The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.
Mohammed DourariAhmed Fouzi TarchounDjalal TracheAmir AbdelazizRoufaida TiliouineTessnim BarkatWeiqiang Pang
This paper performs an experimental evaluation of thermolysis-driven gases generated by the thermal decomposition of 1 M LiPF6+EC/DMC=1/1 v/v electrolytes at various decomposition temperatures,pyrolysis durations,and oxygen concentrations.Carried out in a home-built autoclave filled with pure helium,the experiment reveals that as the decomposition temperature increases,more types and larger quantities of gases will be released.Specifically,the experimental results demonstrate trends of logistic growth in the volume concentration of CO2,C2H6O,C2H4,CO,and C2H4O2 with the increase of decomposition temperature.With a prolonged pyrolysis duration,while volume concentrations of certain gases,such as CO2,C2H6O,C2H5F,and CO would increase,the concentration of C2H4O2 actually decreases.Moreover,concentrations of both C2H4 and C2H5F will first decrease and reach their minimum values at 1%v/v oxygen concentration,and then they would quickly climb back at higher oxygen concentrations,while the concentrations of C2H6 and C2H3F would decrease monotonically.It is envisioned that the detailed experimental results and findings on the gas generation pattern of 1 M LiPF6+EC/DMC=1/1 v/v electrolytes can facilitate the development of an early warning mechanism of thermal runaway based on gas sensing technology,which can be effectively applied to monitor the potential thermal failures of lithium-ion batteries with the same type of electrolyte and thus promote the thermal safety of battery packs in safety-critical applications.