Thermal Decomposition Of Ammonium Perchlorate Research Articles

Self‐Healing Polyurethane Binder with Catalytic Thermal Decomposition Property Based on Metal‐Ligand Interaction

AbstractHydroxyl Terminated Poly Butadiene (HTPB) based polyurethanes are widely used as polymeric binders in energetic formulations & other applications. Hence, customization in structure of HTPB has been investigated to improve their mechanical and thermal properties. Herein, modification of HTPB polyurethane has been reported in this paper by incorporating 2‐hydroxy‐3, 5‐dinitropyridine (DNP) covalently into the HTPB polyurethane matrix in order to exhibit self‐healing properties. The functionalized polyurethane concurrently displays self‐healing capability via metal‐ligand interaction and also catalytic activity towards thermal decomposition of Ammonium Perchlorate (AP). The self‐healing ability was observed by Optical Microscope and up to 96 % healing efficiency was observed by UTM analysis. Further, the catalytic activity was observed with thermal decomposition of Ammonium Perchlorate performed by DSC shows lowering in decomposition temperature by 73 °C. By involving the self‐healing and catalytic activity through single moiety in the polymer chain, this two‐in‐one strategy allows to produce advance binders for energetic formulations.

High-efficiency catalysis of nitrogen-rich metal-organic frameworks and their derivatives for the thermal decomposition of ammonium perchlorate

With the development of aerospace science and technology, requirements for propellants are increasingly high. The thermal decomposition behavior of ammonium perchlorate (AP) directly influences the combustion performance of composite solid propellants. Catalysts play an important role in improving the thermal decomposition behavior of AP. In this study, three novel metal-organic frameworks (MOFs) were prepared using a straightforward method, namely Co[N(CN)2]2 (1; nitrogen content: 43.5%), Cu[N(CN)2]2 (2; nitrogen content: 43.0%), and Pb[N(CN)2]2 (3; nitrogen content: 24.8%). Their crystal structures were characterized and analyzed through single-crystal X-ray diffraction, forming interesting three-dimensional architectures. Moreover, derived composite catalysts under air (4, 6, and 8) or nitrogen (5, 7, and 9) atmosphere were generated by heating MOFs 1, 2, and 3–500 ​°C at a heating rate of 5 ​°C·min−1. The derived catalyst 4 exhibited the best performance. It reduced the decomposition peak temperature of AP by 81.9 ​°C, increased the heat release from 785 ​kJ·g−1 to 1232 ​kJ·g−1, and decreased the apparent activation energy (Ea) of AP from 223 ​kJ·mol−1 to 145 ​kJ·mol−1.

Triazine-Augmented Catalytic Activity of Cyclobutadiene Tricarbonyl Fe(0) Complexes for Thermal Decomposition of Ammonium Perchlorate

The employment of combustion catalysts is an effective way to improve ammonium perchlorate (AP) decomposition performance during the combustion process of composite solid propellants. A classic half-sandwich iron carbonyl complex was proposed as the leading structure for exploring high-performance combustion catalysts, in which functionalized cyclobutadienes (Cb) tune the thermal stability and catalytic activity. The thermolysis of Fe2(CO)9 and substituted alkynes initiated [2 + 2] cyclization of alkyne triple bonds and gave η4-cyclobutadiene iron(0) tricarbonyl complexes, CbR1,R2-Fe-CO (1–6), with decent yields. A molecular structure analysis found that the conjugation of the aromatic substituents aryl, ferrocenyl (Fc), and triazinyl (Tz) finely tuned the coordination bonds around the Fe(0) center. The DSC/TG experiments found a remarkable thermal stability of CbTz,R-Fe-CO (3–6) with characteristic thermolysis temperatures (CTT) as high as 500 °C. The catalytic experiments demonstrated that the CTT of Cb-Fe-CO (2-6) overlapped with AP high-temperature decomposition (HTD). The thermal cross-coupling of HTD of AP and CTT of CbTz,Fc-Fe-CO (6) significantly augmented catalytic AP decomposition, resulting in a maximum energy release as high as 2828 J/g.

