The response of the HMX-based material PBXN-9 to thermal insults: Thermal decomposition kinetics and morphological changes

Glascoe, Elizabeth A.; Hsu, Peter; Springer, H. Keo; DeHaven, Martin R.; Tan, Noel Peter Bengzon; Turner, H C

doi:10.1016/j.tca.2010.12.021

Cited by 18 publications

(9 citation statements)

References 19 publications

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“…The calculated reaction constants also fall into the measured range from 2.5 to 25 s –1 . The most recent experiments registered the narrower range of activation barriers from 23 to 46.6 kcal/mol, with the most reliable data obtained from 33.7 to 46.6 kcal/mol and reaction constants from 8.5 to 17.0 s –1 . Our calculations are also consistent with recent ReaxFF molecular dynamic simulations, which suggested that molecular vacancies accelerate the decomposition of condensed-phase HMX.…”

Section: Kinetics Of the N–no2 Homolysissupporting

confidence: 89%

Surface-Enhanced Decomposition Kinetics of Molecular Materials Illustrated with Cyclotetramethylene-tetranitramine

Sharia

Kuklja

2012

J. Phys. Chem. C

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First principles total energy calculations were combined with variational transition state theory to reveal a surface-induced effect on the decomposition of a molecular material. Explored decomposition reactions were illustrated with energetic molecular solid β-cyclotetramethylene-tetranitramine. Simulated N−NO 2 homolysis reactions demonstrated that initiation of molecular material's degradation is characterized by a reduced activation barrier and significantly accelerated reaction rates for molecules that are placed on a free surface, an internal void, or a vacancy as compared to the perfect bulk crystal.

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Section: Kinetics Of the N–no2 Homolysissupporting

confidence: 89%

Surface-Enhanced Decomposition Kinetics of Molecular Materials Illustrated with Cyclotetramethylene-tetranitramine

Sharia

Kuklja

2012

J. Phys. Chem. C

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“…As the heating rate and temperature increase, HCN and NO 2 dominate and CH 2 O and N 2 O play a lesser role [91]. The DSC and TGA measurements [92] of the HMX decomposition suggested that the activation barrier, E a , falls in the range from 33.7 to 46.6 kcal/mol and the estimated pre-exponential factor log A is between 11 and 17 (s −1 ). A logically justified and data-supported explanation to the previously reported unusually wide range of data (from 13 to 67 kcal/mol) [93,94] was developed only recently [52,53,95,96].…”

Section: Resultsmentioning

confidence: 99%

Molecular Theory of Detonation Initiation: Insight from First Principles Modeling of the Decomposition Mechanisms of Organic Nitro Energetic Materials

2016

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This review presents a concept, which assumes that thermal decomposition processes play a major role in defining the sensitivity of organic energetic materials to detonation initiation. As a science and engineering community we are still far away from having a comprehensive molecular detonation initiation theory in a widely agreed upon form. However, recent advances in experimental and theoretical methods allow for a constructive and rigorous approach to design and test the theory or at least some of its fundamental building blocks. In this review, we analyzed a set of select experimental and theoretical articles, which were augmented by our own first principles modeling and simulations, to reveal new trends in energetic materials and to refine known existing correlations between their structures, properties, and functions. Our consideration is intentionally limited to the processes of thermally stimulated chemical reactions at the earliest stage of decomposition of molecules and materials containing defects.

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“…Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) has been widely used in weaponry and civilian areas, and its initial chemical processes have been investigated for many years. Glascoe et al, 1 Henson et al, 2 and Brill and Karpowicz 3 found that HMX experienced a polymorphic transition from the β to δ phases during thermal decomposition. Ji et al 4 and Sharia and Kuklja 5−7 found that the bonds of N−NO 2 were the weakest, which could trigger explosion.…”

Section: Introductionmentioning

confidence: 99%

Anisotropic Responses and Initial Decomposition of Condensed-Phase β-HMX under Shock Loadings via Molecular Dynamics Simulations in Conjunction with Multiscale Shock Technique

Wei

Song

et al. 2014

J. Phys. Chem. B

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Molecular dynamics simulations in conjunction with multiscale shock technique (MSST) are performed to study the initial chemical processes and the anisotropy of shock sensitivity of the condensed-phase HMX under shock loadings applied along the a, b, and c lattice vectors. A self-consistent charge density-functional tight-binding (SCC-DFTB) method was employed. Our results show that there is a difference between lattice vector a (or c) and lattice vector b in the response to a shock wave velocity of 11 km/s, which is investigated through reaction temperature and relative sliding rate between adjacent slipping planes. The response along lattice vectors a and c are similar to each other, whose reaction temperature is up to 7000 K, but quite different along lattice vector b, whose reaction temperature is only up to 4000 K. When compared with shock wave propagation along the lattice vectors a (18 Å/ps) and c (21 Å/ps), the relative sliding rate between adjacent slipping planes along lattice vector b is only 0.2 Å/ps. Thus, the small relative sliding rate between adjacent slipping planes results in the temperature and energy under shock loading increasing at a slower rate, which is the main reason leading to less sensitivity under shock wave compression along lattice vector b. In addition, the C-H bond dissociation is the primary pathway for HMX decomposition in early stages under high shock loading from various directions. Compared with the observation for shock velocities V(imp) = 10 and 11 km/s, the homolytic cleavage of N-NO2 bond was obviously suppressed with increasing pressure.

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The response of the HMX-based material PBXN-9 to thermal insults: Thermal decomposition kinetics and morphological changes

Cited by 18 publications

References 19 publications

Surface-Enhanced Decomposition Kinetics of Molecular Materials Illustrated with Cyclotetramethylene-tetranitramine

Surface-Enhanced Decomposition Kinetics of Molecular Materials Illustrated with Cyclotetramethylene-tetranitramine

Molecular Theory of Detonation Initiation: Insight from First Principles Modeling of the Decomposition Mechanisms of Organic Nitro Energetic Materials

Anisotropic Responses and Initial Decomposition of Condensed-Phase β-HMX under Shock Loadings via Molecular Dynamics Simulations in Conjunction with Multiscale Shock Technique

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