Xi'an Modern Chemistry Research Institute, Xi'an 710065, China.
Molecules. 2023 Mar 3;28(5):2346. doi: 10.3390/molecules28052346.
The initial interaction mechanism is very important for the design and safety of nano-scale composite energetic materials composed of ammonium dinitramide (ADN) and nitrocellulose (NC). The thermal behaviors of ADN, NC and an NC/ADN mixture under different conditions were studied by using differential scanning calorimetry (DSC) with sealed crucibles, an accelerating rate calorimeter (ARC), a self-developed gas pressure measurement instrument and a DSC-thermogravimetry (TG)-quadrupole mass spectroscopy (MS)-Fourier transform infrared spectroscopy (FTIR) combined technique. The results show that the exothermic peak temperature of the NC/ADN mixture shifted forward greatly in both open and closed circumstances compared to those of NC or ADN. After 585.5 min under quasi-adiabatic conditions, the NC/ADN mixture stepped into the self-heating stage at 106.4 °C, which was much less than the initial temperatures of NC or ADN. The significant reduction in net pressure increment of NC, ADN and the NC/ADN mixture under vacuum indicates that ADN initiated the interaction of NC with ADN. Compared to gas products of NC or ADN, two new kinds of oxidative gases O and HNO appeared for the NC/ADN mixture, while NH and aldehyde disappeared. The mixing of NC with ADN did not change the initial decomposition pathway of either, but NC made ADN more inclined to decompose into NO, which resulted in the formation of oxidative gases O and HNO. The thermal decomposition of ADN dominated the initial thermal decomposition stage of the NC/ADN mixture, followed by the oxidation of NC and the cation of ADN.
初始相互作用机制对于由硝酸铵（ADN）和硝化纤维素（NC）组成的纳米复合含能材料的设计和安全非常重要。采用密封坩埚差示扫描量热法（DSC）、加速量热计（ARC）、自行开发的气压测量仪以及 DSC-热重（TG）-四极质谱（MS）-傅里叶变换红外光谱（FTIR）联用技术，研究了 ADN、NC 及 NC/ADN 混合物在不同条件下的热行为。结果表明，与 NC 或 ADN 相比，NC/ADN 混合物在开、闭两种情况下的放热峰温度都大大提前。在准绝热条件下经过 585.5 min 后，NC/ADN 混合物在 106.4 °C 进入自热阶段，这远低于 NC 或 ADN 的起始温度。在真空条件下，NC、ADN 和 NC/ADN 混合物的净压力增量显著降低，表明 ADN 引发了 NC 与 ADN 的相互作用。与 NC 或 ADN 的气体产物相比，NC/ADN 混合物出现了两种新的氧化性气体 O 和 HNO，而 NH 和醛消失了。NC 与 ADN 的混合并没有改变各自的初始分解途径，但 NC 使 ADN 更倾向于分解为 NO，从而形成氧化性气体 O 和 HNO。ADN 的热分解主导了 NC/ADN 混合物的初始热分解阶段，随后是 NC 的氧化和 ADN 的阳离子化。
