy (E a) of 98.8 kJ·cm−3. The decomposition process of the AP in Al/Co@AP composite follows two-dimensional nucleation and growth model(A2), whereas the pure AP follows different physical models, which are close to three-dimensional nucleation and growth, chain scission and phase boundary-controlled reaction (contracting area) models. The intermetallic reaction between Al and Co in Al/Co@AP is merged into one-step following the A2 physical model. [ABSTRACT FROM AUTHOR]

Highlights: [•] DHDNEBa was firstly synthesized by the process of metathesis reaction with a yield of 95.7%. [•] The most probable kinetic model function of the exothermic decomposition reaction was deduced. [•] ΔS ≠, ΔH ≠,ΔG ≠, T SADT and T b of DHDNEBa were investigated. [•] The thermal decomposition mechanism of DHDNEBa was studied by means of thermolysis/RSFTIR and TG–MS technologies. [ABSTRACT FROM AUTHOR]

• Novel PDA/GO coating methodology using PDA as an interfacial layer can further stabilize thermostable EMs. • The thermal reactivity properties and gaseous products of coated composites are clarified. • The kinetics models of multi-stage decomposition reactions are obtained. The high performance energetic materials (EMs) with reduced sensitivity and improved thermostability are essential for propellant and explosive applications. In this paper, two thermostable derivatives of dibenzotetraazapentene Tetranitro-Benzopyridotetraazapentalene (NBTTP) and Tetranitro-Dipyridotetraazapentalene (NPTTP) are further stabilized by Polydopamine (PDA) and Graphene Oxide (GO) coating, resulting in highly thermostable composites. The thermal behavior and decomposition mechanisms of these composites have been investigated by TG-DSC/FTIR technique. It has been shown that the PDA/GO coating layer is effective to stabilize NBTTP and NPTTP crystals by largely increasing their decomposition activation energy (E a). As a typical product, the NBTTP@PDA/GO-1–1 decomposes in two steps, with the E a 38.0% and 59.0% higher than that of pristine NBTTP, respectively. In comparison, the E a for rate-limiting decomposition step of NPTTP@PDA/GO-1–2 is 92.6% higher than that of NPTTP. After coating PDA/GO, the decomposition heat does not change much, which is about 2259 to 2458 J g−1. The last decomposition step for these composites follows 2D nucleation and nucleus growth model, whereas it is 3D nucleation and growth model for the pristine crystals, indicating a much lower decomposition reaction rate. The major gaseous products of NBTTP and NPTTP are CO 2 , C 2 H 2 , N 2 O, C N, CO, NO and H 2 O. Volatile hydrocarbon products appear in modified NBTTP composites, which are responsible for the slow reaction rates. [ABSTRACT FROM AUTHOR]

• Detail thermal decomposition kinetics of NTO is studied. • Effects of 2D-layered energetic hybrid crystals on the NTO decomposition are elucidated. • Decomposition reaction models have been determined using isoconversional methods. • The used catalysts exhibited higher catalytic activity on NTO. • The decomposition temperature of NTO has greatly decreased after the addition of catalysts. This study deals with the evaluation of the catalytic activity of some highly energetic coordination polymers of triaminoguanidine-transition metal (T-M) complexes, with or without graphene oxide (GO)-T, on the thermal decomposition of NTO. Their catalytic activity was investigated by differential scanning calorimetry (DSC). Isoconversional integral kinetic methods, viz., iterative Flynn-Wall-Ozawa, iterative Kissinger-Akahira-Sunose, Sbirrazzuoli methodology and Trache-Abdelaziz-Siwani methods have been applied to the DSC experimental data to determine the different kinetic parameters. The obtained results displayed that all of the used catalysts exhibited higher catalytic activity and the peak temperature of decomposition has greatly decreased. The apparent activation energies of decomposition were reduced by more than 180 kJ/g. [ABSTRACT FROM AUTHOR]