Patents by Inventor Reddy Damavarapu
Reddy Damavarapu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9850181Abstract: A single-step method for preparing nano-sized cocrystals of explosive material by preparing a coformer solution having an explosive precursor dissolved into a liquid medium and a second explosive precursor dispersed in the liquid medium. The viscosity and solubility of the coformer solution may be modified by addition of binders, plasticizers, surfactants and anti-foaming agents to the coformer solution. The coformer solution is then milled to mechanically form the cocrystals. Further milling produces the desired cocrystal sizes.Type: GrantFiled: June 8, 2017Date of Patent: December 26, 2017Assignee: The United States of America as Represented by the Secretary of the ArmyInventors: Rajen Patel, Victor Stepanov, Reddy Damavarapu, Hongwei Qui
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Patent number: 9790137Abstract: A method of manufacturing a CL-20/HMX cocrystalline explosive which is coated in a polymeric binder, so as to be useful as an explosive molding powder. The cocrystalline material having a desirable average crystal size of from about 300 nm to about 1000 nm, which crystals are intimately coated with a polymeric binder and are produced as granular agglomerates that are less than on average 5 microns in size, and which crystals are relatively easy and safe to handle, transport, store and use. The method involving spray drying a CL-20 and HMX solvent solution containing a polymeric binder to form an intermediary amorphous material—which intermediary is then heated to cocrystallize the CL-20/HMX into the desired size cocrystals and aggregates thereof—which are coated in said polymeric binder.Type: GrantFiled: June 8, 2015Date of Patent: October 17, 2017Assignee: The United States of America as Represented by the Secretary of the ArmyInventors: Victor Stepanov, Reddy Damavarapu, Rajen Patel, Hongwei Qiu
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Patent number: 9701592Abstract: A safe and simple method for synthesizing insensitive nano-size cocrystals of high explosive materials such as HMX and Cl-20 by suspending the explosive materials in a nonsolvent solution and bead milling the solution.Type: GrantFiled: August 6, 2015Date of Patent: July 11, 2017Assignee: The United States of America as Represented by the Secretary of the ArmyInventors: Rajen B. Patel, Hongwei Qiu, Victor Stepanov, Reddy Damavarapu
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Patent number: 8608879Abstract: The present invention is a flare illuminant composition, useful in hand-held signals, which composition is environmentally friendly and economical, containing a commercially available, aromatic, high energy, amine-based organic compound, 5-aminotetrazole, in place of the conventional and toxic KClO4, or, for the known alternative to KClO4, expensive, strontium bis-(1-methyl-5-nitriminotetrazolate)monohydrate.Type: GrantFiled: December 19, 2011Date of Patent: December 17, 2013Assignee: The United States of America as Represented by the Secretary of the ArmyInventors: Jesse J. Sabatini, Gary Chen, Amita Nagori, Reddy Damavarapu
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Patent number: 8492541Abstract: Energetic candidate azido heterocycles and their synthesis are described.Type: GrantFiled: August 3, 2011Date of Patent: July 23, 2013Assignee: The United States of America as Represented by the Secretary of the ArmyInventors: Raja Duddu, Paritosh Dave, Reddy Damavarapu, Rao Surapaneni
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Patent number: 8153786Abstract: Energetic candidate azido heterocycles and their synthesis are described.Type: GrantFiled: July 16, 2008Date of Patent: April 10, 2012Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Raja Duddu, Paritosh Dave, Reddy Damavarapu, Rao Surapaneni
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Patent number: 8133993Abstract: A method for synthesizing pentanitrohexaazaisowurtzintane under neutral reaction conditions. Which synthesis involves treating a solution of hexanitrohexaazaisowurtzitane in ethyl acetate in the presence of a catalytic quantity of palladium on a carbon substrate, until a heterogeneous mixture is formed. This heterogeneous mixture is hydrogenated under a balloon atmosphere until the starting hexanitrohexaazaisowurtzitane is substantially reacted. The resulting pentanitrohexaazaisowurzitane mixture is filtered, dried and recovered from the dried residue through a Si-gel column.Type: GrantFiled: November 26, 2008Date of Patent: March 13, 2012Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Raja Duddu, Paritosh Dave, Reddy Damavarapu, Rao Surapaneni
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Patent number: 8002917Abstract: A method of adjusting the yield of a manufactured compound comprising primarily two energetic materials to yield a product comprising primarily one of the two energetic materials. Specifically, embodiments of the present invention provide a method of purifying a compound primarily comprising RDX and HMX to achieve a desired purity of RDX with an acceptable yield percentage. By adding sufficient acetonitrile (ACN) to the manufactured compound to dissolve it and form a solution; adding a pre-specified volume of water to the resultant solution and stirring sufficiently to precipitate at least the RDX; separating and drying the precipitate, a pre-specified purity and yield percentage of RDX may be obtained by varying the volume of water added. The process uses relatively environmentally benign recyclable solvents at ambient temperature and pressure reducing both environmental impact and energy costs.Type: GrantFiled: February 9, 2009Date of Patent: August 23, 2011Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Veera M. Boddu, Reddy Damavarapu, Krishnaiah Abburi
