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Recently, many activities have been undertaken to reduce the negative impact of transport on the environment, e.g., using propulsion sources and consumed energy. Electric and hybrid vehicles are becoming more and more popular. Methods of measuring the emissivity of the means of transport as well as devices for determining measurements are being developed. This work presents an indicator method (IM) for determining the emissivity of road transport, while omitting the use of quite complicated and expensive research equipment. For typical road vehicles, it is possible to determine the emissivity means of transport, taking into account statistical data. The values of the indicators selected, based on statistical data analysis, were verified by comparing their values with the results of the actual emissivity of air pollutants. As part of the research work, the emissivity values of selected means of transport in a distribution company were determined using the IM method. The results were compared with the actual emissivity measurements. The method of indicative determination of emissivity makes it possible to estimate the initial emissivity level, knowing the type of vehicle and the distance performed as part of the transport work. Thanks to a simple and uncomplicated method, delivery planning can become more sustainable, and the selection of less emissive means of transport can contribute to reducing the negative impact of transportation on the environment.

Double-base propellants, derived from nitrocellulose and nitroglycerin, are a combined solid fuel and oxidiser system. They present smokeless combustion, and are typically utilised for small rocket motor applications. In order to provide stability in combustion performance, ballistic modifiers, which modify the burn-rate properties in three distinct ways, are added to the formulation. However, these additives are lead-based, which poses personal and environmental safety concerns. Moreover, impending European legislation will soon ban their use. Despite years of experimental research, no viable alternative currently exists, and so the impending ban presents a considerable challenge for our defence industries. For this reason, the main aim of this thesis is to develop a better understanding of the fundamental role played by lead as a ballistic modifier. Catalysis with the lead-based ballistic modifier is known to occur at the solid/gas-phase boundary of the propellant, which is known as the burning surface. It is assumed throughout this work that the lead additives, presented as metal salts in the propellant formulation, will decompose to lead oxide in the high temperatures (> 300 C) of the propellant flame. This is taken as the baseline catalytic model. As such, in this work two computational models have been employed; one to investigate catalysis in the solid-state, the other in the gas-phase. The lead additives are known to generate (i) super-rate, (ii) plateau-burn and (iii) mesa-burning effects, and it is known that carbon-soot, which builds up and is subsequently lost from the burning surface, plays an essential (but unknown) role in these burn-rate phenomena. Thus the interaction of carbon with lead oxide is a recurring theme throughout this work. Looking first to the solid-state, Chapter 3 documents a comparative study of the properties of several metal oxides, namely lead, tin and bismuth oxide. Tin and bismuth oxide are ballistic modifiers which demonstrate super-rate burning, but fail to produce plateau- and mesa-rate burning. This chapter examines the chemical reactivities of each metal oxide through computation of their electronic band gaps, surface energies and surface work functions, to deduce any unique properties that separates the behaviour of lead oxide from the other metal oxides. A layer of amorphous carbon is also bound to the stable surfaces of each metal oxide to ascertain whether any significant differences in bond strength and surface integrity arise. Chapter 4 turns its attention to investigate the formulation of industry-standard ballistic modifiers, which are derived from a blend of lead and copper salts. Here the structures of stable small metal oxide clusters which could form in the gas-phase above the burning surface are investigated with respect to their interaction with carbon. The individual roles of each metal in terms of the burn-rate effects are accounted for, and a phenomenological model is proposed that accounts for the three burn-rate effects. Finally, Chapter 5 presents a continuation of the narrative from Chapter 4, and widens the gas-phase discussion to include tin and bismuth oxide. The results obtained further validate the catalytic model presented in Chapter 4. Thus overall, the work reported in this thesis provides an atomistic interpretation of ballistic modifiers in double-base propellants, routed in first principles simulation, that provides a new platform for the continued search for lead-free additives.

RAM- and SCRAM-Jet engines can not generate static thrust and only work at high speeds. This starting velocity of the motor v0 is usually generated by carrier rockets or boosters, which mostly use solid propellants based on ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB). Modern solid propellants based on ammonium dinitramide (ADN) and Glycidyl Azide Polymer (GAP) have significant advantages in terms of environmental compatibility and thermodynamic performance. In the present work, it is shown that the already high burning rate of ADN solid propellants can be more than doubled by means of metallic fibers, which significantly increases the thrust of such engines. In order to achieve such results, 3 wt% of Al-Mg alloy fibers are added to the propellant. A formulation with 3 mm long fibres shows the highest burning rate with 84.0 mm/s at 26.5 MPa. Small scale motor tests confirm these investigations. The burning mechanism is studied by SEM/EDX investigations and by measuring the thermal conductivity. These show that the fibres remain on the burning surface and thus transfer the heat from the flame to the depth of the propellant. The thermal conductivity of samples with AlMg5 fibers is about 22 % higher than the reference.

© Cranfield University 2022. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright owner. This thesis has sought to aid the additive manufacture of propellants using a novel dry powder printing system developed at Cranfield. The energetic performance and hazard safety of crystalline energetic materials is intrinsically linked to crystal properties such as size, morphology, and crystalline phase. By optimisation of cooling, antisolvent, sonocrystallisation, spray drying and microencapsulation, the properties of cyclotrimethylenetrinitramine (RDX) and ammonium perchlorate (AP) have been engineered towards better performance within our printing system. Crystallisation of AP from solution in water has been assessed as a means of producing particles with a controllable particle size and morphology. Slow cooling processes (−7.5 °C hr-1 ) failed to produce material suited for use in propellant formulations. However, by significantly increasing the nucleation rate using rapid cooling crystallisation processes (~ −5 °C min-1 ) the size of generated crystals was greatly reduced, with a d50 range of 79.1 - 152.3 µm, compared to ~ 500 – 2000 µm. The application of ultrasonic radiation via a horn to the rapid cooling crystallisation gave promising results – leading to particle size reduction (d50 range: 33.5 – 43.4 µm) and a reduced frequency of secondary nucleation. Moreover, the average particle size distribution width was reduced from 245 µm to 75 µm by the application of sonication. Flow character, as assessed by angle of repose measurements, was good for these sonicated materials (31.0° to 34.1°). Spray drying and micro encapsulation was assessed as a means of RDX particle size reduction. Initial studies using paracetamol as an inert simulant demonstrated that modifications to spray drying process parameters (flow, atomisation pressure, nozzle diameter and feed concentration) produced measurable changes in particle size and size distribution. However, attempts to rationalise these effects using a multifactorial design of experiment were inhibited with the significant errors retrieved from the model. Attempts to understand how particle properties impact the flow character of a powder led to the observation that increased particle size gave decreased angle of repose. However, the magnitude of change was negligible when compared to the effect of reformulation in the presence of known glidant nanomaterials. Microencapsulation of RDX with cellulose acetate butyrate (CAB) was conducted at a range of operating temperatures between 55 and 100 °C. Both particle morphology and impact Figure of insensitiveness were demonstrably affected by drying temperature, and both were minimised by the use of lower drying temperatures (d50 = 2.60 µm, FoI = 102.0). FoI values for RDX/CAB microparticles correlated negatively with drying temperature, suggesting that the strain imparted by this rapid crystallisation process may be retained in the material thereby acting to influence its hazardous nature. Crystallisation of RDX by antisolvent precipitation and spray drying was assessed with the inclusion of five different tailor-made additives (TMAs). Of the assessed TMAs, 2,4-dimethyl-1nitrobenzene and 1,2-diemthyl-3- nitrobenzene were noteworthy for causing significant particle size reduction of antisolvent precipitated RDX. Crystal size enlargement and aspect ratio elongation was most pronounced when 1,3,5-triazine-2,4-diamine impurity was present. A novel application of the Scherrer equation was employed, to study the effect of TMA inclusion on the constituent crystallites within spray dried microparticles. The investigation revealed reduced coherence length of the (002) plane and extension of the (210) plane when RDX was spray dried in the presence of TMAs. PHD

