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The structural diversity of hybrid qy-HMX crystals with constraint of 2D dopants and the resulted changes in thermal reactivity.
- Source :
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Chemical Engineering Journal . Jun2020, Vol. 390, pN.PAG-N.PAG. 1p. - Publication Year :
- 2020
-
Abstract
- • A variety of novel hybrid qy-HMX crystals with different structure have been prepared and evaluated. • The kinetics models governing the rate-limiting thermolysis reactions are obtained. • The structure and thermal reactivity properties of qy-HMX and corresponding mechanism are clarified. In this paper, the 2D (two-dimensional) high nitrogen triaminoguanidine-glyoxal polymer (TAGP) has been used to dope HMX crystals. Various constraint TAGP-doped HMX crystals (qy-HMX) with higher density and better stability have been obtained due to strong constraint interactions between dopant and HMX molecules. The structure and thermal reactivity properties of qy-HMX are unexpectedly largely affected by a slight change in the way of co-crystallization/precipitation under the same precursor conditions. In particular, the density of qy-HMX could be largely changed in the range of 0.94 g cm−3 to 2.12 g cm−3 due to varied doping state, depending on the crystallization conditions. These qy-HMX crystals are more thermally stable than HMX, showing either no polymorphic transition or increased transition temperature. As a typical example, the polymorphic transition of qy-HMX-211 with doping amount of 21.1 wt% was excluded due to formation of a completely new more stable phase of HMX. The qy-HMX-341 has the highest heat release (1869 J g−1), even higher than that of HMX. The average E a (activation energy) for the polymorphic transition of qy-HMX-341 is about 334.1 kJ mol−1, following a random chain scission model (L2), whereas it is 222 kJ mol−1 for HMX. The E a for thermal decomposition of qy-HMX-341 is 215.7 kJ mol−1, which is 39.8 kJ mol−1 lower than that of HMX. Therefore, the qy-HMX crystal has high potential to be used as a promising high explosive to replace HMX for various applications in the future. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13858947
- Volume :
- 390
- Database :
- Academic Search Index
- Journal :
- Chemical Engineering Journal
- Publication Type :
- Academic Journal
- Accession number :
- 142375162
- Full Text :
- https://doi.org/10.1016/j.cej.2020.124565