Search

[Display omitted] • A facile synthesis of FOX-7 based nitramines was developed. • Title compounds were fully characterized by IR, NMR, EA, and, X-ray analysis. • Newly synthesized compounds have high chemical and mechanical stabilities. • Propellant formulations suggest that compounds 9a-b are green AP replacements. • Compounds 9a-b are able to improve the efficiency of ethanol-based fuel. A variety of amine derivatives was found to react with FOX-7 to give triazine derivatives, which upon nitration gave rearranged nitramines in good to excellent yields. The structures of these triazines and nitramines were determined by various spectroscopic techniques, and elemental analyses. Further the structure of selected compounds namely 4-(dinitromethylene)-1-methyl-1,3,5-triazinane (8a), 4-(((methyl(nitro)amino)methyl)imino)-3,5-dinitro-5,6-dihydro-4H-1,2λ4,5-oxadiazin-2-olate (9a) and 3,5-dinitro-4-(((nitro(2-(nitrooxy)ethyl)amino)-methyl)imino)-5,6-dihydro-4 H -1,2λ4,5-oxadiazin-2-olate (9b) were unambiguously confirmed by single crystal X-ray analysis. These compounds have good thermal stabilities with their decomposition temperatures in the range of 119–188 °C and experimental densities between 1.38 g cm−3 to 1.75 g cm−3. The enthalpies of formation of the new compounds were calculated (Gaussian-03) and combined with their experimental densities to evaluate the propulsive and detonation properties. Compounds 9a and b are found to have excellent energetic properties (9a P = 31.48 GPa, D = 8542 m/s; 9b , P = 31.83 GPa, D = 8518 m/s) that exceed those of TNT, HNS and are comparable to FOX-7 and RDX. The potential of these compounds as solid propellants/oxidizers was explored in detail; compounds (9a, Isp, vac 290.74 s; 9b, Isp, vac 293.00 s; with AP, Isp, vac 291.66 s (9a) and Isp, vac 292.57 s (9b)) were found to be suitable oxidizers for solid rocket propulsion. [ABSTRACT FROM AUTHOR]

Powder Mo&O2 has an important role in the production of coatings with increased resistance to slide in conditions without the use of lubricants. Mo&O2 coatings have the low coefficient of friction and good abrasion characteristics in mechanical stresses. For the purpose of producing coatings of high hardness, Mo&O2 powder is plasma deposited with optimal parameters. The surface shape of oxide powder particles and the coating fracture surface are analysed by SEM, and the microstructure of layers is examined by light microscopy. The coating microstructure consists of Mo lamellae and MoO3 and MoO2 primary oxide thin films, which surround the Mo lamellae. The analysis of the obtained results showed that the Mo&O2 coating layers with the diffusion oxidized Mo particles have such a structure and mechanical characteristics which enable its application in working tools under the conditions of wear and sliding friction without lubricants. [ABSTRACT FROM AUTHOR]

When exposed to air at ambient conditions, AgSO4 slowly reacts with moisture, yielding AgSO4⋅H2O. The crystal structure determination (powder data) shows that it may be described as [Ag(OH2)2][Ag(SO4)2], with some sulfate groups being shared between different Ag2+ cations, resembling in that way its Cu2+ analogue. [Ag(OH2)2][Ag(SO4)2], the first hydrate of a compound of Ag2+, was extensively characterized using many physicochemical methods. [ABSTRACT FROM AUTHOR]