Vapor–liquid equilibria and fluid interface properties of binary mixtures containing either methane or cyclohexane representing fuel and nitrogen or oxygen are reported. The mixtures are studied at different temperatures and pressures, which are chosen such that the temperature of the fuel component is subcritical, while that of the gaseous component is mainly supercritical. Data are obtained from molecular dynamics (MD) simulation, as well as density functional theory and density gradient theory in combination with the PC-SAFT equation of state (EOS). The studied interface properties include surface tension, interface thickness, enrichment, and relative adsorption. Furthermore, bulk vapor–liquid equilibrium properties are computed with two distinct MD methods as well as the PC-SAFT EOS. All approaches are compared to data from highly accurate empirical EOS. Despite the fundamental differences between these methods, very good agreement between the results of MD, density functional theory, and density gradient theory and EOS data is observed for the phase equilibria and interface properties, reinforcing the present predictions. It is found that the equivalence of nitrogen to oxygen is rather limited, in particular for the methane propellant. The disparities are particularly pronounced for low temperatures, where the compositions of the bulk phases differ significantly. As a result, enthalpy of vaporization as well as surface tension attains much higher values for mixtures containing oxygen.

The nitration of chitin monomer in a mixture of nitric acid and acetic anhydride was conducted and a highly nitrated (3R,4R,6R)-3-acetamido-6-((nitrooxy)methyl)tetrahydro-2H-pyran-2,4,5-triyl trinitrate (1) was obtained. Its structure was fully characterized using infrared spectroscopy, NMR spectroscopy, elemental analysis, and X-ray diffraction. Compound 1 possesses good density (ρ: 1.721 g·cm−3) and has comparable detonation performance (Vd: 7717 m·s−1; P: 25.6 GPa) to that of nitrocellulose (NC: Vd: 7456 m·s−1; P: 23 GPa; Isp = 239 s) and microcrystalline nitrocellulose (MCNC; Vd: 7683 m·s−1; P: 25 GPa; Isp = 250 s). However, Compound 1 has much lower impact sensitivity (IS: 15 J) than the regular nitrocellulose (NC; IS: 3.2 J) and MCNC (IS: 2.8 J). Compound 1 was calculated to exhibit a good specific impulse (Isp: 240 s), which is comparable with NC (Isp: 239 s) and MCNC (Isp: 250 s). By replacing the nitrocellulose with Compound 1 in typical propellants JA2, M30, and M9, the specific impulse was improved by up to 4 s. These promising properties indicate that Compound 1 has a significant potential as an energetic component in solid propellants.

The processes that take place within the Internal Ballistics cycle of an artillery round are highly influenced by geometric effects. They are also highly affected by the presence of a combination of energetic materials, such as the propellant, igniter, primer, and the combustible cartridge cases. For a more realistic simulation of these phenomena, a multidimensional and multicomponent numerical model is presented, based on adaptations and improvements of previous models of conservation equations, maintaining a two-phase, Eulerian–Eulerian approximation. A numerical method based on Finite Volumes and conservative flux schemes (Rusanov and AUSM+), with the ability to predict detonation effects, is proposed. As a result, a versatile 3D numerical code was obtained that was tested in the simulation of artillery firing with conventional and modular charges (MACS). Results show the code is able to characterize the heat and mass transfer of the different energetic materials during the combustion of the propellant and the cartridge cases, the gas expansion, and the projectile acceleration.

In this work, Al&ndash, Mg intermetallic powders were characterized and obtained by melting, casting into a steel chill and subsequent mechanical activation in a planetary mill. The method for producing Al12Mg17 intermetallic powder is presented. The dispersity, morphology, chemical composition, and phase composition of the obtained powder materials were investigated. Certain thermodynamic properties of high-energy materials containing the Al-Mg powder after mechanical activation of various durations were investigated. The addition of the Al-Mg powders to the high-energy composition (synthetic rubber SKDM-80 + ammonium perchlorate AP + boron B) can significantly increase the burning rate by approximately 47% and the combustion heat by approximately 23% compared with the high-energy compositions without the Al-Mg powder. The addition of the Al12Mg17 powder obtained after 6 h of mechanical activation provides an increase in the burning rate by 8% (2.5 &plusmn, 0.1 mm/s for the mechanically activated Al12Mg17 powder and 2.3 &plusmn, 0.1 mm/s for the commercially available powder) and an increase in the combustion heat by 3% (7.4 &plusmn, 0.2 MJ/kg for the mechanically activated Al-Mg powder and 7.1 &plusmn, 0.2 MJ/kg for the commercially available powder). The possibility of using the Al-Mg intermetallic powders as the main component of pyrotechnic and special compositions is shown.

