Effect of toughener on desensitizer and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12- hexaazaisowurtzitane (HNIW) based polymer bonded explosives (PBXs)

To improve the mechanical properties of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW) based polymer bonded explosives (PBXs) and promote their application, the effects of tougheners including ethylene-vinyl acetate coplolymer (EVA), styrene-butadiene rubber (SBR), and styrene-butadiene-styrene copolymer (SBS) on paraffin wax (PW), the desensitizer of PBXs, and HNIW based PBXs were investigated. The compatibility, stability, and mechanical properties of toughened desensitizers were determined by theoretical molecular dynamics (MD) simulation and experimental methods. Based on their modulus and elongation ratios, the optimum EVA, SBR and SBS contents in the toughened desensitizers were determined to be 8 wt%, 6 wt%, and 10 wt%, respectively. HNIW based PBXs were prepared with fluororubber 2311 (F₂₃₁₁) and cellulose acetate butyrate (CAB) binders, desensitized using different toughened PWs including PW/EVA, PW/SBR, and PW/SBS under optimal conditions, and analyzed for their mechanical properties, safety properties, and thermal stability. The results suggest that the toughened PW/SBR desensitizer was able to effectively reduce the sensitivity of PBXs and improve their tensile strengths. The tougheners exhibited no significant effects on the thermal ability of HNIW based PBXs. Our research strategy combing theoretical simulation, experimental verification and application study was successfully applied in the development of tougheners to achieve HNIW based PBXs with excellent performances.