The Preparation And Application Research Of Ultra-Fine Nitroguanidine

Nitroguanidine (NQ) is a kind of rodlike crystalline, which applied to the explosive makes the weak fluidity and mechanical performance. In this paper, granular and superfining NQ was prepared by a technology of continuous process. Especially taking an research on the process of spray drying technology, and the physical and chemical properties of ultrafine NQ were analyzed. In addition, ultrafine NQ was applied to the triple base propellant. The special content are as follows.Firstly, the technology of producing ultra-fine NQ was researched by a nano pulverizer and the slurry of ultra-fine NQ was dried by spray drying, SEM and particle size measurement revealed that the average particle diameter of ultra-fine NQ was 1.66μm, and there was no structure collapse phenomenon, no caking. The security of Spray drying was analyzed, the optimum conditions of the spray drying were analyzed, that was determined as:input temperature of 180℃, outlet temperature of 85℃, feed rate of 40mL/min. Under this conditions, the material obtained within a short time of 5min, the moisture content was controlled to 0.22%. The crystal shape and purity of product was analyzed by Raman spectra, FT-IR, XRD and HPLC, it had not carry some new impurities into the production to ensure high purity, and the crystal of NQ were not changed. It confirmed that the method of spray drying will bright an effective and rapid treatment for drying the ultra-fine NQ, Energetic Materials and thermal sensitive Material in the industrial production.Secondly, the study on hygroscopic sorption properties, compactness and flowability of the ultrafine NQ founded that, the humidity absorption percent of NQ increased with the increase of storage time and the decrease of particle size. The compactness and flowability of NQ became weak with the decrease of particle size; The compactness and flowability of NQ by spray drying showed better than NQ by freeze drying. Using TG-DSC thermal analyzer by setting different heating rates to take an experiment on thermal analysis of ultrafine NQ and the raw, and estimated the apparent activation energy, activation enthalpy and self-ignition temperature and other thermodynamic parameters of NQ, the analysis showed that the thermal stability of ultrafine NQ improved.Finally, the computer simulation software was applied to analyze formula, we found that with the decrease of NQ, the increase of NC and NG by a certain percentage in the triple base propellant, the explosion heat, explosion temperature and force capacity of gun propellants were increased, and the main gaseous products generated as CO, H2O, N2. The experiment on shock resistance, compressive strength, tensile strength and the combustion performance of the triple base propellant found that:the shock resistance and tensile strength of the triple base propellant prepared by ultrafine-particulate NQ decreased. The combustion of the triple base propellant prepared by ultrafine-particulate NQ improved, which had a more stable combustion.