The heat flow curves of nitrocellulose (NC)-based propellants are now an important assessment quantity for their quality and safety in storage and service. The measurable heat flow is the summarized effect of the rates of all the reaction heats of the reactions going on in the material. To get a detailed assessment instead the only global one requires knowing the heat flow parts caused by NC and by stabilizer reactions. For this, in turn, one needs to find the reaction enthalpies of the essential NC decomposition reactions and the stabilizer reactions at the temperature of the measurement of the heat flow. These data are not available in the literature. To get meaningful data it was necessary to use quantum mechanical calculations, here so-called DFT (density functional theory) methods, to screen the possible reactions by transition states and the energetic situation between educts and products. For the calculation of the reaction enthalpies and the transition states, the reactants were embedded in a polarizable continuum, which simulates the NC environment for the reactants in NC and for the stabilizer reactions. In addition, to calculate bond dissociation enthalpies of NC and of nitroglycerine a type of shell model was used called ONIOM (‘Our own N-layered Integrated molecular Orbital and molecular Mechanics’ model). The results from the determinations of reaction enthalpies are used in the second part of the publication.

中文翻译：

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基于 NC 的推进剂的热流曲线模拟 - 第 1 部分：使用量子力学方法测定 NC 和稳定剂 DPA 的反应焓和其他反应特性

硝化纤维 (NC) 基推进剂的热流曲线现在是其在储存和使用中的质量和安全性的重要评估量。可测量的热流是材料中发生的反应的所有反应热的速率的汇总效应。为了获得详细的评估，唯一的全局评估需要了解由 NC 和稳定剂反应引起的热流部分。为此，反过来，人们需要找到在热流测量温度下基本 NC 分解反应和稳定剂反应的反应焓。这些数据在文献中是不可用的。为了获得有意义的数据，必须使用量子力学计算，这里是所谓的 DFT（密度泛函理论）方法，通过过渡态和离析物和产物之间的能量情况筛选可能的反应。为了计算反应焓和过渡态，将反应物嵌入可极化的连续介质中，模拟 NC 中反应物和稳定剂反应的 NC 环境。此外，为了计算 NC 和硝化甘油的键解离焓，使用了一种称为 ONIOM 的壳模型（'ø乌尔自己Ñ -layered我ntegrated分子ö rbital和分子中号echanics'模式）。反应焓的测定结果用于该出版物的第二部分。