| Summary: | 碩士 === 國立清華大學 === 化學系 === 99 === The high-nitrogen compounds of high-energy density materials (HEDMs) are different from traditional HEDMs, such as trinitrotoluene, hexogen (RDX), and octogen (HMX), which have lower heat of formation (HOF). In this thesis, HOF and energetic properties of HEDMs are calculated by density functional theory (DFT). Cyclotetratriazoles, whose structures are similar to porphine or corrin, are promising candidates for HEDM. The properties of the designed cyclotetratriazoles are studied. The diazole ring system with six to twelve nitrogen chains are also designed as a second series of HEDMs. The relationship between numbers of nitrogen atoms as well as physical and chemical properties are investigated. Furthermore, the effect of –NO2 substitution are studied in these diazole rings. The HOF, heat of explosion (Q) and density (ρ) are obtained from DFT calculations, and the velocity (D) and pressure (P) of detonation are evaluated by Kamlet-Jacobs equation.
The HOFs of all cyclotetratriazoles are larger than 1000 kJ/mol. Especially, HOF of –N3 substituted compounds is about 2600 kJ/mol. For detonation properties, -NO2 substituted molecule is optimal (D=11.68 km/s, P=40.37 GPa), exceeding the performance of HMX. Furthermore, HOF and Q increase linearly with the number of nitrogen atoms. Notably, -NO2 groups enhance HOF, Q and ρ significantly. The values of D and P in these compounds are higher than those observed for RDX and HMX. The energetic properties indicate that these two series of high-nitrogen compounds are indeed HEDMs.
|
|---|