International audience; There are a number of pressing problems mankind is facing today that could, at least in part, be resolved by space systems. These include capabilities for fast and far-reaching telecommunication, surveying of resources and climate, and sustaining global information networks, to name but a few. Not surprisingly, increasing efforts are now devoted to building a strong near-Earth satellite infrastructure, with plans to extend the sphere of active life to orbital space and, later, to the Moon and Mars if not further. The realization of these aspirations demands novel and more efficient means of propulsion. At present, it is not only the heavy launch systems that are fully reliant on thermodynamic principles for propulsion. Satellites and spacecraft still widely use gas-based thrusters or chemical engines as their primary means of propulsion. Nonetheless, similar to other transportation systems where the use of electrical platforms has expanded rapidly, space propulsion technologies are also experiencing a shift toward electric thrusters that do not feature the many limitations intrinsic to the thermodynamic systems. Most importantly, electric and plasma thrusters have a theoretical capacity to deliver virtually any impulse, the latter being ultimately limited by the speed of light. Rapid progress in the field driven by consolidated efforts from industry and academia has brought all-electric space systems closer to reality, yet there are still obstacles that need addressing before we can take full advantage of this promising family of propulsion technologies. In this paper, we briefly outline the most recent successes in the development of plasma-based space propulsion systems and present our view of future trends, opportunities, and challenges in this rapidly growing field.

A new energetic curing reagent, Glycidyl azide polymer grafted tetrafunctional isocyanate (N100-g-GAP) was synthesized and characterized by FT-IR and GPC approaches. Polytriazole polyethylene oxide-tetrahydrofuran (PTPET) elastomer was prepared by N100-g-GAP and alkynyl terminated polyethylene oxide-tetrahydrofuran (ATPET). The resulting PTPET elastomer was fully characterized by TGA, DMA, FTIR and mechanical test. The above analysis indicates that PTPET elastomers using N100-g-GAP as curing reagent have the potential for use in propellants. The overall formulation test of the composite propellants shows that this curing system can effectively enhance mechanical strength and bring a significant improvement in the interface interaction between the RDX &amp, AP particles and binder matrix.

The evaluation of the shelf life of, for example, food, pharmaceutical materials, polymers, and energetic materials at room or daily climate fluctuation temperatures requires kinetic analysis in temperature ranges which are as similar as possible to those at which the products will be stored or transported in. A comparison of the results of the evaluation of the shelf life of a propellant and a vaccine calculated by advanced kinetics and simplified 0th and 1st order kinetic models is presented. The obtained simulations show that the application of simplified kinetics or the commonly used mean kinetic temperature approach may result in an imprecise estimation of the shelf life. The implementation of the kinetic parameters obtained from advanced kinetic analyses into programmable data loggers allows the continuous online evaluation and display on a smartphone of the current extent of the deterioration of materials. The proposed approach is universal and can be used for any goods, any methods of shelf life determination, and any type of data loggers. Presented in this study, the continuous evaluation of the shelf life of perishable goods based on the Internet of Things (IoT) paradigm helps in the optimal storage/shipment and results in a significant decrease of waste.

To ensure safety and reliability, it is important that the explosives and other materials used in munitions do not interact adversely either physically or chemically. Data obtained by heat flow calorimetry on nitrocellulose-based propellants have been reviewed with the aim of identifying improved chemical compatibility assessment criteria. It was shown that relative and absolute assessment techniques could give contrary sentencing. It was concluded that basing the assessment on the absolute criteria would have the advantage that alternative test temperatures and durations could be utilised. After 7 days at 85 °C the increase in the absolute heat flow of the mixture should be

To ensure safety and reliability, it is important that the explosives and other materials used in munitions do not interact adversely either physically or chemically. Data obtained by heat flow calorimetry on nitrocellulose-based propellants have been reviewed with the aim of identifying improved chemical compatibility assessment criteria. It was shown that relative and absolute assessment techniques could give contrary sentencing. It was concluded that basing the assessment on the absolute criteria would have the advantage that alternative test temperatures and durations could be utilised. After 7 days at 85 °C the increase in the absolute heat flow of the mixture should be

The development of new generations of propellants with better energetic properties may be hampered by unsatisfactory mechanical behaviors in terms of strength and toughness. A micromechanical approach is adopted to provide a better understanding of the existing links between the constitutive phase behaviors and the local damage, and the macroscopic mechanical behavior of these materials. Three model materials have been made and tested in uniaxial tension. The stress-strain responses were recorded while monitoring their volume changes that quantify the macroscopic damage. A qualitative description of the local damage was obtained thanks to scanning electron microscopy images of samples under loading. The micromechanical approach consists in finite elements analyses on periodic microstructures of non-regular polyhedral particles embedded in a soft matrix. An original microstructure generation tool has been developed specifically in order to obtain highly filled isotropic microstructures. Debonding at the matrix/filler interface was taken into account with a cohesive-zone model (CZM). The impact of the CZM parameters is discussed, in an effort to make the link between the CZM parameters and how the local damage appears and develops, and between the cohesive behavior and the shape of the macroscopic stress-stretch responses of the heterogeneous materials. This work was supported by the ANR (France) under contract num-ber ANR-10-EQPX- 37, and the authors thank the Délégation Générale de l’Armement (DGA) and ArianeGroup, Vert-le-Petit (France), for their financial supports.

This paper includes the results of the examination of the single base propellants, double base propellants and double base rocket propellants with the Czech Vacuum Stability Test STABIL. For this method the main term was to analyze and define the best options for preparation of the samples, selection of the optimal mass of the samples and conditions of examination. Chemical stability of these samples was determined according to the STANAG 4556 standard method.

