Modelling water diffusion in plasticizers: development and optimization of a force field for 2,4-dinitroethylbenzene...

Area of Science:

• Computational Chemistry
• Materials Science
• Chemical Engineering

Background:

• Energetic plasticizers like K10 and R8002 are vital components in nitrocellulose binders.
• Nitrocellulose binders are susceptible to decomposition, particularly when dry, impacting material stability.
• Understanding water diffusion is key to predicting and mitigating decomposition pathways.

Purpose of the Study:

• To develop and validate a classical all-atom force field for 2,4,6-trinitroethylbenzene and 2,4-dinitroethylbenzene.
• To apply the developed force field to molecular dynamics simulations of pure and mixed plasticizer systems.
• To calculate water diffusion coefficients in nitrocellulose binder components to inform stability assessments.

Main Methods:

• Electronic and geometry optimization for deriving bonding parameters and partial charges.
• Parameterization using literature values for nitroaromatic compounds, adjusted for accuracy.
• Molecular dynamics simulations to calculate water diffusion coefficients at 298 K and 338 K.

Main Results:

• A validated classical all-atom force field was successfully developed for key nitroaromatic compounds.
• The force field accurately reproduced the densities of the studied molecules and plasticizers.
• Water diffusion coefficients were calculated for the plasticizers and nitrocellulose binder components.

Conclusions:

• The developed force field provides a reliable tool for simulating energetic plasticizers and nitrocellulose binders.
• The calculated water diffusion data offers initial insights into water behavior within these systems.
• This study lays the groundwork for predicting material stability and degradation mechanisms in energetic binders.