Cooling crystallization of 1,1-diamino-2,2-dinitroethylene

For manipulating crystal quality of 1,1-dianzino-2,2-dinitroethylene (DADNE), experiments on the cooling crystallization of DADNE were made as a function of cosol-vents(solvent/anti-solvent mixtures), DADNE concentrations, cooling rates and stirring speeds. When N-methyl-2-pyrrolidone (NMP) and dimethylformamide (DMF) were used as a single solvent, DADNE crystals were shown to be agglomerates with needles or platelets and their yields were about 15-30 %. On the other hand, when cosolvents with water(DMAc+H2O) were used, polyhedron-shaped DADNE crystals with size of 100-200 mu m and yields of 70-80 % were obtained.