Abstract:The physical properties,stabilities and transformations of four polymorphs of hexanitrohexaazaisowurtzitane existing at ambient conditions are discussed. The qualitative identification and quantitative determination of the polymorphs are also involved.

Abstract:The solvent effect on the synthesis of diethylaluminum azide(DEAA) from diethylaluminum chloride(DECA) and sodium azide(NaN₃) is discussed.In electron-donor tetrahydrofuran(THF) or its mixture with hydracarbon as the reaction medium the product is DEAA·THF complex;in weak electron-donor like hydracarbon the reaction product is DEAA which exists as trime;when nonelecton -donor agent like hexane or cyclohexane is used as the reaction solvent,there is no product formed.With increase of electron-donation of the solvent the product yield also increases,for example, the yield of DEAA sequentially increases in the reaction medium of benzene,tuluene.dimethyl and trimethylbenzene.The other chemical effect of solvents on the reaction of NaN₃ and DECA is also discussed.

Abstract:The effect of oxidizer,mass burning rate and combustion temperature on the radiant intensity (RI) of infrared radiation pyrotechnics were experimentally inveztigated in the specific wavelength of 3～5μm and 8～14μm regions. The results show that PTFE (Polytetrafluoroethylene) is an excellent oxidizer having a high RI,the increase of RI is directly proportional to mass burning rate, the increase rate of RI in the range of 3～5μm is higher than those of 8～14μm with the rise of temperature.

Abstract:The catalyses effect of triphenyl bismuth（TPB）on the cure of HTPB-based high burning rate propellant is investigated. The experimental results show that TPB can reduce the curing temperature and time of the said propellant without any negative effect on its processability and mechanical properties. It is found that the optimal dosage of TPB is in the range of 0.006～0.05% of the total weight of the propellant cured at 50℃ for a week.

Abstract:The β secondary transition of 4 nitrocellulose-containing gun propellants is investigated by means of dynamic viscoelastic grapher DDV-VIII-EA. It is found that single-base, double-base, nitramine- and nitroguanidine-based propellants all give an corresponding peak of β secondary transition. Compared with single-base propellant, the peak tan β of double-base propellant at its β secondary transition apparently increases, while those of nitramine-based and NGU-based propellants decrease at their β secondary transition. The experimental frequency shows little influence on the tanδ at their β secondary transition. During aging test, the tan β at β secondary transition of nitramine-based propellant is larger than that of NGU-based, and the former decreases rapidly than the later, but after 600hrs, both tan β peaks are nearly closed to each other. The relationship of β secondary transition with impact fracture strength of the gun propellants is briefly discussed.

Abstract:Recent studies on the modification of ammonium nitrate are reviewed,including the phase stablization of ammonium nitrate and the improvement of hygroscopicity and energy characteristic of ammonium nitrate. Ammonium nitrate propellants will be the development trend of smokeless,low signal and low polluting propellants.

Abstract:The thermal decomposition characteristics of high energy RDX-XLDB propellants with or without catalyst were investigated by means of DSC under different pressures. The results show that the decomposition peak of RDX is the main in the propellant decomposition process and peak temperature shifts to lower temperature with the increase of pressure. The lower the main peak temperature,the high burning rates of the propellant.The main peak temperature of the propel lant with catalysts is lower and,therefore getting higher burning rates.

Abstract:The combustion behaviors of liquid energetic materials, HY91 and OTTO-II, were investigated by using their droplets in the high temperature range of 700～850℃. The ignition delay, lifetime, ignition temperature and average mass burning rate of the droplets were measured by a high-speed camera and two thermocouples. The results show that OTTO-II is ignited earlier than HY91, but its burning rate is much slower than the later. These data obtained are of practical references for improving the igniter and injection device of the regenerative liquid propellant gun（RLPG）.

Abstract:The processing aids used in manufacturing of solid propellants and the principle of their choice are reviewed, including rheological property, approximate surface tension, polarity, solubility and reaction kinetics to the propellant ingredients. Some views on the development of processing aids are presented by the author.

Abstract:The saturated concentration curve and ultimate saturated concentration curve of ammonium nitrate under the action of a special surfactant in expansion process are researched,including the change of temperature,the content of water and concentration ammonium nitrate therein., and the kinetics of crystal nucleus formation and growth of ammonium nitrate in the said process are discussed as well.

Abstract:Propery a method of classifying explosives by fuzzy mathematics is proposed. The Parameters and performances of the well-known and that to be evaluated explosive are classified in fuzzy clusters so as to provide a proper basis for their application.

Abstract:Five geometrically similar nitration reactors filled with polystyrene and water as mediums were used to simulate the rules of residence time distribution（RTD）of the fluid and that of reactor scale-up. The experimental results show that the optimum pilot volume of solid-liquid phase nitration reactor is 0.040 m³. The relevant empirical formula of scale-up is obtained thereof, which can be used as theoretical and experimental reference for the further investigation.

Abstract:The basic principle of transient pulse test of EED and the development history of nondestructive inspecting the firing sensitivity of EED are briefly reviewed. It is recognized that this kind of nondestructive test so far is still a statistic method; the further necessity is to develop a technique being able to individually forecast the property of EEDs and, therefore, the related instrumentation should concurrently be developed.

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