Facile preparation of a nano-Co3O4/C composite catalyst for the thermal decomposition of ammonium perchlorate

Facile preparation of a nano-Co3O4/C composite catalyst for the thermal decomposition of ammonium perchlorate

Superparamagnetic energetic nanoparticles: a surface self-propagation pathway for the thermal decomposition of ammonium perchlorate

Superparamagnetic energetic nanoparticles: a surface self-propagation pathway for the thermal decomposition of ammonium perchlorate

Carbon-Nitride Popcorn-A Novel Catalyst Prepared by Self-Propagating Combustion of Nitrogen-Rich Triazenes.

The interest in development of non-graphitic polymeric carbon nitrides (PCNs), with various C-to-N ratios, having tunable electronic, optical, and chemical properties is rapidly increasing. Here the first self-propagating combustion synthesis methodology for the facile preparation of novel porous PCN materials (PCN3-PCN7) using new nitrogen-rich triazene-based precursors is reported. This methodology is found to be highly precursor dependent, where variations in the terminal functional groups in the newly designed precursors (compounds 3-7) lead to different combustion behaviors, and morphologies of the resulted PCNs. The foam-type highly porous PCN5, generated from self-propagating combustion of 5 is comprehensively characterized and shows a C-to-N ratio of 0.67 (C3 N4.45 ). Thermal analyses of PCN5 formulations with ammonium perchlorate (AP) reveal that PCN5 has an excellent catalytic activity in the thermal decomposition of AP. This catalytic activity of PCN5 is further evaluated in a closer-to-application scenario, showing an increase of 18% in the burn rate of AP-Al-HTPB (with 2wt% of PCN5) solid composite propellant. The newly developed template- and additive-free self-propagating combustion synthetic methodology using specially designed nitrogen-rich precursors should provide a novel platform for the preparation of non-graphitic PCNs with a variety of building block chemistries, morphologies, and properties suitable for a broad range of technologies.

Differences in the catalytic properties of Fe isotopes.

The significant differences in the catalytic properties caused by different 'isotopic catalysts' were discovered for the first time. The commonly purchased Fe2O3 is a 'mixture' of different Fe isotopic oxides which means the catalytic effect of Fe2O3 is theoretically a synthetical result of all isotopic compounds. In this work, the differences in catalytic properties of α-Fe2O3 with natural abundance ratio and separated isotopic α-Fe2O3 (α-54Fe2O3, α-56Fe2O3, and α-58Fe2O3) catalyzing thermal decomposition of ammonium perchlorate (AP) were investigated, and are mainly attributed to the difference in the charge distribution of the nuclei of different iron isotopes. The result suggests that isotope effects in different isotopes when utilized as catalysts are caused by nuclear morphology and the nuclear charge distribution. This study will serve as a base as well as an initiation for future studies of the isotopic catalyst.

In situ growth of copper-based energetic complexes on GO and an MXene to synergistically promote the thermal decomposition of ammonium perchlorate.

In this work, using tri(5-aminotetrazolium)triazine (H3TATT) as an energetic ligand, two new energetic complexes (ECs), Cu(HTATT)(H2O)2 (EC-Cu1) and [Cu3(TATT)2(H2O)2]n (EC-Cu2), have been synthesized under hydrothermal conditions. Their crystal structures, thermal decomposition behaviors and specific heat capacities were determined respectively. In addition, two ECs were combined with GO (graphene oxide) and an MXene (Ti3C2TX) respectively by an in situ growth strategy to obtain four carbon nanomaterials/EC composites, which were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The effects of two ECs and four composites on the thermal decomposition of AP were studied by differential scanning calorimetry (DSC). Among them, the sample containing 8 wt% composite (GO/EC-Cu2) has the best promoting effect on AP, causing the high temperature decomposition peak to overlap with the low temperature decomposition peak of AP, reducing the decomposition peak temperature of AP from 443.6 °C to 308.9 °C, and the heat release is up to 4875 J g-1. Compared with ECs acting solely on AP, composite materials have stronger synergistic and promoting effects. This study provides a new example of the synthesis of carbon nanomaterial/EC composites and the improvement of the performance of AP-based solid propellants.

