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Co-crystallization of cyclic nitramines with sterically crowded molecules, i.e., ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-CL-20) with cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole (BCHMX), is very difficult, but the co-agglomeration (slurry method) of their mixed micro-co-particles gives very good results. CL-20 is present in these co-agglomerates (CACs) in its β-form. Besides the medium of co-agglomeration, also the molar ratio is very important; it is possible to obtain β-CL-20/BCHMX (molar 1.8/1.0) with the impact sensitivity of 14.9 J. The density of these CACs approaches 99.6% of the density of the β-CL-20 crystals. Based on the application of the Raman, FTIR and PXRD techniques, it has been proved that the agglomeration of CL-20/BCHMX micro-co-particles leads to the formation of CACs mostly with the properties of co-crystals (CCs). This also seems to be confirmed by the relationships between the heat of formation and ring-deformation vibrations (in plane) and between the impact sensitivity and the difference in the asymmetric NO2 stretching vibrations in pure CL-20 and its CACs. The CACs studied have lower detonation energies than would be consistent with the percentage of individual coformers in these crystals. An examination of the most sensitive CACs (1.2 J) as a detonator primer has shown the absence of its required acceleration capabilities in the given detonator design. A comparison with literature data and our unpublished preliminary results indicates that the CACs and CCs of this type could have potential beneficial applications in propellants. [ABSTRACT FROM AUTHOR]

[Display omitted] • CACs with linear stirrer(B1) & cross stirrer(B2); B2- yielding novel properties. • BTATz stabilized HMX in the CACs as its α-polymorph & lowest sensitivity (46 J) • α-HMX/BTATz detonation energy (6097 J·g−1) higher to pure β-HMX (5864 J·g−1) • The ε-CL20 stabilized as β-polymorph in CL20/BTATz & lowest sensitivity (20.5 J) • These ideal for propulsion applications & suitable for industrial scale production. Coagglomerated crystals (CACs) of the cyclic nitramines RDX, β-HMX, BCHMX and ε-CL20 with 3,6-bis(1H-1,2,3,4-tetrazol-5-ylamino)-1,2,4,5-tetrazine (BTATZ) were prepared using the "coagglomeration method" (classified as slurry cocrystallization) in two parallel batches, one with a linear stirrer (B1) and another with a cross stirrer (B2). The batch B2 procedure is more suitable because the CACs show a better crystal morphology, higher density, and quality of the crystal surface. These CACs, characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, Raman studies, and differential thermal analysis, convincingly contain cocrystals, in which HMX is stabilized in its α form and CL20 in its β form. On the basis of the results obtained, new relationships were found between the N–N bond stretching and FTIR C–H bond stretching vibrations in CACs, on the one hand, and their impact sensitivity, crystal density, voluminous detonation energy (Q.ρ), heat of combustion and enthalpy of formation, on the other. These evidence that, together with the relation between ring deformation vibrations and the Q.ρ values, correspond to the idea of the method of initiation of energetic materials by impact and shock. The α-HMX/BTATz, prepared by method B2, was surprisingly the least sensitive (46 J) of the CACs studied and had a slightly better detonation energy than that of pure β-HMX (6097 versus to 5864 J·g−1). [ABSTRACT FROM AUTHOR]

Coagglomerated crystals of HNS and HNAB with attractive nitramines [Display omitted] • CACs of HNS (–CH = CH–) and HNAB (-N = N-) with nitramines prepared results were compared. • Spectral & PXRD outputs indicate the formation of co-crystals in co-agglomeration. • HMX converted from β to δ, and CL20 ε to β modifications in co-agglomeration. • CACs with HNS can be less sensitive and more efficient than analogous PBXs. • HMX/HNS can be suitable fillers for special detonators and insensitive ammunition. Co-agglomerated crystals (CACs) of trans -2,2,4,4′,6,6′-hexanitrostilbene (HNS) and trans -2,2′,4,4′,6,6′-hexanitroazobenzene (HNAB) with RDX, β -HMX, BCHMX and ε -CL-20 have been prepared. Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Raman studies and differential thermal analysis (DTA) have confirmed that this process leads to the formation of co-crystals (CCs), in which HMX is present in its δ-form, CL-20 in its β -form and trans -HNS changes its conformation to cis -form. In most cases, these significant structural changes and intermolecular-orientations have improved the impact sensitivities, mainly in some CACs with cis -HNS; for CL-20, on the other hand, the insertion of HNS or HNAB into its crystal lattice is destabilizing. Logical relationships between some FTIR, Raman vibrational modes of the CACs studied and parameters of their initiation and detonation have shown greater information about corresponding molecular structural relationships. The detonation energies of these co-crystals are in most of cases higher than that of correspond to the percentage of the coformers in them. It has been shown that this co-agglomeration can reduce the sensitivity of nitramines (with the exception of CL-20) roughly to the level of the sensitivity of analogous plastic-bonded explosives (PBXs), with the high-performance parameters of the resulting CACs being maintained. From a practical point of view, the combination of HMX and HNS appears to be the most optimal; these CACs at a molar ratio of 1.00/0.11 have exhibited the impact sensitivity of 47 J and the calculated detonation velocity 8.98 km.s−1. [ABSTRACT FROM AUTHOR]

Energetic co-agglomerates (CACs), obtained by agglomeration of the nano-particle mixtures of 1,3,5-trinitrobenzene-2,4-diamine (DATB) with nitramines, and their impact sensitivities: here Cp1 & Cp2 are BCHMX/DATB; Cp3 is RDX/DATB; Cp4 is δ-HMX/DATB; Cp5 is β-CL20/DATB. [Display omitted] • A New method co-agglomeration crystal of the nitramines with DATB. • Formation of co-crystals during co-agglomeration. • Polymorphic change β to δ in HMX and ε to β in Cl20 their co-crystals. • Uniform distributed DATB over HMX makes stable towards external stimuli. • Strong co-relation co-crystals energy content to their N-N and N-O bonds stretching. A new method of atmospheric co-agglomeration of energetic micro-particles has been applied to the preparation of the co-agglomerates of 1,3,5-trinitrobenzene-2,4-diamine (DATB) with 1,3,5-trinitro-1,3,5-triazine (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetraazoctane (HMX), cis -1,3,4,6-tetranitrooctahydroimidazo[4,5–d]imidazole (BCHMX) or 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12- hexaazaisowurtzitane (CL-20). The possible benefits of this method also for the alone production technology of the used nitramines are mentioned. Raman, FTIR and PXRD techniques have proven that resulting co-agglomerates (CACs) are co-crystals (CCs), where HMX is presented in its ȏ-modification and CL-20 in its ß-modification. Thermal analyses of these CCs have shown that the stability has increased in the BCHMX/DATB and decreased in the other CCs prepared. The impact sensitivity has decreased in the RDX and HMX CCs. In BCHMX CCs, this decrease is very low. In the case of ß-CL-20/DATB, its sensitivity is high; this increase is also explaineds in the context of impact sensitivity of a "common" quality of CL-20 in general. Attention is also paid to the relationships between thermochemical, performance- and impact-sensitivity characteristics in correlation with some Raman and FTIR outputs, confirming the formation of co-crystals during co-agglomeration. All these mentioned relationships represent a new insight on the co-crystals investigation. The density of the co-crystals prepared exceeds 99% of the theoretical maximum density of the starting nitramines. Their performance is higher than would correspond to a simple calculation based on the percentage of individual components. [ABSTRACT FROM AUTHOR]