Molecular-scale descriptions and experimental characterizations of nitrocellulose soaked in pure liquid ethanol or diethyl ether respectively at room temperature

Abstract

Studies on nitrocellulose (NC) mixtures with little solubilities were neglected in many cases previously. This investigation was performed to provide supplemental characterizations of NC and its soaked state with pure liquid ethanol or diethyl ether by simulations and practical methods. Above all, a short-chained NC model (polymerisation degree: 8) and a dried NC specimen were characterized for their substitution of nitrate and microstructure. It was confirmed that both the numerical model and practical specimen belonged to low-nitrated NC. The bonding information of a glycosyl unit and nitrate ester were summarized via first-principle calculations. Then, ReaxFF potential based Molecular Dynamic (MD) simulations and soaking tests on binary organic mixtures demonstrated that both ethanol and diethyl ether had limited solubility for our specified NC. However, potential energies and diffusion coefficients of both computational models showed that the interactions from ethanol molecules were relatively stronger than diethyl ether molecules. The viscosities of saturated NC solutions also proved this consequence, as the difference between pure ether and its filtered NC solution was only 0.02 mm2 s−1. Finally, the strong volatility of diethyl ether itself could keep the wetness of NC upper surface shortly, because this was an upward volatilization effect. Due to this effect, the penetration of NC-diethyl ether mixture was higher in the early period of penetration tests.

Hansen Solubility Parameters of Nitrocellulose and Application toward Printable Energetics

“…Depending on the DS, properties such as viscosity, solubility, and chain length are impacted. While NC can be used for lacquers, inks, or coatings at lower nitration (<12%N), at higher nitration (>12%N), it is used exclusively for military applications due to its good energetic properties. , Many early studies, − and recent ones, − have focused on the gelation and corresponding viscosity of NC when treated with different solvents such as alcohols, ketones, or esters. From these works, it is well known that, as the nitrogen content (%N) increases, the NC structure becomes heterogeneously complex, resulting in decreased solubility for typical solvents.…”