The propellant to fill the fuel tanks of the spacecraft, upper stages, and space rockets on technical and ground-based launch sites before fueling should be prepared to ensure many of its parameters, including temperature, in appropriate condition. Preparation of fuel temperature is arranged through heating and cooling the rocket propellants (RP) in the tanks of fueling equipment. Processes of RP temperature preparation are the most energy-intensive and timeconsuming ones, which require that a choice of sustainable technologies and modes of cooling (heating) RP provided by the ground-based equipment has been made through modeling of the RP [1] temperature preparation processes at the stage of design and operation of the groundbased fueling equipment.The RP temperature preparation in the tanks of the ground-based systems can be provided through the heat-exchangers built-in the internal space and being external with respect to the tank in which antifreeze, air or liquid nitrogen may be used as the heat transfer media. The papers [1-12], which note a promising use of the liquid nitrogen to cool PR, present schematic diagrams and modeling systems for the RP temperature preparation in the fueling equipment of the ground-based systems.We consider the RP temperature preparation using heat exchangers to be placed directly in RP tanks. Feeding the liquid nitrogen into heat exchanger with the antifreeze provides the cooling mode of PR while a heated air fed there does that of heating. The paper gives the systems of equations and results of modeling the processes of RP temperature preparation, and its estimated efficiency.The systems of equations of cooling and heating RP are derived on the assumption that the heat exchange between the fuel and the antifreeze, as well as between the storage tank and the environment is quasi-stationary.The paper presents calculation results of the fuel temperature in the tank, and coolant temperature in the heat exchanger, as well the heat flows and the relative amounts of the liquid nitrogen used to cool the fuel RG-1 as compared with other cooling technologies.The RP temperature preparation process using a heat exchanger, placed directly in the tank of the filling system is applicable for any high-boiling RP and has some of the best performance characteristics.Modeling the heating and cooling RP processes in the internal tanks of the ground-based systems using the numerical solution of the equations presented can be applied when calculating the RP temperature preparation processes with estimating their effectiveness and time of heating and cooling operations of RP.

One of the main figures of merit in laser-ablative propulsion is the specific impulse, Isp, defined as the impulse per unit weight of fuel, and it is related to the exhaust velocity, ve, by the acceleration of gravity, Isp = ve/g. Being a key magnitude, Isp needs to be accurately determined. It is usually inferred from other measurable quantities: the impulse coupling coefficient, Cm, defined as the ratio of the target momentum produced to the incident laser pulse energy, and Q∗, the laser energy consumed per unit weight of ablated target material. Thus, Isp is calculated as Isp = CmQ∗/g. However, single pulse ablated mass leading to Q∗ is in the nanogram scale and cannot be directly measured by weighting the targets. So, mass loss measurements are performed by analyzing the volumes of the craters produced by a large number of laser pulses. These procedures lead to larger than desired uncertainties in the Isp values. On the other hand, more precise measurements of Isp can be carried out from the direct measurement of the exhaust velocity of the ejected particles by interferometric methods. In this work, a system based on a Nomarsky interferometer has been set up for the time-resolved diagnostic in the nanometric scale of laser ablation plumes. The performance of the implemented system was first validated by measuring the Isp produced by aluminum targets and solid propellants based on metal/salt mixtures. The Cm dependence on laser parameters and binary composition of these propellants have been determined in previous works with a torsion pendulum and a piezoelectric sensor. Once the interferometer performance is characterized, the Isp produced by solid propellants composed of metal (Zn) and metal oxides (ZnO) matrices doped with nanoparticles of different materials is determined and compared. Fil: Toro Salazar, Cinthya Emma. Departamento de Investigaciones en Láseres y Aplicaciones, CITEDEF- UNIDEF (MINDEF-CONICET) ; Argentina Fil: Rinaldi, Carlos Alberto. Departamento de Micro y Nanotecnología - Centro Atómico Constituyentes - Comisión Nacional de Energía Atómica. Fundación Argentina de Nanotecnologia ; Argentina Fil: Azcárate, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina

This work aims to establish a hierarchy of risks of the stabilizers used in nitrocellulose-based propellants concerning to toxicity, carcinogenicity and mutagenicity. Four stabilizers - diphenylamine, ethyl centralite, akardite-II and 2-nitrodiphenylamine - and their products of degradation were investigated. The prediction of the toxicity was based on the analysis of their structures with the software Lazar, using the OpenTox framework. Our results provide a quantitative reference of the risks involved in the manufacturing and disposal of propellants due to the use of such stabilizers.

Background Current pressurised metered dose asthma inhaler (pMDI) propellants are not inert pharmacologically as were previous chlorofluorocarbons, have smooth muscle relaxant‚ partial pressure effects in the lungs and inhaled hydrofluoroalkane 134a (norflurane) has anaesthetic effects. Volumes of propellant gas per actuation have never been measured. Methods In-vitro studies measured gas volumes produced by pMDIs on air oxygen (O2) levels in valved holding chambers (VHC) and the falls in O2% following actuation into lung ventilator delivery devices. Results Volumes of propellant gas hydrofluoroalkane (HFA) 134a and 227ea and redundant chlorofluorocarbons (CFC) varied from 7 ml per actuation from a small salbutamol HFA inhaler to 16 ml from the larger. Similar-sized CFC pMDI volumes were 15.6 and 20.4 ml. Each HFA salbutamol inhaler has 220 full volume discharges; total volume of gas from a small 134a pMDI was 1640 ml, and large 3885 ml. Sensing the presence of liquid propellant by shaking was felt at the 220th discharge in both large and small inhalers. Because of a partial pressure effect, VHC O2% in air was reduced to 11% in the smallest 127 ml volume VHC following 10 actuations of a large 134a salbutamol inhaler. The four ventilator delivery devices studied lowered 100% oxygen levels to a range of 93 to 81% after five actuations, depending on the device and type of pMDI used. Conclusion Pressurised inhaler propellants require further study to assess smooth muscle relaxing properties.

The PhD thesis presented in this manuscript focused on the elaboration and characterization of propellants with reduced sensitivities. This was accomplished by the use of relatively insensitive energetic materials, in conjunction with the application of the Spray Flash Evaporation (SFE) process. The latter made it possible to obtain nanostructured propellants of ternary composition.The characterization of these propellants by Raman spectroscopy revealed the mechanisms ruling the plasticization of nitrocellulose by the plasticizers used. Scanning electron microscopy analyzes were conducted to determine the particle size of these samples. Their characterization by X-ray diffraction allowed to study their structure and their crystallization. These propellants were shown to be particularly insensitive through analyses by differential scanning calorimetry,pyrotechnic tests in tubes and manometric vessels as well as sensitivity measurements to various types of solicitations., Les travaux de thèse présentés dans ce manuscrit ont porté sur l’élaboration et la caractérisation de poudres propulsives à sensibilités réduites. Ceci a été effectué par l’utilisation de matériaux énergétiques relativement insensibles ainsi que par l’emploi du procédé de Spray Evaporation Flash (SFE). Ce dernier a permis d’obtenir des poudres nanostructurées de composition ternaire. La caractérisation de ces poudres propulsives par spectroscopie Raman a permis de mettre en évidence le mécanisme de plastification de la nitrocellulose par les plastifiants employés. Des analyses de microscopie électronique à balayage ont été menées pour étudier la granulométrie de ces échantillons. Leur caractérisation par diffraction des rayons X a permis d’étudier leur structure et leur cristallisation. Des mesures de calorimétrie différentielle à balayage, des essais de tirs en tubes et en bombe manométrique, ainsi que des mesures de sensibilités à divers types de sollicitations, ont permis de montrer que les poudres obtenues sont particulièrement insensibles.

