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The current demilitarization processes employ open burning/open detonation which is not permitted by the environmental protection agency. Therefore, a systematic study has been carried out to convert waste/rejected nitramine propellant (NP) and fuel-rich-based propellant (FRP) into liquid fertilizer by digesting in dilute nitric acid followed by neutralization with potassium hydroxide and phosphoric acid. The obtained liquid fertilizers were fully characterized for nitrate, phosphate and ammonium ions along with potassium. Further, the effect of liquid fertilizers of NP and FRP on cluster bean plants was studied by taking different concentrations from 25 to 150 mL, and their effects on germination pattern, shoot growth, thickness of stem, size and number of leaves, number of pods and length over a full-grown period of plants were investigated. The results reveal that the germination index increases as the content of liquid fertilizer increases and the same trend was observed with respect to root and shoot growth. Also, broadness and the number of leaves showed an encouraging effect as concentration increases. Further, the final product, i.e. the number of pods of cluster bean and length in each pod was found to be more for liquid fertilizer of NP compared to FRP-based liquid fertilizer.

The incorporation of nanoaluminum in an 86% solid composite propellant formulation poses processing problems when following conventional methods. Therefore, to accommodate an optimum percentage of nanoaluminum in such formulations, a new bicurative system was introduced. Summarizing in the present study, a bicurative system consisting of toluene diisocyanate and isophorone diisocyanate was chosen to enable incorporation of 18% nanoaluminum powder (93 nm) in place of 18% micrometer-sized Aluminum powder. The developed compositions were studied in detail for their mechanical, thermal, sensitivity, and ballistic properties. The mechanical properties data, such as tensile strength, E modulus, and percentage elongation, are almost on par with the values obtained with micrometer-sized aluminum powder using a developed bicurative system. The results of thermal properties reveal that, as the percentage of nanoaluminum increases in the composition, the onset decomposition temperature decreases. The impact and fric...

The performance of solid propellants is often tailored by incorporating energetic materials such as novel oxidizers, energetic binders and ballistic modifiers. Metal oxide nanoparticles are known for their persuasivenature to modify burning rate ofammonium perchlorate based composite propellants. In the present work, nano iron oxide and poly (1-(3-nitrophenyl)-1H-1,2,3-triazol-4-yl) acrylate are incorporated in the composite propellant formulation by partly replacing coarse ammonium perchorate (AP) as well as hydroxy terminatined polybutadiene (HTPB), respectively, and different properties were evaluated. The mechanical properties data revealed that on increasing the percentage of polymer in the composition by partly replacing HTPB, there is an increase in tensile strength while decreasing elongation percentage. Thedata of ballistic properties revealed that on incorporation of nano iron oxide in the composition enhances the burning rate while on partial replacement of HTPB with polymer there is a decrease in burning rate from 11.95 mm s−1 to 8.75 mm s−1, respectively was observed.

This article reports ways to functionalize hydroxyl-terminated polybutadiene (HTPB) by azide groups to impart energetic properties to the polymer. Two different synthetic approaches were explored to synthesize azide-functionalized hydroxyl-terminated polybutadiene (azide-HTPB). The functionalized polymer was analyzed for structural confirmation and determination of important physical and thermal properties. Azide-HTPB obtained by azidation of 10% double bonds of HTPB showed viscosity of 11 Pa.s and a glass transition temperature of −66°C.

Propellants, visco-elastic in nature, show time and temperature dependent behaviour on deformation. Hence, the time–temperature superposition principle may be applied to the visco-elastic properties of propellants. In the present study, dynamic mechanical analyser (DMA) was used to evaluate the dynamic mechanical properties and quantify the storage life of four different propellants based on hydroxyl terminated polybutadiene, aluminium and ammonium perchlorate having different burning rates ranging from 5 mm/s to 25 mm/s. Each sample was given a multi-frequency strain of 0.01 per cent at three discrete frequencies (3.5 Hz, 11 Hz, 35 Hz) in the temperature range - 80 °C to + 80 °C. The storage modulus, loss modulus, tan delta and glass transition temperature (Tg) for each propellant samples have been evaluated and it is observed that all the propellants have shown time (frequency) and temperature dependent behaviour on deformation. A comparison of the log aT versus temperature curves (where aT is horizontal (or time) shift factor) for all four propellants indicate conformance to the Williams–Landel–Ferry (WLF) equation. The master curves of storage modulus (log E versus log ω plots) were generated for each propellant. A plot of E versus time for all propellants was generated up to 3 years, 6 years, and 10 years of time, respectively. The drop in the storage modulus below the acceptable limit with time may be used to predict the shelf life of the propellant. Defence Science Journal, 2012, 62(5), pp.290-294 , DOI:http://dx.doi.org/10.14429/dsj.62.2480

