Hansen Solubility Parameters of Nitrocellulose and Application toward Printable Energetics

Abstract

While there have been many studies on the use of various solvents for processing nitrocellulose (NC), the optimization of these solvents and/or solvent mixtures has not been studied, particularly for the application of additive manufacturing (AM) of energetic materials. To optimize the printability of NC, Hansen solubility parameters (HSPs) of both 12.2% and 13.4% nitrogen content NCs were assessed via broad-spectrum dispersion testing in 17 solvents (acetone, dimethyl sulfoxide, dimethyl formamide, ethanol, methanol, isopropyl alcohol, m-cresol, toluene, xylene, ethyl acetate, ethyl lactate, diethyl ether, chloroform, acetonitrile, diethylene glycol, formamide, and cyclohexane) and a specific binary solvent gradient dispersion method. From the HSPs, solvents were selected for the dispersion of both 12.2 and 13.4% NCs and subsequent printing of these solutions via direct ink write (DIW). For 12.2% NC and 13.4% NC, successful prints were achieved with a solvent/antisolvent mixture of acetone/isopropyl alcohol (IPA) at 30/70 and 80/20 vol %, respectively. The use of HSPs not only indicate that there are multiple solvent mixtures available for the optimal printability of various grades of NC, but also HSPs may be used for the future processing of NC for various applications.

Structure and properties of nitrocellulose: approaching 200 years of research

“…This approach has successfully been applied to identify suitable solvent mixtures for the 3D printing of NC with variable DoN, 82 and to develop novel “green” solvents for NC lacquers. 83 This is despite inconsistent reports of HSPs for NC, 82 which are thought to arise because of difficulties in precisely and consistently determining the point of NC dissolution.…”

“…9 The key variables that describe solubility through a 'likewith-like' solvent model can be summarised by the Hansen solubility parameters (HSPs); 58,81 these are the dispersion forces, the dipolar intermolecular forces, and the hydrogen bonding interactions, all of which will vary with the DoN for NC. This approach has successfully been applied to identify suitable solvent mixtures for the 3D printing of NC with variable DoN, 82 and to develop novel "green" solvents for NC lacquers. 83 This is despite inconsistent reports of HSPs for NC, 82 which are thought to arise because of difficulties in precisely and consistently determining the point of NC dissolution.…”

Solvent–antisolvent interactions in metal halide perovskites

“…More recently, their usefulness has been reported even in improving printable energetics. 92 Perovskite inks contain high concentrations of ionic precursors and the HSP theory does not account for ionic interactions of salts nor molecular complexing in these relatively highly concentrated inks. In the search to include these considerations other researchers report the introduction of further parameters and their combination with HSP.…”

Improved sensitivity of liquid sensing melt-spun polymer fibers filled with carbon nanoparticles by considering solvent-polymer solubility parameters

“…The Hansen solubility parameters (HSP) were conceived to be able to predict the solubility of polymers in solvents. Currently, they are still widely used successfully in the paint/coatings industry and more recently even in printable energetics [37]. The principle is based on the idea that 'like dissolves like', meaning that if a solvent has HSPs very similar to that of a polymer, a high interaction between them is expected.…”