Catalytic effects of nano additives on decomposition and combustion of RDX-, HMX-, and AP-based energetic compositions

Recent advances in catalytic combustion of AP-based composite solid propellants

Synthesis, characterization, migration and catalytic effects of energetic ionic ferrocene compounds on thermal decomposition of main components of solid propellants

Ferrocene-based polymers and their derivatives have the ability to catalyze the burning process of composite solid propellants efficiently. However, the simple and volatile ferrocene migrates to the surface of the solid propellant on prolonged storage, which alters the designed burning parameters and more seriously causes unexpected explosions. To retard migration problems, six novel ferrocene-based polyethyleneimines (PEI-Fcs) were synthesized by the condensation reaction of branched polyethyleneimine (PEI) with ferrocenecarbonyl chloride. The structures of the synthesized PEI-Fcs were characterized using 1H NMR, FT-IR and UV-Vis spectroscopy. The redox properties of the polymers are very important for burning rate catalysts (BRCs). Cyclic voltammetry (CV) revealed that all the PEI-Fcs showed redox properties due to the presence of ferrocene moieties. Migration studies confirmed that the migration of these PEI-Fcs was much slower than that of 2,2-bis(ethylferrocenyl)propane (catocene) and ferrocene. The catalytic effect of PEI-Fcs on the thermal decomposition of ammonium perchlorate (AP) was investigated using thermogravimetry (TG) and differential thermogravimetry (DTG). It was found that in the presence of PEI-Fcs (1–6), the peak decomposition temperature of AP was shifted towards the left (decreased) significantly. The results from the TG and DTG analysis indicated that the novel PEI-Fcs had good catalytic effects of lowering the thermal decomposition temperature of AP and were almost stable up to 220 °C. We expect that these novel PEI-Fcs would have great value as high BRCs for composite solid propellants.

Ferrocene-based polyethyleneimines for burning rate catalysts

Recent progress on ferrocene-based burning rate catalysts for propellant applications

Synthesis, characterization, migration studies and combustion catalytic performances of energetic ionic binuclear ferrocene compounds

With the aim of developing low-migratory burning-rate (BR) catalysts for solid propellants, a series of transition-metal complexes of 5-ferrocenyl-1H-tetrazole (HFcTz), [Cu2(bpy)2(FcTz)4]·2C2H5OH (1), [Pb(phen)2(H2O)3](FcTz)2·H2O (3), [Cu(phen)3](FcTz)2·8H2O (4), [Mn(phen)2(H2O)2](FcTz)2 (5), [Mn(bpy)(H2O)4](FcTz)2 (6), [Ni(phen)3](FcTz)2·9H2O (7), and [Co(phen)3](FcTz)2·9H2O (8) (bpy = 2,2′-bipyridine; phen = 1,10-phenanthroline), were synthesized and structurally characterized. Only a limited number of single crystals of [Pb2(phen)4(CO3)](FcTz)2·phen·9H2O (2) were formed so only its crystal structure was analyzed. The complexes show high thermal stability. Cyclic voltammetry investigations suggested that 1 and 3–7 exhibit quasireversible redox systems. Their catalytic effects on the thermal degradation of ammonium perchlorate (AP), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and 1,2,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) were evaluated by differential scanning calorimetry (DSC) and thermogravimetric (TG) methods. The optimum content of the new compounds in AP, RDX, and HMX was established to be 5, 5, and 2 wt.-%, respectively. They exhibit high catalytic activities in the thermal decomposition of AP and RDX. Among them, 6 was found to be the best ferrocene-based BR catalyst.

5‐Ferrocenyl‐1H‐tetrazole‐Derived Transition‐Metal Complexes: Synthesis, Crystal Structures and Catalytic Effects on the Thermal Decomposition of the Main Components of Solid Propellants

Two energetic catalysts, 3,5-dinitro-2-pyridonate of lead (II) (Pb(2DNPO)2, 1) and 3,5-dinitro-4-pyridone-N-hydroxylate tetrahydrate of copper (II) (Cu(4DNPOH)2(H2O)4, 2) were characterized by elemental analysis, FT-IR, TG-DSC and structurally characterized by X-ray single-crystal diffraction analysis. X-ray powder diffraction analysis of complex 1 confirmed the phase homogeneity of the polycrystalline sample. Crystal data for 1: monoclinic, space group P 21/n, a = 8.5253(9), b = 9.2938(10), c = 19.654(2) A, β = 102.289(2)°, V = 1521.6(3) A3, Z = 4; 2: monoclinic, space group P 21/n , a = 8.3705(10), b = 9.9307(12), c = 10.5771(12) A, β = 98.021(2)°, V = 870.62(18) A3, Z = 2. The complex 1 is a one-dimensional coordination polymer with each Pb(II) atom being six-coordinated, forming a heavily distorted octahedral geometry, by two nitrogen and four oxygen donors. Each ligand links the Pb(II) ions in a chelating bridging mode using nitrogen and oxygen atoms of its pyridonate part. The complex 2 is a copper (II) complex with a compressed octahedral geometry. The Cu(II) atom locates on the equatorial positions defined by oxygen atoms of four water molecules. Its axial positions are filled with two oxygen donors of the pyridine-N-hydroxylate moieties of two ligands. The abundant hydrogen bonds link the molecules into one-dimensional chains. Both the complexes represent the first two examples of the energetic catalysts containing dinitropyridine derivatives characterized crystallographically

The first two structurally characterized energetic catalysts derived from dinitropyridone

Six copper(II) and lead(II) salts of p-nitrocalix[n]arene (n=4, 6, 8) were synthsized and characterized. The DSC curves of all salts showed exothermic decomposition. Sensitivity studies revealed that all the salts with the exception of the lead salt of p-nitrocalix[6]arene (NCPb6) are relatively insensitive materials. Investigations of the catalytic activities showed that most of the salts displayed high activities in thermal decomposition of NC-NG and RDX. As evaluated in this work, the salts enhanced the burning rates of both double base (DB) and RDX-component modified double base propellants. The best catalytic effect was obtained with NCPb6, which increased the burning rate of the DB propellant to the order of about 200 % (2–6 MPa) and 103–198 % (8–20 MPa) while decreasing the pressure index (n) to 0.22 (20–22 MPa).

Xuezhong Fan

Papers

Synthesis, characterization, migration and catalytic effects of energetic ionic ferrocene compounds on thermal decomposition of main components of solid propellants

Synthesis, characterization, migration studies and combustion catalytic performances of energetic ionic binuclear ferrocene compounds

5‐Ferrocenyl‐1H‐tetrazole‐Derived Transition‐Metal Complexes: Synthesis, Crystal Structures and Catalytic Effects on the Thermal Decomposition of the Main Components of Solid Propellants

The first two structurally characterized energetic catalysts derived from dinitropyridone

Synthesis, Characterization, and Combustion Catalytic Activities of Copper(II) and Lead(II) Salts of p‐Nitrocalix[n]arenes (n=4, 6, 8)