ABSTRACT: The purpose of this article is to present a study on the technological development of propellants, which are used in solid and hybrid rocket motor, that have been employing hydroxyl-terminated polybutadiene (HTPB) as a binder, for the past ten years. The results prove that major research conducted on propulsion technologies continues using HTPB as a binder, with China and the United States being the countries with greater publications, and Brazil appearing at the fifth position in the ranking. The scientific and technological information was collected from articles, conference papers, reviews (over the last ten years) and patents granted in the United States by scientific and USPTO patent databases.

ABSTRACT: The research for low toxicity and no damage to the environment has stimulated the development of specific investigation lines in many areas. Inevitably, the criteria for safe handling, sensitivity and, above all, specific impulse (efficiencies) of propellant compositions are still superior in relation to ecological appeals. Nowadays, however, the solid or liquid propulsion, as aerospace as military, has already compounds to efficiency and eco-friendly characteristics. This study aimed at describing “green” alternatives to propulsive systems.

Abstract: Hypergolic reactions may be useful in civil and military applications. In the area of rocket propulsion, they constitute a potential field due to the reduced weight and complexity of fuel injection systems, allowing yet controlled use of the propulsors. This manuscript aimed at presenting different hypergolic systems and their particularities, comparing them with chemical propulsion svstems, which are most commonly employed in rocket motors, for example.

Abstract The 2,4,6-triamino-1,3,5-trinitrobenzene (TATB) is perhaps the most thermostable and insensitive explosive known. Its low sensibility to shock makes it suitable for military and civil applications. TATB application is done either alone or in combination with another high energetic material. This study aimed at reporting the review about many processes to produce TATB and the problems associated with them, as well as suggest techniques like Fourier Transform Infrared Spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC), which can be useful in the characterization of this energetic compound.

Resumo: Embora a composição química seja a mesma, as propriedades físico-químicas dos polimorfos podem ser totalmente distintas, como, por exemplo, a condução ou não de eletricidade. Discute-se até mesmo a legalidade de reconhecê-los como produtos totalmente novos, dadas as características próprias que um polimorfo pode ter em detrimento de outro. Fato é que os diferenciais de solubilidade, estabilidade e formação de sítios ativos de fases distintas de uma substância despertam interesse dos variados setores economicamente ativos. Não são poucos os materiais energéticos polimórficos, ou precursores deles, que também apresentam aplicações terapêuticas. Portanto, algumas das técnicas desenvolvidas pela lucrativa indústria farmacêutica para o estudo do polimorfismo podem ser adaptadas às necessidades da indústria de material de defesa. Este trabalho visou apresentar materiais energéticos e farmacológicos reconhecidos por seu polimorfismo, bem como discorrer sobre propriedades, técnicas de caracterização e estudo de transição de fase nesses materiais.

Abstract: Despite the same chemical composition, the physicochemical properties of polymorphs can be totally different, such as leading or not electricity. The legality of recognize them as completely new products is discussed, in front of the characteristics that a polymorph may have over another. The fact is that the differential solubility and stability and formation of active sites in different phases of a substance engage the interest of many active sectors of the economy. There are no few polymorphic energetic materials, or their precursors, which also have therapeutic applications. Therefore, some of the techniques developed by the lucrative pharmaceutical industry to study the polymorphism can be tailored to the needs of the war industry. This paper presents energetic and pharmacological materials recognized for their polymorphism and discuss properties, characterization techniques and the study of phase transition in these materials.

Resumo: A adição de partículas metálicas nanométricas em sistemas de propulsão, tais como propelentes sólido, líquido, híbrido e de motores aspirados, "ramjet", tem sido recentemente mais pesquisada. Significante aumento na velocidade de queima e no impulso específico são algumas das vantagens do uso de nanopartículas de materiais energéticos em diferentes tipos de sistemas de propulsão. O alumínio tem sido largamente empregado como aditivo metálico em materiais energéticos, e recentemente em um novo sistema de propulsão (aluminum/ice propulsion, Alice). Estudos mostram que a vantagem do uso de nanopartículas de alumínio em substituição das partículas micrométricas facilita a ignição de sistemas e permite melhor incorporação dos componentes nas formulações, melhorando sua homogeneidade. Alguns dos processos de combustão que requerem altas pressões e temperaturas podem ocorrer em condições moderadas devido ao aumento da área superficial dos reagentes, nesse caso, de aditivo metálico.

Abstract: The addition of nanosized metal particles in propulsion systems such as solid and liquid propellants, hybrid propellant and ramjet motors has recently became a major focus of research. Significant increases in the burning velocity and in the specific impulse are some of the advantages of using nano-scale energetic materials in many different types of propulsion systems. Aluminum has been largely employed as a metallic additive in energetic materials, also in a recently new propulsion system (aluminum/ice propulsion, "Alice"), and some studies show that the advantages of using nanosized aluminum instead of microsized aluminum are facilitating the ignition of the systems and allowing better incorporation of the components in the formulations and improving its homogeneity. Some of the combustion processes that require high pressures and even higher temperatures can occur in moderate conditions due to the increase of the surface area of the reactants, in this case, the metallic additive.

Abstract: 2,2’, 4,4’, 6,6’- hexanitrostilbene (HNS) is an energetic material, a nitroaromatic compound, with thermal and chemical stabilities, which is employed in the aerospace industry. In this work, the Arrhenius parameters (activation energy and pre-exponential factor) of thermal decomposition reaction were studied and the results were compared with the values reported in the literature. The Kissinger method, applied to DSC’s nonisothermal data of the decomposition temperature was chosen for this study. The activation energy determined for the thermal decomposition of HNS revealed values from 428 kJ.mol-1 to 477 kJ.mol-1, under the experimental conditions employed.

The pentaerythritol-tetranitrate (PETN) is a nitroether used in explosives and propellant formulations. Due to its suitable properties, PETN is used in booster manufacture. Knowing the thermal decomposition behavior of an energetic material is very important for storage and manipulation, and the purpose of this work is to study the kinetic parameters of the decomposition of PETN, compare the results with literature data and to study the decomposition activation energy differences between two crystalline forms of PETN (tetragonal and needle) by means of differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FT-IR) is used to study the two crystalline forms.

2,4,6-trinitrotoluene (TNT) is an energetic material that shows scarce crystalline properties that can be improved by addition of 2,2',4,4',6,6'-hexanitrostilbene (HNS) in the crystallization process. HNS is a very important high explosive used in a variety of military, aerospace and industrial formulations owing to its suitable properties. It is an insensitive and thermal stable explosive that can be produced from 2,4,6-trinitrotoluene (TNT). The purpose of this work is the quantitative determination of HNS and TNT in explosives by thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR).

2,2',4,4',6,6'-hexanitrostilbene (HNS) is a very important high explosive that is used in a range of military, aerospace and industrial formulations owing to its suitable properties. It is an insensitive and thermaly stable explosive that can be produced from 2,4,6-trinitrotoluene (TNT). This paper shows the characterization of synthesized HNS by different techniques, such as elementary analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR) and through the determination of the heat of combustion in a calorimeter.

Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) or octogen is a white crystalline substance which occurs in four polymorphous forms. It is used in a wide variety of military and industrial formulations owing to its suitable properties. Researchers have demonstrated the usefulness of this energetic material in explosive components. In the present work we apply differential scanning calorimetry (DSC) to measure the a ® d solid-solid phase transition energy of HMX. The results obtained by Kissinger's and Ozawa's methods were 487 and 495 kJ/mol, respectively.