ABSTRACT The liquid components, such as plasticizer, in the charge of solid propellant can potentially migrate into the liner contacting with propellant gradually, causing negative effects on the energetic performance, mechanical properties, and combustion properties of the propellant, as well as its interfacial adhesion properties with the liner. The study and prediction of the migration of the liquid components by experimental means remain challenging. In the present work, nitroglycerin (NG) and 1,2,4-butanetriol trinitrate (BTTN) were used as the model plasticizers to explore the factors affecting the migration of plasticizers into three different liners including polyoxyethylene (PEG)/polyisocyanate (N-100), hydroxyl-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) and polydimethylsiloxane (PDMS)/tetraethoxysilane (TEOS) by molecular dynamics simulation. The cohesive energy densities (solubility parameter), surface tensions, interfacial tensions, contact angles and diffusion coefficients of the plasticizers and liners were determined. It was found that the cohesive energy densities (solubility parameter) and surface tensions of the liner prepolymer and nitrate esters were in the order of PDMSHTPB/IPDI-NG>PDMS/TEOS-NG and PEG/N-100-BTTN>HTPB/IPDI-BTTN>PDMS/TEOS-BTTN. Comparing different plasticizers, the order of diffusion coefficient in all liners is NG>BTTN, indicating NG is much easier to migrate into liners than BTTN. These simulation results are consistent with the experimental migration trends of NG into the corresponding liners, indicating that the molecular dynamics simulation can be used to study and predict the migration of plasticizers in various liners accurately and conveniently.

中文翻译：

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硝酸酯增塑剂在与推进剂接触的不同衬管中迁移的分子动力学模拟

摘要 固体推进剂中的增塑剂等液体成分可能逐渐迁移到与推进剂接触的衬里，对推进剂的能量性能、力学性能、燃烧性能以及界面附着力产生负面影响。与衬垫的属性。通过实验手段研究和预测液体成分的迁移仍然具有挑战性。在目前的工作中，硝酸甘油 (NG) 和 1,2,4-丁三醇三硝酸酯 (BTTN) 被用作模型增塑剂，以探讨影响增塑剂迁移到三种不同衬垫中的因素，包括聚氧乙烯 (PEG)/聚异氰酸酯 (N- 100), 通过分子动力学模拟，羟基封端的聚丁二烯 (HTPB)/异佛尔酮二异氰酸酯 (IPDI) 和聚二甲基硅氧烷 (PDMS)/四乙氧基硅烷 (TEOS)。确定了增塑剂和衬垫的内聚能密度（溶解度参数）、表面张力、界面张力、接触角和扩散系数。发现衬里预聚物和硝酸酯的内聚能密度（溶解度参数）和表面张力按PDMS的顺序排列HTPB/IPDI-NG>PDMS/TEOS-NG 和 PEG/N-100-BTTN>HTPB/IPDI-BTTN>PDMS/TEOS-BTTN。比较不同的增塑剂，在所有衬垫中扩散系数的顺序是NG>BTTN，表明NG比BTTN更容易迁移到衬垫中。这些模拟结果与NG向相应衬管中的实验迁移趋势一致，表明分子动力学模拟可以准确、方便地研究和预测增塑剂在各种衬管中的迁移。