Design, preparation, and combustion performance of energetic catalysts based on transition metal ions (Cu2+, Co2+, Fe2+) and 3-aminofurazan-4-carboxylic acid.

Development of energetic catalysts with high energy density and strong catalytic activity has become the focus and frontier of research, which is expected to improve the combustion performance and ballistic properties of solid propellants. In this work, three energetic catalysts, M(H2O)4(AFCA)2·H2O (AFCA = 3-aminofurazan-4-carboxylic acid, M = Cu, Co, Fe), are designed and synthesized based on the coordination reaction of transition metal ions and the energetic ligand. The target products are characterized by single crystal X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, optical microscopy, and scanning electron microscopy. The results reveal that Cu(H2O)4(AFCA)2·H2O crystallizes in the monoclinic space group, Dc = 1.918 g cm-3. Co(H2O)4(AFCA)2·H2O, and Fe(H2O)4(AFCA)2·H2O belong to orthorhombic space groups, their density is 1.886 g cm-3 and 1.856 g cm-3, respectively. In addition, the designed catalysts show higher catalytic activity than some reported catalysts such as Co(en)(H2BTI)2]2·en (H3BTI = 4,5-bis(1H-tetrazol-5-yl)-1H-imida-zole), Co-AzT (H2AzT = 5,5'-azotetrazole-1,1'-diol), and [Pb(BTF)(H2O)2]n (BTF = 4,4'-oxybis [3,3'-(1-hydroxy-tetrazolyl)]furazan) for the thermal decomposition of ammonium perchlorate (AP). The high-temperature decomposition peak temperatures of AP/Cu(H2O)4(AFCA)2·H2O, AP/Co(H2O)4(AFCA)2·H2O, and AP/Fe(H2O)4 (AFCA)2·H2O are decreased by 120.3 °C, 151.8 °C and 89.5 °C compared to the case of pure AP, while the heat release of them are increased by 768.8 J g-1, 780.5 J g-1, 750.9 J g-1, respectively. Moreover, the burning rates of solid propellants composed of AP/Cu(AFCA)2(H2O)4·H2O, AP/Co(AFCA)2(H2O)4·H2O and AP/Fe(AFCA)2(H2O)4·H2O are increased by 2.16 mm s-1, 2.53 mm s-1, and 1.57 mm s-1 compared with the case of pure AP. This research shows considerable application prospects in improving the combustion and energy performance of solid propellants, it is also a reference for the design and preparation of other novel energetic catalysts.

ZIF-8 derived ZnO: a facile catalyst for ammonium perchlorate thermal decomposition

ZIF-8-derived porous ZnO is a facile, low-cost and environmentally benign catalyst with exceptional catalytic efficiency for ammonium perchlorate thermal decomposition at minimal catalyst usage.

A strategy for modulating the catalytic active center of AP thermal decomposition and its application: La-doped MgCo2O4

La diffuses into the main lattice of MgCo2O4 (Lax-MgCo2O4), exposing more Co3+ active centers: (1) La3+, O2−, high Co3+ concentration, high conductivity promote AP decomposition. (2) The highly active Lax-MgCo2O4 becomes potential catalyst for CSPs.

Enhanced Catalytic Effect of Ti2CTx-MXene on Thermal Decomposition Behavior of Ammonium Perchlorate.