Conventional gun propellants exhibit the phenomenon of nitrocellulose (NC) decomposition. Besides an effect on thermal stability of propellants, decomposition of NC has an effect on the mechanical integrity of the propellant grains. Enhanced grain fracture may lead to unacceptable changes of the pressure build-up. The effect of ageing on NC molecular weight, mechanical properties and performance has been investigated for the main propellants of 155-mm cartridge-bags. Grain fracture appears to affect the peak pressure much more than the muzzle velocity. This effect is strongly related to the loading density and can for a great part be explained by internal ballistic simulations.

Conventional gun propellants exhibit the phenomenon of nitrocellulose (NC) decomposition. Besides an effect on thermal stability of propellants, decomposition of NC has an effect on the mechanical integrity of the propellant grains. Enhanced grain fracture may lead to unacceptable changes of the pressure build-up. The effect of ageing on NC molecular weight, mechanical properties and performance has been investigated for the main propellants of 155-mm cartridge-bags. Grain fracture appears to affect the peak pressure much more than the muzzle velocity. This effect is strongly related to the loading density and can for a great part be explained by internal ballistic simulations.

Since common energetic materials are not easily compatible with existing additive manufacturing techniques, the Energetic Materials department of TNO in the Netherlands worked closely together with the Additive Manufacturing and Material Solutions groups of TNO to develop new types of energetic material that can be processed in standard 3D printers, aiming at better performance and greater flexibility in the manufacturing of energetic products. This contribution gives an overview of potential applications for additive manufacturing of energetic materials, ranging from rocket propellants to explosives, gun propellants, and other applications. The paper then briefly describes TNO’s research efforts since 2013 into AM of energetic materials. Next, the work performed on additive manufacturing of gun propellants, using stereolithography, is described in more detail, including the results of the material development and characterization, and performance test results, including test firings with a 30 mm gun. The paper concludes with an overview of the current status of the research at TNO, as well as a definition of the next steps to be taken and a vision of the future of additive manufacturing of energetic materials.

Three planar miniaturized perchlorate membrane sensors (3×5 mm(2)) are prepared using a flexible Kaptan substrate coated with nitron-perchlorate (NT-ClO4) [sensor 1], methylene blue-perchlorate (MB-ClO4) [sensor II] and indium-porphyrin (In-Por) [sensor III] as electroactive materials in PVC membranes plasticized with 2-NPPE. Sensors I, II and III display near-Nernstian response for 1.0×10(-5)-1.0×10(-2), 3.1×10(-5)-1.0×10(-2) and 3.1×10(-6)-1.0×10(-2) mol L(-1) ClO4(-) with lower detection limits of 6.1×10(-6), 6.9×10(-6) and 1.2×10(-6) mol L(-1), and anionic calibration slopes of 50.9±0.4, 48.4±0.4 and 57.7±0.3 mV decade(-1), respectively. Methods for determining perchlorate using these sensors offer many attractive advantages including simplicity, flexibility, cost effectiveness, wide linear dynamic response range (0.1-1000 ppm), low detection limit (1.2×10(-6) mol L(-1)≡0.1 ppm), small sample test volume (100 μL), safety, short response time (20 s), long life span (~8 weeks), and extended wide working pH range (4.5-8.0). The sensors show high selectivity in the presence of some inorganic ions (e.g., PO4(3-), SO4(2-), S2O3(2-), NO2(-), NO3(-), N3(-), CN(-), Cl(-), Br(-), I(-)) and automation feasibility. Indium-porphyrin based membrane sensor (sensor III) is used as a detector in a wall-jet flow injection set-up to enable accurate flow injection analysis (FIA) of perchlorate in some fireworks without interferences from the associated reducing agents (sulfur and charcoal), binders (dextrin, lactose), coloring agents (calcium, strontium, copper, iron, sodium), color brighten (linseed oil) and regulators (aluminum flakes) which are commonly used in the formulations. The sensor is also used for perchlorate assessment in some propellant powders. The results fairly agree with data obtained by ion-chromatography.

This paper examines the effect of mixer size on the density of the propellant and it also explores the role of the propellant density with regards to burning rate and burn rate pressure index. Propellant samples were prepared in the four different size (15, 70, 200 and 1000 g) mixers with identical input of ingredients to examine the effect of mixer size on density and burning rate of the composite solid propellant. It was noticed that density and burning rate of the propellant changes significantly with change in the mixer size from 15 g to 1000 g. This is because for the smaller mixers the surface area to volume ratio is large and the actual percentage of aluminum and ammonium perchlorate (especially coarse) that goes into the propellant reduces. High burning rate with decrease in mixer size is also accompanied with increase in burn rate pressure index. The composition analysis was also carried out and it is noticed that the actual percentage of the ingredients is different from the intended percentage of the ingredients and percentage change is more when the mixer size decreases. � 2013 IAA.

This paper proposes the use of micron-sized aluminum (pyral, average particle size 3.66 ?m) with a higher specific surface area as a good candidate to enhance the burn rate of the composite propellant. Experiments were performed in the pressure range of 10 to 70 bar in a window bomb for measuring the burn rate. Comparison of these burn rate results with those obtained using micron- and nanosized aluminum found that the performance of pyral was in between that of micron- and nanosized aluminum. The reason for the high burn rates observed with pyral is due to the flake like appearance of pyral with a large specific surface area. It is argued that, if the specific surface area is large, then the thickness becomes the characteristic length scale. This ensures the heat release from the aluminum combustion to occur closer to the propellant surface as the thickness of pyral is in nanometers. Both the x-ray diffraction and heat of formation analyses indicated that pyral had higher purity than nanoaluminum, which has an implication to the specific impulse of the propellant. In addition to this, it shows that the micron-sized catalyst is effective with pyral, whereas it is ineffective with nanoaluminum. This study also reports the mechanical properties of the propellant containing pyral.

