Property Estimates for Hydroxyl Terminated Polybutadiene (HTPB) Type R45M Derived from Atomistic Molecular DynamicsSimulations

Abstract

Seeking to parameterize models for simulating the deflagration of hydroxyl-terminated polybutadiene type R45M, we employed atomistic molecular dynamics (MD) methods to obtain estimates for some of R45Ms transport and thermophysical properties. Estimates for densities, enthalpies of vaporization, and self-diffusion coefficients were derived from simulations of hydroxyl-terminated 6-ethenenyl2,8,12,16-octadecatetraene (EODT, C20H32) oligomer systems. The dependencies of the predictions on the number of monomers per oligomer (n), system size, simulation temporal duration, and force-field type were evaluated. Comparisons to measured values indicate the predictions merit. In addition, we coupled MD-based estimates for the HO(EODT)nOH systems enthalpies of vaporization with estimates for their gas-phase enthalpies to estimate R45Ms enthalpy of formation and heat capacity as a function of temperature. The enthalpy of formation estimates at 298 K were observed to be in reasonable agreement with a recently published aggregation of such values. Heat capacity estimates were in reasonable agreement with values we measured. The potential to employ the self-diffusion coefficient predictions as a basis for parameterizing a theorized framework for modeling condensed-phase chemical kinetics is discussed.

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Document Details

Document Type
Technical Report
Publication Date
Jul 03, 2023
Accession Number
AD1204916

Entities

People

  • Chiung-chu Chen
  • Christopher P. Stone
  • Claresta Dennis
  • In-Chul Yeh
  • Jeffrey D . Veals
  • Michael J. McQuaid

Organizations

  • Naval Air Warfare Center, Weapons Division
  • United States Army

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  • Quantum Chemistry
  • Regression Analysis.
  • Rocket Propulsion.