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Publication number: 20100200128Abstract: A method of adjusting the yield of a manufactured compound comprising primarily two energetic materials to yield a product comprising primarily one of the two energetic materials. Specifically, embodiments of the present invention provide a method of purifying a compound primarily comprising RDX and HMX to achieve a desired purity of RDX with an acceptable yield percentage. By adding sufficient acetonitrile (ACN) to the manufactured compound to dissolve it and form a solution; adding a pre-specified volume of water to the resultant solution and stirring sufficiently to precipitate at least the RDX; separating and drying the precipitate, a pre-specified purity and yield percentage of RDX may be obtained by varying the volume of water added. The process uses relatively environmentally benign recyclable solvents at ambient temperature and pressure reducing both environmental impact and energy costs.Type: ApplicationFiled: February 9, 2009Publication date: August 12, 2010Inventors: VEERA M BODDU, Reddy Damavarapu, Krishnaiah Abburi
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Patent number: 7304164Abstract: 1-Methyl-2,4,5-Trinitroimidazole is synthesized starting from 4-nitroimidazole using stepwise nitration method and further methylation using Dimethylsulphate. It is relatively insensitive to impact and its thermal stability is excellent. The calculated detonation properties indicate that its performance is about 30% better than TATB. It can be prepared easily, with reasonable yield, starting from commercially available Imidazole. Results from impact sensitivity, friction sensitivity, time-to-explosion temperature and vacuum stability tests indicate that it is less sensitive than both RDX and HMX. The good oxygen balance and measured heat of formation data of this material indicate that its propellant performance should be good.Type: GrantFiled: October 13, 2006Date of Patent: December 4, 2007Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Reddy Damavarapu, C. Rao Surapaneni, Nathaniel Gelber, Raja G. Duddu, MaoXi Zhang, Paritosh R. Dave
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Patent number: 7109359Abstract: The invention relates to a novel polyazido compound: 2,2-dinitro-1,3-diazidopropane.Type: GrantFiled: August 15, 2003Date of Patent: September 19, 2006Assignee: The United States of America represented by the Secretary of the ArmyInventors: Paritosh R. Dave, Raja G. Duddu, Reddy Damavarapu, Nathaniel Gelber, Kathy Yang, C. Rao Surapaneni
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Patent number: 6998485Abstract: The compound 3a,8a-bis-azidomethyl-3a,4,8a,9-tetrahydro-3H,8H-bis-[1,2,3]triazolo[1,5-a;1?,5?-d]pyrazine, whose structure is depicted below, is disclosed:Type: GrantFiled: August 15, 2003Date of Patent: February 14, 2006Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Paritosh R. Dave, Raja G. Duddu, Reddy Damavarapu, Nathaniel Gelber, Kathy Yang, C. Rao Surapaneni
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Patent number: 6965042Abstract: The compound 2,2-bis(azidomethyl)oxirane, whose structure is depicted below, is disclosed:Type: GrantFiled: August 15, 2003Date of Patent: November 15, 2005Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Paritosh R. Dave, Raja G. Duddu, Nathaniel Gelber, Kathy Yang, C. Rao Surapaneni, Reddy Damavarapu
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Patent number: 6841690Abstract: This invention relates to a series of novel compounds having the general structures A and B: including 2-azido-2-azidomethyl-1,3-diazidopropane (1), 2-azidomethyl-2-hydroxy-1,3-diazidopropane (2), 2-azidomethyl-2-nitrato-1,3-diazidopropane (3), 2-azidomethyl-2-nitro-1,3-diazidopropane (4), 2,2-dinitro-1,3-diazidopropane (5), methallyidiazide (6), a dimer of methallyidiazide (6), comprising 3a,8a-Bis-azidomethyl-3a,4,8a,9-tetrahydro-3H,8H-bis[1,2,3]triazolo[1,5-a;1?,5?-d]pyrazine (6-Dimer), 1,3-diazidoacetone (7), and 2-Oximido-1,3-diazidopropane (8). Also shown are reaction intermediates of these compounds, including 2,2-bis(chloromethyl)oxirane (9), and 2,2-bis(azidomethyl)oxirane (10).Type: GrantFiled: August 15, 2003Date of Patent: January 11, 2005Assignee: The United States of America, as represented by the Secretary of the ArmyInventors: Paritosh R. Dave, Raja G. Duddu, Reddy Damavarapu, Nathaniel Gelber, Kathy Yang, C. Rao Surapaneni
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Patent number: 5977418Abstract: The invention is a process for regioselective nitration of substituted aromatic compounds and the corresponding reaction products. The reaction is conducted in the presence of a solid zeolite with small pores and with nitrogen pentoxide as the nitrating agent. The reaction products have a very high proportion of para-nitro substituted isomer.Type: GrantFiled: January 20, 1998Date of Patent: November 2, 1999Inventors: Reddy Damavarapu, Keerthi Jayasuriya, Thomas J. Kwok
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Patent number: 5946638Abstract: A method is described for the regioselective nitration of substituted aromatic compounds. The reaction is effected by heating the aromatic compound to a temperature within the range of 70-90.degree. C. in the presence of a solid zeolite catalyst and adding concentrated nitric acid to the heated mixture, the concentration of the acid ranging from 90-98%, by weight.Type: GrantFiled: August 7, 1998Date of Patent: August 31, 1999Inventors: Keerthi Jayasuriya, Reddy Damavarapu
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Patent number: 5387297Abstract: The compound 2,4-dinitroimidazole is highly insensitive towards impact and its thermal stability is excellent. The calculated detonation properties results indicate that its performance is about 30% better than TATB. It can be prepared easily with good yield starting from inexpensive starting materials. Results from impact sensitivity, friction sensitivity time-to-explosion temperature and vacuum stability tests indicate that 2,4-dinitroimidazole is less sensitive than both RDX and HMX. Its good oxygen balance and measured heat of formation data of this material indicate that its propellant performance is good.Type: GrantFiled: November 26, 1993Date of Patent: February 7, 1995Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Reddy Damavarapu, Keerti Jayasuriya, Theodore Vladimiroff, Sury Iyer