重视创新，实现火炸药的跨越式发展

依据火药与炸药在现代武器装备中的重要地位和作用,以及未来高技术战争对武器的要求,阐明了火炸药创新的内涵于重视知识创新,加强技术创新,推进管理创新。提出了加速火炸药创新的五项研究课题。     

Effects of Twin‐Screw Extrusion Processing on the Burning Rate of Composite Propellants

A new process for continuous manufacturing of composite propellants has been developed using Twin Screw Extrusion (TSE). The effects of TSE‐processing on the burning rates of an ammonium perchlorate (AP)‐based composite propellant have been characterized over a wide composition range (79 to 87 wt. % AP) and a wide range of screw speeds (45 to 85 RPM) using a quadratic model for an experimental Response Surface Analysis (RSA) based on the Kowalski, Cornell, and Vining (KCV) algorithm. Using Student‘s T‐test, it was determined that burning rates obtained from strand‐burning rate tests at 3.5 MPa, 7.0 MPa, and 10.5 MPa are affected only by the individual ingredients, the interaction between the coarse AP particles and the binder, and the screw speed. Measured burning rates were found to be 40% to 100% higher than Petite Ensemble Model (PEM) predictions, which was accounted for by modifying the PEM through a power law relationship with pressure that includes a rule‐of‐mixtures dependence of the exponent and coefficient on the weight fraction of coarse and fine AP particles. The resulting modified PEM reduced differences between the predictions and experimental data by 79% at 3.5 MPa, 83% at 7.0 MPa, and 78% at 10.5 MPa.     

A Desorption Electrospray Ionization Mass Spectrometry Study of Aging Products of Diphenylamine Stabilizer in Double‐Base Propellants

Double‐base propellants consisting of nitrocellulose, nitroglycerin and stabilizer undergo chemical and physical changes upon aging, leading to changes in ballistic power and presenting explosive hazards. During aging, PTFE seals of the glass ampoules used in the aging studies undergo a yellow discoloration. This report studies the discoloration of the liners using desorption electrospray ionization (DESI), a gentle surface analysis technique based on electrospray ionization. The color bodies in the PTFE liners were identified by DESI together with tandem mass spectrometry to be the nitrated derivatives of the diphenylamine stabilizer: dinitro‐, trinitro‐, and tetranitrodiphenylamine. While increased nitration decreases vapor pressure of the DPA species, an increase in solubility in the PTFE liners occurs. This may account for these species not previously being observed during early aging studies as they are preferentially absorbed into the liners, which were not extracted prior to high performance liquid‐ chromatography analysis.     

Munitions Propellants Residue Deposition Rates On Military Training Ranges

Training with live munitions is an integral component of preparing the modern military for warfare. Energetic compounds, such as propellants and explosives, are consumed during the use of these munitions. These compounds are never fully consumed, however, and the deposition and accumulation of energetic residue on training ranges is the result. This paper summarizes 10 years of research into propellant deposition rates for common military munitions used in the USA and Canada. Research indicates that the firing of howitzers and tanks leave very little residue, the firing of mortars can result in moderate deposition of propellant residue, small‐arms firing positions have the potential for significant residue accumulation, and training with shoulder‐fired rockets and 40 mm machine guns can result in dangerous quantities of unburned propellants. Residue rates vary widely for the weapon systems tested, from 10⁻⁶ % for large rocket systems to over 70 % for shoulder‐fired rockets.     

Synthesis and Energetic Properties of 4,4′,5,5′‐Tetranitro‐2,2′‐biimidazolate(N4BIM) Salts

This paper describes the synthesis and characterization of several salts of 4,4′,5,5′‐tetranitro‐2,2′‐biimidazolate (N4BIM). Each of the salts were characterized chemically, thermally, morphologically, as well as with respect to destructive stimuli (impact, electrostatic discharge, friction, thermal). These salts show promise as propellant ingredient additives, and in particular, the bis‐triaminoguanidinium salt of N4BIM displays excellent burn rate and combustion behavior. Our combustion studies have shown that TAGN4BIM displays a fast burning rate and has the lowest pressure dependence exponent yet measured for a triaminoguanidinium salt.     

Stability of Non‐isothermally Treated Double‐Base Propellants Containing Different Stabilizers in Comparison with Molecular Orbital Calculations

In this research work some malonanilide derivatives (M1‐M5) have been prepared and used as stabilizers for double‐base propellants (DBPs). Their stabilization effect has been compared with the effect of N,N‐diethyldiphenylurea (C1) as a classical stabilizer. Thermal analysis (TA) study under non‐isothermal conditions was carried out on propellant samples containing stabilizers. This study gave information about the thermal stability effect of different stabilizers on DBPs, thermal decomposition and some thermodynamic parameters. The non‐isothermal (TGA and DSC) results show that the o‐dinitromalonanilide (M3) has the highest thermal stability effect on the propellant samples. The molecular orbital calculations such as energy gap (ΔE), net charge, E_LUMO, E_HOMO, IP, and E_a were done and compared with TA experimental data. It was finally concluded that there is no single factor controlling the stabilizing effect of different stabilizers on thermal stability of DBPs. There is a group of factors that play important role in detecting the stabilizing effect of stabilizers on DBPs such as energy gap, charge density on the o‐position of the benzene ring and the net charge on the benzene ring itself.     

Effects of Relaxed Modulus on the Structure Integrity of NEPE Propellant Grains during High Temperature Aging

The nitrate ester plasticized polyether (NEPE) propellants were accelerated aged at 65, 70, and 75 °C, respectively. The dynamic mechanical properties of NEPE propellants were determined with the dynamic mechanical analysis method. The strength limit of NEPE propellants was tested by the uniaxial tension test. The relaxed modulus and strength limit both decreased. By calculating the structural integrity of NEPE grain, the effects of modulus changes on the structure integrity were analyzed. The results provide a reference for the life prediction of solid rocket motor containing an NEPE propellant.     

HNF/HTPB propellants: Influence of HNF particle size on ballistic properties

The burning rate characteristics of solid composite propellants can be modified via different methods. One of these is the application of different oxidizer particle sizes in the propellant. The effect of the use of fine and coarse particles of the oxidizer hydrazinium nitroformate (HNF) in hydroxyl-terminated polybutadiene (HTPB)-based propellants is reported in this paper. The fine HNF particles were obtained by means of a grinding process. The fine and coarse HNF grades were characterized regarding their hazardous and thermal stability properties, as well as the influence of a cured and uncured HTPB binder on these characteristics. The ballistic properties of three (two monomodal and one bimodal) HNF/HTPB-based propellants show that the use of fine HNF (5-10 μm mean size) leads to a lowering of the pressure exponent of the propellant, implying that the propellant burning rate can be tuned by varying the mean size of the HNF grades present in the propellant.     

A New Method for Determining the Vapor Pressure of Nitroglycerine Above Solid Rocket Propellants

Measuring the vapor pressure of compounds such as nitroglycerine (NG) which have a low volatility has not been a straightforward task in the past. There are a wide range of values in the literature for the vapor pressure of NG and furthermore, there is little information regarding the vapor pressure of this compound above solid rocket propellant formulations. We have devised a new method for determining the vapor pressure of NG both above the pure material and solids containing this nitrate ester. The values obtained for pure liquid NG are in good agreement with some previously published values. It was also found that the vapor pressure of this compound is slightly lowered when it is incorporated into solid rocket propellant formulations.