| In this work,based on high-voltage electrospinning technology,a method of preparing energetic submicron composite fiber was carried out and the preparation process was optimized.Hence,nitrocellulose?NC?and glycidyl azide polymer?GAP?were selected as composite binders to support energetic submicronparticles.NC/GAP?NC/GAP/submicron-TATB?1,3,5-triamino-2,4,6-trinitrobenzene??NC/GAP/submicron-HNS?2,2?,4,4?,6,6?-hexanitro-stilbene?and NC/GAP/submicron-LLM-105?2,6-diamino-3,5-dinitropyrazine-1-oxide?energetic submicron composite fiber were synthesized by this technology.The morphology and structure were characterized by scanning electron microscopy?SEM?,infrared transform infrared spectroscopy?IR?,X-ray diffraction?XRD?,X-ray photoelectron spectroscopy?XPS?,and Brunauer–Emmett–Teller?BET?,and the thermochemistry performance and mechanism of energetic submicron composites were analyzed by DSC and thermal-infrared spectrometry online?TG-IR?.The impact sensitivity was investigated by testing specialty height?H50?and energy performance was calculated and evaluated.Electrospinning technology provided a feasible technology for development of new energetic submicron composite.?1?NC/GAP fibers were prepared by electrospinning technology and the effects of precursor solution concentration,spinning voltage,feed rate,and receiving distance on the morphology and diameter distribution of NC/GAP submicron fibers were explored.The SEM images were compared to optimize process conditions of electrospinning and obtained uniform NC/GAP fibers with a diameter of 0.641?m.?2?TATB submicronparticles were prepared by high-energy ball milling and blended with NC and GAP to obtain NC/GAP/submicron-TATB composite fibers.The results of SEM and BET showed the submicron fibers possessed 3D network structure and large specific surface area.The EDS results displayed that only C,N,and O exist on the surface of the submicronfibers.DSC and TG-IR tests proved that the submicron composite fibers showed significantly higher thermal decomposition rate and lower thermal decomposition peak temperature.In addition,the introduction of TATB submicronparticles in NC/GAP matrix resulted in an observably increase of H50 and chamber temperature?Tc?.?3?NC/GAP/submicron-HNS composite fibers were prepared by the above method and their thermolysis properties,impact sensitivity and energy performance were analyzed.The results demonstrated that the average diameter of the submicroncomposite fibers was1.074?m and the distribution was uniform.By DSC testing,the thermodynamic and kinetic parameters were obtained.The results indicated NC/GAP/submicron-HNS composite fibers had a lower activation energy and the thermal decomposition reaction was easier to proceed.The evaluation results of energy performance showed that the Isp was 2032 N·s·kg-1,which was higher than that of NC/GAP submicron fibers.This indicated that HNS submicron particles were conducive to the improvement of energy performance.In addition,the introduction of HNS submicron particles made fibers more insensitivity to impact.?4?Another new energetic material LLM-105,which had both high energy performance and low sensitivity,was introduced into the precursor solution after ball milling for blending.The obtained submicronfibers are continuous.Some LLM-105 submicronparticles were uniformly loaded on the surface of NC/GAP,and another part were embedded in submicronfibers.Thermal analysis results showed that the NC/GAP/submicron-LLM-105submicroncomposite fibers had only one exothermic peak,indicating that the three substances of NC,GAP,and LLM-105 decomposed simultaneously and had a synergistic effect.The negative impact of reduced energy conversion efficiency was offset by the increase of heat release.Energy performance was improved.The special height of submicron fibers was significantly higher than that of NC/GAP,indicating that the addition of LLM-105 was conducive to the improvement of safety performance. |
PDF Full Text Request