Sixteen propellant formulations based on ammonium perchlorate (AP), hydroxyl-terminated polybutadiene, and aluminium particles have been tested for size distribution of aluminium agglomerates emerging from their burning surface. The formulations are based on a bimodal size distribution of AP particles. Ten of the formulations exhibit one or two plateaus/mesa in their burning rate variation with pressure (zero/negative pressure exponent of burning rate). The relevant formulation variables, namely, coarse and fine AP sizes and coarse-to-fine ratio, aluminium size and content, and two different curing agents, have been varied. Tests are performed in the 1-10 MPa pressure range. A direct correlation between burning rate and agglomerate size exists for propellants with normal burning rate trends but a neutral or inverse correlation is observed for those exhibiting plateau burning behaviour. Larger the parent aluminium size, lesser the agglomeration, as expected; but the effect of aluminium content is non-monotonic. The coarse AP size influences the aluminium agglomerate size as expected from the pocket model regardless of plateau burning effects. The agglomerate size decreases with increase in fine AP size, however. A computer model developed earlier at this laboratory for prediction of aluminium agglomerates based on three-dimensional packing of particles and deduction of AP particles with attached leading edge diffusion flames is applied to the present formulations. The model under-predicts the agglomerate size, only marginally for propellants that do not exhibit plateau burning rate trends, but substantially, otherwise. This is because it does not take into account effects of binder melt flow and is independent of the curing agent of the binder. � 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Results of a testing campaign to assess multiple commercially available three-dimensional printer materials for effectiveness in an arc-ignition system for hybrid rockets are presented. Previously, a form of additive manufacturing known as fused deposition modeling was used to fabricate high-density acrylonitrile butadiene styrene (ABS) fuel grains so that, when properly layered, they possess unique electrical breakdown properties. When subjected to an inductive charge, an electrical arc flows along the layered material surface and seeds combustion when the arc occurs simultaneously with the introduction of an oxidizing flow. This study investigates commercially available three-dimensional printable materials to search for equivalent or possibly superior fuel alternatives to ABS. Test specimens include photopolymers processed using polyjet (stereolithography) and fused-deposition printing. Comparison metrics include general arc ability, pyrolysis rate, dissipated power, characteristic velocity, and ability for multiple restarts. Initially, an ensemble of eight commonly available “printable” polymers was evaluated, and only four printable materials (high- and low-density ABS, VeroClear®, and white polycarbonate) were found to possess effective sparking properties. In follow-on burn tests, only high- and low-density ABS and VeroClear performed effectively as fuel materials. White polycarbonate would not ignite using the arc method. High-density ABS exhibited the best overall ignition properties and characteristic velocity.

Energetic cocrystals, or energetic materials that consist of two or more components that form a unique crystalline structure with unique properties, are currently being investigated as a possible method for decreasing the sensitivity of high energy density explosives for use in powerful solid composite propellants. Fuels more powerful than those in current use have not been practical because of their increased safety hazard due to higher sensitivity to being ignited. This has been one of the barriers that has prevented solid composite propellants from seeing significant improvements in performance. This study is an attempt to characterize a cocrystal of HMX and ammonium perchlorate (AP) of 2:3 molar mass ratio. The cocrystal was compared to the equivalent physical mix and baseline propellants of HMX and AP. Planar laser induced fluorescence (PLIF) was performed to measure hydroxyl (OH) concentrations in the propellants’ flames. It appeared that the flame structure of the cocrystal was very similar to that of HMX, as well as the distribution of OH concentrations around the flame. The results were inconclusive, and it is believed that the cocrystal’s constituents were not sufficiently bonded at the molecular level; thus, the cocrystal was instead more a mixture of smaller individual crystals of HMX and AP. Future research could include cocrystals created by varying methods, and perform cyano (CN) PLIF to characterize these cocrystals, which may display a better defined region of interest in the flame that can be more closely studied and answer more questions.

International audience; Hall-effect thrusters (HETs) operated with xenon are one of the most commonly used electric propulsion technologies for a wide range of space missions, including drag compensation in low Earth orbit, station-keeping, and orbital insertion, as access to space becomes more affordable. Although anomalous electron transport, the electron drift instability (EDI), and secondary electron emission (SEE) have been studied experimentally and numerically in xenon-based HETs, the impact of alternative propellants is still poorly characterized. In this work, a two-dimensional particle-in-cell/Monte Carlo collision code is used to model the (r – θ) plane of a HET operated separately with four different noble gases: xenon, krypton, argon, and helium. Models for electron induced secondary electron emission (SEE) and dielectric walls are implemented in order to investigate the coupling between the propellant choice and the radial thruster walls. For all conditions and propellants studied, an EDI and enhanced electron cross-field transport are observed. The frequency of the instability, as well as the electron mobility, is compared with analytical expressions from a recently developed kinetic theory. Confirming this theory, it is shown that while the frequency of the EDI depends on the propellant mass, the electron mobility appears to be almost independent of the propellant choice.

An analytical framework is developed to understand and predict the thermoacoustic instability in solid rocket motors, taking into account the non-orthogonality of the eigenmodes of the unsteady coupled system. The coupled system comprises the dynamics of the acoustic field and the propellant burn rate. In general, thermoacoustic systems are non-normal leading to non-orthogonality of the eigenmodes. For such systems, the classical linear stability predicted from the eigenvalue analysis is valid in the asymptotic (large time) limit. However, the short-term dynamics can be completely different and a generalized stability theory is needed to predict the linear stability for all times. Non-normal systems show an initial transient growth for suitable initial perturbations even when the system is stable according to the classical linear stability theory. The terms contributing to the non-normality in the acoustic field and unsteady burn rate equations are identified. These terms, which were neglected in the earlier analyses, are incorporated in this analysis. Furthermore, the short-term dynamics are analysed using a system of differential equations that couples the acoustic field and the burn rate, rather than usingad hocresponse functions which were used in earlier analyses. In this paper, a solid rocket motor with homogeneous propellant grain has been analysed. Modelling the evolution of the unsteady burn rate using a differential equation increases the degrees of freedom of the thermoacoustic system. Hence, a new generalized disturbance energy is defined which measures the growth and decay of the oscillations. This disturbance energy includes both acoustic energy and unsteady energy in the propellant and is used to quantify the transient growth in the system. Nonlinearities in the system are incorporated by including second-order acoustics and a physics-based nonlinear unsteady burn rate model. Nonlinear instabilities are analysed with special attention given to ‘pulsed instability’. Pulsed instability is shown to occur with pressure coupling for burn rate response. Transient growth is shown to play an important role in pulsed instability.

