Study On Preparation And Properties Of UV Curing Delay Composition

In order to explore new technologies and methods that can improve the delay precision and manufacturing level of delay composition,RDX,ammonium perchlorate,magnesium powder and solidified slurry were taken as research objects,and the formula of UV curing delay composition was designed and printed successfully.The formula ratio of UV curing resin slurry and UV curing delay composition slurry was optimized by orthogonal test.RDX,Ammonium Perchlorate(AP)and magnesium powder were added as fillers in the slurry of UV curing delay composition to improve the combustion performance of UV curing delay composition.RDX and ammonium perchlorate were refined by solvent-non-solvent method,and magnesium powder was coated and modified by stearic acid,so as to reduce the sedimentation rate and improve the dispersibility of RDX and ammonium perchlorate in liquid resin.Finally,the UV curing delay composition was printed and molded by 3D printer,and the combustion performance,delay time and delay precision of the delay composition were tested.The experimental results show that:(1)The dispersion of refined ammonium perchlorate and RDX in photocurable resin is obviously improved,and it has better stability in the printing process;When the coating ratio m(stearic acid):m(magnesium powder)=1:3,stearic acid has a relatively good coating effect on magnesium powder,and its sedimentation rate in the resin is the lowest,which is conducive to the smooth printing and molding of ultraviolet curing delay composition;(2)Through orthogonal experimental design,the optimum formula of UV curing resin was determined as epoxy acrylate resin(EA)48.350%,reactive diluent(HDDA:HPA=1:1)46.330%,photoinitiator(TPO)4.390%and auxiliary agent 0.930%.The viscosity of240m Pa·s,curing speed of 2.080s,curing hardness of 3H,shrinkage rate of 6.710%;(3)Through orthogonal experimental design,the optimum formula of UV-curable delay agent slurry is RDX 7.530%,ammonium perchlorate 62.370%,magnesium powder 3.220%and curing slurry 26.880%.The average delay time of ultraviolet curing delay composition is12.430s and the standard deviation is 0.0173s,The average burning rate is 0.805mm/s and the standard deviation is 0.00122 mm/s.(4)DTA test results show that there is an endothermic peak at 256.37?,and the endothermic enthalpy of the UV curing delay composition is 16.690J/g.The exothermic peak appears at 311.48?,and the exothermic enthalpy of the UV curing delay composition is282.970J/g;The fire transfer performance test shows that the UV curing delay composition has a certain fire transfer energy,which can successfully ignite potassium picrate gunpowder transmission with density of 2.573g/cm~3and magnesium-potassium nitrate gunpowder transmission with density of 2.845 g/cm~3.