Study On Thermal Compatibility Of Nitrogen-rich Azole Compounds With Gun Propellant Raw Materials

Nitrogen-rich azole compounds 5-aminotetrazole(5-AT),1,5-diaminotetrazole(DAT)and3,6,7-triamino-7H-[1,2,4]triazolo[4,3-b][1,2,4]triazole(TATOT)have the advantages of high nitrogen content,high enthalpy of formation,high density and good thermal stability.Adding them into propellant as solid filler is expected to reduce the explosion heat and improve the workability.Differential scanning calorimetry(DSC)and thermogravimetry(TG)were used to study the thermal decomposition behavior of the three compounds and gun propellant matrix components NC(nitrocellulose),absorbent powder,high-energy solid fillers such as NQ(nitroguanidine),RDX(cyclotrimethylenetriamine),CL-20(hexanitrohexaazaisowurtzite),and binders such as TPU(polyurethane thermoplastic elastomer),GAP(glycidyl azide polymer),GAP-ETPE(energy-containing thermoplastic elastomer),the thermal decomposition kinetic parameters were calculated,and their compatibility was studied.The compatibility between the three compounds and the propellant components was further studied by vacuum stability test(VST).According to the compatibility evaluation grade of national military standard,the DSC test results show that 5-AT has poor compatibility with NC,double-based absorbent powder,NQ,RDX and CL-20,and good compatibility with GAP and GAP-ETPE;DAT has poor compatibility with NC,double-based absorbent powder,NQ,RDX,CL-20,TPU,GAP and GAP-ETPE(2),and good compatibility with GAP-ETPE(1)and GAP-ETPE(3);TATOT has good compatibility with NC,absorbent powder,RDX,CL-20,TPU,GAP,GAP-ETPE,but poor compatibility with NQ.The VST test results show that 5-AT is incompatible with NC,had moderate reaction with absorbent powder,and has good compatibility with NQ,RDX and CL-20;DAT has poor compatibility with NC;TATOT has good compatibility with NC,NQ and RDX.In view of the good compatibility between TATOT and the basic raw materials of gun propellant,the TATOT-containing double-base propellant samples B₁ and B₂ were prepared by the semi-solvent method,and the NQ-containing propellant sample B₀ was prepared as a comparison.The thermal stability of the propellant samples was studied by DSC and TG methods,and the mechanical properties of the propellant samples were studied by simply supported beam impact tests.In the prepared propellant sample,compared with the sample B₁,the TATOT content of the sample B₂ is reduced,the thermal stability and impact strength are better.When the solid filler content is the same,the impact strength of the propellant sample B₀containing NQ is higher than that of the propellant sample B₁ containing TATOT,and the thermal stability is better.