Thermal study of the decomposition of HTPB hybrid rocket fuel in the presence of azo-tetrazolate-based high nitrogen content high energy materials

摘要

Azo-tetrazolate salts and their derivatives have identical negatively charged conjugated nitrogen rings and two varied positively charged cations. The varied cations are guanidinium, aminoguanidinium, diaminoguanidinium, triaminoguanidinium and ammonium. Azo-tetrazolate salts and their derivatives were synthesized and fully characterized by multinuclear spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). Hydroxyl-terminated polybutadiene (HTPB) has been used as a fuel and/or binder for devices such as hybrid and solid rockets. Present-day work on HTPB includes studying its thermal decomposition in the presence and absence of energetic material. Varying concentrations of energetic materials were used to create samples of crosslinked HTPB, which were utilized for the analysis. Different percentages (10, 15, 20%) by mass of azo-tetrazolate-based high nitrogen materials were used. Crosslinking agent polymethylene polyphenyl isocyanate (PAPI) was added to the polybutadiene R45-M resin and was maintained at 15% by mass in all samples. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) were performed to investigate the effect of additives. This is carried out within an atmospheric air setting at a heating rate of 5 degrees C/min. Plain HTPB has three exothermic peaks under air, with the first occurring at 206.82 degrees C, the second peak at 350 degrees C and the third peak beginning (onset) at 421.67 degrees C. Total decomposition of the mixtures is exhibited by the third exothermic peak, which ends at 600 degrees C. The effect of mixing these high energy compounds was determined using TG and DSC. Indications are that the resulting high energy compound/HTPB mixtures may provide a better performing fuel for future hybrid rocket formulations.