CL-20重结晶过程中的晶型转变研究进展

介绍了不同晶型六硝基六氮杂异伍兹烷(HNIW,CL-20)(包括α-、β-、γ-、ε-及ζ-)的结构、热稳定性及性能。综述了CL-20的重结晶方法(包括溶剂-非溶剂法和溶剂挥发法)以及在溶液中的晶型转变。认为:ε-CL-20最有应用价值,不能直接合成,它需通过重结晶得到,但结晶时的晶型转变会降低ε-CL-20晶型的纯度,从而影响爆轰性能。讨论了溶剂和温度对CL-20晶型转变的影响。根据Ostwald规则,从热力学和动力学角度解释了CL-20的晶型转变过程。指出了现有研究的不足,提出了通过控制CL-20的晶型转变路径、优化重结晶条件,以获得晶型纯度高的ε-CL-20的新思路。

Review on Polymorphic Transformation in CL-20 Recrystallization

The crystal structure,thermal stability,and properties of all polymorphs(including α-,β-,γ-,ε-and ζ-) of CL-20 were introduced.Recrystallization method of CL-20 including solvent-non-solvent method and solvent evaporation method,and the polymorphic transformation of CL-20 in solution were summarized.Considering that ε-CL-20 has the most application value and cannot be prepared directly.It is still necessary to be recrystallized but the polymorph of CL-20 would transform to others in this process which could cause the polymorph purity of ε-CL-20 decreasing,and then affecting the explosive performance of CL-20.The factors affecting the polymorphic transformation of CL-20,such as solvent and temperature were discussed.According to the Ostwald′s rule,the polymorphic transformation of CL-20 in solvent could be explained from the aspects of kinetics and thermodynamics.The deficiency of current research was depicted and the preparation way of ε-CL-20 with high purity through controlling the polymorphic transformation path and optimizing the recrystallization conditions were proposed.