Method for controlling crystal form of 2, 4-dinitroanisole

Abstract

The invention relates to a method for controlling the crystal form of 2, 4-dinitroanisole, and belongs to the technical field of energetic material synthesis. According to the method disclosed by the invention, products alpha-DNAN and beta-DNAN with different crystal forms are obtained by adopting the same raw materials of CDB, sodium hydroxide and methanol and controlling a synthesis process. According to the method disclosed by the invention, synthesis and preparation conditions of the alpha crystal form and the beta crystal form are defined, and a guarantee is provided for safe and reliable use of the 2, 4-dinitroanisole in weaponry. According to the method disclosed by the invention, in the actual production process, the situation of unstable performance of the casting body caused by volume change of the casting body due to crystal form doping can be reduced, and a safer guarantee is provided for subsequent product treatment, storage and transportation processes.

Description

technical field [0001] The invention relates to the field of organic chemical technology, especially the field of synthesis of energetic materials, in particular to a method for controlling the crystal form of 2,4-dinitroanisole. Background technique [0002] 2,4-Dinitroanisole, code name DNAN, molecular formula C 7 h 6 N 2 o 5 , the molecular weight is 198.14, and the structural formula is: [0003] . [0004] DNAN is a white or pale yellow needle-like crystal, which can be used as a pesticide, dye intermediate or energetic material in different fields, especially as a new type of melt-cast explosive carrier, which is considered to have important application prospects. [0005] It has been 170 years since DNAN was first synthesized in 1849. Due to its medium energy, it has no advantages as a main explosive, so it was ignored for a long time after World War II. Compared with TNT, DNAN has better safety performance. Therefore, with the improvement of weapons and equip...

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Problems solved by technology

For example, in 1987, Nyburg, S. C et al reported the crystal structure of DNAN in "Structures of 2,4-Dinitroanisole and 2,6-Dinitroanisole" (Document 1), including unit cell parameters, symmetry, bond length and angle and other data, but no mention of the crystal form

In 1992, Malinovskii, S. T. et al. reported the crystal structure of DNAN and Nyburg et al. The similar crystal parameters published by the author clearly show that its melting point is 94-95°C, but there is still no mention of the crystal form.

In 2006, Davies, P. J. et al. "Characterisation of 2,4-Dinitroanisole: An Ingredient for Usein Low Sensitivity Melt Cast Formulations" (Document 3) reported that DNAN has two crystal forms, with melting points of 94-96°C and 86- 88°C, but crystal parameters are not provided

In 2007, Xue Gang from Hebei University of Technology et al. in "Crystal structure of 2,4-dinitroanisole, C 7 h 6 N 2 o 5 "(Document 4) reported a crystal structure different from Malinovskii, S. T., provided crystal parameters, but did not mention the melting point

In 2014, Wang Hongxing and others from Xi’an Modern Chemistry Research Institute used Perkin-Elmer DSC-2C differential scanning calorimeter to analyze the endothermic peak at 95.6°C when studying the casting performance and thermal safety performance of DNAN, and the melting point was obtained by fitting calculation. 94.5°C, but no product crystal form is mentioned

In 2016, Hubei Dongfang Chemical Co., Ltd.’s invention patent (Patent No. CN201610317074.7) of “A Method for Continuous Synthesis of 2,4-Dinitroanisole” mentioned a continuous synthesis of 2,4-Dinitroanisole The method of nitroanisole, the melting point of DNAN obtained is 96°C, but no crystal form is mentioned

ChagitDenekamp et al. only qualitatively stated that the β crystal form is easy to appear during supercooled crystallization, but they lack exact conditions. They did not directly obtain pure α-DNAN and β-DNAN according to the report of Takahashi and Tamura et al.

However, the accidental appearance of different crystal forms is risky for the application of DNAN. If crystal form doping occurs in the actual production process, it may cause volume changes or defects in the molten cast, resulting in unstable performance and possible Increase the sensitivity of explosives, which will have adverse effects on the subsequent processing, storage, and transportation processes, and even cause danger and cause safety accidents

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