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Thomas J Bruno - One of the best experts on this subject based on the ideXlab platform.
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thermal decomposition kinetics of kerosene based Rocket Propellants 1 comparison of rp 1 and rp 2
Energy & Fuels, 2009Co-Authors: Jason A Widegren, Thomas J BrunoAbstract:The decomposition kinetics of the kerosene-based Rocket Propellants RP-1 and RP-2 was studied. For RP-2, decomposition reactions were performed at 375, 400, 425, and 450 °C. For RP-1, decomposition reactions were only performed at 450 °C because we had previously studied decomposition at 375, 400, and 425 °C. All of the decomposition reactions were performed in stainless-steel ampule reactors. At each temperature, the extent of decomposition as a function of time was determined by analyzing the thermally stressed liquid phase by gas chromatography. These data were used to derive global pseudo-first-order rate constants that approximate the overall rate of decomposition for the fuel. For RP-2, the rate constants ranged from 1.33 × 10−5 s−1 at 375 °C to 5.47 × 10−4 s−1 at 450 °C. The rate constants for the decomposition of RP-1 are not significantly different in that temperature range. One use of these rate constants is for the design and planning of physical property measurements at high temperatures. On t...
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preliminary surrogate mixture models for the thermophysical properties of Rocket Propellants rp 1 and rp 2
Energy & Fuels, 2009Co-Authors: Marcia L Huber, Eric W Lemmon, Lisa S Ott, Thomas J BrunoAbstract:We have developed surrogate mixture models to represent the thermophysical properties of two kerosene Rocket Propellants, RP-1 and RP-2. The surrogates were developed with a procedure that incorporated experimental data for the density, sound speed, viscosity, thermal conductivity, and the advanced distillation curves for samples of the two fuels. The surrogate for RP-1 contains four components (α-methyldecalin, n-dodecane, 5-methylnonane, and heptylcyclohexane), and the surrogate for RP-2 contains five components (α-methyldecalin, n-dodecane, 5-methylnonane, 2,4-dimethylnonane, and heptylcyclohexane). Comparisons with experimental data demonstrate that the models are able to represent the density, sound speed, viscosity, and thermal conductivity of both fuels to within (at a 95% confidence level) 0.4, 2, 2, and 4%, respectively. The volatility behavior, as measured by the advanced distillation curves, is reproduced to within 0.5%.
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stabilization of biodiesel fuel at elevated temperature with hydrogen donors evaluation with the advanced distillation curve method contribution of the united states government not subject to copyright in the united states
Energy & Fuels, 2009Co-Authors: Thomas J Bruno, Arron Wolk, Alexander NaydichAbstract:Recently, we introduced the concept of an advanced distillation curve measurement. The new metrology features several important aspects. First, we incorporate a composition explicit data channel for each distillate fraction (for both qualitative, quantitative, and trace analysis). The temperature, volume, and pressure measurements are of low uncertainty, and the temperatures are true thermodynamic state points that can be modeled with an equation of state. These two features make the measurements suitable for equation of state development. The approach also provides consistency with a century of historical data, an assessment of the energy content of each distillate fraction, and where needed, a corrosivity assessment of each distillate fraction. We have applied the new method to fundamental work with hydrocarbon mixtures and azeotropic mixtures, and also to real fuels. The fuels we have measured include Rocket Propellants, gasolines, jet fuels, diesel fuels (including oxygenated diesel fuel and biodiesel...
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variability of the Rocket Propellants rp 1 rp 2 and ts 5 application of a composition and enthalpy explicit distillation curve method
Industrial & Engineering Chemistry Research, 2008Co-Authors: Lisa S Ott, Amelia B Hadler, Thomas J BrunoAbstract:We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This method is a significant improvement over current approaches, featuring a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and an assessment of the energy content of each distillate fraction, among other features. The most significant modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to the measurement of a wide variety of fluids, including hydrocarbons, gasoline, jet fuel, diesel fuels (both petroleum-derived and biodiesel), and crude oils. In this paper, we present the application of the technique to representative batches of the Rocket Propellants RP-1, RP-2, and TS-5. We not only present the distillation curves but also utilize the composition-explicit information to characterize distillat...
