Preparation, Thermal and Sensitivity Properties of Nano-Sized Spherical Nitrocellulose Composite Crystal

The sensitivity study of propellants has been the concern of many researchers, and many achievements have been gained in this field. Nitrocellulose was replaced by some energetic thermoplastic elastomers to prepare insensitive high energy propellants, which is an effective method for reducing the sensitivity of propellants. However, the propellants based on these binders still have some defects. Preparation and application of insensitive nitrocellulose may overcome these drawbacks and becomes a potential candidate to be used as an ingredient of insensitive high energy propellants without energetic thermoplastic elastomers. To reduce the sensitivity of nitrocellulose, a nano-sized spherical nitrocellulose composite crystal was prepared by pretreatment, degradation and nitration of microcrystalline cellulose. The products were characterized by TEM, FT-IR, XRD, XPS, elemental analysis, TGA, DSC and sensitivity tests. Results show that the prepared nano-sized cellulose is spherical with a diameter in the range of 15-30 nm and displays a composite crystal with two kinds of crystalline structure. The nano-sized spherical nitrocellulose composite crystal has a higher crystallinity and nitrogen content and less impact sensitivity in comparison with the common nitrocellulose. The improvement of crystal quality of nitrocellulose using composite crystal method is beneficial for reducing the impact sensitivity of nitrocellulose.