The main objective of these studies was the synthesis and characterization of new energetic binders and their use in some propellant formulations. Following the working plan elaborated, the synthesis and characterization of the following compounds has been done successfully: GAP; energetic Monomer BAMO; energetic Binders; copolymer GAP/PolyBAMO. The scale up for the synthesis of copolymer GAP/PolyBAMO and PolyBAMO using GAP as initiator has been done and they were fully characterized by IR, (1H, 13C) NMR-spectroscopy, GPC, elemental analysis, OH-functionality, differential scanning calorimetry (DSC) and sensitivity tests (friction, impact). For this two scale up synthesis some propellant formulations were carried out and the results of mechanical and burning properties have been compared with GAP propellants.

Synthesis and characterization of energetic ABA-type thermoplastic elastomers for propellant formulations has been carried out. Following the working plan elaborated, the synthesis and characterization of Poly 3- bromomethyl-3-methyl oxetane (PolyBrMMO), Poly 3- azidomethyl-3-methyl oxetane (PolyAMMO), Poly 3,3-bis-azidomethyl oxetane (PolyBAMO) and Copolymer PolyBAMO/AMMO (by TDI end capping) has been successfully performed. The thermoplastic elastomers (TPEs) were synthesized using the chain elongation process PolyAMMO, GAP and PolyBAMO by diisocyanates. In this method 2.4-toluene diisocyanate (TDI) is used to link block A (hard and mono- functional)) to B (soft and di-functional). For the hard A-block we used PolyBAMO and for the soft B-block we used PolyAMMO or GAP.This is a joint project set up, some years ago, between the Chemistry Division of the Institute of Aeronautics and Space (IAE) - subordinated to the Brazilian Ministry of Defense - and the Fraunhofer Institut Chemische Technologie (ICT), in Germany. The products were characterized by different techniques as IR- and ( ¹ H, ¹³ C)NMR spectroscopies, elemental and thermal analyses. New methodologies based on FT-IR analysis have been developed as an alternative for the determination of the molecular weight and CHNO content of the energetic polymers.

This paper shows different aspects related to the application of different thermal analysis techniques in the study of energetic materials. The criteria used to choose the best technique and an exact approach to adjust the experimental data with a proper model are here discussed. The paper shows how to use the different thermal analysis results to help develop new compounds, to study the stability of some energetic materials and their compatibility, and the conditions necessary for a secure storing environment.

This paper shows different aspects related to the application of different thermal analysis techniques in the study of energetic materials. The criteria used to choose the best technique and an exact approach to adjust the experimental data with a proper model are here discussed. The paper shows how to use the different thermal analysis results to help develop new compounds, to study the stability of some energetic materials and their compatibility, and the conditions necessary for a secure storing environment.

O propósito deste trabalho foi determinar os parâmetros cinéticos de decomposição térmica para uma amostra de propelente base simples e base dupla. Os dados obtidos pela calorimetria exploratória diferencial foram ajustados para o modelo cinético de pseudo-primeira ordem de Flynn, Wall e Ozawa. Os respectivos parâmetros obtidos foram: BS REX 1200 (Ea) (2,3 ± 0,2) 10² kJ mol-1 e (A) 1,34 10(25) min-1; BD-111 (Ea) (1,6 ± 0,1) 10² kJ mol-1 e (A) 3,31 10(17) min-1. O espectro de infravermelho da amostra de propelente base dupla indicou a presença de salicilato, justificando o comportamento de decomposição observado na respectiva curva térmica.The purpose of this work was to determine the kinetics parameters of the thermal decomposition of a sample single-base (BS) and double-base (BD) propellants. The experimental data obtained by differential scanning calorimetry (DSC) were adjusted to the pseudo-first order kinetic model of Flynn, Wall and Ozawa. The respective parameters obtained are: BS REX 1200 (Ea) (2.3 ± 0.2) 10² kJ mol-1 and (A) 1.34 10(25) min-1; BD-111 (Ea) (1.6 ± 0.1) 10² kJ mol-1 and (A) 3.31 10(17) min-1. IR spectrum has confirmed the presence of salicilate in the double-base (BD) propellant and some correlations corroborate the conclusions about the decomposition mechanism.

Advances in experimental, high-speed techniques can be used to explore the processes occurring within energetic materials. This review describes techniques used to study a wide range of processes: hot-spot formation, ignition thresholds, deflagration, sensitivity and finally the detonation process. As this is a wide field the focus will be on small-scale experiments and quantitative studies. It is important that such studies are linked to predictive models, which inform the experimental design process. The stimuli range includes, thermal ignition, drop-weight, Hopkinson Bar and Plate Impact studies. Studies made with inert simulants are also included as these are important in differentiating between reactive response and purely mechanical behaviour. Graphical abstract

A tensile module system placed within a FEI NovaNanoSEM 650 Scanning Electron Microscope (SEM) was utilized in this work to conduct in-situ tensile testing of propellant material samples. This tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under tensile force. The test specimens utilized were one quarter sized JANNAF samples (31.75 mm length by 6.34 mm width by 3.175 mm thickness). A test plan was developed with varying the experimental parameters of the tensile module system and studying how they affect the failure mechanism of the samples. The experimental parameters varied included strain rate and sample temperature (-54°C, +21°C, +40°C). Stress-Strain diagrams were recorded during the in-situ tensile tests, and these results were coupled with the in-situ images and videos of the samples captured with SEM analysis. This in-situ tensile module system allows for the study of many other propellant and related materials in the near future.

The surveillance of gun propellants is basically performed either by an investigation into the thermal behavior of the propellant or by the determination of its remaining effective stabilizer content. Over the years it is shown that the surveillance of NC based gun propellants is necessary. NC based materials are intrinsically unstable, and can cause many accidents. Some accidents were caused by old unstable material, other ones were initiated by the extreme conditions during storage, like during expeditionary operations of military forces. And in quite a few cases it was a combination of these. Surveillance tests have changed over the years, and the last philosophy is to test the propellants as close as possible in comparison to the way they are stored [1] for this way of testing the Heat Flow Calorimetry (or microcalorimetry) method is the optimum. Older methods like the Abel heat test, Methyl Violet Test, Bergman-Junk stability test, are test methods an analysis of the current status, without or very limited prediction behavior. Besides that the temperatures are relatively high, the measuring value is quite strongly dependent of the observer/operator. In general these tests are applied for propellants and sometimes explosives, although the general application worldwide (as far they are in use by countries) is propellants.