Muhamed Suceska - One of the best experts on this subject based on the ideXlab platform.
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theoretical evaluation of tkx 50 as an ingredient in Rocket Propellants
Zeitschrift für anorganische und allgemeine Chemie, 2021Co-Authors: Thomas M Klapotke, Muhamed SuceskaAbstract:Dihydroxylammonium-5,5’-bistetrazolyl-1,1’-diolate (TKX-50), is one of the most promising energetic materials that has been reported in recent time. TKX-50 shows great potential for future application as a secondary explosive, due to its sensitivity and explosive performance data. In this work, we report initial computational results which have been undertaken to investigate the viability of the application of TKX-50 as an energetic ingredient in Rocket Propellants.
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the applicability of chromatographic methods in the investigation of ageing processes in double base Rocket Propellants
Central European Journal of Energetic Materials, 2013Co-Authors: Sanja Matecic Musanic, Muhamed Suceska, Ruzica CuljakAbstract:The ageing of double base (DB) Rocket Propellants is the result of chemical decomposition reactions and physical processes, causing degradation of a number of relevant propellant properties (such as reduction in stabilizer and nitroglycerine (NG) content, reduction of the mean molecular mass of nitrocellulose (NC) etc.), which is reflected in a decrease in the reliable service life time of DB Propellants. This is the reason why the study of processes of ageing and their consequences (effects) is so important. In this paper we have studied the kinetics of DB Rocket propellant decomposition during their artificial ageing, i.e. at elevated temperatures. The kinetic parameters were obtained by measurements of the stabilizer/Ethyl Centralite (EC) content and the mean molecular mass reduction of NC, during artificial ageing at temperatures of 80, 85 and 90 °C. Consumption of the EC was observed using High Performance Liquid Chromatography (HPLC), whilst the reduction in the mean molecular mass of NC was monitored using Gel Permeation Chromatography (GPC). It has been shown that artificial ageing of DB propellant causes significant EC consumption and a reduction in the mean molecular mass of NC, from the very beginning of ageing. EC is entirely consumed after 120 days at 80 °C, and is followed by the intensive reactions of NC decomposition. Significant changes in the mean molecular mass of NC starts after 60 days of ageing at 90 °C (or ~250 days at 80 °C). The results obtained from the kinetic data have shown that the activation energy of DB propellant decomposition, determined on the basis of changes in the mean molecular mass of NC is 145.09 kJ·mol-1, whilst the activation energy 246 S. Matecic Musanic, M. Suceska, R. Culjak of decomposition obtained on the basis of EC consumption is 142.98 kJ·mol-1, which is consistent with available literature values [1, 2].
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study of mechanical properties of naturally aged double base Rocket Propellants
Central European Journal of Energetic Materials, 2010Co-Authors: Muhamed Suceska, Matecic S Musanic, Ivona Fiamengo, Sanko Bakija, Ante Bakic, Janos KodvanjAbstract:Various chemical reactions and physical processes (such as stabilizer consumption, migration and evaporation of nitroglycerine, decomposition of nitroglycerine and nitrocellulose, etc.) take place in double based Rocket Propellants grains over the time, even under ambient storage conditions. The overall effect of these reactions and processes are changes of physical, chemical, thermal, ballistic and mechanical properties of Rocket Propellants with storage time, i.e. the reduction of the Propellants performances and safe service life. The aim of this work was to evaluate the mechanical changes of Rocket Propellants – sustainers, built in in-service antitank guided missiles systems, induced by natural ageing at ambient conditions during up to 35 years of storage. The mechanical and viscoelastic properties were tested using a dynamic mechanical analyser, an uniaxial tensile and compression tester, and a notch toughness tester. The results have shown that the changes of the studied mechanical and viscoelastic properties are evident, although the results of the tests are rather scattered (as a consequence of measuring uncertainty, different ageing histories of Propellants, etc.) or changes of some properties are not too pronounced. For example, after 15 years of storage at ambient conditions the glass transition temperature increases for about 5 °C, the tan δ in the glass transition region decreases for about 5%, the storage and loss modulus at 25 °C increase for about 15%, Young modulus at 23 °C increases up to 30%, the notch toughness at -30 °C decreases up to 15%, etc. Along with these tests, the stabilizer content determination and proving ground ballistic tests were also done.
