Study On Synthesis And Properties Of Energetic Binder DFAMO-AMMO

Energetic binder further improved the energy characteristics of solid propellants and polymer-bonded explosives,and enhanced the capability of long-range strike and high-efficiency damage of weapon systems.With the development of the novel energetic binder system in recent years,it has been widely used in solid propellants and polymer-bonded explosives,which has become one of the hot spots of energetic materials.Structure design and performance optimization is one of the key technologies.In this paper,3-difluoromethylamino-3-methyloxetane(DFAMO)and 3-azidomethyl-3-methyl-oxetane(AMMO),which used as monomer of energetic binder,and a new type of energetic binder prepolymer DFAMO-AMMO(PDA)was designed and synthesized,its structure characterization,the process optimization,the thermodynamic and the chemical compatibility were studied in this paper.The main works were listed below:DFAMO was synthesized from tris(hydroxymethyl)ethane,which used as raw material,by esterification,cyclization,amination,amide protection and fluorination.AMMO was synthesized from tris(hydroxymethyl)ethane by cyclization,esterification and azidation.PDA was synthesised via cationic solution polymerization,where boron trifluoride ethyl ether and 1,4-butanediol used as initiator system,and 1,2-dichloroethane as solvent.The structure of PDA were characterized by FTIR,NMR and EA.The glass transition temperature of the PDA was measured by DSC and the functionality was determined by esterificationthe,the results showed that the Tg=-39.7?,the functionality f=1.71.The optimum conditions for the cationic solution polymerization of the PDA were studied,including the molar ratio of DFAMO/AMMO,the monomer dropping time and the reaction time to the polymerization.The optimum process conditions were as follow:the molar ratio of DFAMO/AMMO= 5/5,the monomer dropping time 1.5h,reaction time 2d,reaction temperature 0?,C/I= 0.5.The thermal decomposition behaviors of PDA were examined in different heating rate by differential scaning calorimetiy(DSC).Then the spectorgram were analyzed and the exothermic peak temperatures in different heating rate were obtained,futher a series of thermodynamic characteristic parameter of PDA were calculated by Ozawa and kissinger method.The results showed PDA exhibited a two stage decomposition process,the apparent activation energy values were 110.79?113.25KJ/mol for the first stage of decomposition,while 176.03?176.21KJ/mol for the second stage of decomposition,and the correlation coefficient r=0.99.It can be concluded that the test results were more accurate.What's more,the comptibility of PDA with common soild propellant component was studied by DSC method.The results showed that the binary systems of PDA with the energetic components RDX,TNT,TATB,PETN,AP,AN,KNO3,A1 power,Al2O3,NDPA and C1 were compatible,the grade was A;PDA with NQ was slightly sensitive,the grade was B;while the binary systems of PDA with CL-20,NC,Mg power,C.B.and PbO3 were sensitive,the grade was C;and with HMX,B power,DPA and PNMA were incompatible,the grade was D.