物理化学学报 >> 2016, Vol. 32 >> Issue (8): 1950-1959.doi: 10.3866/PKU.WHXB201605071

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烷基咪唑离子液体CnmimCl(n=4, 6, 8)对CL-20重结晶的影响

郑晓頔,朱艳丽*(),董睿,焦清介   

  • 收稿日期:2016-01-07 发布日期:2016-07-29
  • 通讯作者: 朱艳丽 E-mail:zhuyanli1999@bit.edu.cn
  • 基金资助:
    国家自然科学基金(51304024)

Effect of Alkyl Imidazole Ionic Liquids CnmimCl (n=4, 6, 8) on CL-20 Recrystallization

Xiao-Di ZHENG,Yan-Li ZHU*(),Rui DONG,Qing-Jie JIAO   

  • Received:2016-01-07 Published:2016-07-29
  • Contact: Yan-Li ZHU E-mail:zhuyanli1999@bit.edu.cn
  • Supported by:
    The project was supported by the National Natural Science Foundation of China(51304024)

摘要:

六硝基六氮杂异戊兹烷(CL-20)是高能量密度材料的典型代表之一。重结晶制备高品质CL-20的一个重要难题是晶体微观结构的调控。本文通过在CL-20重结晶过程中加入微量离子液体作为晶形控制剂,探究离子液体浓度、种类和添加方式(加入溶剂或者反溶剂)对CL-20晶体微观结构的影响规律。结果表明:通过改变离子液体的添加方式、种类和浓度,能够实现CL-20晶体尺寸和晶体形貌的调控。热分析结果表明:离子液体的加入可以使εγ晶型转变温度提前多达12.6℃;重结晶CL-20的分解峰温和热稳定性提高,放热量增加,最高可达1344 J·g-1。溶剂中1-己基-3-甲基咪唑氯盐(DmimCl)的加入,能够结晶出没有尖锐棱边和角的类八面体形CL-20晶体,晶粒细小,分解峰温均提高了6℃以上,放热量均在1100 J·g-1以上,是较理想的晶形控制剂。

关键词: CL-20, Ostwald规则, 热分析, 晶形控制剂, 重结晶, 离子液体

Abstract:

Hexanitrohexaazaisowurtzitane (CL-20) is considered to be a representative high energy density material. It is important to control the microstructure of the crystal during recrystallization to ensure the quality of CL-20. In this study, the effects of different types and concentrations of ionic liquids on CL-20 were investigated by adding them to the solvent or anti-solvent during recrystallization. Three types of ionic liquids acting as a morphology control additive can reduce the crystal size of recrystallized CL-20. Thermal analysis shows that most ionic liquids added to solvents or anti-solvents can increase the transition temperature from the ε crystal to the γ crystal by up to 12.6℃, and the decomposition peak temperature increases so the thermal stability of CL-20 improves. The heat output increases to 1344 J·g-1. When DmimCl is added into the solvent, recrystallized CL-20 has smaller particle size and an octahedral shape without sharp edges or agglomeration. With different concentrations of DmimCl in the solvent, the decomposition peak temperature of recrystallized CL-20 increases more than 6℃and the heat output is more than 1100 J·g-1. Therefore, DmimCl is an ideal morphology control additive.

Key words: CL-20, Ostwald rule, Thermal analysis, Morphology control additive, Recrystallization, Ionic liquid

MSC2000: 

  • O642