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artificial ageing of double base Rocket propellant effect on dynamic mechanical properties
Journal of Thermal Analysis and Calorimetry, 2009Co-Authors: Matecic S Musanic, Muhamed SuceskaAbstract:The ageing of double base Rocket Propellants (DB Rocket Propellants), which is a consequence of chemical reactions and physical processes that take place over time, has significant effect on their relevant properties (e.g. chemical composition, mechanical properties, ballistic properties, etc.). The changes of relevant properties limit the safe and reliable service life of DB Rocket Propellants. This is the reason why numerous research efforts are devoted to finding out reliable methods to measure the changes caused by ageing, to assess the quality at a given moment of time, and to predict remaining life-time of DB Rocket Propellants.
Himanshu Shekhar - One of the best experts on this subject based on the ideXlab platform.
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Mathematical Formulation and Validation of Muraour's Linear Burning Rate Law for Solid Rocket Propellants
2020Co-Authors: Himanshu ShekharAbstract:Abstract: Linear variation of burning rate with pressure (burning rate, r = H + Sp), referred in the literature as Muraour's law, is adopted as the burning rate law for solid Rocket Propellants. The two constants 'H' and 'S' are the vacuum burning rate and the slope of burning rate variation, respectively. The conventional power law of the burning rate, r = ap n , is also analyzed and its practical, anomalous behaviour such as zero burning rate at zero pressure, the reduction in pressure sensitivity of the burning rate at higher pressures, the lower burning rate for the high pressure index in typical situations etc, are explained with illustrations. Like the conventional power law of burning rate, the linear burning rate law considered here is also empirical but mathematically simpler than the power law. Using burning rate and pressure data from various literature sources similar regression coefficients are observed for the conventional power law as well as for the alternative linear burning rate law. The mathematical concept for the evolution of the pressure time profile with the considered linear burning rate law is developed and validated practically with the actual firing of Rocket Propellants as uninhibited, tubular configurations in a ballistic evaluation motor (BEM). Close matching of the firing curve, predicted by the conventional power law and by the proposed linear burning rate law validates the mathematical formulation. The considered linear burning rate law is simple, easy to apply and gives a better representation of the burning rate behaviour of solid Rocket Propellants
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Viscoelastic Characterization of Different Solid Rocket Propellants Using the Maxwell Spring-Dashpot Model
2016Co-Authors: Himanshu Shekhar, D. K. KankaneAbstract:Abstract: A single spring and a single dashpot in series was utilized to simulate the stress-strain curve for different classes of solid Rocket Propellants, namely extruded double base Propellants (EDBP) and composite Propellants (CP), in the uniaxial tensile mode in a constant rate of travel machine. The propellant behaves as a viscoelastic material and invariably exhibits stress relaxation, which cannot be simulated by elastic mechanical property parameters. In order to generate a complete stress-strain curve of a solid Rocket propellant under tensile testing, different classes of solid Rocket Propellants were evaluated and the stress-strain curve generated was modelled using the single spring-single dashpot Maxwell fluid model. Using two constants, called the spring constant (K) and the damping factor (D), it was possible to generate a complete stress-strain curve. Mathematical formulation gives the stress (σ) – strain (ε) relation as ( ) () () ()dtdDKedtdD //1 / εεεσ ⋅⋅−−⋅⋅ =. Additionally the physical nature of the spring constant resembles that of the elastic constant and the damping coefficient gives the contribution of the viscous part of the load bearing capacity of soli
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studies on stress strain curves of aged composite solid Rocket Propellants
Defence Science Journal, 2012Co-Authors: Himanshu ShekharAbstract:Mechanical property evaluation of composite solid Rocket Propellants is used as a quick quality control tool for propellant development and production. However, stress-strain curves from uni-axial tensile testing can be utilised to assess the shelf-life of Propellants also. Composite Propellants (CP) of two varieties cartridge-loaded (CLCP) and case-bonded (CBCP) are utilized in Rocket and missile applications. Both classes of Propellants were evaluated for mechanical properties namely tensile strength, modulus and percentage elongation using specimens conforming to ASTM D638 type IV at different ageing time. Both classes of Propellants show almost identical variation in various mechanical properties with time. Tensile strength increases with time for both classes of Propellants and percentage elongation reduces. Initial modulus is also found to decrease with time. Tensile strength is taken as degradation criteria and it is observed that CLCP has slower degradation rate than CBCP. This is because of two facts–(i) higher initial tensile strength of CLCP (1.39 MPa) compared to CBCP (0.665 MPa) and (ii) lower degradation rate of CLCP (0.0014 MPa/day) with respect to CBCP (0.0025 MPa/day). For the studied composite Propellants, a degradation criterion in the form of percentage change in tensile strength is evaluated and shelf life for different degradation criteria is tabulated for quick reference. Defence Science Journal, 2012, 62(2), pp.90-94 , DOI:http://dx.doi.org/10.14429/dsj. 62.773
