叠氮增塑剂/硝化棉共混物的分子动力学模拟

目的 揭示叠氮增塑剂与硝化棉的相互作用机理,探索叠氮类增塑剂结构与性能间的关系,筛选能量性能和稳定性均较好的叠氮化合物。方法 建立硝化棉(NC)、1,3–二(叠氮乙酰氧基)–2–甲基–2–硝基丙烷(DAMNP)、1,3–双(叠氮乙酰氧基)–2–乙基–2–硝基丙烷(ENPEA)和1,8–二叠氮基–3,6–氧杂辛烷(AZTEGDN)纯物质模型以及NC/DAMNP、NC/ENPEA、NC/AZTEGDN共混物体系的微观分子模型,利用分子动力学模拟(MD)方法,对叠氮增塑剂/硝化棉的微观性质进行预测。分析共混体系的溶度参数、MSD值、结合能、径向分布函数、力学性能和玻璃化转变温度等性能。结果 DAMNP、ENPEA、AZTEGDN与NC之间的溶度参数差值较小。ENPEA与NC的结合能最大,DAMNP次之,AZTEGDN最小。3种增塑剂与NC的相互作用主要为vd W相互作用。加入增塑剂分子可以改善NC的运动能力,由于AZTEGDN的分子结构体积小,改善效果明显。径向分布函数分析结果进一步证明,NC与增塑剂分子间存在较强的氢键作用。结论 添加叠氮增塑剂可以改善NC的运动能力、力学性能,降低NC的玻璃化转变温度,起到了良好的增塑效果。

Molecular Dynamics Simulation of Azide Plasticizer/Nitrocellulose Blends

The paper intends to reveal the interaction mechanism between azide plasticizers and nitrocellulose, explore the relationship between the structure and properties of azide plasticizers, and screen azide compounds with good energy performance and stability. Through the construction of the microscopic molecular model of NC, DAMNP, ENPEA, AZTEGDN and their blends., and the method of molecular dynamics simulation (MD), the paper predicts the microscopic properties of azide plasticizer/nitrocellulose, and analyzes the solubility parameters, MSD, binding energy, radial distribution function, mechanical properties and glass transition temperature of the blend system. The difference in solubility parameters between DAMNP, ENPEA, AZTEGDN and NC is small. The binding energy of ENPEA is the largest, followed by DAMNP and AZTEGDN. The interaction between the three plasticizers and NC is mainly vdW interaction. The addition of plasticizer molecules can clearly improve the motility of NC due to the small molecular structure of AZTEGDN. The radial distribution function analysis results further proved that there is strong hydrogen bond between NC and plasticizer. The addition of azide plasticizer can improve the movement ability and mechanical properties of NC, reduce the glass transition temperature of NC, and play a good plasticizing effect.