The geometry and the potential curve of thermal decomposition for 1,1′dimethyl-5,5′-azotetraol (1-DMAT) are calculated by ab initio quantum chemistry method. The structural characteristics and decomposition mechanism are carefully studied. It is found that the terrazzo ring satisfies 4n+2 rule and it is a conjugated π-system for 1-DMAT. The azotetrazol has aromatic characteristic and its thermal decomposition can proceed in two steps: ring opening and separation N2. The activation energies of the two steps are 243.5kJ/mol and 64.01kJ/mol, respectively. The ring opening is the rate-controlling step.
The geometry and the potential curve of thermal decomposition for 2,2′dimethyl-5,5′-azotetraol (2-DMAT) are calculated by ab initio quantum chemistry method. The structural characteristics and decomposition mechanism are carefully studied. It is found that the terrazzo ring satisfies 4n+2 rule and it is a conjugated π-systems for 2-DMAT. The azotetrazol has aromaic characteristic and its thermal decomposition can proceed in two steps: ring opening and N2 separation. The activation energies of the two steps are 152.3kJ/mol and 44.67kJ/mol respectively. The ring opening is the rate-controlling step.
The geometries of resins with single-layer (SG),double-layer (DG) and triple-layer (TG) were calculated with the quantum chemistry method. The geometries and net charges of atoms were obtained. The calculated average distances between layers were 0.5348 nm and 0.5051 nm and the action energies were -9.6355 kJ/mol and -32.2803 kJ/mol for resins DG and TG,respectively. Higher electronegative polar atoms can easily form hydrogen bonds with hydrogen atoms of other resin molecules,resulting in resin aggregates. The minimum cross-sectional diameters of resin molecules are too large to enter the pores of zeolite,so they are likely to crack on the surface of zeolite.
