Syntheses and Analyses of N,N′‐Dinitrourea

Abstract

N,N′‐Dinitrourea was prepared through nitration of urea at low temperature in mixed acids in 67 % yield. The prepared material was pure and found to be stable at room temperature. The properties of N,N′‐dinitrourea were analysed by: TG, DSC, ignition test in Wood's metal bath, NMR, MS, FT‐IR, gaspycnometry and BAM impact and friction sensitivity tests. N,N′‐Dinitrourea was found to have a very high density and positive oxygene balance. It was, however, found to be sensitive both to impact and friction.

Analyses of the thermal decomposition of urea nitrate at high temperature

“…Nitrourea (H 2 NCONHNO 2 ) can also be produced from dehydration of UN [27]. These unstable nitrated compounds, if produced early in the process, are well known [28,29] to decompose into N 2 O, CO 2 , HNCO, NH 3 and H 2 O gaseous species in different quantities as also observed in the early stages and over most of the whole degradation process in our TG-FTIR-MS study. It should be mentioned that nitric acid produced in phase I (143-168 • C) and in phase II (168-360 • C) were coming from two different sources: decomposition of urea nitrate (reaction 1) and ammonium nitrate (reaction 6), respectively.…”

Achieving layered stacking within acyclic compounds through a tenon-and-mortise strategy

“…2f). Moreover, although DNU exhibits high energy (density (d): 1.980 g cm −3 ), its stacking mode endows the compound with poor stability (T d : 90°C; IS: 1 J; FS: 5 N; decomposing in air), thus limiting its practical application [28,29]. Here, we anticipated that the proposed tenon-and-mortise strategy would be employed to construct layered stacking within DNU, thereby improving its stability.…”