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Nandi A.K.,High Energy Materials Research Laboratory | Shirsagar A.S.,High Energy Materials Research Laboratory | Thanigaivelan U.,High Energy Materials Research Laboratory | Bhattacharyya S.C.,Advanced Center for Energetic Materials | And 3 more authors.
Central European Journal of Energetic Materials | Year: 2014

The thermally stable, insensitive, high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is manufactured by amination of 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) in toluene with NH3 gas. It is an isothermal, singlefeed, semi-batch, gas-liquid heterogeneous, reaction crystallization process. The amination process is discussed by applying the chemical engineering methodology of mass transfer and reactive crystallization processes based on Two-Film Mass-Transfer (TFMT) theory. Kinetic expressions have been developed to define the chemical reactions as well as the physical phenomena (mass transfer) associated with this process. A single expression has been derived to explain the dependence of the ammonia consumption rate on various process parameters. Subsequently, the influence of various process parameters on the product quality (particle size and chloride impurity content) has been studied on the laboratory scale. Finally, the process has been established in the pilot plant, with optimized process conditions, to realize TATB of desired particle size and chloride content. The effects of feeding excess ammonia, and the presence of mercaptans/hydrogen sulphide impurities in poor quality toluene on the formation of certain undesirable by-products in TATB, are also discussed.

Kumari D.,Indian Defence Institute of Advanced Technology | Singh H.,Indian Defence Institute of Advanced Technology | Patil M.,University of Mumbai | Thiel W.,Max Planck InstitutfurKohlenforschung | And 2 more authors.
Thermochimica Acta | Year: 2013

This paper describes the synthesis and characterization of two novel tetra-azido energetic plasticizers from readily available commercial sources possessing good thermal stability. Two new energetic azido esters named bis(1,3-diazido prop-2-yl)malonate (1) and bis(1,3-diazido prop-2-yl)glutarate (2) have been synthesized and characterized by IR, 1H NMR, 13C NMR, HRMS, thermal analysis, and compatibility tests. Both azido esters (1 and 2) show good thermal stability with decomposition temperatures of 233.5 C and 232.6 C. Their densities are measured to be 1.25 g/cm3 and 1.27 g/cm3, respectively. Glass transition temperature (T g) of both compounds 1 and 2 is -69 C and -68 C and after addition with binder shows reduction in Tg of polymer-plasticizer blends as compared to Tg of polymer only with single decomposition temperature values which indicate the presence of single phase homogeneous system. Thermal decomposition kinetics of both compounds was determined by DSC, using non-isothermal Kissinger and Friedman differential isoconversional method. Density functional theory calculations on compounds 1 and 2 predict positive heats of formations. AbbreviationsFTIRFourier transforms infrared spectrum 1H NMRproton nuclear magnetic resonance13C NMRcarbon nuclear magnetic resonanceHRMShigh resolution mass spectrometryTLCthin layer chromatographyTG/SDTAthermo gravimetric/standard deviation thermal analyserTGAthermo gravimetric analysisp-TSApara toluene sulphonic acid © 2013 Elsevier B.V. All rights reserved.

Shekhar Pant C.,Advanced Center for Energetic Materials | Santosh M.S.S.N.M.,Advanced Center for Energetic Materials | Banerjee S.,Indian Defence Institute of Advanced Technology | Khanna P.K.,Indian Defence Institute of Advanced Technology
Propellants, Explosives, Pyrotechnics | Year: 2013

The paper reports the energization of Hydroxyl-Terminated Polybutadiene (HTPB) by functionalizing explosophore -NO2 over the HTPB backbone, resulting in the formation of conjugated nitro-alkene derivative of HTPB. A convenient, inexpensive and efficient "one pot" procedure of synthesizing Nitro-Functionalized Hydroxyl-Terminated Polybutadiene (Nitro-HTPB) is reported. The reaction was carried out with sodium nitrite and iodine. To retain the unique physico-chemical properties of HTPB, functionalization by -NO2 group was restricted to 10 to 15 % of double bonds. The Nitro-HTPB was characterized by FTIR, 1H NMR, VPO, DSC, TGA etc. The polymer has shown good thermal stability for practical applications. The kinetic parameters for the decomposition of Nitro-HTPB at 150-300 °C were obtained from non-isothermal DSC data. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pant C.S.,Advanced Center for Energetic Materials | Mada S.S.N.M.S.,Advanced Center for Energetic Materials | Mehilal,Explosives Research & Development Laboratory | Banerjee S.,Indian Defence Institute of Advanced Technology | Khanna P.K.,Indian Defence Institute of Advanced Technology
Journal of Energetic Materials | Year: 2016

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. Copyright © Taylor & Francis Group, LLC.

Kumari D.,Indian Defence Institute of Advanced Technology | Anjitha S.G.,University of Mumbai | Pant C.S.,Advanced Center for Energetic Materials | Patil M.,University of Mumbai | And 2 more authors.
RSC Advances | Year: 2014

A modular approach towards a series of novel di azido, tetra azido and hexa azido esters is introduced here. The methodologies adopted towards their synthesis are short, environmentally friendly, cheap and scalable. Detailed computational, physical and thermal studies of these plasticizers with binders have been carried out. Our results reveal impressive properties in terms of thermal stability, sensitivity, nitrogen content, oxygen balance, kinetics and heat of formation of synthesized plasticizers and their compatibility with energetic binders. This journal is © the Partner Organisations 2014.

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