Thermally induced polymorphic transformation of Hexanitrohexaazaisowurtzitane (CL-20)

Liang, Wenhao; Wang, Jingna; Liu, Hongni; Meng, Zihui; Qiu, Lili; Wang, Shushan

doi:10.1016/j.powtec.2021.10.025

Cited by 24 publications

(5 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[15][16][17][18][19][20][21] Various energetic materials, including 1,3,5-trinitro-1,3,5-triazinane (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are found to be polymorphic. 8,[22][23][24][25][26][27][28] Korsunskii et al 29 first found ε-HMX in cyclohexanone with a strict experimental environment as a byproduct in the preparation of phase transition. Liu et al 30,31 carried out a comprehensive calculation of the molecular structure and mechanism of energetic materials.…”

Section: Introductionmentioning

confidence: 99%

Study on the crystal structure and properties of a new crystal form of 3-nitro-1,2,4-triazole-5-one (NTO)

Wang,

Zhang,

Wang

et al. 2024

CrystEngComm

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Study on the crystal structure and properties of a new crystal form of 3-nitro-1,2,4-triazole-5-one (NTO)

Wang,

Zhang,

Wang

et al. 2024

CrystEngComm

View full text Add to dashboard Cite

show abstract

“…Influences of polymorph on foods (cocoa butter), dyes, and pigments (quinacridone, reproduced with permission from ref . Copyright 2016, the Royal Society of Chemistry), energic materials (CL-20, reproduced with permission from ref . Copyright 2021, Elsevier B.V.), and pharmaceuticals (ritonavir, reproduced with permission from ref .…”

Section: Introductionmentioning

confidence: 99%

“…Only Form V (β 2 ) could achieve an excellent texture and mouthfeel. In dyes and pigments, the widely used compound “quinacridone” has four polymorphs displaying different colors: red in forms α I , α II , and γ and yellow in form β. , In energic materials, the density and crystal packing of polymorph could greatly affect the explosion energy and sensitivity, respectively. , Four polymorphs with known structures of the explosive CL-20 (hexa-nitro-hexa-aza-isowurtzitane) have been reported in which the most compact form ε has the most insensitivity and favors the highest safety . In pharmaceuticals, polymorph screening is considered as an irreplaceable step during the drug development process, since polymorph could affect the stability, solubility, and bioavailability of drugs.…”

Section: Introductionmentioning

confidence: 99%

Recent Advances in Polymorph Discovery Methods of Organic Crystals

Yao

Zhang

Wang

et al. 2022

Crystal Growth & Design

View full text Add to dashboard Cite

Polymorphism, the ability of the same substance to crystallize in more than one crystal structure, is a common phenomenon in organic crystals, influencing the physicochemical properties of solid materials in many important fields (foods, dyes and pigments, high energic materials, pharmaceuticals, etc.). The utilization of various polymorph discovery methods could increase the possibility of finding polymorphs with desired properties, achieving an optimal performance of the final product. Recently, there has been a steady development of polymorph discovery in both experimental and computational methods. To better guide the polymorph discovery, this paper reviews the recent advances in the polymorph screening methods of organic crystals, mainly including solution crystallization, melt crystallization, and crystal structure prediction. This paper also summarizes the nucleation theory in polymorphic systems to understand the formation of polymorphs and highlights the mechanisms of polymorph discovery by the kinds of methods. Finally, challenges of polymorph discovery are briefly discussed, aimed to shorten the screening time and make the polymorph discovery more effective.

show abstract

“…It is the prominent representative of the third-generation explosives and the most promising high energy density compound, which is expected to replace the commonly used octahydro-1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazocine (HMX) at present [25]. Nevertheless, CL-20 is a poly-crystalline explosive and easily converts from εto γphase during the temperature range 140-200 • C, resulting in the decrease in CL-20 density and the increase in volume, with the production of new pore groups [26][27][28]. Until now, there have been few studies on the pore structure changes during the phase transition of CL-20.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the Evolution of Nano-Scale Defects of CL-20 Crystals under Thermal Treatment by Wide/Small-Angle X-ray Scattering

Zhang

Wang

et al. 2022

Materials

View full text Add to dashboard Cite

Nano-scale crystal defects extremely affect the security and reliability of the explosive charges of weapons. In order to understand the evolution of nano-scale defects of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-isowurtzitane (CL-20) explosive crystals under thermal treatments, the specific surface, volume fraction and size distribution of the nano-scale defects were studied by using Wide Angle X-ray Scattering (WAXS) and Small Angle X-ray Scattering (SAXS) during the temperature range from 30 °C to 200 °C. The results showed that the number and size of the pores in CL-20 powder did not change significantly during the heating process before phase transformation (30–160 °C). At 170 °C, CL-20 began to convert from ε- to γ- phase, and the specific surface and volume fraction of the nano-scale defects increased significantly. Further investigation of the pore size distribution showed that the number of pores with a small size (radius 9–21 nm) changed particularly significantly, resulting from the cracking of the CL-20 crystal powder during phase transition. At 200 °C, the phase transition was completed and γ-CL-20 was created, and the small-sized pores gradually grew into medium-sized (radius 21–52 nm) pores over time when the temperature was fixed at 200 °C.

show abstract

Thermally induced polymorphic transformation of Hexanitrohexaazaisowurtzitane (CL-20)

Cited by 24 publications

References 33 publications

Study on the crystal structure and properties of a new crystal form of 3-nitro-1,2,4-triazole-5-one (NTO)

Study on the crystal structure and properties of a new crystal form of 3-nitro-1,2,4-triazole-5-one (NTO)

Recent Advances in Polymorph Discovery Methods of Organic Crystals

Investigation on the Evolution of Nano-Scale Defects of CL-20 Crystals under Thermal Treatment by Wide/Small-Angle X-ray Scattering

Contact Info

Product

Resources

About