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longitudinal strain dependent variation of poisson s ratio for htpb based solid Rocket Propellants in uni axial tensile testing
Propellants Explosives Pyrotechnics, 2011Co-Authors: Himanshu Shekhar, A D SahasrabudheAbstract:Poisson’s ratio of HTPB based composite propellant is estimated at break using double dumbbell specimens as per ASTM D638 Type IV standard and its value obtained by change in the volume of specimens is calculated as approximately 0.25. This major finding contradicts the behaviour of solid Rocket Propellants in respect of Poisson’s ratio, which is reported to be 0.5. Further, Poisson’s ratio varies almost linearly with strain even in linear portion of stress-strain curve in uni-axial tensile testing as per theoretical calculations. It must be noted that no change in volume does not necessarily indicate constant Poisson’s ratio equal to 0.5. SEM scan indicates that the rate of reduction of Poisson’s ratio with longitudinal strain accelerates after dewetting due to the formation of vacuoles. Bilinear variation of Poisson’s ratio with longitudinal strain is observed. One slope is valid in pre-dewetting region, calculated from close form solution and other slope is valid for post-dewetting region, which is measured at break. Measurement of Poisson’s ratio at various longitudinal strains indicates uni-linear variation and not a bilinear variation with a kink. It is also observed that Poisson’s ratio is different along different lateral directions of the propellant specimen. Poisson’s ratio in two orthogonal directions perpendicular to longitudinal axis is calculated as 0.17 and 0.30. As ASTM Specimen has rectangular cross-section of approximate size 6×4 mm, the directional behavior of Poisson’s ratio may be attributed to initial dimensions. Prismatic propellant specimen with square cross-section of 115×6×6 mm dimension do not show any variation in respect of Young’s modulus, tensile strength and percentage elongation as compared to ASTM specimen. Directional behavior of Poisson’s ratio with almost similar numerical value is again observed, thus ruling out dependence of this behavior on different initial dimensions of propellant cross-section. The propellant slurry flow during vacuum casting, directional curing and orientation of specimen with respect to web of the cast propellant are mainly responsible for this directional behaviour of Poisson’s ratio for the composite Propellants. Composite Propellants behave as compressible material in most of the region and near failure region or at higher strains; Poisson’s ratio is not anywhere close to 0.5, instead it is close to 0.25.
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effect of temperature on mechanical properties of solid Rocket Propellants
Defence Science Journal, 2011Co-Authors: Himanshu ShekharAbstract:Mechanical properties of solid Rocket Propellants are dependent on temperature. Any change in temperature brings significant change in the tensile strength, percentage elongation, and elastic modulus of the propellant. Different classes of operational solid Rocket Propellants namely extruded double-base Propellants, composite, extruded composite and nitrarte ester polyester Propellants were evaluated at different temperatures in the operating range of the Rockets and missiles preferably in the range of –50 oC to +55 oC. It was observed that for each class of propellant, as temperature reduces, propellant becomes hard. This is depicted by increase in elastic modulus and tensile strength of the material. However, trend of percentage elongation is not very uniform. Extruded double-base Propellants show less percentage elongation (around 1 per cent) at reduced temperature (–50 oC) probably due to brittleness. So is the trend with case-bonded composite Propellants. However, reverse trend is exhibited by cartridge-loaded composite Propellants and nitrate ester polyester Propellants. Such Propellants show higher percentage elongation (6 per cent for CLCP and 35 per cent for NEPE) at reduced temperature (–50 oC). This makes such Propellants tough and more area under stress-strain curve at reduced temperature is observed. Defence Science Journal, 2011, 61(6), pp.529-533 , DOI:http://dx.doi.org/10.14429/dsj.61.774
L Galfetti - One of the best experts on this subject based on the ideXlab platform.