Nanomaterials are finding applications in explosives and propellant formulations due to their large surface area and high surface energy. This high surface energy is responsible for the low activation energy and increase in burning rate of the composition. Therefore, a successful attempt has been made to prepare nano-ammonium perchlorate using a nonaqueous method by dissolving ammonium perchlorate (AP) in methanol followed by adding the dissolved AP to the hydroxyl-terminated polybutadiene (HTPB), homogenization, and vacuum distillation of the solvent. The nano-AP thus formed was characterized using a NANOPHOX particle size analyzer (Sympatec, Germany), transmission electron microscopy (FEI, Hillsboro, OR), X-ray diffraction (PANalytical B.V., The Netherlands) and scanning electron microscopy (Ikon Analytical Equipment Pvt. Ltd., Mumbai, India) for particle size, purity, and morphology, respectively. The thermal behavior of nano-AP was also studied using differential thermal analysis–thermo gravimetric an...

Fluorocarbon polymers are used to enhance thermal stability and electrostatic protection of composite propellant compositions. A precipitation technique has been developed to coat ammonium perchlorate (AP) using a copolymer of hexafluoropropylene and vinylidene fluoride (HFP-VF) with the help of solvent-counter solvent method. The coated AP has been used to prepare propellant compositions in different ratio based on hydroxyl terminated polybutadiene (HTPB), aluminium powder along with uncoated AP and studied for viscosity build-up and visco-elastic behaviour as well as mechanical, ballistic, thermal and sensitivity properties keeping 86% solid loading. The data on viscosity build-up indicate that as the percentage of viton coated AP increases end of mix viscosity and viscosity build-up increase accordingly. The mechanical properties data reveal that tensile strength and percentage elongation are found in increasing order. The burn rate of the composition also increases on higher percentage of HFP-VF coated AP. The thermal stability of composition increases as the percentage of HFP-VF coated AP increases. The data on sensitivity indicate that impact sensitivity decreases on increasing the percentage of HFP-VF coated AP while no change is observed in friction sensitivity value.

Most of the composite propellant compositions contain solid loading up to 86 per cent. The main solid ingredients of composite propellant are ammonium perchlorate (AP) and aluminium powder. Therefore, it is a must to characterise these to improve processibility and quality of composite propellant. Effect of particle size on propellants slurry viscosity and ballistic parameters are well documented, however, the effect of oxidizer particle shape is not reported. In the present study, different methods for size and shape characterisation are discussed and effect of size and shape of AP on composite propellant properties are studied. The data indicate that as size of AP decreases, propellant slurry viscosity increases and burn rate increases. The particles having higher shape factor provides less endof mix (EOM) viscosity of propellant slurry and burn rate. Further, effect of size of ground AP on shape is also investigated. From the data thus obtained, it is inferred that as size of ground AP decreases, shape factor decreases, and particles become more irregular in shape.Defence Science Journal, 2009, 59(3), pp.294-299, DOI:http://dx.doi.org/10.14429/dsj.59.1523

A new series of composite propellant compositions, based on ammonium perchlorate,hydroxy-terminated polybutadiene and having metallic fuel as aluminium powder, have beendeveloped. Pressure cast-cum-cured compositions have also been developed with toluenediisocyanate (TDI), isophorone diisocyanate (IPDI), and a mixture of both curatives, i.e., TDIand IPDI, respectively, to study their effect on processibility, mechanical and ballistic propertiesof the compositions. The data indicate that the compositions based on bicurative have a potlife of 7 - 8 h, viscosity build up is from 13280 poise to 14080 poise after 4 h, and the smoothprocessibility of the slurry is enhanced. Further, the mechanical properties are in the range12.2 kg/cm2, 40.2 kg/cm2, and 40.2 per cent for tensile strength, E-modulus and elongation,respectively, and burn rate is almost the same, i.e., 16 ±0.5 mm/s.

Ammonium perchlorate has been pulverised by an impact mill (air classifier mill) to study the influence of different operating parameters, viz., effect of mill speed, classifier speed, feed rate, and damper opening (suction rate) on the particle size. Further based on the different grinding parameters, an empirical equation has been developed and used for the prediction of particle size. The experimental results indicate that the values are very close to the predicted ones. In addition, particle size distribution has also been studied by applying different model equations and it has been found that Rosin-Rammler model is the most suitable model for this operation.

Potassium, rubidium, and cesium salts of 5,7-diamino-4,6-dinitrobenzofuroxan (CL-14) have been prepared by reacting sodium salt of 5,7-diamino-4,6-dinitrobenzofuroxan with alkali metal nitrate in an aqueous medium. The structure of the compounds was unequivocally confirmed by spectra data, elemental analyses, and estimation of metal content. Further, the compounds have been evaluated for explosive and thermal properties and found more suitable as compared to alkali metal salts of 4,6-dinitrobenzofuroxan (DNBF).

