原位红外光谱研究CL-20分子骨架内外基团的温度响应规律  

Temperature Response Law of the Internal and External Groups of CL-20 Molecule Skeleton by In-situ Infrared Spectroscopy

作　　者：赵浪 孙杰[2] 睢贺良[2] 于谦[2] 银颖 ZHAO Lang;SUN Jie;SUI He-liang;YU Qian;YIN Ying(School of Material Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Institute of Chemical Materials,China Academy Of Engineering Physics,Mianyang 621999,China)

机构地区：[1]西南科技大学材料科学与工程学院,四川绵阳621010 [2]中国工程物理研究院化工材料研究所,四川绵阳621999

出　　处：《含能材料》2019年第10期845-852,共8页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金资助(21805260)

摘　　要：为深入认识ε晶型六硝基六氮杂异伍兹烷(ε-CL-20)分子的骨架内、外基团在升温过程中的结构演化规律,采用原位傅里叶变换红外光谱(in-situFT-IR),结合差示扫描量热(DSC),对ε-CL-20骨架内外基团的温度响应规律进行了定量比较分析。结果表明,ε-CL-20骨架外基团(-NO2、C-H)的红外吸收峰强度随温度升高经历了三个变化阶段:线性下降阶段(ZⅠ)、加速降低阶段(ZⅡ)和第二次加速降低阶段(ZⅢ),可分别对应于CL-20晶体热膨胀、热致相变与热分解过程;分子骨架内C-N伸缩振动同样经历上述三个阶段,但ZⅡ、ZⅢ区域起始温度均明显高于骨架外基团,表明无论是热致相变还是热分解过程,骨架外基团对温度都更为敏感,而在更高温度下,骨架内基团才会对温度产生响应;骨架内C-C伸缩振动的温度响应特点更为复杂:随着温度的升高,其峰强仅经历一次加速降低阶段,同时C-C伸缩振动出现与ε-γ相变密切相关的新特征峰,表明相变过程使得分子骨架内C-C键的振动模式发生了明显变化,进一步升温后发现新特征峰的面积相对占比在不断增加,说明这种骨架内振动模式的变化直至热分解结束前仍在不断进行。To further understand the structural evolution law of internal and external groups of ε-phase 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(ε-CL-20) molecule skeleton during the heating process,the temperature response law of internal and external groups of ε-CL-20 skeleton was quantitatively compared and analyzed by in-situ Fourier transform infrared spectroscopy(in-situ FT-IR)and differential scanning calorimetry(DSC).Results show that the infrared absorption peak intensity of external groups(-NO2,C-H)of ε-CL-20 skeleton undergoes three change stages as temperature increases:linear decrease(ZⅠ),accelerated decrease(ZⅡ),and second accelerated decrease(ZⅢ),which correspond to the thermal expansion, thermally induced phase-transition and thermal decomposition process of CL-20 crystal,respectively.The C-N stretching vibration inside the molecular skeleton also undergoes the above-mentioned three stages,but the initial temperature of ZⅡ and ZⅢ regions are significantly higher than that of the external group,indicating that the external groups are more sensitive to temperature than internal groups,whether thermally induced phase-transition or thermal decomposition,while the internal groups of the skeleton respond to temperature only at higher temperature.The temperature response characteristics of C-C stretching vibration inside molecular skeleton are even more complex.As temperature increases,the peak intensity of C-C stretching only undergoes an accelerated reduction process,and a new characteristic peak of C-C stretching vibration is observed,which is closely related to ε-γ phase transition,illustrating that the phase transition process makes the vibration mode of C-C bond inside the molecular skeleton change significantly.After further heating,the relative proportion of the new characteristic peak area is continuously increasing,showing that the change of the vibration mode inside the skeleton is still ongoing until the end of thermal decomposition.

关 键 词：六硝基六氮杂异伍兹烷(CL-20) 原位红外光谱 骨架内外基团 温度响应规律 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O64[理学—物理化学]