红外光谱研究HNIW热分解残余物的热分解

IR Spectroscopic Study on the Thermal Decomposition of Thermal Decomposition Residues of Hexanitrohexaazaisowurtzitane(HNIW)

制备了HNIW热失重分别为91.8%的残余物Res.1和90.1%的残余物Res.2,在氩气气氛下通过热重-差示扫描联用仪(TG-DSC)对残余物Res.1以10℃/min的升温速率加热到300、400、550、600、800℃,得到5种样品,分别为Res.1-300、Res.1-400、Res.1-550、Res.1-600、Res.1-800。结果表明,氩气气氛有利于氰基(-CN)的生成;大气气氛则有利于碳二亚胺的生成。采用原位红外光谱对HNIW在10℃/min升温速率、大气气氛下加热至232.0℃以上的残余物进行研究,结果表明,C-C键与部分C-N键断裂氧化产生活性中间物种-异氰酸酯,异氰酸酯进一步与相关基团反应生成碳二亚胺。探讨了454.7℃的残余物的空间结构,与碳二亚胺两端相联的聚合片段平面是共平面或相互垂直的。

Residue l（Res. 1） and Residue 2 （Res. 2） with mass loss of 91.8% and 90.1% were prepared. The Res. 1 were heated to 300,400,550,600,800℃ by thermogravimetry-differential scanning calorimetry （TG-DSC） in an argon atmosphere at a heating rate of 10℃/min. Samples of Res. 1-300, Res. 1-400, Res. 1 550,Res. 1-600, Res. 1-800 were obtained. The results show that the argon atmosphere is favourable to production of cyano--group （-CN） and the air atmosphere is favourable to production of carbodiimide. In-situ IR spectroscopy was applied to investigate the residues of HNIW above 232.0℃ at a heating rate of 10℃/min in the air atmosphere to reveal forming mechanism of canbodiimide. It is discovered that the active intermediate isocyanate come from cleveage and oxidation of C--C bonds and a part of C--N bonds. Then reactions between isocyanate and coherent functional groups proceed to produee carbodiimide. The space stucture of the residue at 454.7℃ is discussed. Two planes of the polymer fragments which connected to two sides of carbodiimide are probably eoplanar or perpendicular with each other.