A tensile module system placed within a FEI NovaNanoSEM 650 Scanning Electron Microscope (SEM) was utilized in this work to conduct in-situ tensile testing of propellant material samples. This tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under tensile force. The test specimens utilized were one quarter sized JANNAF samples (31.75 mm length by 6.34 mm width by 3.175 mm thickness). A test plan was developed with varying the experimental parameters of the tensile module system and studying how they affect the failure mechanism of the samples. The experimental parameters varied included strain rate and sample temperature (-54°C, +21°C, +40°C). Stress-Strain diagrams were recorded during the in-situ tensile tests, and these results were coupled with the in-situ images and videos of the samples captured with SEM analysis. This in-situ tensile module system allows for the study of many other propellant and related materials in the near future.

Boron's energy potential as a combustion fuel can be harnessed by using nanosize solid particulates. In this study, functionalized boron nanoparticles were produced through highyield ball milling techniques. The organic surface coating protected oxide-free boron nanoparticles from air oxidation and at the same time promoted dispersion in polar and nonpolar liquid fuels. For dispersion in hydrophobic fuels, oleic acid was used as ligand, and its interaction with boron nanoparticles was studied using XPS, FTIR, 13C-NMR and TGA. Results show that oleate species bonded to boron nanoparticles through a bridging bidentate interaction. Furthermore, undissociated oleic acid molecules persisted on the surface which may be anchored through intercalation with covalently bonded oleate species. Hydrogenation of boron through H 2 gas milling provides an alternative pathway of increasing ignitability and specific impulse of boron nanoparticles. It was also used to alkylate boron nanoparticles for dispersion in liquid hydrocarbon fuels. Boron nanoparticles were also milled with hypergolic ionic liquids to increase their energy density. Spectroscopic experiments that probed interactions of boron with 1-methyl-4-amino-1,2,4-triazolium dicyanamide([MAT][DCA]) and 1-butyl-3-methyl-imidazolium dicyanamide([BMIM][DCA]) suggest that a possible B-N binding exist between the amino substituent of [MAT][DCA] and the dicyanamide anion of both ILs.

This paper examines scanning electron micrographs for the size of cells that appear on the burning surfaces of (1) single crystals and pressed pellets of ammonium perchlorate (AP), and (2) mixtures of fine AP particles with polymeric binder, quenched by rapid depressurization at different pressures. While the cellular structures in self-deflagration of AP are well known yet unexamined quantitatively, those on fine AP/binder mixtures are examined in the context of their mid-pressure extinction leading to plateau burning rate behavior of propellants containing them. The results are an experimental validation of the theoretical predictions of Margolis and Williams (1988) [1] based on diffusional-thermal coupling in the intrinsic stability of combustion of premixed solids. � 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

The surveillance of gun propellants is basically performed either by an investigation into the thermal behavior of the propellant or by the determination of its remaining effective stabilizer content. Over the years it is shown that the surveillance of NC based gun propellants is necessary. NC based materials are intrinsically unstable, and can cause many accidents. Some accidents were caused by old unstable material, other ones were initiated by the extreme conditions during storage, like during expeditionary operations of military forces. And in quite a few cases it was a combination of these. Surveillance tests have changed over the years, and the last philosophy is to test the propellants as close as possible in comparison to the way they are stored [1] for this way of testing the Heat Flow Calorimetry (or microcalorimetry) method is the optimum. Older methods like the Abel heat test, Methyl Violet Test, Bergman-Junk stability test, are test methods an analysis of the current status, without or very limited prediction behavior. Besides that the temperatures are relatively high, the measuring value is quite strongly dependent of the observer/operator. In general these tests are applied for propellants and sometimes explosives, although the general application worldwide (as far they are in use by countries) is propellants.

A tensile module system placed within a FEI NovaNanoSEM 650 Scanning Electron Microscope (SEM) was utilized in this work to conduct in-situ tensile testing of propellant material samples. This tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under tensile force. The test specimens utilized were one quarter sized JANNAF samples (31.75 mm length by 6.34 mm width by 3.175 mm thickness). The focus of this study was to vary the experimental parameters of the tensile module system and analyze how they affect the failure mechanism of the samples. The experimental parameters varied included strain rate and sample temperature (-54oC, +25oC, +40oC). Stress-Strain diagrams were recorded during the in-situ tensile tests, and these results were coupled with the in-situ images and videos of the samples captured with SEM analysis. This in-situ tensile module system allows for the study of many other propellant and related materials in the near future.

Kao i sve energetske supstance, baruti i raketna goriva su termodinamički nestabilni, zbog čega, tokom skladištenja, dolazi do njihove kemijske dekompozicije (starenja). Proces starenja dovodi do promene njihovih funkcionalnih karakteristika, i do smanjenja sigurnosti u toku skladištenja zbog potencijalne opasnosti od samozapaljenja. U raduje objašnjen mehanizam dekonpozicije nitroestara i fenomen kemijske stabilnosti baruta i raketnih goriva. Izvršena je komparativna analiza naše i NATO metodologije za kontrolu kemijske stabilnosti, a posebno su navedeni uočeni nedostaci u dosadašnjoj primeni standarda SNO 8069/91. Kao optimalno rešenje ovog problema predloženo je prihvatanje odgovarajućih STANAG standarda koji regulišu ovu problematiku. / As the other energetic substances, propellants are thermodynamically unstable. Thereby, during storing, they undergo chemical decomposition process (aging). Aging process are cause changing their functional properties and decreasing safe during storage because of potential hazard from self ignition. The decomposition mechanism of nitro esters and chemical stability phenomena of propellants are shortly discussed in these papers. The compared analysis of domestic and NATO methodology for investigation of chemical stability is realized. The observed deficiencies in up to now application of standard SNO 8069/91 are specially mentioned. As optimal solution of this problem it is supposed to accept corresponding STANAG standards that regulate this problematic.

In the Brazilian Complete Spacial Mission, the research of Vehicle Satellite Launcher is important. The solid propellant composite used in this vehicle is made with ammonium perchlorate, aluminiun powder and hydroxy terminated polibutadiene resin. In the propellant the bonding agent has a function to promote the interaction between solids and polimeric matrix, improving mechanical properties as stress, strain, aging characteristics and moisture embrittlement. Due its importance in propellant, bonding agent is consider as industrial secret and the literature about it is generic, without greater informations.