Transition metal carbonitrides (MXenes) are promising catalysts due to their special structures. Recently, many studies have shown that MXenes have a catalytic effect on the thermal decomposition of ammonium perchlorate (AP). However, the catalytic effects have not been extensively investigated. Therefore, it is important to illustrate the catalytic mechanisms of pure MXene in AP thermal decomposition. Herein, the catalytic properties of Ti2CTx for ammonium perchlorate (AP) thermal decomposition were investigated by numerous catalytic experiments. The results showed that the high-temperature decomposition (HTD) decreased by 83 °C, and the decomposition heat of AP mixed with Ti2CTx increased by 1897.3 J/g. Moreover, the mass spectrum (MS) data showed that the NH3, H2O, O2, N2O, NO, HCl, and NO2 were formed. In addition, according to the X-ray diffraction (XRD), Raman spectrum, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and X-ray photoelectron spectra (XPS) results, the Ti2CTx nanosheets can adsorb the gaseous products and react with them in-situ, generating anatase-TiO2 and carbon layers. The Ti2CTx, as-resulted anatase-TiO2, and carbon can synergize and further catalyze the thermal decomposition of AP when both electron and proton transfers are accelerated during AP decomposition.

Effect of fluorine-containing thermite coated with potassium perchlorate on the thermal decomposition behavior and kinetics of ammonium perchlorate

In the last decade, the decomposition of ammonium perchlorate (AP) has been a major research topic, which is extensively studied by the scientific community. The present work aims to understand the effect of nanothermite on AP thermal decomposition. MgAl-PTFE nanothermite mechanically activated by arrested reactive milling was coated with potassium perchlorate (KP) and characterized. The obtained results revealed that the characteristic XRD signals of phase compositions remain unchanged, indicating that the ball-milling and chemical synthesis processes do not damage the chemical structure of the main components. The SEM micrographs showed that MgAl was uniformly distributed within the PTFE matrix. To assess the decomposition kinetics and understand the catalytic effect of the prepared MgAl-PTFE and MgAl-PTFE@KP on the thermal behavior of AP, DSC analyses were performed. It is demonstrated that the activation energy decreases by about 6%, revealing that the presence of nanothermites promotes the thermal decomposition process of AP.

Preparation of ferrocene‐based Schiff base derivatives for the thermal decomposition of ammonium perchlorate

AbstractAmmonium perchlorate (AP) is a common oxidizer and accounts for over 60 wt% in composite solid propellants (CSPs). Ferrocene (Fc)‐based compounds have become one of the most widely used burning rate catalysts (BRCs) for AP decomposition due to their outstanding catalytic effect. To improve the anti‐migration ability of Fc‐based compounds during long‐time storage, seven Fc‐based Schiff base derivatives were synthesized. Their molecular structures were characterized by UV‐Vis, FT‐IR,1H NMR,19F NMR, ESI‐MS and EA. Meanwhile, their electrochemical behaviors and catalytic effects for AP decomposition were studied by CV and TG techniques. The results showed that these synthesized compounds had good catalytic effect, obviously reducing the thermal decomposition temperature of AP. Moreover, their anti‐migration properties were also investigated by the aging test of simulated propellant. The results showed that they had better anti‐migration ability than commercial BRCs (catocene,Cat). This study demonstrates that Fc‐based Schiff base compounds are possible BRCs for AP‐based propellant.

Dense, Three-Dimensional, Highly Absorbent, Graphene Oxide Aerogel Coating on ZnCo2O4/ZnO Particles Exerts a Synergistic Catalytic Effect for Ammonium Perchlorate Thermal Decomposition.

