Study On Recrystallization Process Of TATB

At present, the morphology modifiers have been widely used in the morphology control technology of explosives. And the seed-growth method is useful to control the particle size distribution of crystal. The composition of these two during the recrystallization process is help to obtain high quality crystals of TATB. In this paper, MS has been used to analyze the interactions between the important growth face of TATB and the morphology modifiers. The influence of the morphology modifiers, stirring speed, method of cooling, initial cooling temperature of TATB/DMSO saturated solutions and seed-growth method on the morphology and the particle size distribution of TATB crystal has been studied according to the crystal growth theory. The physical and chemical properties of TATB has been tested and analyzed by SEM、XRD、HPLC、Micron particle size tester and DSC.MS simulation results showed that the crystal facets of (1-10), (100) and (010) could adsorb morphology modifiers with polar functional groups by hydrogen bond interaction, while the crystal facets of (001) could adsorb morphology modifiers with benzene by π-π stacking interaction. The surface energy of crystal face could be effectively changed by the addition of different kinds of morphology modifiers during the recrystallization process. Then, the relative growth rate of crystal face would change with it, so that the target crystal morphology would be obtained. This provides a theoretical basis for the selection of crystal modifier to control the crystal morphology of TATB.The test of single-factor experiment showed that the optimum conditions of recrystallization for preparation of target morphology of TATB is below:the TATB/DMSO saturated solution cooled from 125℃ to 75℃ at a linear rate of ～1/min, then naturally cooled to room temperature, the TATB raw materials (the purity was 98.25%) would be refined into the particles about similar spherical and the purity was 99.82%, if using 0.496% TW-20 surfactant as morphology modifier and the stirring speed was 300 r/min, while the TATB raw materials would be refined into flaky crystal and the purity was 99.83%, if using 0.478% TEBAC as morphology modifier and the stirring speed was 100 r/min. More importantly, further study showed that seed-growth method would help to obtain more regular TATB with narrower particle-size distribution and the purity was 99.85% under the optimal conditions of spherical particles., In addition, recrystallization can improve the crystallinity. The recrystallized TATB with different crystal morphologies but similar particle size had approximate DSC exothermal peak between 377.61℃ to 382.84℃, so recrystallization did not change the thermal stability of TATB. Therefore, high quality TATB could be obtained by recrystallization.