Study On Concentration Distribution And Stability Of Surface Deterrent In High Energy Propellant

Raman spectroscopy and closed explosives methods are used to analyze the concentration distribution and stability of surface deterrent in high-energy propellants.Small molecule deterrent like dibutyl phthalate(DBP),deterrent polypropylene adipate(PPA)with high molecular and a new deterrent tripropargyl trimellitate(TPTM)are used to treat the surface deterrent of three double-base propellants with different plasticizer contents and an azide nitramine propellant with high plasticizer,which is used to analyze the effects of the type of deterrent,the content of plasticizer in the propellant and the deterrent process on the surface deterrent concentration distribution in the propellant.Thermal accelerated aging tests are detected to analyze the migration of three surface deterrent in propellants with different plasticizer contents.The main findings are as follows:(1)Raman spectrometer is used to measure different positions of the deterrent layer in the propellant.Excitation light will generate fluorescence and annihilate its Raman peak,making it impossible to measure the concentration distribution of deterrent agents accurately.Hence,a closed explosive device is used to compare the surface deterrent propellant and non-deterrent propellant.The distribution of the surface deterrent in the propellant can be analyzed by processing the L ～ B curve of the combustion process.At the same time,the migration law of the surface inert agent in the propellant can be well characterized,combined with the thermal accelerated aging test and the closed explosive device test.(2)In the DAG115 azide nitramine propellant with higher plasticizer content,the diffusion depth of the small molecule deterrent agent DBP is the deepest,and the concentration gradient in the surface layer of the gun propellant is the smallest;The new type of deterrent agent TPTM has the shallowest diffusion depth and the largest concentration gradient on the surface of the gun propellant;The polymer deterrent agent PPA is somewhere in between.In the three-base gun propellants with different plasticizer contents of SJ1,SJ2,and SJ3,the distribution law of the concentration of the small molecular deterrent agent DBP and the high molecular deterrent agent PPA is similar,the higher the content of plasticizer in the gun propellant,the deeper the diffusion depth of the deterrent agent,and the smaller the concentration gradient of the deterrent agent in the surface layer.(3)The wet deterrent process and dry deterrent process were used to treat the deterrent of the propellant surface.The diffusion depth of the deterrent and the concentration gradient distribution of the surface inert agent were basically consistent.The diffusion depth of the deterrent is basically the same as the concentration gradient distribution of the deterrent on the surface.In the wet deterrent process,the order in which the deterrent are added has little effect on the concentration gradient of the deterrent in the propellant.At the two deterrent temperatures of 50 °C and 60 °C,the diffusion depth of the deterrent is basically the same.The surface gradient of the deterrent at 60 °C is relatively large.(4)Under 60 ℃ thermal accelerated aging test conditions,both the small molecular deterrent agent DBP and the high molecular deterrent agent PPA show significant migration in high energy gun propellants with high plasticizer content.and as the content of plasticizer in the propellant increases,the migration of the deterrent agent is easier,and the migration of DBP is significantly greater than that of PPA;For the new deterrent agent TPTM,the azido group in the azide nitramine gun propellant reacts to form a network macromolecule,which can effectively prevent the migration of the deterrent agent,and the combustion performance before and after thermal accelerated aging is basically unchanged.