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microstructure effects in aluminized solid Rocket Propellants
Journal of Propulsion and Power, 2010Co-Authors: Luigi T Deluca, L Galfetti, G Colombo, F Maggi, V A Babuk, A Bandera, V P SinditskiiAbstract:Experiments concerning the ballistic characterization of several nanoaluminum (nAl) powders are reported. Most studies were performed with laboratory composite solid Rocket Propellants based on ammonium perchlorate as oxidizer and hydroxyl-terminated polybutadiene as inert binder. The ultimate objective is to understand the flame structure of differently metallized formulations and improve their specific impulse efficiency by mitigating the two-phase losses. Ballistic results confirm, for increasing nAl mass fraction or decreasing nAl size, higher steady burning rates with essentially the same pressure sensitivity and reduced average size of condensed combustion products. However, aggregation and agglomeration phenomena near the burning surface appear noticeably different for microaluminum (μAl) and nAl powders. By contrasting the associated flame structures, a particle-laden flame zone with a sensibly reduced particle size is disclosed in the case of nAl. Propellant microstructure is considered the main controlling factor. A way to predict the incipient agglomerate size for μAl Propellants is proposed and verified by testing several additional ammonium perchlorate/hydroxyl-terminated polybutadiene/aluminum formulations of industrial manufacture.
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nanoaluminum as a solid propellant fuel
Journal of Propulsion and Power, 2009Co-Authors: V A Babuk, Luigi T Deluca, Ildar N Dolotkazin, Alexey Gamsov, Andrey Glebov, L GalfettiAbstract:Experimental studies on the burning of nanoaluminum-based solid Rocket Propellants are carried out. Data on the properties of condensed combustion products, mechanisms of their formation, and burning-rate law are obtained. Based on these data, a physical picture is developed of the considered burning-propellant classes. Mathematical modeling of burning nanoaluminum in composite solid Rocket Propellants is carried out. The influence of nanoaluminum on ignition temperature of the metal fuel and burning-rate law is shown. The results of this study allow carrying out the analysis and selection of good-quality Propellants using nanoaluminum.
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ageing behaviour of htpb based Rocket propellant formulations
Central European Journal of Energetic Materials, 2009Co-Authors: Sara Cerri, Manfred A Bohn, Klaus Menke, L GalfettiAbstract:The ageing of HTPB propellant formulations containing nanoAl is investigated. During natural ageing the material undergoes a series of slow physico-chemical degradation reactions. By using accelerated ageing conditions it is possible to simulate the material behaviour at different time-temperature conditions especially focused on the in-service conditions. The mechanical and ageing behaviour of aluminised solid Rocket Propellants were investigated in terms of uniaxial tensile strength, DMA measurements, impact and friction sensitivity tests, SEM analyses.
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burning of metallized composite solid Rocket Propellants from micrometric to nanometric aluminum size
3rd Asian Joint Conference on Propulsion and Power (AJCPP) 2008, 2008Co-Authors: Luigi T Deluca, L GalfettiAbstract:A survey is offered of the present status of microaluminized Propellants industrially used worldwide in most space applications, but new directions are also pointed out making profitable use of the nanoaluminized Propellants currently tested in many laboratories. Different industrial- and research-type of solid Rocket Propellants, mainly but not only, of the well-known family oxidizer/Al/HTPB (oxidizer being AP, AN or a mixture of the two) were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano. In general, they feature the same nominal composition but implement different grain size distributions of the oxidizer or metal fuel. The basic properties of all formulations were compared to that of a standard propellant already certified for flight.