As a new type of carbon material, graphene oxide aerogel (GA) is widely used in catalysis due to its porous structure, high-efficiency adsorption, and superb conductivity. In this study, GA was prepared into a dense coating layer surrounding ZnCo2O4/ZnO particles to form a composite GA-ZnCo2O4/ZnO by means of a hydrothermal, blast drying, and vacuum-freeze-drying approach applied to catalyze the thermal decomposition of ammonium perchlorate (AP). The physicochemical properties of the obtained GA-ZnCo2O4/ZnO were characterized by different analytical methods. Scanning electron microscopy (SEM) analysis exhibited that GA is coated on the surface of ZnCo2O4/ZnO, forming a dense layer. Brunner Emmet Teller (BET) measurement results show that GA-ZnCo2O4/ZnO has a smooth macropore distribution curve and a larger specific surface area. Moreover, The catalytic effect investigation on AP with GA-ZnCo2O4/ZnO: the high temperature decomposition (HTD) peak temperature of AP in the presence of 5 wt % GA-ZnCo2O4/ZnO was reduced from 441 to 294 °C, and the exotherm of AP was expanded from 205 to 1275 J/g at a heating rate of 15 °C/min. Through the calculation, GA-ZnCo2O4/ZnO makes the activation energy and Gibbs free energy of the AP pyrolysis lower so that the reaction is easier to occur. Thermogravimetric-mass (TG-MS) spectrometry revealed that during thermal decomposition of AP, GA-ZnCo2O4/ZnO leveraged the synergistic catalysis of ZnCo2O4/ZnO and GA that boosted the flow of electrons from ClO4- to O2 and increased the absorption of the gas product to accelerate the AP pyrolysis. These results provided a facile strategy to prepare GA-based composite catalysts with extraordinary application prospects in the domain of solid propellants.

Fluorocarbon nanosheet@copper oxide microspheres: Simultaneous promotion the decomposition of ammonium perchlorate and ignition performance of aluminum

Carbon fluoride nanosheets modified by CuO/Cu2O microspheres (FCN@CuO/Cu2O) were prepared by a simple method and characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and thermogravimetry coupled with differential scanning calorimetry and mass spectroscopy. The catalytic effect of FCN@CuO/Cu2O on the thermal decomposition of ammonium perchlorate (AP) and the effect on the combustion performance of aluminum (Al) were studied. The combination of CuO/Cu2O microspheres and carbon fluoride nanosheets promoted the decomposition of AP and improved the ignition performance of Al. The decomposition temperature of AP was lower than that of pure AP after adding a small amount of FCN@CuO/Cu2O. The results also showed that FCN@CuO/Cu2O effectively eroded the alumina film on the Al particles. The ignition temperature of Al was reduced after adding FCN@CuO/Cu2O.

Synthesis of CuII and CdII Metal-Organic Frameworks Based on 4,5-Bis(1-hydroxytetrazol-5-yl)-1,2,3-triazole and Their Effects as the Catalyst in Ammonium Perchlorate Thermal Decomposition.

Two new three-dimensional (3D) energetic metal-organic frameworks (EMOFs), namely, [Cu(OBTT)(NC2H8)2]n (1) and [Cd3(OBTT)2(H2O)2]n·4H2O (2), where H3OBTT = 4,5-bis(1-hydroxytetrazol-5-yl)-1,2,3-triazole, were prepared, and their structures were characterized by single-crystal X-ray diffraction analysis, which revealed that the EMOFs feature a rigid 3D framework architecture. The possibility of these two EMOFs as potential catalysts for the thermal decomposition of ammonium perchlorate (AP) was investigated. The results show that they have significant catalytic activity, up to reducing the peak temperature of AP decomposition from 704.0 to 613.6 K and contracting the decomposition temperature range from 451 to 320 K, which is almost one-third less than the decomposition temperature range of pure AP. The Kissinger and Ozawa-Doyle methods were used to calculate the kinetic parameters of the thermal decomposition of pure and mixed AP samples. The experimental results suggest that compound 1 has potential applications in the field of explosives and propellants. All properties suggest that compound 1 can be used as a potential catalyst.

Polymeric Carbon Nitride/Iron Oxide Composites: A Novel Class of Catalysts with Reduced Metal Content for Ammonium Perchlorate Thermal Decomposition.

