Molecular Dynamics Simulation of Polyether Compatibility with Nitrate Ester Plasticizers: as Anti-Migration Liners

Document Type : Regular Article

Authors

Faculty of Chemistry and Chemical Engineering, Malek Ashtar University of Technology, Tehran, Iran

Abstract
Liners serve as both a barrier layer and an adhesive, bonding the insulation to the propellant. Plasticizer migration is a frequently observed phenomenon in solid propellants, often leading to detrimental effects on mechanical stability and performance.  Absorbent plasticizer liners have emerged as a next-generation solution, offering both anti-migration properties and adhesive capabilities. In this study, the anti-migration effects of three polyethers, including polyethylene glycol (PEG), polypropylene glycol (PPG), and polytetrahydrofuran (PTHF) as liners in the presence of plasticizers 1,2,4-butanetriol trinitrate (BTTN),  trimethylolethane trinitrate (TMETN), and triethylene glycol dinitrate (TEGDN), were studied using NPT-molecular dynamics simulation (NPT-MD) with the Compass III force field. The binding energy, solubility parameter, and radial distribution function of polyethers containing 20% plasticizers were calculated.  The mixture of PEG and TEGDN exhibited the highest binding energy and compatibility. The solubility parameter reflects the strength of non-bonded intermolecular forces, indicating compatibility. The radial distribution function analysis showed strengthened van der Waals interactions, confirming compatibility. Molecular dynamics simulation results showed that polyethylene glycol is a suitable liner with anti-migration properties in propellants.

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