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nano aluminum as energetic material for Rocket Propellants
Materials Science and Engineering: C, 2007Co-Authors: L Meda, L Galfetti, G Marra, F Severini, L T De LucaAbstract:A characterization of differently sized aluminum powders, by using BET (specific surface measurements), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS), was performed in order to evaluate their performance in solid propellant. These aluminum powders were used in manufacturing composite Rocket Propellants, that are based on Ammonium Perchlorate (AP) as oxidizer and Hydroxyl-Terminated-PolyButadiene (HTPB) as binder. The reference formulation was AP/HTPB/Al with 68/17/15 mass fractions, respectively. The ballistic characterization of studied Propellants, made in terms of steady burning rates, showed how better is the performance of nano-aluminized compared to micro-aluminized Propellants. Measurements of Al powder ignition time and temperature were also carried out.
Djalal Trache - One of the best experts on this subject based on the ideXlab platform.
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burning rate of pvc plastisol composite Propellants and correlation between closed vessel and strand burner tests data
2020Co-Authors: Abderrahmane Mezroua, Djalal Trache, Michel H. Lefebvre, Kamel KhimecheAbstract:The objective of this study is to assess two different methods used to determine the burning rates of solid Rocket Propellants and to find a convenient correlation of the measured data. The well-known strand burner test (Crawford test) and the closed vessel test were employed. In order to clarify the relation between the two techniques, a composite propellant containing polyvinyl chloride (PVC) as matrix and ammonium perchlorate (AP) as an oxidizer is used. It is prepared using normal AP (without heat treatment, nPoAP) or porous AP (after heat treatment, PoAP). Dioctyl phthalate (DOP) or dibutyl sebacate (DBS) was used as plasticizer. The PVC-Plastisol propellant burning rate behavior with respect to pressure, oxidizer nature, and propellant composition is analyzed. The obtained results show an acceptable correlation between the two techniques over the pressure range from 5 to 25 MPa.
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effect of amide based compounds on the combustion characteristics of composite solid Rocket Propellants
Arabian Journal of Chemistry, 2015Co-Authors: Djalal Trache, Luigi T Deluca, F Maggi, Ilaria Palmucci, Kamel Khimeche, Marco Fassina, Stefano Dossi, G ColomboAbstract:Abstract Oxamide (OXA) and azodicarbonamide (ADA) are among the known burning rate suppressants used in composite solid Rocket Propellants. Much research has been carried out to understand mechanism of suppression but literature about the action of OXA and ADA on the combustion characteristics of propellant is still scarce. Here, a systematic study on coolant-based Propellants has been undertaken spanning from thermal analyses of ingredients to a variety of burning processes of the corresponding Propellants. Thermal gravimetric analysis and differential thermal analysis on individual coolants are carried out to study their behaviour with temperature. It was noticed that the thermal decomposition of OXA exhibits only endothermic effects, whereas that of ADA presents both endothermic and exothermic effects. Successive experiments on solid propellant looking at burning rate characterization, condensed combustion product collection and visualization, pressure deflagration limit and thermochemical analysis gave a greater insight and enabled better understanding of the action of coolants during combustion. It is proposed that OXA and ADA are acting on both the condensed and gas phases. Also, the nature of coolant is a key parameter, which affects the burning rate pressure index. Increase of agglomerate size and of pressure deflagration limit was obtained in the coolant-based Propellants, confirming the trend given in the literature.
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The influence of porosity of ammonium perchlorate (AP) on the thermomechanical and thermal properties of the AP/polyvinylchloride (PVC) composite Propellants
Journal of Thermal Analysis and Calorimetry, 2014Co-Authors: Abderrahmane Mezroua, Kamel Khimeche, Michel H. Lefebvre, Mokhtar Benziane, Djalal TracheAbstract:The influence of porous ammonium perchlorate (P_OAP) on the thermomechanical and combustion behavior of solid Rocket Propellants based on polyvinylchloride binder has been investigated. Differential scanning calorimetry, differential thermogravimetry, dynamic mechanical thermal analysis, and scanning electronic microscopy measurements were used for thermomechanical and thermal decomposition properties assessment. The results obtained indicate that lower glass transitions of the Propellants and catalytic effect of combustion are obtained with P_OAP.
