三氨基三硝基苯基高聚物粘结炸药热力学性质的理论计算研究

Hang Fan, Guan Song He, Zhi Jian Yang, Fu De Nie, Peng Wan Chen*

*此作品的通讯作者

科研成果: 期刊稿件文章同行评审

6 引用 (Scopus)

摘要

The thermodynamic properties of insensitive high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) based polymer bonded explosives (PBXs) are investigated by using first principle calculation and molecular dynamics simulation. The results include the phonon dispersion relations, interface thermal conductances, and thermal conductivities of TATB based PBXs. Both TATB and PVDF structures are optimized, in which the optimized lattice constants accord with previous results. The phonon dispersion relation of TATB and PVDF are calculated based on lattice dynamics. All interatomic force constants are calculated by the finite displacement method (numerical derivatives from perturbed supercells). The calculated phonon dispersion relation of TATB and heat capacity are in general agreement with experimental and theoretical results. The imaginary frequencies are observed in both TATB and PVDF dispersion relation. The imaginary frequencies are mainly due to the smaller calculated supercell size and temperature effect. The phonon mode of TATB and PVDF are assigned at Γ point. Based on the calculated phonon dispersion, some information including heat capacity, phonon density of states and phonon mode assignment is derived. The TATB possesses 144 phonon modes including 3 acoustic-phonon modes and 141 optical phonon modes. The anylized phonon mode of TATB shows that -NO2 dominates the phonon DOS in low frequency zone, phenyl rings dominate in middle frequency zone and -NH2 dominates in high frequency zone. By analyzing the phonon density of states and capacity, both TATB and PVDF imply that low-frequency vibration dominates the thermal conductivity. The thermal conductivity is determined for TATB by using the equlibrium molecular dynamics method and an established TATB force field. The TATB model is built with 2880 atoms. The structure of TATB is optimized by using molecular mechanics, then this system is relaxed by using a Nose-Hoover thermostat and barostat with a damping factor of 50 fs cin time steps of 0.1 fs. The calcultated thermal conductivity at room temperature shows good agreement with experimental result. The interface thermal conductance of TATB-PVDF is calculated by using a diffusive mismatch model. The interface thermal transport still follows Fourier's law of heat conduction, and ballistic thermal transport mechanism is not involved. By using the above results, the thermal conductivity of mixture TATB-PVDF system is analized with a simple series model. The particle size smaller than 100 nm significantly suppresses the mixture system thermal conductivity.

投稿的翻译标题Theoretical study of interface thermodynamic properties of 1,3,5-triamino-2,4,6-trinitrobenzene based polymer bonded explosives
源语言繁体中文
文章编号106201
期刊Wuli Xuebao/Acta Physica Sinica
68
10
DOI
出版状态已出版 - 20 5月 2019

关键词

  • First principle calculation
  • Molecular dynamics
  • Thermodynamic properties
  • Triaminotrinitrobenzene

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引用此

Fan, H., He, G. S., Yang, Z. J., Nie, F. D., & Chen, P. W. (2019). 三氨基三硝基苯基高聚物粘结炸药热力学性质的理论计算研究. Wuli Xuebao/Acta Physica Sinica, 68(10), 文章 106201. https://doi.org/10.7498/aps.68.20190075