The ever-growing number of space launches triggering an enormous release of metallic dead weight into the atmosphere has become a global concern. Despite technological advancements, the inclusion of environmental concerns in space research has become the need of the hour. Here, we report the impact of iron oxide (Fe2O3)-doped polymeric carbon nitride (gCN) composites with varying metal contents (namely, GF1, GF2, and GF3 with iron contents of 0.1, 0.25, and 2 mmol, respectively) as a new class of catalysts for ammonium perchlorate (AP) thermolysis. Morphology studies revealed the dendritic morphology of the synthesized Fe2O3, and X-ray photoelectron spectroscopy (XPS) analysis confirmed the effective interaction between Fe2O3 and gCN in the composites. Among all of the synthesized composites, GF2 shows superior catalytic competence toward AP decomposition by amalgamating the double-stage decomposition process into a single stage followed by a considerable decrease in the decomposition temperature. The kinetic parameters calculated for the thermal decomposition of AP with and without catalysts using the KAS method substantiated the above results by significantly reducing the activation energy from 173.2 to 151.7 kJ/mol. Later, thermogravimetric and mass-spectrometric (TG-MS) analysis gives a clear idea about the catalytic efficiency of the synthesized catalyst GF2 toward AP decomposition from the accelerated emission of decomposition products NO, NO2, Cl, HCl, Cl2, and N2O in the presence of GF2. In a nutshell, gCN/Fe2O3 will open up new horizons in the field of synthesis of new catalytic systems with minimal metal content for composite solid propellants.

Influence of the thermal stability of ammonium perchlorate in presence of heteroleptic copper (I) complexes bearing ethane-1,2-diimine and biphosphines

The present article contributes to a detailed study of the influence of copper (I) heteroleptic complexes on the thermal stability of ammonium perchlorate (AP). The studied complexes (C1–C4) are based on ethane-1,2-diimine analogues and biphosphines. The complexes C1–C4 were synthesised and characterised by NMR, HRMS, and, in the case of C1 and C3, X-ray diffraction. The effect of C1–C4 on the thermal stability of AP was studied by differential scanning calorimetry technique. These results show that the compound C4 increased the AP maximum exothermic peak from 415 °C to 432 °C and decreased the heat released from 1093 J g−1 to 414 J g−1, exhibiting the higher retardant effect on the thermal decomposition of AP, in contrast to the other evaluated complexes and the reported compounds.

Enhanced anti-migration performance of carbon nanotubes confined ferrocenyl compounds and their synergistic catalytic activity on the thermal decomposition of ammonium perchlorate

To retard high-migration issues of the commercialized ferrocene-based burning rate catalysts (BRCs), six commercial ferrocenyl derivatives (FcR), including catocene, N, N-dimethylaminomethyl ferrocene, n-butylferrocene, tert-butylferrocene, n-octylferrocene and ferrocene, were filled into carbon nanotubes (CNTs) by ultrasonication. The CNTs incorporated ferrocene nanocomposites (FcR@CNTs) were characterized by TEM, SEM, BET, XPS, FTIR, Raman and XRD techniques, which indicated that the ferrocenes are successfully filled into the CNTs. The anti-migration and anti-volatility tests unveiled that the FcR@CNTs exhibit neglectable migration tendency after four weeks of aging at 50 °C and low volatility when tested at 70 °C for 24 h. The combustion catalytic results displayed that the FcR@CNTs nanocomposites play a vital role in promoting the thermal decomposition of ammonium perchlorate (AP), with the best one lowering the peak temperature of high-temperature decomposition stage (HTD) of AP by 114.2 °C and increasing its released heat by 160%. And it was found that the smaller the diameter of a CNT is, the lower the peak temperature of AP and the higher the released heat of AP. In addition, the decomposition mechanism of AP catalyzed by FcR@CNTs(L1) was studied by thermal decomposition kinetics, in-situ solid FTIR and TG-FTIR-MS methods. The results revealed that the nanocomposites can absorb more generated NH3 and HClO4 gases during AP decomposition with formation of superoxide anions (O2−), accelerating the oxidation of N2O to NO, and promoting the AP decomposition at lower temperature. Thus, a possible decomposition mechanism of AP catalyzed by FcR@CNTs is proposed.