Chromium, Iron and Copper salts of 4,6-dinitrobenzofuroxan have been prepared by reacting sodium salt of 4,6-dinitrobenzofuroxan with chromium nitrate nonahydrate, ferric nitrate nonahydrate and cupric nitrate trihydrate, respectively. The compounds have been characterized by elemental analysis, spectral data (IR and NMR) and metal content. Some properties including thermal and explosive behaviour of these compounds have been investigated and reported. Further, these molecules have also been investigated in composite propellants as burn-rate modifiers. The preliminary data suggest that iron salt of 4,6-dinitrobenzofuroxan is better than ferric oxide, generally used as a burn-rate modifier for hydroxy-terminated polybutadiene (HTPB) based composite propellants.

Two new initiatory molecules, e.g. rubidium and cesium salts of 4,6-dinitrobenzofuroxan (DNBF) have been prepared by reacting sodium salt of 4,6-dinitrobenzofuroxan (DNBF) with rubidium nitrate and cesium nitrate, respectively, at 60 °C in aqueous medium. The characterisation of compounds by IR, 1 H -NMR, elemental analysis and metal content is described along with some of the evaluated thermal and explosive properties. The results indicate that cesium salt of DNBF (Cs-DNBF) appears promising initiatory and may suitably replace potassium salt of DNBF (K-DNBF), being used currently in initiatory compositions.

RDX/HMX based Plastic Bonded Explosives (PBXs) with epoxy resin as a binder have been formulated and studied in detail for their explosive, mechanical and thermal properties. The effect of pressure on the moulding powder has also been optimized to achieve maximum loading density and compression strength. Further, these PBXs have been analysed for homogeneity and coating of binder over RDX/HMX crystals. The data suggest that epoxy resin based PBXs have higher loading density, higher mechanical strength and higher velocity of detonation (VOD) as compared to polyurethane based PBXs.

Different compositions have been prepared by incorporating nano sized chromium oxide from 0.25 % to 1 % in HTPB/AP/Al based composite propellant formulation having 86% of solid loading and studied its effect on viscosity build-up, thermal, mechanical and ballistic properties. The findings reveal that on increasing the percentage of nano Cr2O3 in the composition, there is an increase in end of mix viscosity, elastic modulus and tensile strength while elongation decreases accordingly. The data on thermal properties envisage the reduction in thermal decomposition temperature of ammonium perchlorate as well as formulations based on HTPB/AP/Al. The data on ballistic properties reveal that there is an enhancement in burning rate from 6.11 mm/s to 7.88 mm/s at 6.86 MPa, however, marginal increase in pressure exponent (‘n’ values) from 0.35 to 0.53 with 1 wt % of nano Cr2O3 was observed in comparison to reference composition without chromium oxide.

Different composite propellant mixtures have been prepared using ammonium perchlorate, aluminium powder and hydroxyl terminated polybutadiene by varying the percentage of plasticiser and addition of toluene diisocyanate at different temperatures, and studied their different properties such as viscosity build-up, mechanical and ballistic properties and sensitivity. The data on different plasticiser level indicate that on decreasing the plasticiser content, there is a significant enhancement in end of mix viscosity, tensile strength and modulus while elongation decreases drastically. The data on sensitivity of the studied mixtures reveal that on decreasing the percentage of plasticiser, the sensitivity increases, accordingly. Further, the data on the effect of addition of TDI at different temperatures (35-60 degrees C) infer that on increasing the addition temperature of TDI there is a decrease in end of mix viscosity i.e. 800Pas at 35 degrees C to 448Pas at 60 degrees C. Moreover, there is no effect on mechanical and ballistic properties on higher temperature addition of TDI was observed.

5,7-Diamino-4,6-dinitrobenzofuroxan (CL-14) has been synthesized by a cost-effective method. CL-14 was characterized by spectral data (IR, NMR and mass) and elemental analysis. The compound was evaluated in plastic bonded explosives (PBX) using polyurethane (PU) as binder. The thermal, mechanical and explosive properties of PBX composition from preliminary tests are also reported. Good thermal stability as well as good insensitiveness are indicated.

A method for the determination of chloride content in 1,3,5-triamino-2,4,6-trinitrobenzene is described, involving its conversion into 1,3,5-trihydroxy-2,4,6-trinitrobenzene (water soluble) by treatment with hot aqueous NaOH. The chloride ions thus set free are precipitated as AgCl by adding a large amount of silver nitrate solution and then titrating the excess of silver ions with ammonium thiocyanate potentiometrically.