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Modern, Safe, and Affordable Processes for Production of Energetic Polymers (BAMO-AMMO)


The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: Develop safe, novel, and cost-effective processes for the commercial manufacture of energetic polymers (BAMO-AMMO) suitable for formulating advanced, high-performance materials. DESCRIPTION: To achieve the goal of extending the range of current and future precision fire munitions for the US Army’s mission of performance overmatch, materials with energy greater than currently available are necessary. One of the methods to increase overall performance of a propulsion system is the use of high energy thermoplastic elastomers (ETPEs). These materials are formed by linking two or more polymeric building blocks, one of which is typically crystalline in nature and one of which is amorphous, into a single polymer chain. The specific properties of a given ETPEs is controlled by a number of factors including characteristics of the building block molecules and linking agents, average polymer molecular weight, and distribution of molecular weights. ETPEs have been shown to have promising key properties such as good flame temperature, stability and performance. BAMO-AMMO, one of the ETPE material, an energetic block copolymer, offers desirable performance, good mechanical properties, high energy, is clean burning, and is chemically compatible with a wide range of materials such as nitramines. Significant efforts have been performed in developing BAMO-AMMO such as tailoring the “soft” AMMO and “hard” BAMO blocks of the copolymer to tailor the final mechanical properties. However, the current manufacturing processes for BAMO-AMMO prevent the ETPE from being affordable or manufactured with high throughput. The polymerization reactions need excessive amounts of reaction time (up to 96 hours) and extensive workup and isolation. The focus of this SBIR project shall include multidisciplinary research and development effort focusing on a robust, scalable and affordable manufacturing process for BAMO-AMMO and its precursors using modern technologies. PHASE I: Develop and demonstrate lab-scale synthesis method (~25-50gms per batch) using novel processing concepts to produce BAMO-AMMO material. Material from each small batch will be further characterized to compare properties with legacy material. Study the material residue after burning of the selected BAMO-AMMO batch materials. Perform analysis of rheological and physical properties of the BAMO-AMMO materials at various temperature, humidity and treatments. Additional characterization tests will be performed including, thermal analysis, gel permeation chromatography (GPC), dynamic mechanical analysis (DMA), melt viscosity, Teflon adhesion test, and nuclear magnetic resonance (NMR). Other testing may be performed to determine specific safety properties and other performance or structural characteristics of interest. Complete feasibility studies at the laboratory scale will focus on the polymerization process: chemical process steps, isolation of product, and waste stream processing with particular emphasis on safety and throughput. Material produced from the proof of concept demonstration (25-50 gram scale) will be sent to the Army for further characterization to ensure results are consistent and meet expectations. Chemical stability, in addition to multi-ingredient compatibility (including nitramines and other oxidizers) will be assessed by methods such as Vacuum Thermal Stability (VTS) as outlined in MIL-STD-286C or equivalent. PHASE II: Review the results from the Phase I feasibility study. Down select and optimize the synthesis process of the desired BAMO-AMMO material. Demonstrate the process by producing hundreds of grams of BAMO-AMMO in the scale of 250-500gms per batch according to desired material properties. Perform thermal and necessary safety testing for proper handling and shipping material to USG. Characterize BAMO-AMMO material properties and ensure results are consistent and meet expectations. In support with USG, formulate and produce propellant geometry using BAMO-AMMO to characterize final product for thermal analysis, mixing, rheological, mechanical, and combustion properties. Provide with the full process design for BAMO-AMMO manufacture and transition plan. Provide cost analysis on the synthesis process to manufacture BAMO-AMMO in larger quantities. The design and transition plan will guide Phase 3 efforts, which will focus on qualification of the material in propellant applications selected by the US Army. PHASE III DUAL USE APPLICATIONS: If this program is demonstrated to be successful, this energetic polymeric material technology can be applied to various military applications. Military application includes propellants primarily for large caliber (60mm, 81mm, 105mm, 120mm, 155mm), medium caliber (20mm, 25mm, 30mm and 40mm) as well as small arms (5.56mm, 7.62mm and 0.50 calibers) ammunitions. The likely transition partner is the Joint Program Executive Officer for Armaments & Ammunitions. REFERENCES: 1. Braithwaite, P.; Sanderson, A.; Wardle, R. “Optimization of BAMO-AMMO for gun propellants”, JANNAF conference, 2000.; 2. Sikder, A.K.; Reddy, S. “Review on Energetic Thermoplastic Elastomers (ETPEs) for Military Science” Propellants, Explosives, Pyrotechnics, 2013, 38, 14-28.; 3. Wardle, R.B.; Cannizzo, L.F.; Hamilton, R.S.; Hinshaw, J.C. Final Report “Energetc oxetane thermoplastic elastomer binders” AD-A278307, Thiokol Corporaton, 1992.; 4. "Thermoplastic elastomer-based low vulnerability ammunition gun propellants " US Patent#US4919737A; "High energy thermoplastic elastomer propellant" US Patent# WO1998021168A1 KEYWORDS: High Energetic Polymers, Energetic thermoplastic elastomers (ETPE), BAMO-AMMO
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